Question: is there any particular reason to use diffie-hellman over rsa for key exchange?

Response:
The Diffie-Hellman (DH) ephemeral key exchange is preferred over RSA because it ensures perfect forward secrecy, which RSA alone is incapable of providing.
This means that the confidentiality of session keys is maintained even if the long-term keys are compromised at a later date.
DH key pair generation is also noted for its speed advantage when it comes to creating ephemeral keys.
Additionally, in terms of security, a DH key of 1024 bits is suggested to be stronger than an RSA key of the same length.


Question: what is the difference between federated login and single sign on?

Response: Federation is a principle, while SSO is just a use case: a Federated Identity (FID) management system is where the user stores their credentials, and this provides single access to multiple systems across different enterprises; and Single Sign-On (SSO) allows users to access multiple services with a single authentication credential—user ID and password, smart card, one-time password token, or a biometric device—to access multiple or different systems within a single organization.


Question: elegant ways to handle if(if else) else

Response: To improve code organization and readability, consider extracting a sequence of operations into a separate function that utilizes a return statement.


Question: difference between nohup, disown and &

Response:
Using & causes the program to run in the background, while nohup and disown, although largely unrelated, serve to suppress SIGHUP (hangup) signals, preventing the program from being automatically killed.
If you have a running job, disown can be used to modify it.


Question: im a manager. how can i improve work relationships and communication with programmers?

Response:
You should get to know the programmers personally.
This will help you get to know the good and bad things about the company, the workplace and any projects.
You can start getting to know them by having informal chats with your team in a neutral atmosphere, which may involve inviting them out for a beer.
Talking to your team could also be done in a more formal way in the form of scheduled "two-ways" in which the team gives you updates and airs any concerns, while you give them updates on the business side and plan with them to resolve their concerns.
Basically, you want to ask your programmers how things are going, and actually listen to them by providing a way for them to be open about their problems without incurring a career backlash or involving any corporate politics.
You should also respect them and make the effort to earn their respect, which can be done by showing interest and appreciation for their work.
For a lot of developers sincerity, honesty and otherwise a flexible work environment are very important, so you should look into fostering an atmosphere of agile development.
This may involve setting schedules and deadlines that are achievable, and if new designs or plans are introduced, the schedules and deadlines should be readjusted.
Even better would be to let the developers themselves decide the deadlines as they are the ones actually doing the work, so should have a better idea of how long any given task should take.
Then again, you yourself might want to dedicate a small portion of your time as part of the development team, for example 8 hours a week, working as junior developer under the team lead.
This will help you learn the dynamics of the team and get to know them even better.
In terms of what else you can do, talking a firm stand in front of your team and backing them all the way will help build trust, as does open communication and actually following through on what you say you will do.
Furthermore, as a manager, you should of course, excel at what you do, which will in turn engender the all important communication, which will allow your developers to learn and grown in their roles.
Finally, a raise never hurts!


Question: what is the fastest way to send massive amounts of data between two computers?

Response:
For straightforward situations where security is not a concern, netcat is a good tool to use for transferring data.
Another effective tool for fast data transfer speeds is bbcp.
In cases where having a backup is more important than exact hard drive copies, backupPC can significantly reduce transfer times for large volumes of data.
When transferring data, using direct NFS mounts then local cp or rsync maximizes network capacity, much more so than encrypted transfers.
If you don't have budget constraints, implementing an Intel Xeon E5 12 core drive connector provides an effective and powerful solution.
If transfers faster than 1Gb are needed and 10Gb options are too expensive, NIC-teaming may offer a satisfactory lower cost solution.
Finally, setting up systems with shared storage could be an advantageous approach, especially if data transfer between machines is a recurring task.


Question: what is the difference between urgent pointer and urgent flag in tcp?

Response:
The URG flag in TCP segments is utilized to indicate to the receiving station that part of the segment's data is urgent and should be processed with higher priority.
The URG TCP flag plays a critical role in managing priority traffic within a network, specifically between defined sources and destinations.


Question: how to simulate slow internet connections on the mac

Response:
To manage network traffic speeds, you may employ techniques like ipfw piping on OS X 10.9 or earlier, as well as dnctl and pfctl on Mac OS X 10.10 or later, to create virtual pipes and enforce bandwidth limitations.
Additionally, tools like @sitespeed.io/throttle can be installed on a Mac to easily throttle network traffic, either using command-line parameters or predefined profiles for various types of network conditions.


Question: how to clear journalctl

Response:
Configure journald to retain only the amount of data you're interested in by scheduling it to limit disk space usage.
Modify the /etc/systemd/journald.conf file to set a maximum usage parameter, such as SystemMaxUse=100M or SystemMaxUse=1M, and then restart the systemd-journald service for the changes to take effect.
Additionally, using journalctl, you can vacuum the logs by size or time, for instance, keeping only logs from the past two days (` journalctl --vacuum-time=2d`) or limiting the size to 500 MB (`journalctl --vacuum-size=500M`).
A very brute force method to clean the entire log: `$ sudo journalctl --vacuum-time=1seconds` and `journalctl --rotate journalctl --vacuum-time=1s` to remove the active files as well or to merge all journals and clean them up on CentOS-7, `journalctl -m --vacuum-time=1s` or simply `sudo journalctl --vacuum-files 1` .
If those commands don't work, as in some systems like CentOS, you might have to use a command like `sudo rm -rf /run/log/journal/`.
To directly clear log entries, you can overwrite the system.journal file using a simple change directory and overwrite command (`cd /run/log/journal/<temp-string>/ >system.journal `) after backing up the file (`cp /run/log/journal/<temp-string>/system.journal /mylog/dir/back/system.journal.bak`) if needed.
Persistent configuration changes can be achieved by creating a dedicated config file in the /etc/systemd/journald.conf.d/ directory, which will maintain a small log size indefinitely and can be reverted easily if necessary.
Lastly, should you need to remove logs for a specific service, performing a journalctl --rotate will archive the logs, enabling the --vacuum-time command or other vacuuming options to take effect on them.


Question: what is the difference between a key escrow and a recovery agent?

Response: A key escrow is someone who holds the keys for each user, while a recovery agent has a master key.


Question: perks for new programmers

Response:
There are many perqs that new programmers would like to see in the workplace, one in particular pertaining to having a sense of purpose: including autonomy, professional challenges, a clear career path, trust, and intelligent inclusive leadership.
Another important area centers on mentorship, training, availability of books and other learning materials, and being part of a professional, respectful team.
Flex-time, telecommuting and remote work are also highly valued.
Most new programmers expressed a desire to have the right tools, technology and equipment such as monitors, optical mouse, whiteboards, cell phones, and home internet, among others.
A good benefits package, PTO, and gym memberships were also considered essential.
Many wanted a relaxed work environment, including war rooms and private or self-designed offices that featured amenities such as pool tables, coffee machines, TVs, snack bars, deli delivery, catering and soda fountains, as well as a casual dress code.
Other desires included going out to restaurants together or other team building activities, maintaining work-life balance and working where the Programmers Bill of Rights are respected.


Question: how to redirect output of wget as input to unzip?

Response:
When downloading files using wget, and some say you must download your files to a temp file and not bother trying to pipe the output into unzip.
The zip manual says that archives read from a standard input are not supported.
Because zip files are identified by a central directory located at the end of the file; some users believe that standard zip tools use the lseek function to read them, which isn't possible with dynamic content such as FIFO or pipes, leading to errors.
A possible workaround is to use an alternative compression method like tar.gz.
Some say that with the Java Development Kit (JDK) installed, you can pipe the download directly into the Java Archive Tool (jar), using jar: wget -qO- http://example.org/file.zip | jar xvf /dev/stdin.
Alternatively, BusyBox's unzip utility is capable of handling standard input and allows the extraction of all files from a piped download using wget -qO- http://downloads.wordpress.org/plugin/akismet.2.5.3.zip | busybox unzip -.
Lastly, for a single-file zip archive, you can utilize zcat or gunzip to directly extract the file while downloading it.


Question: keyboard shortcut for locking screen in macos sierra?

Response:
Apple has removed this shortcut due to security concerns and Bluetooth issues, but users can opt for Hot Corners as an alternative solution instead.
If one wishes to put their computer to sleep, they can press the power button for about half a second; however, there's a risk of initiating a restart if the button is held down too long, and other methods may be necessary for keyboards lacking a power button.
For Sierra and preceding versions, using keychain settings or Hot Corners is recommended to lock the screen.
Alternatively, lock the screen by using the CTRL+Shift+Power Button or CTRL+Shift+Eject-Key.
Individuals can create a custom keyboard shortcut to lock the screen using Automator to execute a shell script; the shortcut should function upon pressing, although the service may have to be accessed through the menu bar initially.
Hammerspoon offers another scriptable method to define key bindings for locking the screen or starting the screen saver.
A user can put their Mac to sleep using the "hs.caffeinate.lockScreen()" command or the "⌘ command + option + ⌽⏻" keyboard shortcut on macOS Sierra, but the screen saver approach is preferred.
MacBook Pro users with the Touch Bar can allocate one of the virtual keys for locking the Mac, which is configurable through the System Preferences Keyboard section.
Lastly, macOS High Sierra (10.13) has introduced a built-in 'Lock Screen' feature in the Apple menu, which can be quickly accessed with a straightforward keyboard shortcut.


Question: how does systemd use /etc/init.d scripts?

Response:
Systemd is designed to be compatible with older SysV init scripts.
The compatibility of systemd with traditional van Smoorenburg rc (SysV) scripts is accomplished by using a conversion tool called systemd-sysv-generator.
This generator creates service units that allow the van Smoorenburg rc scripts from /etc/init.d to run if there is no native systemd service unit already present.


Question: how to print an image across two pages

Response:
One option to print an image across multiple pages is copy and paste the image into Pages or another application and then go to Page Setup to create a custom page size like 8"x20"; after doing this, you can scale the image to fit the new page size.
Alternatively, you can open the image in Preview CMD+a to select all Grab selection handle, and drag until exactly in the middle of the picture, adjust the selection handle to the desired dimensions and print from there.
You can also print through Safari, which will automatically span the image over several pages.
Another method using Safari is opening the image and adjusting the Scale in the Print Settings to span the image across multiple pages before printing.
Similar methods can be used through exporting the image to a program like Excel, which has print scaling, or as a PDF to Adobe Reader, which offers a poster printing feature that allows for large-scale prints over multiple pages.
The Apple Numbers app is also capable of printing a PDF or image over many pages.
For those seeking specialized software, PosteRazor and other programs exist that can cut an image for printing across multiple pages; some of these programs only work with PDFs, but you can print to PDF then open it in another program, if necessary.


Question: how to correctly add a path to path?

Response:
One simple method involves appending the new path to the existing PATH using either PATH=$PATH:/opt/bin or PATH=/opt/bin:$PATH.
An alternative solution employs a combination of commands, utilizing awk and sed to ensure the uniqueness of the added path within the variable: PATH=$(echo -n $PATH | awk -v RS=: -v ORS=: '!x++' | sed "s/\(.*\).\{1\}/\1/").
On Mac OS X, an effective approach is to add the path name (e.g., /mypathname) to the file /etc/paths.
For a more sophisticated implementation, two functions, pathadd and pathrm, can be utilized.
Another straightforward method involves exporting the new path to the PATH variable: export PATH=$PATH:/new-path/.
Additionally, a concise and efficient way is to use the syntax PATH="${PATH:+${PATH}:}~/opt/bin".


Question: what is the difference between inner join and join?

Response:
Join and Inner Join are the same.
The inner keyword is optional as all joins are considered to be inner joins unless otherwise specified.


Question: is ipv10 a joke or a serious rfc draft?

Response: The author is probably serious about his proposal, but he doesn't appear to realize how ridiculous the scheme he is proposing is, despite not garnering any serious support for the proposal; so, it's both serious and a joke, but the joke's on the author.


Question: choosing between single or multiple projects in a git repository?

Response:
Tools like git bisect become more difficult to use when you fracture your repository into sub-repositories.
While splitting the model, controller, and UI might seem sensible, it's not always the best approach.
A multi-repository approach can be a reasonable solution, especially when a single repository would be too large to be efficient.
It's essential to ensure that functional domains are properly stand-alone in their respective repositories, treating each service as its repository.


Question: are there naming conventions for variables in shell scripts?

Response:
In terms of coding style when naming variables or constants, one approach is to use both uppercase and lowercase, as demonstrated by examples like MY_CONSTANT and my_variable.
Digits can be separated to make the number more readable (e.g. 1_000_000_000).


Question: shortcut key for fullscreen mode

Response:
To toggle fullscreen mode, you can use the button in the top right of each window, or the keyboard shortcut, depending on the application.
For most applications, the keyboard shortcut is ^+⌘+F (Control+Cmd+F).
If you prefer customizing the shortcut, you can do so in System Preferences by selecting the "Keyboard" icon, then the "Keyboard Shortcuts" tab, and choosing 'Application Shortcuts'; In this menu, set your desired combination, such as CMD+CTRL+F.


Question: how to output only file names (with spaces) in ls -al?

Response: For listing files in a directory without showing files with spaces in their names, you could use the 'ls -lA | awk '{print $9}'" command.


Question: how accurate is business logic should be in a service, not in a model?

Response:
The appropriate placement of business logic depends on the use case.
In most generic scenarios, it is advised to adhere to business logic situated in the service layer.


Question: is bitly com a virus?

Response: bit.ly itself does not distribute malware.


Question: how do i download an ios app (ipa) file to my mac after itunes 12.7 update?

Response:
You can utilize the Mac "Apple Configurator 2" Update button solution to download an iOS App (IPA) file to your Mac after the iTunes 12.7 update.
Alternatively, iMazing 2.5 for Mac and PC offers the capability to download apps from the App Store and install .ipa files.


Question: how do i know if dd is still working?

Response:
Send it a signal using the kill command to report its current status.
This signal varies by system, with INFO being used for BSD systems and USR1 for Linux.
Alternatively, you can use lsof to watch positions within files for commands reading or writing files with `lsof. lsof -o -p1234 # where 1234 is the process ID of the command lsof -o /path/to/file `or use ddrescue.
You can attach strace to a running process to see if it's blocked or active, or initiate another dd process if concerned about sending signals.
On OS X, pressing Ctrl+T in the dd terminal will display its output status and CPU usage.
Viewing disk I/O activity can also be done with iotop, which indicates disk read/write activity per program.
If you anticipate the need to monitor progress, consider starting your operation with pv, a tool designed for monitoring data transfer progress and speed, or go the other way and use dd to read and pv to write.
Real-time information about the dd process can be gleaned from the `wchar line in /proc/$pid/io`, and an example PHP script shows how to display the written bytes without changing terminals: `<?php / Time between refreshs in seconds */ $refresh = 1; / * Start of Script */ if (!($pid = exec('pidof dd'))) exit("no dd running\n"); $history = array(); $break_ms = $refresh * 1000000; $start_time = exec("ls -ld /proc/$pid --time-style=+\"%s\" | egrep -o [0-9]{10}"); fprintf(STDOUT, "PID: %s\n", $pid); fprintf(STDOUT, "START TIME: %s\n\n", date("Y-m-d H:i:s", $start_time)); while (true) { if (isset($curr)) array_push($history, $curr); if (count($history) > 10) array_shift($history); $oldest = reset($history); $latest = end($history); / * get number of written bytes from /proc/$pid/io */ #if (!($curr = exec("cat /proc/$pid/io | grep ^write_bytes | sed 's/write_bytes: //g'"))) # break; /* prepare proc_open() parameter */ $descriptorspec = array( 0 => array('pipe', 'r'), // stdin 1 => array('pipe', 'w'), // stdout 2 => array('pipe', 'w'), // stderr ); $process = proc_open("cat /proc/$pid/io | grep ^write_bytes | sed 's/write_bytes: //g'", $descriptorspec, $pipes); if (!is_resource($process)) break; $stdout = stream_get_contents($pipes); $stderr = stream_get_contents($pipes); proc_close($process); if (!empty($stderr)) break; $curr = trim($stdout); / * caculate elapsed time from start */ $time_elapsed = time() - $start_time; / * avg speed since start */ $avg = $time_elapsed > 0 ? round($curr / $time_elapsed) : 0; / * avg speed of last 10 updates */ if (count($history) > 0) $speed = human_file_size(round(($latest - $oldest) / count($history) / $refresh)); $output = sprintf("\rBYTES WRITTEN: %s  :: CURRENT: %s/s :: AVERAGE: %s/s :: ELAPSED: %s", $curr, human_file_size($curr), isset($speed) ? $speed : 0, human_file_size($avg), gmdate("H:i:s", $time_elapsed)); printf("%s%s", $output, str_repeat(" ", exec("tput cols") - strlen($output))); usleep($break_ms); } fprintf(STDOUT, "\ndd has finished!\n\n"); function human_file_size($size,$unit="") { if( (!$unit && $size >= 1<<30) || $unit == "GB") return number_format($size/(1<<30),2)." GB"; if( (!$unit && $size >= 1<<20) || $unit == "MB") return number_format($size/(1<<20),2)." MB"; if( (!$unit && $size >= 1<<10) || $unit == "kB") return number_format($size/(1<<10),2)." kB"; return number_format($size)." bytes"; }`.
Moreover, switching to dcfldd(1) is another option for a more convenient display of dd operations.
With recent versions of coreutils (v8.24 or later), dd itself includes a progress option to show its progress natively.
Lastly, you can use the progress utility, which showcases the advancement of a running dd command and leverages the `/proc/$pid/fd and /proc/$pid/fdinfo`.


Question: how do i find how long ago a linux system was installed?

Response:
To check the creation date of the root filesystem, one can utilize the "dumpe2fs" command on systems where this is applicable.
For Red Hat-based distributions such as CentOS, Scientific or Oracle, the command "rpm -qi basesystem" can be used to reveal the installation date of the base system, which is typically the system installation date.


Question: what is the difference between upstream and downstream in open source software development?

Response:
Upstream developers are involved at the beginning in the creation of software, commonly referred to as being "up the well".
Downstream, on the other hand, is akin to flowing "downwards to the ocean", where developers utilize the completed software to build further applications and tools.
Those who are upstream are engaged in developing the products that will be eventually released.


Question: programming cleanly when writing scientific code

Response:
When coding, it's important to consider the purpose of your programming, which will influence the aspects you need to focus on.
Adhering to the Unix principle of "Keep It Simple, Stupid" (KISS) can be very beneficial, as can the practice of doing one thing at a time and doing it well.
Embracing the Don't Repeat Yourself (DRY) principle, you should avoid copying and pasting code and instead create reusable functions or at least use caution when copying and pasting code to prevent introducing errors or unnecessary complexity.
To enhance the clarity of your code, it's essential to add detailed commentary throughout your work and explain things to yourself as you progress.
It's also recommended to cite mathematical formulas within comments to ensure the reproducibility and understanding of your code.
Making your code easy to test with both good and bad data sets is also crucial, and you should structure your code to facilitate the addition of new test cases.


Question: should you write your back-end as an api?

Response:
There is not a clear-cut answer that one way is better than the other.
It depends on the type of application and the type of market you are in.
However, if your project is meant to live for a while and is slightly complex, always have an API.
Additionally, If third parties are expected to use the system or if there is potential for reusability, constructing a well-defined API is beneficial.
Having an API not only makes your back end reusable but also allows for more security and better design.
On the contrary, if you don't have immediate plans to create alternative frontends, such as mobile or desktop apps, or a separate web application accessing the same backend, then introducing a web service layer might not be necessary.


Question: why do phishing e-mails use faked e-mail addresses instead of the real one?

Response:
The goal of a phisher is typically to prompt recipients to send replies directly to a specified address to avoid email frameworks that screen for authenticity.
Phishers want their spoofed emails to seem legitimate to unsuspecting users.
This aligns with the broader aim of spammers, which is to reach as broad an audience as possible, focusing specifically on the most naive or gullible individuals.


Question: how can i list and edit all defined aliases in terminal?

Response:
To display any active aliases in your terminal, simply type "alias" at the prompt and any active aliases will be listed.
If you wish to remove an alias within your current session, you can use the unalias command; however, to prevent the alias from loading in future sessions, you must locate and remove the alias definition from its initialization file.


Question: how to know who connect to my iphone hotspot?

Response:
Unfortunately, no GUI exists in iOS for finding details about connected devices to the wireless hotspot (i.e., tethered devices), although you can use a network scanner app like Net Analyzer running on your iPhone, you can see who’s connected.

Some suggest that you can go to Settings, tap on the name of your Hot spot and you'll see the names of the devices connected you can then click on the names of the connected devices to remove them once you log into your iCloud account.

It has also been claimed that you can go to Settings/Cellular/go down to the CELLULAR DATA section and click Personal Hotspot that has a Data amount next to it, and you will see a list of each device and the amount of data they have used on the hotspot.


Question: pdf cannot be opened because it is from an unidentified developer?

Response:
The document is likely marked as executable, so you need to remove the executable bit from the file.

It could also be because the file was downloaded from the internet; Safari marks it as quarantined to make it harder for malware to execute, so use the command xattr <file> and check if one of the output lines is com.apple.quarantine, and, if so, use xattr -d com.apple.quarantine <file>.


Question: on developing deep programming knowledge

Response:
One recommendation is to read content from knowledgeable individuals like Eric Lippert and then solve problems firsthand.
Another recommendation is to acquire Reflector or any other decompiler start opening up some of the most used .NET libraries to learn how the internals work.
Furthermore, you can enhance your C# expertise by writing a C# compiler or other tool.
Studying the language specifications in depth for the ones that want to gain expertise is advised.
Further advice is to hold off learning more languages and first concentrate on one language and delve into its complexities before learning another.
Another approach is immersing yourself in programming language communities, like comp.lang.c++.moderated, programming in your selected language and examining code written by others.
Actively seeking out questions about language syntax and semantics, even those you're unfamiliar with, is a proactive method to build expertise.
True proficiency in programming requires delving into the compiler and runtime, then start reasoning (and building) software at the next level of abstraction lower in the stack.
Lastly, "reading the Fine Manual" and familiarizing yourself with language specifications is essential.


Question: do group imessages say delivered?

Response: No, there are no delivery or read receipts for group messages.


Question: how can one manage thousands of if...then...else rules?

Response:
To manage the complexity of building applications, especially when handling a multitude of conditional statements, it's recommended to split up the various business logic into separate classes/modules.
Utilizing rules engines can centralize numerous conditional statements, allowing users to edit them without knowledge of programming.
Also, creating independent rules in a rule engine and potentially developing a domain-specific language to express these rules may improve the handling of complex conditions.
Considering logic programming solutions such as Prolog may provide additional benefits.
It's useful to separate different problematic areas, particularly those with extensive conditional statements, and refactor them using techniques to create manageable segments (exit early is a big help).
Another perspective is to think of rules and constraints as inputs rather than code, which enables flexible program configuration.
It's also crucial to select appropriate software or computer languages, like Matlab or R, which are designed to handle complex systems and support advanced modeling techniques such as Monte Carlo Markov Chains or neural networks.
Decision Learning Trees, like the ID3 Algorithm, are powerful tools that can provide clarity in decision-making processes.
Additionally, a rules engine such as Java's jBPM or Oracle's BPM can further simplify application configuration.
Machine learning techniques can model scenarios based on discrete factors and use mathematical models such as bipartite graphs or cellular automata to simulate behavior.
Finally, adopting an async or multithreaded approach that uses a dynamic set of rules for decision-making can provide a more efficient and adaptable system.


Question: what is the difference between waterfall model and v model?

Response:
The main difference between the waterfall model and the V model is that in the waterfall model, the testing activities are carried out after the development activities are over.
On the other hand in the V model, testing activities start with the first stage itself.
In other words, the waterfall model is a continuous process, while the V model is a simultaneous process.


Question: should websites be allowed to disable autocomplete on forms or fields?

Response:
Some security testers always advise disabling auto complete, while others suggest “secure” auto-complete should never be disabled, but “automatic” auto-complete should be disabled by default.

Others only object if a form field that asks for sensitive data (e.g., a credit card number), is NOT a password field, and does NOT have autocomplete=off, the rationale being that browsers manage autocomplete for passwords quite sensibly, but for non-password fields the autocomplete behavior is not desirable (for example, someone else might use the computer, go to an e-commerce checkout page and see the credit card details autocompleted).

However, note that there is no reason known why a website should try to disable saving of passwords, and Chrome, Safari, IE, and Firefox ignore it.


Question: ctrl-s hangs the terminal emulator?

Response:
Some users find the ability to control the terminal output using Ctrl-S to freeze and Ctrl-Q to resume helpful, as it allows for managing the flow of terminal information.
The terminal scroll lock is enabled by C-s and disabled by C-Q, allowing or preventing the terminal from automatically scrolling during command output.


Question: is pcie-based flash storage same as ssd?

Response: Yes and no: SSD, or Solid State Drive, has flash storage inside, but SSD is a special form factor, in most cases meaning that it is designed to fit in places that a normal 2.5" HDD would be installed; PCIe is a different form factor.


Question: what does synchronize mean in mac mail?

Response:
While Get Mail will only fetch new mail in the Inbox, synchronize will look for changes in the IMAP configuration, look for changes in the folder structure of your account, and probably a lot more.

If you make changes on one Mac, you can use Synchronize to make a second Mac aware of the changes.

Synchronize basically double counts and double checks each and every message to make sure things are 100% correct, so resolving noise/errors/lost messages, incorrect statuses, and other real life bumps and errors.


Question: is hostgator storing my password in plaintext?

Response:
Hostgator might be passwords in plain text, which would indicate a significant issue.
Simple single-iteration SHA functions are inadequate due to the ease of brute-forcing with modern GPUs, suggesting more complex password hashing functions like scrypt or argon2.
The encrypted nature of a password doesn't guarantee its security during transmission, particularly if it is sent over email without encryption.
Moreover, it is possible that passwords are stored in an encrypted form rather than plain text.
There is an explicit declaration that passwords are not kept in plain text, but rather encrypted text - a practice that still lacks security compared to hashing and salting.
Lastly, it was confirmed that the storage of passwords in plain text or equivalent was a reality and that such information was also transmitted in plain text, with references to the Plaintext Offenders list as evidence of this continuing problem since 2011.


Question: what does it mean when someone keeps a digital touch message from you?

Response: Selecting the keep option will not remove items from the conversation; rather it's just a way to save space.


Question: firmware-iwlwifi has no installation candidate?

Response: To incorporate the firmware-iwlwifi package on a Debian system, amend your /etc/apt/sources.list file to include "non-free".


Question: how do i install gcc via homebrew?

Response:
You can simply run brew install gcc.
Another option is to install GCC 4.8 by using brew tap homebrew/versions followed by brew install [flags] gcc48.


Question: can facetime calls be tapped?

Response:
FaceTime calls are known to have strong encryption which is generally adequate for most users' needs.
However, there is a potential for skilled individuals, equipped with the necessary tools and the inclination to invest time, to crack FaceTime's encryption, although it's unlikely that the average person would be a target for such efforts.
FaceTime's security is reinforced by the use of end-to-end encryption with AES-256, ensuring that only the sender and receiver have access to the contents of the communication, according to details revealed in an Apple white paper from February 2014.


Question: replace text edit as the default text editor

Response:
With duti, you can use command lines to configure certain filetypes to open with predefined applications like Sublime Text.
However, Magic Launch offers the flexibility to set your default applications for file types, such as txt files to open with Sublime Text without the need for command lines.


Question: how do i move a window whose title bar is off-screen?

Response:
For managing windows on a computer screen, you might want to try Window > Zoom from the menubar.
Windows that are resizable could be moved by dragging them horizontally from the bottom edge.
Also, on OSX 10.9.1, holding the option (or alt) key while clicking the Window menu should arrange the windows correctly.
Moreover, pressing the alt/options key while resizing a window from its bottom side can resize both the side being dragged and its opposite side simultaneously and bring the toolbar back into view.
In applications, such as Filezilla, without a window menu, dragging the lower corners while holding option is a viable solution.
Additionally, holding the shift key while dragging any edge can also modify the window size.
An alternative method is to temporarily increase the screen resolution to reveal the off-screen title bar.
This can be done by navigating to System Preferences > Displays > Display and selecting Scaled.


Question: why mtu should match in ospf?

Response:
Enforcing matching MTUs is important to maintain performance requirements within routing protocols like OSPF.
Additionally, it is recommended to avoid IP fragmentation by designing OSPF protocol packets to be split into smaller packets.


Question: is it ok to use the root user as a normal user?

Response:
In most cases, it's a significant security and stability risk to be logged in as root user since it exposes your entire computer system to potential threats.
Additionally, using the root account indiscriminately can result in a high risk of losing or having personal information stolen, having system-critical functions and files altered or moved and making mistakes that have a high impact on your system.
Inadvertent actions as root can have severe repercussions, accidentally altering critical system files beyond easy repair.
However, while some argue that the risks of using the root user by default are exaggerated and acknowledge that Unix's permission system may have limitations, they do not believe it is as dire as others imply.
In any case, it's recommended to keep ownership of personal files separate from the root user and exercise caution when operating with administrative privileges.
Some programs, including Homebrew, cannot be used as root, which may lead to issues with permissions and organization, outweighing potential security concerns.
For specialized tasks such as penetration testing with tools like Backtrack or Kali Linux, the superuser role is acceptable.


Question: what is dd if dev zero?

Response:
It can be used to erase specific portions of your hard drive, such as the first 4096*4096=16MB and the last 512*4096=2MB.
This command overwrites the specified device, in this case, "sda," with zeroes, making it useful for cleaning a drive before forensically copying data.
Additionally, it's employed to assess the quality of inserted USB drives or MicroSD cards.


Question: should i be concerned if the fbi has logged onto my ubuntu vps?

Response:
In most situations, your primary concern should not be with the fbi.gov hostname potentially being connected to your VPS.
It's essential to be alert if anyone has gained unauthorized access to your server.
The possibility that a hacker has acquired the credentials to log into your VPS is a serious issue to be concerned with.
Additionally, it is unlikely that a serious investigator or task force would be obvious enough to use a government domain like fbi.gov directly.
Assume that the fbi.gov host is fake and your system has been compromised, and take immediate action because once it's known to be vulnerable, it may be used for nefarious purposes.
The recommended immediate action in such a situation is to 'nuke' or completely erase and reinstall your system.
If it were a genuine mistake from the FBI, this would imply a significant level of incompetence.
Your focus should be more on the integrity of your system rather than the FBI possibly logging in, as tampering with logs indicates a serious compromise.
Anyone accessing your system without authorization should be thoroughly investigated, and replacing your system with a decoy for forensic analysis while setting up a honeypot to monitor the hacker's actions is advisable.


Question: what does -- (double-dash) mean?

Response:
The phrase marks the end of parameter (option) list.
It's a convention to signal the end of command options in Bash, after which only positional arguments are recognized.
This is a specification where '--' denotes the completion of the options.
According to utility syntax guidelines, a first non-option argument '--' should be treated as a delimiter to conclude options.
For POSIX-complaint utilities and those that parse options using the POSIX getopt() API, '--' signifies the cutoff point for options.


Question: i changed one method signature and now have over 25,000 errors. what now?

Response:
Test the changes you've made to your code.
Creating a comprehensive regression test suite for your large project can be dull, but it helps confidently release updates and speeds up the release process if automated efficiently.


Question: why do i see a rst, ack packet instead of a rst packet?

Response: Once the connection is established, all packets need to have ACK set and match the sequence number of the received packets for reliable transport/security; RST without ACK will not be accepted.


Question: what is the difference between default gateway and router?

Response:
A router can be configured to function as a gateway, providing connectivity for a local network segment to other networks.
This is essentially the same device, seen from different perspectives.
A router specifically facilitates IP packet routing between various networks, whereas a gateway, which is also a router, gives access to and from the local network for IP packets.
It is important to note that while all gateways must possess routing capabilities, not all routers are gateways, with the difference largely resting on their role in the network.
Gateways have a broader range of communication abilities because they can employ multiple protocols and can function at any layer within the OSI model.


Question: are private, unguessable urls equivalent to password-based authentication?

Response:
Private or hard-to-guess URLs are not equivalent to password-based authentication and should not be considered equivalent.
A private URL is recognized as somewhat weaker than authentication with credentials because it can more easily leak in various ways, such as through browser caching, server logging, or appearing in referer headers on other sites.
Pretty much all authentication schemes boil down to proving you know a secret, whether it's a password or a URL.
A secret URL is just as secure as a secret password but passwords are easier to keep secret than URLs, because it is known that passwords must remain secret.
Security-wise, a secret URL is not bound to a specific user; on the other hand, a password is linked directly to a unique user account, offering more granular control over access.
Furthermore, most password authentication systems have a limited number of attempts at guessing a password for a user before further authentication attempts are either locked out, or limited, but implementing similar controls for URL schemes might be more difficult and it may be hard to stop someone setting up to work their way through your 'random' URL space.


Question: how can i explain sql injection without technical jargon?

Response:
SQL injection is an attack method where a nefarious individual attempts to extract unauthorized information from a website.
This vulnerability arises due to a weakness in how certain websites process user inputs, which can allow an attacker to gain access to the database storing all the user information.
A practical demonstration of the attack can effectively convey its implications, showing how a seemingly benign input can lead to unexpected and potentially harmful outcomes.
It operates by manipulating a system's functionality, where the system mistakenly executes commands entered by the attacker as if they were legitimate.
A query might have parameters (data) inserted into it that end up being interpreted as instructions, causing it to malfunction.
It can be likened to a Mad Lib, where unexpected phrases drastically alter the story if the provided sentences are not closely regulated.
The prevention of SQL injection necessitates code that smartly differentiates between commands and data inputs, ensuring that users cannot alter the intended actions.
Using cartoon characters to frame an educational story about SQL injection might be an engaging method of explanation to a lay person.
Finally, the issue can be humorously conveyed using the example of Bart Simpson's prank calls, demonstrating how careless repetition of input can lead to unintended consequences.


Question: never do in code what you can get the sql server to do well for you - is this a recipe for a bad design?

Response:
SQL is intended specifically for handling data itself, without being burdened by the business rules and logic that determine the form of a query; these aspects should be managed within the coding environment.
It is acknowledged that code ought to dictate the business logic, and the database should simply serve as a straightforward storage mechanism devoid of logic.
Implementing business rules and structures within the database can be advantageous, aiding in the automatic management of elements like record counters and ensuring the integrity of relationships, thus promoting data integrity.
Nevertheless, careful consideration must be given to where data processing occurs, as relying solely on the SQL server for all computations may not always be the most effective or scalable solution, especially when other less costly resources are available for computation.


Question: whats the story behind super cow powers?

Response:
Jason Gunthorpe was the main maintainer and developer of Apt in its early days, and he had a fondness for cows, which seemingly influenced the inclusion of cow-based jokes and easter eggs within Apt.
It has been suggested that the "Super Cow" reference within Apt might be connected to the "Cow and Chicken" cartoon that was popular when Apt was under development.


Question: terminal prompt not wrapping correctly

Response:
Your issue may stem from incorrect COLUMNS & LINES environment variable settings, which usually adapt automatically when resizing the terminal but can be manually set with the `resize` command.
Terminal prompts should enclose non-printable sequences within `\[` and `\]` to make bash recognize the actual prompt length (with  \r\n outside of the \[...\]) or alternatively, use `\001` and `\002` instead of `\[` and `\]`.
In scenarios where the size of the window assumed by the terminal is not the same as your actual window size, use `$ shopt checkwinsize` in bash to correct the terminal's understanding of the window size.
Furthermore, complications can arise from using wide unicode symbols, and in such cases, escaping 2 out of 3 of these symbols is recommended to provide bash with an accurate character count.


Question: why does the ipv6 header not include a checksum?

Response:
All the common link-layer protocols, like Ethernet or WiFi, have their own error checking and error correction mechanisms, so physical transmission errors are already unlikely, making this redundant.
The benefits of including a checksum in the IPv6 header were minimal.


Question: alternative to windows snipping tool for mac osx

Response:
Use the keyboard shortcut ⌘+⇧+3, while the shortcut ⌘+⇧+4 lets you capture a custom area you select by clicking and dragging.
Additionally, using ⌘+⇧+4 followed by space allows you to capture a specific window of your choice.
Moreover, you can use the built-in Grab app to take screenshots in the Utilities folder.
Alternatively, the Preview app has an in-built feature to take screenshots with options such as selecting an area, a window, or the entire screen.
The Snip app is another tool you might like, which can be downloaded for free from the Mac App Store.
You might consider dedicated screenshot tools like Easycrop, SnapNDrag, Grab, Skitch, or Jing for more advanced functionality like annotations and sharing.


Question: can you see how often someone checks your location?

Response:
When using Find My Friends, individuals don't receive notifications or have access to logs showing how often they've been located by others; the location is shared only upon request and not at regular intervals.
However, theoretically, a person can determine if they've been looked up via a Ping if they have the necessary tools and expertise.


Question: how can i skip the trash when deleting a file?

Response:
A secure method to erase files on a Mac involves the Terminal command rm, combined with the -P option, which overwrites files three times with differing byte patterns before deletion.  Another approach is using the Trash Without application from the Mac App Store.
An application, Trash X, exists with features that allow instant deletion or shredding of files and folders, with the option to perform actions on selected disks.
For automation, you can create an Automator service or application to execute the rm command, potentially adding a -P parameter for extra security; this custom solution can also include confirmation prompts and auditory feedback.
There's also Skip The Trash, a free tool with features like regular and admin-level deletion and integration into Finder's context menus.
For users preferring keyboard shortcuts, the combination of ⌘ Command⌥ Option⌫ Delete can permanently delete files after receiving a warning prompt.
Additionally, within OS X El Capitan, you can modify the "Move to Trash" action to "Delete Immediately" using the alt/option key in the File menu.


Question: how to connect wireless keyboard to mac from login screen?

Response: Unplug ALL USB devices, have your wireless keyboard and mouse turned on, and restart.


Question: how can i wrap text at a certain column size?

Response: A lesser-known tool that can accommodate your requirements is wrap from GNU Talkfilters: wrap -w 80 < textfile.


Question: do symlinks take up space?

Response: Symbolic links occupy some storage space, specifically the space needed to maintain the name and target of the link, as well as a small amount of additional metadata.


Question: what is the rootless feature in el capitan, really?

Response:
Rootless, know officially as System Integrity Protection, limits the power of the root account, so that even if you become root, you don't have full control over the system.
Essentially, it adds another layer of protection, which prevents malware from gaining root access.


Question: how do you extract a single folder from a large tar.gz archive?

Response:
When handling tar files, it is important to use relative paths without a leading slash when extracting specific folders, as indicated by the command: tar -xvf foo.tar home/foo/bar.
Be cautious about security and the potential of overwriting important system files or your work, when not thoroughly checking the contents of an archive before extraction.


Question: what can someone do with my mac address?

Response:
The disclosure can be linked to your real identity and may enable tracking through data collected from WiFi networks, or it can be used to falsify a device's MAC address to gain access to some service.
Moreover, malicious actors could exploit the information to associate the tracked device with an actual person, facilitating targeted attacks against security vulnerabilities in network drivers.
The MAC address, in the wrong hands, could also be manipulated to disguise one's network card as yours when interacting with a gateway, introducing the possibility of unauthorized access or activities.
Uniquely identifying your computer across multiple sessions is another potential misuse of the MAC address.


Question: are passwords stored in memory safe?

Response:
To keep the password safe and secure from end-to-end, particularly in .NET environments, you can use the PasswordBox control paired with the SecureString class.
It comes down to ensuring nobody can escalate to obtain these privileges.
When you store a password in RAM, you are trusting the OS to keep that confidential.
However, the safeguarding of passwords goes beyond software measures; if an attacker has physical access to your machine, they can potentially read your keys directly out of your memory.
Even with encrypted keys, certain attacks, such as the cold boot attack, can compromise password security and retrieve your password.
To further mitigate risks, especially on machines with multiple users or software you do not trust, avoid doing any security-sensitive computing.
Additionally, consider running proprietary projects and trusted tasks on separate machines to ensure better security through physical separation.
While certain precautions can be taken, like zeroing out secrets from memory after use, it should be noted that these measures cannot prevent all forms of physical attacks.
Moreover, interfaces like FireWire and Thunderbolt present an additional risk as they can be exploited to bypass operating system protections and access plaintext passwords, so passwords stored in plaintext in RAM shouldn't be considered as safe.


Question: what is the difference between writing test cases for bdd and tdd?

Response:
Behavior Driven Development (BDD) emerges as an extension and revision of Test Driven Development (TDD).
While the differences between the two are nuanced, they primarily revolve around language and perspective, with BDD often associated with 'outside-in' or 'mockist' tests.
BDD introduces a novel vocabulary, shifting the focus when writing unit tests.
In TDD, the emphasis lies on unit tests for every function, irrespective of what it does, whereas BDD a subset of TDD concentrates on software that holds relevance.
Notably, BDD allows modification at a lower abstraction level through code refactoring.
It's worth noting that employing a BDD framework, such as Fit or Cucumber, may result in slower tests and necessitate additional infrastructure.


Question: how to move files to trash from command line?

Response: You can do so by using the terminal command osascript: osascript -e "tell application \"Finder\" to delete POSIX file \"${PWD}/${InputFile}\"".


Question: what is the minimum distance for single mode fiber?

Response:
Single-mode optical fibers typically operate at 1310 or 1550 nm wavelengths.
The minimum cable distance for all SFPs, including both multimode and single-mode fibers, is documented to be 6.5 feet (2 meters).


Question: are all magsafe chargers the same?

Response: Yes, although it ships with an adapter of 45 watts, 60 watts, or 85 watts; you can use a higher-rated adapter with a Mac that draws less power, and going the other way is also safe, but the Mac will either not charge, charge slowly, or work fine, depending on how much power it needs from moment to moment.


Question: can ipv6 talk to ipv4?

Response:
In the context of internet protocols, IPv4-only hosts and IPv6-only hosts cannot directly communicate with each other.
This delineation creates significant challenges during the transition phase to IPv6, as the two protocols are inherently unable to operate together directly.
However, a process called dual-stacking can facilitate some interoperability, but this is not cost effective and suffers from several limitations and performance issues.


Question: if immutable objects are good, why do people keep creating mutable objects?

Response:
It depends on your preference, and on what you want to achieve.
Mutability is often chosen for its convenience, as it simplifies the process of updating in place, particularly when dealing with large projects.
Representing game characters with mutable objects not only enhances game performance significantly but also aligns with our inevitable perception of the real world, which is inherently based on mutable objects.
Moreover, certain data structures are notably easier to implement using mutable objects.
Some functionalities become challenging with immutable objects, such as bidirectional relationships.
Without mutable objects you have no state, so non-thread-safe, mutable objects are fine if you are not using multiple threads.
However, in single-threaded scenarios, mutable objects can be perfectly acceptable.
The default mutability in imperative languages, exemplified by Java Beans relying on a specific style of mutating objects, further contributes to the prevalent use of mutable objects.
Frameworks like Hibernate and JPA essentially dictate the use of mutable objects, emphasizing the ease of development they bring, which often outweighs the advantages of immutable objects in many projects.
The ease of setting multiple values after object instantiation makes mutable objects useful in scenarios where a substantial amount of state needs to be assigned to an object.
Also, if you need to change the object after creation then a mutable Person object will be better.
Having the state of an object be mutable makes it possible to have the identity of the object which encapsulates that state be immutable; many programs are designed to model real-world things which are inherently mutable.
Additionally, the prevalence of mutable components in essential computer building blocks, such as CPUs, RAM, cache, and disks, reinforces the widespread use of mutable objects in programming.
Immutability allows for substantial compiler optimizations due to the guarantee that data will not change, often leading to performance benefits and a reduction in state-related bugs.
Yet, mutable objects remain prevalent, possibly because developers are still blending object-oriented programming with imperative procedural programming.
Furthermore, mainstream languages do not support immutability well, possibly deterring developers from adopting it unless they switch to more modern languages that naturally accommodate immutability.


Question: how can i mount sftp/ssh in finder on os x snow leopard?

Response:
You can do so using Cyberduck, a versatile app suitable for multiple platforms, which is freely available.
Another solution to consider is installing osxfuse and sshfs through Homebrew and Cask.


Question: is there an airdrop client for microsoft windows?

Response:
On Windows machines, install Pidgin and enable its Bonjour account to allow file transfers, which can also be done with Macs using iChat since AirDrop is exclusive to Lion.
Unfortunately, there isn't an AirDrop equivalent for Windows, but services like Dropbox with "Enable LAN Sync" could be used for local network file synchronization.
For a cross-platform solution, Snapdrop offers similar functionality to AirDrop, although it requires devices to be on the same LAN and employs WebRTC or WebSockets for direct peer-to-peer communication.


Question: why is my host name wrong at the terminal prompt when connected to a public wifi network?

Response:
When connected to a public WiFi network, your Mac may pick up a hostname from the DHCP server.
If you notice that the hostname is incorrect, it might be associated with a workgroup from a previous connection, possibly through a corporate VPN.
In such cases, you can use the sudo scutil command to manually set your hostname and resolve the issue.


Question: is anaconda safe to install?

Response:
Yes, it is safe to install Anaconda; however, there is no such thing as a 100% guarantee of security.
Installing any software, including Anaconda, on the same device used for online banking may not be entirely "safe" in the sense of having no risk at all, as you can't be certain about what the software is doing.


Question: how to use gps/maps without an internet connection?

Response:
To use GPS without the internet, Maverick for Google Android is available in both a limited free version and a paid version, as offered by Code Sector.
In England and much of Europe, ViewRanger is highly recommended for its support of the Ordnance Survey and other official maps.
Google Maps 5.0 introduces support for an offline mode, enhancing its usability without an internet connection.
Though Google Maps provides some offline functionality, HERE Maps is deemed the best free option due to its comprehensive offline capabilities, nearly worldwide map coverage, and various navigational features.
Additionally, MapFactor offers OSM-based offline navigation, which is fairly basic but shows potential, and TomTom maps can be purchased within the app.
Locus is favored for its fantastic offline and off-road abilities, with support for large offline map tile sets and a user-friendly interface, available in both a free ad-supported version and an affordable paid version.
Maps With Me offers a swift and free lite version for offline map usage.
Lastly, OsmAnd, which utilizes OpenStreetMap data, is an open-source app capable of storing detailed maps on a phone's storage in a compact vector format.


Question: how can i see what ip address my android phone has?

Response:
To easily know the IP address, you can go to the Wi-Fi Settings and navigate to Menu > Advanced.
Another method is dialing *#*#4636#*#* on your phone to open the Testing menu, where you can then select Wi-Fi information and Wi-Fi Status.
Additionally, OS Monitor is an application that provides network details, including interface names, IPv4 and IPv6 addresses, MAC addresses, and packet statistics.
For developers, using adb shell netcfg | grep wlan0 from a desktop with an Android device connected via USB is effective for showing the interface details.
Another option involves installing a terminal emulator app like Terminal Emulator from Jack Palevich and entering the netcfg to obtain network information.
For both WiFi and Mobile Data, using a terminal emulator app with the command ~$ ip -o a is a viable approach that does not require root access.


Question: virtualbox 5.1.28 fails to install on macos 10.13 due to kext security

Response: If you're experiencing issues with the "allow" button, reboot into safe mode and use the command line `sudo spctl --master-disable` to bypass the problems you are encountering.


Question: why is it not possible to use the cut command to manipulate a file in the finder?

Response:
In Finder it's no possible to cut files.
However, there are apps available that allow this functionality, namely MoveAddict and TotalFinder.
Otherwise, on Mac the keyboard commands are Cmd-C then Opt-Cmd-V for cut and paste respectively.
Or if you prefer using the mouse, you can drag the file to the target folder's parent, wait for it to spring open, and then continue dragging the file to where you want it.


Question: project is nearly done, but procedural spaghetti code. do i rewrite or just keep trying to ship it?

Response:
One option is to choose an architecture and gradually migrate the codebase to it.
Alternatively, you could focus on getting the product to a viable state, known as the Minimum Viable Product (MVP), and then proceed with shipping it.
Redesign and rewriting are viable strategies, but it's crucial to implement them incrementally on a working system.
Despite the procedural spaghetti code, shipping the product is still a valid option.
You can provide your customers with a usable product and then consider refactoring based on future needs or feature requests.
In the end, it's essential to finish the project and ship it.


Question: is social-engineering an actual threat

Response: Yes, any system is as weak as the weakest member, and that is the human being, which may include secretarial staff.


Question: iterm - going one word backwards and forwards

Response:
Ctrl-[ b jumps back a word or you can use Esc instead or Ctrl-[, and f to go forward.
Use Alt-f for forward and Alt-b for backward.
After editing preferences to select natural text editing, you can move a word backwards using Option ⌥ + ← and a word forwards using Option ⌥ + →.
In vi mode, hit Esc, then b to move one word backward (w for forward).


Question: where can i find good dictionaries for dictionary attacks?

Response:
A comprehensive list of passwords collected by Ron Bowes is available at: http://www.skullsecurity.org/wiki/index.php/Passwords.
The CrackLib dictionaries are also a notable resource for password security.
You can also find them in a blog written by g0tmi1k, which can be accessed at http://blog.g0tmi1k.com/2011/06/dictionaries-wordlists/.
A critical addition to password security resources is the crackstation wordlist, which includes an extensive compilation of dictionaries and leaked databases.
It can be helpful to utilize the compilation at https://github.com/danielmiessler/SecLists for popular passwords, usernames, and attack types.


Question: what exactly is posix?

Response:
POSIX is a subset of UNIX, designed to be compatible across Unix-like environments on different operating systems.
As the Portable Operating System standard, it outlines specific utilities, APIs, and services an operating system should provide.
It was established as an IEEE Standard in 1988 to unify the various UNIX forks and UNIX-like systems.
POSIX 7 significantly expands ANSI C by defining C API with additional file operations such as mkdir, dirname, symlink, and readlink among others, with these APIs defining underlying system concepts like processes, where Linux system calls are often employed for compliance.


Question: is my developers home-brew password security right or wrong, and why?

Response:
Complicated code does not offer better security and inventing your own falls under that category.
Designing crypto algorithms and implementing them correctly and securely is very hard; you should only do this if you know what you are doing.
There are plenty of flaws in the algorithm although weak hashing protocols are used.
Here are some of the issues found: the algorithm is nonsensical; you use things which attackers know; mt_rand is not secure as a random number generator; a single 31-bit number is not secure; it's not a good idea to use crypt on the username; shuffling an MD5 hash is not a good idea; and the variable names are incorrect.
In the age of cheap massively-parallel GPUs, this is too weak for modern use.
It is a good idea to demonstrate how many attacks per second can be executed with this algorithm versus prevailing standards.
It is better to use a more well-documented scheme.
Use public vetted high-level libraries like BouncyCastle instead of a home-brew of low level crypto-primitives.
Good security means that everyone can know how the system works and it is still secure.


Question: is it possible to use boot camp with windows 10 from an external hdd?

Response:
This is possible and one approach is to use the instructions originally for Windows 8, with some different terminal commands for Windows 10.
Another approach is, if you have Parallels or VMWare, get hold of two free Windows Utilities, miniTools for formatting and setting up the external drive and WinToUSB.
Additionally, you can use commands which are in the ISO instead of using the Automated Installation Kit.
After the progress reaches 100% and integrity checks are through, you'll have a WIM file alongside the ESD file, run: Dism /apply-image /imagefile:install.wim /index:1 /ApplyDir:E:\ /CheckIntegrity.
Start from scratch and follow the steps, googling each one before starting and getting information on hardware requirements.
An alternative approach is to run Boot Camp Assistant to put the Windows drivers onto a separate USB stick and to download Windows 10.
Then transfer the ISO to your Windows installation, go into Windows: Install Windows ADK, uncheck all alternatives except "Deployment Tools", double click the Windows ISO to mount it as a drive Plug in the external USB drive, plug in the external USB drive and open an elevated command prompt.
Finally, a simple method is to use Windows GO.


Question: what should you do if you catch encryption ransomware mid-operation?

Response:
In the event of a potential ransomware attack causing file encryption, it is advised to immediately remove the machine from all network connections.
For further investigation and potential solutions, use a different computer that is not impacted by the ransomware.
To prevent the ransomware from continuing its encryption process, completely power off the affected machine abruptly by cutting the power directly, without going through the normal shutdown procedure.
In a case where the infection begins to encrypt files, putting the computer into hibernation can help preserve the encryption key that is in the memory, which may assist in future recovery efforts.
Alternatively, you can suspend the ransomware process without terminating it, and disconnect from networks including Wi-Fi and potentially Bluetooth.
A direct and immediate shutdown of the computer, without trying to pay the ransom, is recommended for limiting the damage caused by the virus.
Should you encounter ransomware on your PC, you can also boot from a Linux Live CD, which enables you to backup and possibly restore data without the interference of the ransomware.


Question: throttle the download speed of wget or curl while downloading

Response:
Both wget and curl support limiting your download rate, for example, curl --limit-rate <speed>; where --limit-rate=20k will limit the retrieval rate to 20KB/s.

You can stop wget and restart it with a different speed; when downloading multiple pages at once, the --wait option makes wget wait a certain number of seconds between requests.

It is possible to limit the traffic rate using the tc and netem tools, but this will limit the rate for the network interface of the computer; use Token Bucket Filter (TBF) to limit output.


Question: how can i make press any key to continue

Response:
Use "read -n 1 -s -r -p 'Press any key to continue'".
This command will only require a single character to resume, won't display the key pressed, and will interpret input strings in their raw form, disregarding backslash escapes.


Question: what does the @ mean in ls -l?

Response: It indicates that the file/directory has extended attributes, other than ACL.


Question: why cant i mitm a diffie-hellman key exchange?

Response: Diffie-Hellman is not generally resistant to Man in the Middle attacks.


Question: what is the exact difference between a 'terminal' a 'shell' a 'tty' and a 'console'?

Response:
In Unix terminology, the terms terminal, tty, and console are closely linked, with "terminal" essentially being synonymous with "tty," a text input/output environment, while "console" refers to a physical terminal.
The "shell" is what users interact with, serving as the command line interpreter.
Originally, terminals were hardware devices through which users interacted with computers, evolving from teletypewriters (TTYs) to keyboards and displays.
As for "consoles", they're often the main physical terminals connected directly to a machine, and they behave like ttys within the operating system.
Shells are user interfaces for logging in and initiating other programs, predominantly known in Unix as command-line shells.
The distinction between terminal and shell responsibilities is split, for example, with regards input, the terminal converts keys into control sequences and the shell converts control sequences into commands.
With regards to output, for example, the shell emits instructions and the terminal acts on them.
Furthermore, the shell never sees the output of the instructions.


Question: how do i disable the select input method notification?

Response:
Some custom roms, particularly CM9 and AOKP, have settings that allow the disabling of certain features, like notifications.
You can use Titanium Backup to create a backup and then uninstall specific system components like "Android keyboard".
In CyanogenMod versions such as 9 and 10.2, you can turn off Selector notifications by going to the system settings and adjusting the language and input options.
To use only one keyboard on your device, you can go into language settings and disable all others that you don't need, and additionally, disable other stock keyboards through the application settings.
On Xperia devices specifically, there's an option to disable the "Smart Keyboard" feature from the settings menu to change keyboard functions.
In Android versions like ICS, you can navigate to the system apps settings to find and disable the default keyboard listings if you wish to use a different input method.
The "Disable" function in Android allows you to turn off certain system applications and is not contingent upon having root access.
This function does not remove the application but prevents it from operating and can be used to manage both keyboard notifications and bloatware apps.


Question: what is aosp rom android?

Response: An AOSP ROM is essentially a ROM that is built on the Android Open Source Project, and in its most original form, it refers to ROMs that are unmodified from the code provided by Google.


Question: does pressing a car remote many times offer denial of service attack for rolling codes?

Response:
It is possible to render a key fob useless by desynchronizing it from the car, which can be done by repeatedly pressing the button out of the car's range, i.e., at least 256 times.
An attack aiming to disable the rolling code feature in key fobs, which is used for authentication, would generally not be a successful denial of service attack on a car.


Question: how do i stop my ipad connecting to my iphone?

Response:
To ensure that personal and company data are kept separate on your Apple devices, it's recommended to use different Apple IDs for your iPad and iPhone.
If you prefer to use the same Apple ID for both devices, you can manage which data to sync by going to the iCloud settings and disabling the switch for apps where you don't want to sync data.
For example, to prevent website history from syncing across your devices, you should turn off iCloud for Safari, and turn off iCloud for Messages to stop text messages from syncing.
Additionally, you may need to disable Text Message Forwarding on your iPhone to stop SMS from appearing on your iPad.


Question: how to prevent mac from changing the order of desktops/spaces

Response: Go to System Prefs > Mission Control and Uncheck Automatically rearrange Spaces based on most recent use.


Question: how do i remove a user from a group?

Response:
The `gpasswd --delete user group` command can be used.
Specifically on Debian, the `deluser user group` command within the adduser package is available, and if this package is not present, manual editing of `/etc/group` and `/etc/gshadow` using commands like `vigr` and `v-s' -s' is an alternative.
For systems such as Solaris 5.9, the command `usermod"  "G "" username` can be used to remove all supplementary groups from a user.
On SUSE distributions, the command `usermod -R group user_name` eliminates a user from a particular group.
The traditional method involves editing the `/etc/group` file with superuser privileges to remove a user from the group list directly.
Lastly, in the absence of the `-a' option, the `usermod` command can remove users from all groups except the specified new group.


Question: lets encrypt for intranet websites?

Response:
If you are looking for an internal Certificate Authority (CA) service for an Intranet, then a public CA like Let’s Encrypt may not work at all, as it is for publicly reachable sites only; Let's Encrypt connects back to its servers to manage the cert request and signing, and can only issue certificates for valid DNS names.

For a proper solution you can run an own boulder instance, i.e. the letsencrypt server part, on your network, but if you're only having a few servers running boulder, running “letsencrypt” yourself is probably not the best choice, and you can use more simple tools like easy rsa.


Question: how to append multiple lines to a file

Response:
You can append content to a file using `printf` with the syntax `printf '%s\n %s\n' 'Host localhost' 'ForwardAgent yes' >> file.txt`.
Similarly, you can use SED to insert text at the end of a file with the command `sed -i '$ a text to be inserted' fileName.file`.
For operations that require elevated privileges, `sudo` can be paired with `sed`, as in `sudo sed -i '$ a text to be inserted' fileName.file`.
Another method is to use `echo` with the `-e` option to control newline characters, such as `echo -e "Greeting 1\nGreetings 2\n" >> greetings.txt`.
Additionally, `tee` can be used to append text to files using a command like `tee -a ~/.ssh/config << END Host localhost ForwardAgent yes END`.


Question: is winmail dat a virus?

Response: It's possible that the winmail.dat file is malware due to it containing theming.


Question: how secure is blacking out sensitive information using ms paint?

Response:
When using MS Paint to black out sensitive information, the original pixels are effectively destroyed, making it a safe option for ensuring privacy.
The method has been acknowledged as secure for removing sensitive data, suggesting confidence in its safety from multiple sources.


Question: tdd who writes the tests?

Response:
In Test-Driven Development, the tests must be written by the developer.
It can also be done by the person writing the component.  Functional testing is a QA process that can and should be done by a QA team.
However, these tests can also be done by the developer, although a non-developer might be better suited for the task, as the developer may not be aware of all the ways a user might use the application.


Question: quoting within $(command substitution) in bash

Response:
The correct syntax for assigning the output of the dirname command to a variable in a shell script, without issues arising from whitespaces or wildcard characters, is `DIRNAME=$(dirname "$FILE")`.
This approach works when one makes an assignment to a scalar (not array) variable.


Question: cat line x to line y on a huge file

Response:
An effective method for achieving this is combining the `head` and `tail` commands like this: head | tail, as it avoids reading more lines than necessary.
It has been suggested to consider the `sed` solution, although it might not be the fastest.
For instance, if X=57890000 Y=57890010, run the command `sed -n -e "$X,$Y p" -e "$Y q" filename`.
For a fast operation using line numbers, employing `tail` and `head` in commands, like: `tail -n "+$X" /path/to/file | head -n "$((Y-X+1))"` is recommended, especially when dealing with a large part of a file.


Question: how can i install the command line tools completely from the command line?

Response:
To install the Command Line Tools for Xcode on an Apple system, users can download the Command Line Tools package directly from the Apple Developer site.
There are methods to fully automate the installation of Xcode Command Line Tools, which includes downloading the XCode 4.x CLTools packages from their official download site via direct links.
The setup for the command line tools can also be made version-independent, by using softwareupdate and an os variable that adapts to different macOS versions.
Moreover, installing Homebrew on the system will also automatically install the command line tools.


Question: what is wired memory?

Response:
Wired memory is used for core functions of the Mac OS X operating system and cannot be reallocated by other applications.
Wired memory is basically used by your computer for internal bookkeeping of various sorts.
It includes memory used by core functions such as tracking applications, open files, and network connections and the memory used by integrated video chips.
Wired memory stores data that must always be accessible so it cannot be transferred to disk.
When additional memory is installed in a system, wired memory increases accordingly.


Question: how can i configure mac terminal to have color ls output?

Response:
You can add alias ls='ls -G' to your ~/bash_profile to get colored ls output.
Edit: ~/bash_profile or ~/profile and add the following line to simply enable color output via ls: export CLICOLOR=1.
For the Catalina version, you need to add export CLICOLOR=1 in ~/zshrc.
Another option is to use the GNU ls which is part of the 'coreutils' program.
You can also customize the prompt color (and its format) by adding: PS1='\[\e[0;33m\]\h:\W \u\$\[\e ' to ~/bash_profile or ~/profile file.
Or add export PS1=" \[\033[34m\]\u@\h \[\033[33m\]\w\[\033[31m\]\[\033[00m\] $ ".
Alternatively, use the built in Terminal --> Preferences, Settings pane to set the default skin, and edit the ANSI colors to your liking.
It's also easy to use Oh My Zsh for adding color and other tricks to my Terminal.


Question: how do i get the md5 sum of a directorys contents as one sum?

Response:
For the file contents within a tree, $ find -s somedir -type f -exec md5sum {} \; | md5sum.
If you need to be able to detect that anything in a tree has changed, not just file contents, ask tar to pack the directory contents up for you, then send it to md5sum: $ tar -cf - somedir | md5sum.
To identify differences between two directories, a command such as diff -qr dir1 dir2 can be utilized.
Md5deep is a utility that offers recursive examination of directories and comparison of file hashes; you can hash every file recursively with > md5deep -r -l . | sort | md5sum d43417958e47758c6405b5098f151074 *.
For moderate and extremely large volumes of data, certain command lines involving 'find .-xdev -type f -print0 | LC_COLLATE=C sort -z | xargs -0 cat | md5sum -' for moderate volumes and 'find .-xdev -type f -print0 | LC_COLLATE=C sort -z | xargs -0 tail -qc100 | md5sum -' for large volumes, can be employed.
For faster checksum calculation of large directories, consider GNU Parallel: find -s somedir -type f | parallel -k -n 100 md5 {} | md5, maintaining order with -k flag and adjusting -n parameter for optimal runtime.
For fast and consistent hashing of directory contents, tar remains the preferred method, especially when additional parameters are applied to control for metadata differences.


Question: what are the pros/cons of deb vs. rpm?

Response: The openSUSE Build Service (OBS) and zypper are key factors that make RPM packages more appealing than deb for both packagers and users.


Question: where should i put software i compile myself?

Response:
It is recommended to compile your software and then create an FC package, which can be managed through a package manager like yum.
Placement for the compiled software can be in directories like /opt or /usr/local, with a preference for isolation. .
By adding the executable's path to your PATH environment variable, the software's accessibility is facilitated without affecting other users.
If you intend to include the software in your $PATH, avoid /usr/local to prevent conflicts with distro-installed software, and consider using your $HOME directory as a location to prevent the need for superuser access.
For source code, /usr/local/src is a proper directory, and using symbolic links for convenient management between versions is a common practice.
When it comes to installation and removal, creating a simple rpm package or using Stow as a simple package manager is beneficial.
System-wide installations can be made under /usr/local/stow/package-version using stow or in ~/.local following the XDG standard if you do not have write permissions for /usr/local.
Adhering to the Filesystem Hierarchy Standard (FHS), it's recommended to put binaries in /usr/local/bin, source code in /usr/local/src, and libraries in /usr/local/lib.
Some developers may opt for a personal setup, such as a custom directory within their home directory, adding that path to their environment variables like PATH, LD_LIBRARY_PATH, and PKG_CONFIG_PATH.
Some say to use /usr/local for system-wide installations and /opt for applications not trusted enough to be system-wide with per-app prefixes—i.e. /opt/firefox-3.6.8, /opt/mono-2.6.7, and so on in Debian-like systems.
The decision to use /opt or /home/username depends on whether you want the application to be available for all users or only specific users, respectively.
Lastly, the Filesystem Hierarchy Standard (FHS) specifies using /usr/local for applications compiled from source or /opt/ for third-party applications not supported by your operating system vendor.


Question: what is akmod in fedora?

Response:
Akmods are used to effectively manage kernel-related modules and drivers, particularly those that are not included with the operating system or are third-party, in order to ensure availability for the current kernel variant a user may be running, such as a custom-compiled kernel or one from an alternate source.
Akmods serve a similar function to dkms but with a notable advantage: they only require the maintenance of a single kmod spec file that is compatible across both repository build systems and individual user systems.


Question: where do executables look for shared objects at runtime?

Response:
In Linux, it is well-documented within the ld(1) man page that the linker behavior involves a specific sequence of paths to find the necessary shared libraries, starting with any paths indicated by -rpath or -rpath-link options.
The difference between -rpath and -rpath-link is that directories specified by -rpath options are included in the executable and used at runtime, whereas the -rpath-link option is only effective at link time.
For locating dynamic libraries in Linux, the linker tries LD_LIBRARY_PATH environment variable ((DYLD_LIBRARY_PATH on OSX), directories listed in the executable's rpath, directories on the system search path, which (on Linux at least) consists of the entries in `/etc/ld.so.conf plus /lib and /usr/lib`.


Question: what should i do about gmail ad asking me for password?

Response:
The Google ad domain appears to have been compromised, so take the following steps: make sure that you have antivirus and anti-spyware software installed; change your password as soon as possible with an ad blocker; and contact Google and report this, supplying them with details like your IP, URL, screenshots, date/time, and as much information as you have.

Most importantly, never log in to a prompt like that; you can test whether the ad was fake by going to a genuine Google site, ensuring that Google owns the TLD and ssl certificate, such as going to gmail.com – if it logs you in, it was fake.


Question: how do i do a ls and then sort the results by date created?

Response:
For listing files sorted by their creation or birth date/time on systems that support this functionality, you can employ the command `ls -lt --time=birth` to achieve the desired output.
Additionally, with the advent of coreutils version 8.32 or later, this capability has been further refined, allowing `ls` to display and sort files using the birth time with the `--time=birth` option, so 'ls -l --time=birth'.


Question: move folder content up one level

Response:
To move files one level up, use `rsync -vua --delete-after foo/`, or `cp -vaR foo/. . && rmdir foo/`, or (with dotglob option enabled)`shopt -s dotglob #` will include filenames beginning with a dot.
Be sure to use both '*' and '.*' to include all files that begin with a dot, for example `mv subfolder/* subfolder/.* .`.
If you prefer to copy instead of move, the shorthand command `cp */* .` can be utilized to copy contents from subfolders to one level up, or to a new destination with `cp */* /destination`.


Question: how to extract specific file(s) from tar.gz

Response:
When extracting a specific file from a tarball, you can specify the path if the file is in a subfolder by using the command `$ tar --extract --file=test.tar.gz subfolder/extract11`.
Be sure to write the file name exactly as it appears when listed by the command `tar ztf test.tar.gz`.
If you need to extract multiple files from a large tarball, you can use the command `gunzip < thousands.tar.gz | tar -x -v --files-from hundreds.list -f -`.


Question: how do i reset the scrollback in the terminal via a shell command?

Response: ⌘K is a shortcut for the action "View > Clear scrollback" and, in an update, this command can be automated with this command with AppleScript: osascript -e 'tell application "System Events" to keystroke "k" using command down'.


Question: can you put a kindle book on 2 devices?

Response:
You can register multiple Kindle applications or devices to a single Amazon account, so you can read the same book on multiple devices.
In fact, you may simultaneously access most Kindle store purchases on up to six Kindles or Kindle-supporting devices that are registered with your Amazon account.
Moreover, some Kindle books have a feature that lets you lend them to another Kindle user for a period of up to two weeks.


Question: how long does it take to replace a battery in a mac?

Response: The battery is easily swapped in 10 to 35 minutes.


Question: how can i diagnose a bridging (ethernet) loop?

Response:
Eyeball it: if the switches have port indicators, you should be able to see which ports are the most active.

SNMP monitoring: if you've got SNMP (or similar) usage stats, look at the interface statistics for the busiest switch and the busiest ports and check if any has hit 100% usage.

Also, check the CPU usage (usually "show process cpu history"), as looped interfaces will usually hit your CPU pretty hard, unless you're running a high end switch.


Question: where on the file system are sms messages stored?

Response:
SMS/MMS data is stored in databases on Android phones.
The specific location of these databases may differ between different phone models.
Generally, on most Android devices, the absolute path to the SMS and MMS databases is /data/data/com.android.providers.telephony/databases/mmssms.db.
However, this default path was different before Android KitKat 4.4, after which it moved to `/data/data/com.android.providers.telephony/databases/mmssms.db` from `/data/data/com.android.providers/telephony/databases/mmssms.db`.
With the release of Android Nougat, the path appears to have changed again to data/User_DE/0/com.android.providers.telephony/databases on some devices like the Nexus 6.


Question: pptp vpn client for macos sierra or ios 10?

Response: The FlowVPN client is free and supports PPTP and OpenVPN on macOS Sierra and High Sierra.


Question: is it ok to split long functions and methods into smaller ones even though they wont be called by anything else?

Response:
Splitting long functions into shorter ones is a common practice and is recommended as a better way to write code.
This approach is endorsed by authors like Robert C. Martin, who suggests using descriptive function names to make the code self-explanatory.
Additionally, maintaining Locality of Reference, which refers to the organization of related code in proximity to each other, can greatly enhance the readability and understanding of the code.
Balancing these aspects is crucial, and avoiding absolute rules such as 'always' or 'never' is typically advised.


Question: why do we use su - and not just su?

Response:
su - username initializes a clean login shell with the specified user's environment, while su username starts a shell with the current environment settings.
If no username is specified, su assumes root account as default.


Question: why do game developers prefer windows?

Response:
One major factor is the overwhelming user base of Windows, which surpasses Linux and Mac, making it a pragmatic choice due to the sheer size of over 90% of its market share.
With 95% of PC users utilizing Windows, especially in the realm of PC gaming, it has become the predominant environment for game developers, with even those who use Mac or Linux most often running Windows games through some virtualization or emulation.
In contrast, Linux is considered a mess for development, with Windows offering better backward compatibility and platform stability.
The substantial backing of Windows by a large organization that actively promotes game development on its platform plays a pivotal role.
Additionally, the lack of a central institution and the unavailability of essential tools make Linux less appealing to developers.
Also, if you've used Windows in the past then switched to something else, it's a hassle.
The market share of Windows on the desktop is bigger than that of OS X which in turn is bigger than that of Linux, along with money, influence and brand.
Political and control factors contribute to the preference for Windows, while the broader end-user base ensures a more significant market and potential revenue for Windows games compared to Linux games.
Access to top-notch development tools is another advantage that Windows offers developers.
Furthermore, the combination of genuinely open development, deployment, and a large, active customer base makes Windows a compelling choice for game development.


Question: is pvst compatible with rstp?

Response:
It's feasible to combine PVST and MST, considering that RSTP necessitates MST, though stability might be a concern and planning is essential.
Using RSTP alongside PVST+ while deactivating STP in interconnection links is an option if maintaining two separate STP instances is possible.
For interoperability between RSTP and PVST+ regions, it is critical to have VLAN 1 enabled on any trunk connections.


Question: can ssl traffic be sniffed?

Response:
Technically, you could sniff the traffic, but it would be encrypted and useless to you.
This is because the SSL prevents such snooping and you would need the certificate trusted by the device to intercept and decrypt it.
However, by exploiting the FREAK TLS vulnerability, it is possible to inject data into SSL negotiations and make the decryption of traffic via a man-in-the-middle possible.
Also, if you want to decrypt the traffic between your client and the device, then it is possible with a proxy.


Question: can csv files contain viruses?

Response:
Yes, there are some examples of malicious CSV files causing random "code" execution.
Moreover, CSV files may contain arbitrary system commands that will be executed on the machine where you are opening the file.


Question: how can i figure out whats slowly eating my hd space?

Response:
To visualize what is consuming disk space on your system, it is recommended to utilize apps like GrandPerspective or Disk Inventory X.
Alternatively, Disk Cartography can be employed to reveal hidden system files and sort files by size, such as only showing those larger than 1 GB.


Question: how to run grep with multiple and patterns?

Response: "Git grep" is a command that can be used for combining multiple patterns using Boolean expressions: "git grep --no-index -e pattern1 --and -e pattern2 --and -e pattern3" will print lines that match all the given patterns simultaneously.


Question: agile for the solo developer

Response:
The concept of "Cowboy Development" refers to a form of Agile tailored for solo developers.
An alternative to structured Agile methodologies could be to work in well-defined sprints or deliberately adopt a Kanban approach.
Agile is effective for both teams and individuals, as it focuses on adapting processes to meet changing project requirements and continuously delivering value.
A critical aspect of most Agile methodologies is unit testing, which ensures the integrity and functionality of code throughout development.


Question: why am i not getting notifications when someone texts me?

Response: This doesn't seem to be an issue with your phone's settings, rather the conversation is marked as "Do Not Disturb".


Question: not all files are visible over mtp

Response:
Using USB storage mode instead of MTP is a known workaround for a bug in Android that causes files to remain invisible when accessing a device using MTP, but this is not an option for all devices, such as the LG Optimus L5.
Clearing the data of the “Media Storage” app and then using the SDrescan app to rebuild the media database is a suggested approach.
Third-party apps like AirDroid can be used for sharing files over the network.
Directly going to the settings to clear the data for 'Media Storage' and then rebooting can often restore the visibility of files within Windows Explorer: settings > apps > all applications > media storage > tap 'clear data'.
Navigating to Menu > System Settings > Storage > Unmounting and mounting the SD card from the system settings can trigger a rescan of media files on the card.
Moving a movie file to another directory like "Playlist" using a file manager before connecting the device to a PC is another trick to consider.
The SD Scanner app can be effective without requiring root permissions and is compatible with Android 5.0.2, although it may be limited in functionality.
Disconnecting the USB cable from the phone, clicking Clear Data or Force Stopping the Media Storage application, and then reconnecting the cable can also help to rescan and rebuild the media list.
A simple yet effective method for some users has been renaming a missing folder via a File Explorer app on the phone, such as "Music" changed to "Music 1".


Question: i dont have administrator account on my mac

Response:
One approach is to create a new administrator account by restarting the Setup Assistant.
Alternatively, you can Boot into Recovery Partition, choose Terminal from the Utilities menu, and type the following: resetpassword.
Another option involves creating an admin group and account by using the dscl utility.


Question: how do you know if someone checks your location on iphone?

Response:
On the device, there is no clear indication that it is being tracked, as the GPS usage alone is not a definitive sign of tracking.
However, by navigating to the General -> Privacy settings, the user can discern if a service like Find My iPhone (FMI) is actively using location services or has been used recently, based on the color of the arrow icon.
If desired, location sharing can also be facilitated through the installation of the Find Friends application, which openly communicates location requests to the user.


Question: click is not working trackpad?

Response: The trackpad may be fixed by putting in a new battery, or look inside your computer for the small screw next to it and make a 1/4 turn left or right to adjust the click on the trackpad.


Question: how to stop os x from writing spotlight and trash files to memory cards and usb sticks?

Response:
To do so, I utilize two tools: Clean Eject, which is a free application, and a custom-made Automator Service, which I have not made public.
These tools are integrated with a hotkey, enabling me to quickly clean and eject a volume.


Question: confirmed evidence of cyber-warfare using gps history data

Response:
One example is Strava, which updated its global heat map and showed some areas in supposed desert areas full of activity, revealing locations and activities of soldiers at U.S. military bases; another is Polar, which dropped two pairs of coordinates over sensitive government locations and facilities, making it possible to find the names of personnel who track their fitness activities, dating as far back as 2014.

In another example, Ukrainian artillery units used FancyBear, a malware-infused app, to compute shooting solutions for their D-30 122mm towed howitzer, resulting in these units suffering suspiciously high losses; and a Russian soldier on duty posted pictures automatically tagged with GPS data that showed he was in Ukraine, at a time when Russia was denying having troops there.


Question: i dont program in my spare time. does that make me a bad developer?

Response:
It doesn't make you a bad developer and it's possible to become a good software developer while only coding at work.
However, programming in your spare time can make you a better developer.
Also, you should be advised that some industries are more competitive than others, so mastering your skills and developing your knowledge should definitely be a consideration.
That being said, whether or not you program outside work does not automatically make you a "good" or "bad" programmer.


Question: should we define types for everything?

Response:
You shouldn't create types or classes for everything in your code.
It's beneficial to consider encapsulating multiple primitive values into a single value or class if you need to validate these values or find yourself using them frequently and widely.


Question: why does man print gimme gimme gimme at 00:30?

Response:
This is an easter egg in man.
When you run man without specifying the page or with -w, it prints "gimme gimme gimme" at 00:30.
This playful feature is a nod to the Abba song called "Gimme Gimme Gimme a Man After Midnight".


Question: is multicast on the public internet possible? and if yes: how?

Response: You cannot multicast on the public Internet, but you can multicast across the public Internet to another site by using a tunnel that supports multicast.