Question: paint.net alternative for mac os x

Response:
Skitch is recommended for its ability to share ideas with annotations, shapes, and sketches quickly.
Alternatively, Mac's built-in Preview.app provides tools for adding annotations, arrows, shapes, text, magnifying glass and more, although it is not as lightweight as Skitch.
For more complex editing capabilities, Gimp can be utilized, though it comes with a steeper learning curve.
Pinta is another free option, offering a simple and powerful way to draw and manipulate images across different platforms.
Preview.app is also suitable for its quick startup time and seamless integration with OS X's Mail.app for markup purposes; it provides lightweight snapshot creation that can include menus and the mouse pointer, but for more advanced annotation needs, Skitch might be the better choice.
If you use Google Drive instead of Dropbox, Marqueed is a suitable online tool for image annotation.
TechSmith's Snagit, while not free, provides various annotation features for screenshots on Mac and Windows.
Lastly, Patina, available on the Mac App Store, offers a user-friendly interface with features like continuous object rotation and transparent image saving.


Question: dd vs cat -- is dd still relevant these days?

Response:
The dd command is incredibly useful and includes LOTS of options that cat is not able to accommodate, for example, only dd can open a file without truncating or appending, or seek from the shell; cat can be a workable substitute, but it is not a dd replacement.

dd is very useful for backing up the boot sector of a hard drive or other storage device, and is similarly useful for backing up the headers of encrypted volumes, and while cat might be able to be twisted into doing this, it may not perform the rewriting part reliably.

dd is particularly useful if you need to write with sudo.


Question: how to sync two folders with command line tools?

Response:
For synchronization tasks, one can utilize the "unison tool" developed by Benjamin Pierce of U Penn.
Another option is the "Fitus/Zaloha.sh" which is a bash shell script relying solely on standard Unix commands.


Question: two html elements with same id attribute: how bad is it really?

Response:
It is recommended to never duplicate IDs within the same document, as it is against the specification and can cause issues with JavaScript's getElementById function.
If the standard for validating HTML is strictly enforced, code with duplicate IDs would fail such checks, which is the expected behavior.
Unique identifiers within a given scope are fundamental for programmers, and non-unique IDs break this important rule and fail validation checking.
Many JavaScript libraries, such as jQuery, may not work as expected given non-unique IDs, which can lead to confusing code and unexpected behaviors.


Question: sharing browser links between pc and phone

Response:
GTalkSMS (Google Code Project Page) enables forwarding links to your PC using XMPP/GTalk.
Utilizing Google Chrome on both PC and Android while signed in with the same Google account provides the convenience of having your browsers synced.
Additionally, Chrome sync, Firefox sync, and Opera link are all viable methods for synchronizing current open tabs and bookmarks between devices.
Similarly, MAXS can be used to exchange clipboard contents over XMPP.
Social bookmarking services like Papaly offer user-friendly interfaces and sync capabilities with existing bookmarks.
With Pushbullet, sharing a webpage from a phone and pushing it to the Windows/Mac app or Chrome extension is trivially easy.
For a dependable solution, Google Keep is recommended as it outperforms other options.


Question: where are apache file access logs stored?

Response:
The location of Apache's access log files depends on your Apache configuration.
A common location for these log files is within the /var/log directory and its subdirectories, or in /var/log/httpd directory.
On Debian or Ubuntu Linux systems, the /etc/apache2/apache2.conf leads to ${APACHE_LOG_DIR} environment variable instead of the log directory itself, so use $ sudo tail -f /var/log/apache2/access.log.


Question: is there a mac os x terminal version of the free command in linux systems?

Response:
On Mac OS X, to view memory usage, you can utilize a terminal command akin to 'free', called 'top'.
While no exact equivalent of 'free' comes with Mac OS X, alternative methods such as using 'system_profiler' or 'sysctl' commands can provide similar information.


Question: good detailed explanation of /etc/network/interfaces syntax?

Response:
In the context of network interfaces, a VLAN interface specifies its "father" or primary interface, while a bridge interface defines the interfaces that are its members.
When discussing services for network interfaces, `ifup` and `ifdown` play a role, indicating that they pertain to bringing interfaces up or down.


Question: how secure is chrome storing a password?

Response:
Chrome, under Windows, employs encryption for stored passwords using Data Protection API (DPAPI), which is considered secure as it is tied to the user's login credentials.
However, Chrome has a vulnerability to password dumping, requiring technical expertise or malware for exploitation, indicating that general browser password storage is only safe from non-technical individuals.


Question: linux how do symlinks work?

Response:
The symlink uses the real file's name as a reference point within the file system: the operating system, upon accessing a symlink, follows through to the actual target file.
Once the file is reached and the inode is in use, the original path used via the symlink becomes irrelevant as the inode is the main reference for file operations and will be used for any further read or write operations on that file.


Question: how to connect two monitors to macbook pro 2011?

Response:
You can do so using a USB Displaylink adapter, like one manufactured by OWC, or any USB to DVI display adapter.
It's also possible to daisy-chain 2 Thunderbolt displays, or connect one mini DisplayPort monitor to the end of a Thunderbolt chain and connect your Mac to your Thunderbolt Display.
Alternatively, you could try the Matrox DualHead2Go Digital ME, with the Mini DisplayPort version a good recommendation.


Question: blacking out a part of a pdf, or redaction of text

Response:
If you have Adobe Acrobat, you can use its dedicated redaction tools for this purpose.
Another option is using PDFPen, which provides a redaction tool that works properly.
ScanTango is another tool that offers redaction features.
For a free solution, you can convert the PDF to an image or JPG and then save it as a PDF again in Preview.
GIMP, a free photo editor, can be used to open the PDF as an image and apply redactions using tools like the line tool.
PDF Studio version 8 includes a manual redaction tool within its content editing features.
Alternatively, you can use Preview on Big Sur, which now has a dedicated Tools/Redact menu item for deleting the content being redacted.


Question: how can i add (subtract, etc.) two numbers with bash?

Response:
Arithmetic in POSIX shells is done using $ and double parentheses (( )): echo "$(($num1+$num2))".

There is also expr: expr $num1 + $num2 In scripting $(()) is preferable since it avoids a fork/execute for the expr command.

You can also use $[ ... ] structure, using built-in mechanisms in Bash, which is faster and more convenient to use; everything between $[, and ] is treated as an expression, so it is unnecessary to precede the variables with $.


Question: how do i run a .sh or .command file in terminal

Response:
To do so, open up Terminal and type in: 'sh /path/to/file' then press enter.
An even faster way to do this would be to type sh and a space and then drag the file to the window and release the icon anywhere on the window.
Alternatively, if you wish to run a script directly from Finder, change the file's extension to .command—for example, naming it script.command—then double-click it.
This action will open Terminal and execute the script, provided you have set the right permissions to allow execution.


Question: my isp uses deep packet inspection; what can they observe?

Response:
Deep packet inspection involves analyzing all of your traffic, including details like the IPs you are connecting to, port numbers, protocols, and other specifics about the network connection.
Despite encryption like HTTPS, metadata can still be read by your ISP.
With deep packet inspection, everything you do, if transmitted in plain text, can be seen.
An ISP can detect the presence of VPN traffic, although not the encrypted data within the VPN packets, and may even block such traffic.


Question: how big is the pipe buffer?

Response:
The pipe buffer capacity is not consistent across different systems and can also change within the same system.
Specifically, on Mac OS X, the default capacity is 16,384 bytes, but this can increase to 65,536 bytes under certain conditions, such as large writes being made to the pipe or a decrease to a single system page when there's heavy usage of kernel memory by pipe buffers.
Experimental results from running a script on a Mac OS X 10.6.7 system show that for write sizes of up to 16,384 bytes, the successful bytes written before the error remained at 16,384, but when the write size was increased to 32,768 bytes and above, the successful bytes before error jumped to 65,536 or resulted in no successful writes for even larger sizes.
On a Linux 3.19 system, the same script demonstrated that regardless of the write size, from 1 byte to 65,536 bytes, the successful bytes before the error consistently remained at 65,536.


Question: how do i set an environment variable on the command line and have it appear in commands?

Response: Use the command "TEST=foo && echo $TEST".


Question: is it bad that my macbook air is passing me electricity?

Response:
Electric shock from your Mac is not normal and could be incredibly dangerous.
This issue should be taken as the default concern for any consumer electronics causing similar sensations.
If you encounter such an issue with your device, it might indicate a minor fault.
Using a grounded power outlet is advisable to prevent electric currents from passing through the body.
Though some users have reported feeling vibrations without adverse effects on themselves or the computer, it's generally more responsible to address any such electrical issues.


Question: write to ntfs-formated drives on yosemite

Response:
All recent OS X releases, including Yosemite, have native support for NTFS.
However, for those seeking additional solutions, Paragon NTFS is a commonly used third-party application.
Alternatively, there is a simplified process with a single installer called Hackintosh Zone, providing a free NTFS driver specifically designed for Mac OS X.


Question: how can i type unicode characters without using the mouse?

Response:
First, enable Unicode Hex Input in System Preferences -> Keyboard -> Input Sources.
In System Preferences, select "Keyboard," then choose "Input Sources".
Alternatively, Press CTRL+CMD+space to bring up the characters popover, type in the code point, press the down arrow to select the symbol, and then press ENTER to complete the process.


Question: how to monitor cpu/memory usage of a single process?

Response: If you know process name you can use top `-p $(pidof <process_name>)` to monitor CPU/memory usage.


Question: should ipv4 icmp from untrusted interfaces be blocked?

Response: No, ICMP should not be blocked because it's vital signalling protocol and the internet does not function without it.


Question: what is the difference between iphone backup and sync?

Response:
Backup involves transferring your personal data, such as application settings, text messages, and voicemails from your mobile device to your computer.
Sync refers to the process of copying new applications, music, videos, or books from iTunes to your phone, or from your phone to iTunes.
While backup copies everything, sync focuses on specific media items selected through iTunes and it is up to the user to customize what gets synced.


Question: how can i instruct yum to install a specific version of package x?

Response:
Download the rpm file and then command yum to execute a local installation.
To obtain the needed packages, a resourceful website to visit is rpmfind.com, where you can search for the specific package name.


Question: how to create a text file in a folder

Response:
To create a text file in a folder, one option is to navigate to the desired directory in Terminal and execute the command: touch file.txt.
Another method is to prepare an empty text file on the desktop to use as a template, then Option/Alt-drag it to the desired folder to create a copy.
Alternatively, Mac users can download utilities like NewTextFileHere and NewRTFHere that integrate with Finder and allow the creation of text or RTF files within a currently open folder.
The Easy New File Creator app offers a Finder extension for macOS that adds the ability to create new files in the Finder context menu, with customization options for the file name and type.
Moreover, BetterTouchTool provides a convenient "Create New File in Current Folder" action that can streamline this process.


Question: list usb devices on osx command line

Response: To view USB device information on a Mac, you can run the command `system_profiler SPUSBDataType`.


Question: how to move phone contacts to google?

Response:
To transfer contacts on a HTC Hero 2.1, you should press the menu button, select "Import/Export," and then choose "Import from SIM card".
On any Android device, you can use vCardIO to import-export any vCard 2.1 formats, whether they contain single or multiple contacts.
For Samsung Galaxy S phones, you can export contacts to the SD card and then, through a browser, import them to Gmail, which synchronizes them back to the phone as Google contacts.
Contact Remover Plus on the other hand is an option that allows moving contacts between different accounts, including social media, and provides a solution for duplicate contacts.
With Galaxy devices, you can also go to your contacts list, choose Merge Accounts, and then merge with your Google Account for a cloud backup.
Another way could be to email the contacts to yourself and then import them to the desired account on your new phone.
Alternatively, you can merge contacts directly with your Google account through the contacts menu, which will then sync these contacts to Gmail if sync is enabled.


Question: how secure are the fido u2f tokens

Response:
U2F can use an encrypted channel with public key cryptography, which ensures that only the correct server can receive the one-time token.
This security feature means that if a U2F device is used on a phishing site, it will not release the token, effectively preventing unauthorized access.
The design also includes measures to prevent tracking across multiple services by avoiding the disclosure of using the same device on different sites.
U2F is considered secure and is currently the best option due to the process of standardization it's undergoing, along with significant industry support and adoption.
The FIDO specification outlines that during online service registration, a user's device will generate a new key pair, keeping the private key and registering the public key with the service.
Authentication involves the device proving it holds the private key by signing a challenge.
This signing process is enabled only after the user unlocks the private keys locally on the device, done through secure methods like fingerprint scanning, entering a PIN, using voice commands, inserting a second-factor device, or pressing a button.


Question: how to stop the find command after first match?

Response:
Within GNU or FreeBSD's find utility, you can effectively stop the search after locating the first item by using `-quit predicate: find . ... -print -quit`, and with NetBSD, `find . ... -print -exit `.
Other options include `find . -name something -print -quit` which terminates find after the first match after printing it, and `find . -name something -print | head -n 5` which terminates find after a specific amount of matches and print results.


Question: are passwords saved in cookies?

Response: Usually the passwords aren't stored in cookies.


Question: whats the most appropriate directory where to place files shared between users?

Response:
The appropriate directory for placing files to be shared between users is recommended to be /srv, as simplicity is a key goal of FHS.
In instances involving Network-Attached Storage (NAS), using /export/srv is suggested.


Question: how can i activate buttons with just the keyboard?

Response:
For many dialog boxes, you can quickly select options by pressing the Command key (⌘) plus the first letter of the option you want to choose.
The tab key (⇥) allows you to cycle between buttons, and pressing enter (↩) activates the default option, while the space bar selects the highlighted button.
Moreover, the shortcut ⌘+ serves as "Cancel" in some applications.
Alternatively, you can enable a specific setting in the System Preferences under Keyboard and Shortcuts, where you select "All Controls" rather than just "Text boxes and lists only"; similarly, there's an option in System Preferences to use keyboard navigation to move focus between controls.


Question: delete line in vi

Response:
Use the "dd" command, which will remove the line, allowing you to paste it later with "p" and also accepts positional modifiers, allowing you to use "dk" to delete the previous line or specify a repetition like "5dd" to delete multiple lines.
Press ESC to make sure you're in normal mode for the "dd" command to work.
In visual mode, you can select multiple lines with "shift+v" or columns using "ctrl+v", and then pressing "d" to delete.
You can also use "S" delete rather than "dd", which puts you in Insert mode.


Question: do websites track mac address?

Response:
Generally, remote sites can only learn your public IP address and not your device's MAC address, except when using IPv6 with an EUI-64 address, which could potentially reveal your MAC address.
It is generally not possible for websites to determine your MAC address; however, certain conditions, such as being on the same network segment as the server or instances where ISPs embed MAC addresses in reverse DNS records, could allow for this information to be obtained.


Question: how to access tmp folder on mac?

Response:
One possibility is to use a browser (Chrome, Firefox), and enter in the URL bar: file:///tmp.

Alternatively, you can use the menu Go -> Go to folder, and enter the path of the folder you wish to see in the resulting dialog.


Question: how to turn off all animations on os x

Response:
It's not possible to disable all animations on OS X with one global setting, so the best thing to do is to disable them on a one-by-one basis as and when you encounter one you don't like.
If you aim to disable specific animations, you can utilize hidden preferences with specific commands in Terminal to achieve this.
Some example commands being; write -g NSAutomaticWindowAnimationsEnabled -bool false, and; write -g NSScrollAnimationEnabled -bool false.
If you're not comfortable with Terminal, an alternative is Mountain Tweaks, which offers a graphical user interface (GUI) to adjust the behaviour of OS X.


Question: what are the security reasons for disallowing the plus sign in email addresses?

Response:
There is no inherent security risk with using a '+' in email addresses, as this is allowed by email formatting standards.
The restriction of '+' often results from certain systems utilizing a whitelist approach for email characters, excluding symbols they do not anticipate, such as '+'.


Question: do any security experts recommend bcrypt for password storage?

Response:
One opinion advises that Thomas Ptacek, a security researcher, advises the use of bcrypt while they are themselves more interested in PBKDF2 as a key derivation function that applies a pseudo-random function to the input password along with a salt.
However, businesses required to comply with U.S. NIST or FIPS standards, bcrypt is not a valid option, as it doesn't meet those specific compliance requirements.


Question: how to download portion of video with youtube-dl command?

Response:
In order to extract video content, combine youtube-dl with ffmpeg because this feature on youtube-dl is not implemented yet and it will not work alone.
You can also use `youtube-skip-dash-manifest -g "URL"` with special flags to acquire separate video and audio streams for further processing with ffmpeg.
Additionally as tested with version 2017.08.27.1, youtube-dl also allows passing arguments: 'youtube-dl -x --postprocessor-args "-ss 00:13:00.00 -t 00:04:00.00" https://youtu.be/...' directly to the postprocessor to refine the download process.


Question: what makes docker more secure than vms or bare metal?

Response:
Most opinions agree that there is no inherent security advantage that Docker containers have over hardware-based solutions like "bare metal" or VMs, and it may even be less secure.
Claiming that Docker or VMs are more secure than one another would be a massive oversimplification.
Docker containers are not more secure than VMs; for instance, vulnerabilities found within the Linux kernel can be a significant threat in containerized environments, since containers share the host's kernel.
It is not advised to compare the two "out of the box" and make a decision, instead, a process is needed in place to strengthen either solution.
There are clear and open attack surfaces for Docker containers, especially if an attacker gains root access on the host or within a container.
Docker containers are not Inherently “more secure” but the ability to swiftly deploy and destroy container instances has certain security advantages, notably the opportunity to redeploy clean code after a security breach.
While Docker leverages useful security technologies like LXC, SELinux, and AppArmor, Docker's common usage often leads to security concerns, underscoring that it is not inherently more secure than non-container solutions.
Understanding that a VM is generally more secure than a Docker container can be more straightforward when considering the structural differences between the two.
Lastly, one reason that Docker may seem more secure is due to its design philosophy of sandboxing individual processes.


Question: how and when do i use hmac?

Response:
HMACs are utilized to confirm both the integrity and authenticity of a message.
This cryptographic technique ensures that the data has not been tampered with or replaced.
Specifically, HMACs offer a method to digitally sign data using symmetric keys instead of relying on public key infrastructure (PKI) systems.
This allows for the verification (authentication) without the need for public and private key pairs, but it does require careful management of the shared secret keys.


Question: what hacking competitions/challenges exist?

Response:
For those interested in "war games" related to cybersecurity, one can delve into puzzle-like challenges found on websites such as OverTheWire.org or by visiting http://www.wechall.net/sites.php for a list of challenge sites.
Furthermore, cyber competitions like iCTF, DC3, and NetWars SANS are available, each with their respective websites and a variety of security-focused CTF competitions.
In the realm of hacking competitions, Wargames are accessible 24/7, enabling participants to join at their convenience to tackle various challenges on a provided server.
Plus, you can engage in challenge-based competitions like "Over The Wire" and "Smash The Stack Intruded," where you'll encounter various tasks to solve individually.
Those looking for additional resources can explore Capture.thefl.ag, which offers a rich repository of information, including a live CTF calendar and numerous online practice games.
For web hacking enthusiasts, the Spider Challenge from Spider.io presents a time-sensitive and competitive quest to locate hidden codes through a series of clues.
Exploit-exercises.com offers different exercises such as Nebula, Protostar, and Fusion, focusing on Linux security challenges and memory corruption issues.
A comprehensive guide to various competitions can be found at http://ctf.forgottensec.com, equipped with descriptions, links to write-ups, and beginner resources.
Lastly, http://ctftime.org/ serves as a valuable platform to stay informed about upcoming CTF events and to access rankings and write-ups.


Question: what is mvc, really?

Response:
The Model-View-Controller (MVC) is an architectural pattern separating the business logic from the presentation, differentiating domain logic from the user interface, and allowing for a clear division of concerns within an application.
MVC accomplishes this by dividing the application into three interconnected parts.
The "Model" component represents the application's knowledge or data and is responsible for the behavior, data management, and notification of changes to its observers.
The "View" element acts as a presentation filter, highlighting certain attributes of the model and suppressing others, capable of rendering data into a form suitable for the user.
The "Controller" is the intermediary between the user and the system, arranging for relevant views to be displayed and translating user output into appropriate model updates.
Overall, MVC is considered a pattern for organizing code to improve maintainability, helping to manage program complexity, and facilitating the maintenance or extension of software by clearly separating structural and behavioral concerns.
It is described generally as a concept or family of related patterns rather than being strictly definitional, and despite criticism for becoming somewhat of a buzzword with misinterpreted definitions over time, MVC remains a significant concept in software design.
Lastly, in a mobile application context, MVC can be identified where the view is an xml layout, the controller is the activity managing user interaction, and the model is a standalone class handling logic.


Question: where can i find default microsoft fonts calibri, cambria?

Response: If you are using homebrew, consider trying the homebrew-fonts-nonfree tap for additional resources.


Question: username and/or password invalid - why do websites show this kind of message instead of informing the user which one was wrong?

Response:
There's a generic security principle which says you shouldn't provide unsolicited information to unauthorized users; you don’t want someone to know whether it was the username or password that was wrong so that you are not as susceptible to brute-force or dictionary attacks.

Sometimes applications are also unaware whether the UserName or Password is wrong due to the way they have the authorization routine programmed.

Providing ambiguous answer is also useful to prevent a user enumeration attack, where a company is trying to gather valuable information on whether their customers have accounts with a competing web shop.


Question: do changes in /etc/security/limits.conf require a reboot?

Response: It's not necessary to reboot, but you should close active sessions, as these sessions still use old values.


Question: what is the difference between flash and bootflash?

Response: Bootflash is the generic term generally used to denote the flash of both the route flash and switch flash.


Question: view apps full package name?

Response:
The APK extractor application can be a helpful tool to find out the qualified name of any installed app.
If you're seeking to discover the launching activity of an app, looking into the LogCat is recommended, as it displays the activity that is started when the app is launched.
For those who are adept with adb and Linux, the grep command `adb shell ls -al /data/data/ | grep 'yourAppName'` can be very useful in quickly searching for app names if you have root access.
The OS Monitor app is another powerful resource for gaining information on running processes within Android.
Various apps like Elixir 2 can reveal the package name of an installed application.
A simple alternative could be to share the app from the Google Play Store and observe the shared URL to identify the package name or to long press on the app icon and select "Application info".
Using Link2SD is another effective method to find out app package names and other related information.


Question: agpl - what you can do and what you cant

Response:
AGPL introduces, in addition to GPL, the notion of who the user is.
The distinction is significant because while GPL considers the operator of the server as the user, AGPL expands this to include the actual end users of a web service or application.
Hence, if these end users are utilizing your application, you are effectively distributing the app, thereby necessitating adherence to GPL's conditions.
Regarding the distribution of (A) GPL-licensed software, it cannot be shipped with the final product even as an isolated application—for instance, bundling them in the same archive or storage is prohibited.
However, providing instructions on acquiring the GPL software separately and integrating it with your application is permissible.


Question: whats the difference between ike and isakmp?

Response: ISAKMP is part of IKE: IKE establishes the shared security policy and authenticated keys; ISAKMP is the protocol that specifies the mechanics of the key exchange.


Question: is xss client or server side?

Response:
XSS, or Cross-Site Scripting, is a security vulnerability that can manifest on both the client and server sides depending on the entity responsible for the actual HTML construction.
On the client side, where the attack itself occurs, there are mitigation measures available, such as XSS-Protection.
The nature of XSS makes it a server-side vulnerability, often categorized as a "client-side exploit of a server-side vulnerability".


Question: pass the output of previous command to next as an argument

Response:
The grep & pcre:`command | grep -oP '\$>\s+rate\s+\(\K[^\)]+'` Pass the output of a previous command to the next as an argument.
In practice, one might use a command to retrieve the output of another command, which could involve extracting process IDs or other relevant data.


Question: how can i monitor all outgoing requests/connections from my machine?

Response:
To monitor network connections, you can utilize the "netstat" command, which lists all active connections including TCP, UDP, and RAW and shows the associated processes.
Other options include: the "ss" command; "conntrack" for those running Solaris or a derivative; iptables LOG target for simple comprehensive traffic logging in Linux; "tcpdump" to inspect all IP traffic on a given interface, with the ability to filter traffic as required; or "nethogs," which is able to group connections by the originating application.


Question: why is cd not a program?

Response:
Shells also provide a small set of built-in commands (builtins) implementing functionality impossible or inconvenient to obtain via separate utilities (such as cd, break, continue, and exec) which cannot be implemented outside of the shell because they directly manipulate the shell itself.

cd in addition to being a shell builtin, is actually also a program on POSIX compliant OSes.

If cd was a different process then it would have to change the current working directory of its parent (shell), which is not possible in Unix.


Question: how do i update android on my device?

Response:
If your device has an official update available, you should use the official method to update it.
However, if no official update exists and you possess programming knowledge and understand Linux device drivers, you might consider attempting to create a custom ROM for your device.


Question: how do i find my ip address from the command line?

Response:
You can use ipconfig getifaddr en1 for wireless for wireless interfaces, or ipconfig getifaddr en0 for ethernet.
Also, ifconfig or ifconfig -a shows you the list of interfaces along with their IP and MAC addresses.
Another option is to type curl ifconfig.me in the terminal.
If you are using Yosemite 10.8 or 10.10, you can use the command: ifconfig | grep "inet " | grep -Fv 127.0.0.1 | awk '{print $2}'.
Or you cam create an .aliases dotfile for frequent ip lookup: alias ip="dig +short myip.opendns.com @resolver1.opendns.com" alias localip="ipconfig getifaddr en0".
Alternatively, you can a bash script with the following content: #!/bin/bash wget -qO - http://ipecho.net/plain; echo.
Finally, to find the IP address of the current network interface, run: ifconfig -l | xargs -n1 ipconfig getifaddr.


Question: how do you hide your best friends on snapchat?

Response: You cannot hide the best friends list in snapchat, although you could block the users to remove their name from the list.


Question: why is rhel not free?

Response: Red Hat charges for compiling the software from source RPMs and for providing enterprise-level support; additionally, it does freely provide the source RPMs, from which users can build the binary version of their distribution.


Question: how to download songs from another itunes account?

Response: You cannot change 'ownership' of the files to another account, but you can turn on Home Sharing on both machines, then add this music to the new library, and use your account to authorize it; alternatively, you could possibly copy the files into the library, use iTunes Match to download the files from iTunes in the Cloud, then delete the local files.


Question: how do i automate a key press in applescript?

Response: Run a script in AppleScript Editor to automate a key press: an example given is activating the application "Firefox" and using a loop to send keystrokes repeatedly with random delays.


Question: looping through files with spaces in the names?

Response:
When dealing with shell variables that contain spaces, it is advisable to employ double quotes as in `diff "$file" "/some/other/path/$file"` to prevent issues with word-splitting.
A zsh solution for file is  (/*.csv(ND.)) { do-something-with $file }.
((D) to include hidden files, (N) to avoid the error if there's no match, (.) to restrict to regular files.
Bash 4.3 and above now supports it partially as well: shopt -s globstar nullglob dotglob for file in /*.csv; do [ -f "$file" ] || continue [ -L "$file" ] && continue do-something-with "$file" done.
Additionally, Bash users have the `readarray` command at their disposal, which facilitates the handling of arrays, particularly when used with here-strings for splitting variables containing newlines.


Question: how to convert a heif/heic image to jpeg in el capitan?

Response:
Users advise that tifig is an excellent command line tool that works very well, as it is fairly straightforward to compile on modern platforms, including El Capitan.
Additionally, ImageMagick is a recommended command line tool option for converting HEIC images to JPG.
For users operating macOS Big Sur, using the terminal with sips commands offers a native method for image conversion from HEIC to JPEG, with the ability to process batches of files and even remove the original files.


Question: how to apt-delete-repository?

Response: To remove a repository, you have to do 2 things: remove it from sources.list, then use apt-key del to delete it, using sudo apt-key del 73C62A1B.


Question: where do files go when the rm command is issued?

Response:
The file gets unlinked, so the data is still sitting there on disk, but the link to it is removed, meaning the file is effectively nowhere, gone, vanished.

In Unix-style filesystems (including on Linux), files are not really "at" any particular place; if there are still hardlinks, the files are wherever the hardlinks you didn't delete are, but if there are no hardlinks left, the files are gone.

Files removed with rm are gone, but given that most filesystems only remove the reference to the data and indicate that the blocks as free, but the file's data is never deleted, so you could try to locate your data reading directly from the device, for example by searching for the not-yet-overwritten blocks by certain patterns.


Question: how to transfer messenger messages to new iphone?

Response: As of March 2019, to transition to a new device or alternate account access, you need to add a password to your Messenger.


Question: what is the purpose of .bashrc and how does it work?

Response:
A .bashrc file has the purpose of providing a place where you can set up variables, functions and aliases, define your PS1 prompt and define other settings used every time you open a new terminal window.
A .bashrc works by being run each time you open up a new terminal, window or pane.


Question: what is wrong with magic strings?

Response:
Magic strings are challenging to monitor because their purposes are often unclear and they typically lack any form of reuse, making maintenance difficult due to the necessity of altering multiple files across various projects.
Additionally, in compiled languages, a magic string's correctness isn't guaranteed during compilation; only at runtime is it confirmed whether the string adheres to a required pattern, increasing the risk of errors, like typos, which can turn into serious bugs.


Question: how does gratuitous arp work?

Response: Gratuitous ARP is sent as a broadcast frame, and is a sort of "advance notification" that updates the ARP cache of other systems before they ask for it (no ARP request); in the Gratuitous ARP, the Opcode field is set to 2, which indicate a Response.


Question: find command: how to ignore case?

Response: With GNU find, or other versions of find that have it, the command is as follows: `find . -iname "WSFY321.c"`.


Question: just how secure is a pattern lock?

Response:
The security provided by pattern locks on touchscreen phones is questionable as it can be easily compromised.
In certain circumstances, the security offered by the Android Pattern lock is not robust.
On certain rooted devices, exploits involving adb commands can threaten the security of the phone, although not all adb commands necessitate root access.
Pre-setting "USB debugging" also plays a role in potential vulnerabilities.
It should be noted that enabling "USB debugging" heightens vulnerability, although even with it disabled, a seasoned hacker might discern other methods to access the device's data.
Overall, the Android Pattern lock's inherent glitches and flaws render it a relatively weaker security option that doesn't encrypt the device's contents.
Furthermore, it's been demonstrated that an individual doesn’t require extensive technical knowledge to exploit the weaknesses in touch screen lock mechanisms.


Question: how to list disks, partitions and filesystems in linux?

Response:
For managing block devices on a system, several tools are available such as fdisk -l, parted -l, and notably, lsblk, which is considered quite handy for listing block devices.
Additionally, the df command allows quick inspection of the file systems, although it does not display the file system type.
The UUIDs is useful for boot scripts and configurations like /etc/hdparm: `$ sudo lsblk --output NAME,FSTYPE,LABEL,UUID,MODE NAME FSTYPE LABEL UUID MODE sda brw-rw---- ├─sda1 ntfs WinHyperX 2D6BFC4E0CDCFAD8 brw-rw---- ├─sda2 ext4 HyperX ef761208-bab3-4a26-87d2-ed21a7f5a1bb brw-rw---- └─sda3 swap 74259007-a80b-4866-b059-0bdbe6331040 brw-rw---- sdb brw-rw---- └─sdb1 ext4 4TB 91e32977-0656-45b8-bcf5-14acce39d9c2 brw-rw---- sr0 brw-rw---- mmcblk0 brw-rw---- └─mmcblk0p1 exfat 9C33-6BBC brw-rw----`.


Question: best app to switch between all open windows

Response:
The Optimal Layout app, priced at $14, offers keyboard shortcuts for swiftly arranging and switching between windows.
Senebier is presented as a free alternative, with further details available on its website.
Quicksilver (or Spotlight) can be invoked on a desired application, such as Safari, and allows users to search for and select window titles via keystrokes.
Contexts is an intuitive alternative to Witch for Mac users, notable for its keyboard and mouse window switching capabilities, as well as an optional side panel that enhances window and application management.
Hyperswitch is acknowledged as a compatible and aesthetically pleasing free option, albeit it has ceased updates as of May 2021 and lacks support for Apple's M1 silicon.
Karabiner is highly recommended for its extensive options and keyboard customization, particularly its "Tab mode" for app switching and window cycling.


Question: how to detect the encoding of a file?

Response:
It is not possible to determine a file's encoding with absolute certainty without metadata or a header indicating the encoding.
Due to the potential for multiple encodings to share the same byte sequences, even a "smart guess" can be ambiguous, and encoding menus exist to manually select an encoding in software like Notepad++.


Question: if my team has low skill, should i lower the skill of my code?

Response:
Maintaining your programming skills is essential, but it may be necessary to modify your coding approach to prioritize clarity for those who maintain it.
While not lowering the skill of your code, you can ensure code expressiveness and maintain consistency in coding style across a team's work, which is crucial.
Elevate the quality of your comments, especially around more complex sections, without overwhelming the code with excessive commentary.


Question: why wont my ipad send text messages?

Response: Only an iPhone with cell connection can send SMS messages, though users with iMessage accounts can receive text messages; hence, Apple iPads cannot send SMS messages to non-Apple devices nor an iMessage to a phone number not registered with iMessage.


Question: how can i use my pcs keyboard on the android emulator?

Response:
To enable the keyboard in your Android emulator, you should modify the config.ini file located in your .android directory.
If you're building the emulator from source, modify the property in the "external/qemu/android/avd/hardware-properties.ini" file by changing the default value from "no" to "yes" in the "hw.keyboard" section, and subsequently rebuild using the "make" command.


Question: can you see when someone is looking at your location?

Response:
When using Find My Friends, your friends will not be aware if you check their location; they won't get any notifications or a log of such activities.
However, arguably, someone could, in theory, detect if you have requested their location if they have the right technical tools and expertise.


Question: why is the same origin policy so important?

Response:
Google Analytics has the potential to perform any action they choose with your users due to the nature of script tags creating exceptions to same-origin policy restrictions.
It is likewise crucial to recognize that the origin of the document in which the script operates, rather than the origin of the script itself, is what the same-origin policy considers significant.


Question: can you pair multiple bluetooth headphones to iphone?

Response:
It is possible to do so: you can use an additional device called a Bluetooth (BT) splitter, or you can connect two SkyGenius headphones to one iPhone without any splitter using a function they call "ShareMe".

Apparently, Apple is rolling this capability out in a feature called Airplay.


Question: batch renaming files

Response:
In Bash or other POSIX-compatible shells, use the command `for f in *.png; do mv -- "$f" "${f#image}" done`.
Similarly, on Debian and related systems, Perl's `rename` works similarly with `rename -v 's/image//' *.png`, and there's a variant from util-Linux that functions with `rename image '' *.png`.
The `zmv` command in the zsh shell is also a powerful batch rename tool once it's enabled, which involves inserting `autoload zmv` into your `~/.zshrc` and using it with the syntax `zmv 'image(*.png)' '$1'`.
In Perl, try `perl -nlE '$old=$_; s/image//; qx(mv $old $_)'`, applicable for various tasks beyond renaming, or `$ rnm -l 's/^image//' '*.png'` for Windows and Linux systems.
You can also use the simple command `mmv "image*.png" "#1.png"` where `#1` corresponds to a match in the original file pattern.
`https://github.com/shenwei356/brename` is a practical cross-platform command-line tool for safe batch renaming that includes features like file filtering and renaming with regular expressions.
Or use shell brace expansion with `for N in {0001..1000}; do mv "{image,}$N.png"; done`.


Question: a tech from mackeeper wishes access to my computer for licensing and activation. is this a scam?

Response:
Avoid allowing remote access to your computer for licensing or engaging software, as it's unnecessary and raises skepticism regarding intent or competence.
MacKeeper is malware, and you are advised to uninstall it, use MalwareBytes for removal, and inform your credit card company of the scam if you've been charged for it.
Emphatically, any unsolicited request for computer access is a scam, and no legitimate entity requires such access.
Individuals claiming to represent MacKeeper may be actually scammers with the goal of controlling your computer.


Question: how do i limit the number of files printed by ls?

Response:
You could try: ls -U | head -4.

Similarly, try: ls -ld -- *() will list the first 4 files.


Question: dmg how to change password?

Response: You can change it by first selecting the DMG in Disk Utility, then go to Images>Change Password.


Question: ssh key-type, rsa, dsa, ecdsa, are there easy answers for which to choose when?

Response:
DSA and ECDSA keys are of fixed length and are considered US government standards, while RSA is better known and allows for longer key lengths, making it arguably more secure due to its more extended key capability.
RSA keys are known for their widespread compatibility, working across various platforms, whereas ECDSA is a newer option that is not as widely supported yet, with some older systems potentially experiencing difficulties.
Recent changes in OpenSSH 7.0 and higher no longer allow the use of DSA keys by default, even though it used to work everywhere as per the SSH standard.
ECDSA keys are comparatively smaller for a similar level of security, but like DSA, they are vulnerable to poor random number generation, which can compromise the key.
For practical compatibility and to avoid potential issues with different systems and services, RSA is recommended over DSA or ECDSA.


Question: is there a quick way to relink my homebrew kegs?

Response:
Execute the command `brew list -1 | while read line; do brew unlink $line; brew link $line; done`.
This will unlink and then relink all installed formulae, which is essential because dependent tools may not function if the formulae they rely on aren't properly linked.
Another method mentioned involves the directory `/usr/local/Library/LinkedKegs` and requires listing the contents and unlinking, then forcefully linking each item found, which is performed by the command `ls -1 /usr/local/Library/LinkedKegs | while read line; do echo $line brew unlink $line brew link --force $line; done`.
It's critical to ensure that write permissions to `/usr/local/lib` are set before attempting this process.
Furthermore, if multiple versions of a formula are installed, one would need to handle these separately.
First, relink all the formulae that can be linked with the `--force` option, after which `brew doctor` can be run to identify any issues.
For formulae with multiple versions, use `brew info` to select the desired version and then `brew switch` to activate it.
It's also advisable to unlink any keg-only formulae linked incorrectly during the relinking process.


Question: is `sudo` almost useless?

Response:
Most anything without a Secure Attention Key is “almost useless”, and Sudo has no real security purpose against a malicious third-party, so, yes, it is basically useless for that purpose.

However, it depends on how you configure Sudo, and it can be far from useless, as an admin can assign privileges flexibly and granularly and have accountability options (decent logging), but Sudo should be configured so that you are asked for a password.


Question: is it free to facetime?

Response: Both FaceTime and FaceTime Audio are data and never go through the phone network as a regular phone call, so you will be charged in the same way as using the internet for other purposes on your phone, either Wi-Fi or mobile data, depending on your scenario.


Question: runaway distnoted process

Response:
In managing distnoted issues, a cron job can be set up to routinely terminate distnoted.
You can debug distnoted by initializing a log file which causes the CFNotificationCenter service to log all notifications.
Also, the distnoted process settles quickly once Emacs is closed.
Or you could choose to kill it automatically every minute.
Another approach to managing distnoted includes checking for excessive CPU usage and only then terminating it.
Finally, errors with distnoted often arise when an application misuses macOS's notification API.
Noted culprits have been iTerm2, Emacs and iTunes.


Question: how do i remove the google chrome notifications bell icon from the mac os x menu bar?

Response:
Previously in Chrome, users had the ability to hide the Notification Icon from the menu bar under "Chrome -> Hide Notification Icon" without delving into chrome flags.
In Chrome for OS X v35.0.1916.114, there was a feature called "Enable Rich Notifications Mac, Windows" which has since changed to "Notification Center behavior Mac" and can be accessed in chrome://flags.
However, as of Google Chrome version 47.0.2526.73, the Notification center, identified by a bell icon, is no longer available.


Question: in arch linux how can i find out which package to install that will contain file x?

Response:
Since pacman 5.0, there is built-in functionality for searching the database with the -F option.

From ArchWiki: $ pacman -Qo df.

The google way:www.archlinux.org/packages/ bin/filename.


Question: time difference between developing with unit tests vs no tests

Response:
The later you test, the more it costs to write tests because the longer a bug lives, the more expensive it is to fix; be sure to focus on where the gain is, and consider a suite of tests.
For one some software engineer, writing tests means they get the work done 25% faster because unit tests they are the most efficient way to catch and isolate bugs and to gain confidence that the code is good, which aligns with the findings of a case study in The Art of Unit Testing.
Unit tests also increase business value.
A study has shown that Test-Driven Development (TDD) can increase development time by 15%–35% while significantly reducing pre-release defects by 40%–90%, although these figures could change as teams gain more experience with TDD.
TDD encourages writing less code and, hence, fewer potential errors while also eliminating unnecessary features that would otherwise be included.
With experience, the extra time needed to write tests that some software engineers need upfront can be about 25%, and unit tests are best when built into the development process from the beginning.
It's advised to focus on testing critical and complex parts of an application for greater efficacy.
Some believe that automated tests, especially system tests, are beneficial over the lifespan of a project and can alleviate the issue of recurring retesting when new functionality is added or when refactoring.


Question: can i zip an entire folder using gzip?

Response:
Gzip does not inherently zip an entire directory; it serves purely as a compression algorithm.
In contrast, using the gzip command with the -r switch will result in each file within a directory being compressed separately, not as a single zip file.
To compress a whole folder, you can use `tar -cvf - dir | pigz -9 > /path/to/dir.tar.gz` syntax.
Alternatively, the zip utility allows the recursive compression of a folder with the syntax `zip -r <zip file name> <folder to zip>`.


Question: do bright wallpapers spend more battery than dark ones?

Response:
AMOLED displays consume less energy when showcasing dark colors because they generate their own light, resulting in fewer light emissions for darker imagery.
In contrast, LCD displays tend to use slightly less power when displaying white because less energy is required to filter light through the crystals for white compared to darker colors.
On OLED, AMOLED, and Super AMOLED screens, using dark wallpaper and themes can save battery, but this is not the case with LCD screens.
In practice, one could observe up to 20% battery saving by opting for dark wallpaper and dark-themed apps on the appropriate screen technology.


Question: allow setuid on shell scripts

Response:
One solution to the problem is to call the shell script using a program that can use the setuid bit, similar to sudo functionality.
An alternative method is to create an alias for running sudo along with the name of the script, which, despite being more complex to configure, can reduce the need to repeatedly enter sudo.


Question: how to view progress when encrypting a disk?

Response:
Open up the Terminal and enter the command: diskutil cs list or with APFS starting with 10.13, use diskutil apfs list.
If you prefer a concise answer, you can run the command diskutil cs list | grep -e "Conversion" -e "Volume Name".
Another approach is to use a loop with a sleep interval; for instance, while true; do diskutil cs list | grep 'Conversion Progress' ; sleep 30; done.
Alternatively, you can use the watch command: watch -n 5 "diskutil cs list | grep -e Conversion -e Volume\ Name".
For APFS, you can check decryption progress with while true; do diskutil apfs list | grep 'Decryption' ; sleep 720; done or encryption progress with while true; do diskutil apfs list | grep 'Encryption Progress' ; sleep 60; done.
If you are using fdesetup, you can check the status using fdesetup status, and for Catalina, the command is while : ; do printf "$(date) - " ; diskutil apfs list|grep Encryption ; sleep 300;done.


Question: when should i not kill -9 a process?

Response:
It is generally recommended to use the regular kill command, often `kill -s TERM` or `kill -15`, before resorting to `kill -9`.
`kill -9` should never be used on specific processes, such as mount, because it does not allow the process the opportunity to clean up resources, close socket connections, or tidy up temporary files, which can lead to system instability.
Instead, it's better to try to terminate the process cleanly with other signals like `kill -15` (TERM), `kill -2` (INT), or `kill -1` (HUP) first, and only use `kill -9` as a last resort.
However, there are cases where `kill -9` is necessary and appropriate, such as when a process is entirely unresponsive.
For <defunct> processes, which cannot be killed directly, one should first attempt to use signals like `kill -15` on their parent processes.
Before using `kill -9`, ensure that the process isn't engaged in critical operations and that it has flushed its caches, especially for database processes.


Question: what are the implications of nsa surveillance on the average internet user?

Response:
The average internet user is not significantly affected by privacy issues from NSA surveillance since they tend to share a lot of information about themselves online willingly.
However, the existence of surveillance programs such as PRISM does pose a real risk of expanding their scope beyond their original intent, which can lead to misuse and misinterpretation of collected data.
Despite increased worry about privacy from some individuals, most people believe they have nothing to hide and are not concerned unless they see a direct impact on themselves, while more worried ones will try to figure out how to hide things.


Question: how to rsync over ssh when directory names have spaces

Response:
If you need to transfer a filename that contains whitespace, you can either specify the --protect-args (-s) option, or you'll need to escape the whitespace in a way that the remote shell will understand.
For instance: rsync -av host:'file\ name\ with\ spaces' /dest.


Question: what are high memory and low memory on linux?

Response:
"High Memory" refers to the application or user space, the memory that user programs can use and which isn't permanently mapped in the kernel's space, while "Low Memory" is the kernel's space, which the kernel can address directly and is permanently mapped.
The user cannot access the Low Memory as it is set aside for the required kernel programs.


Question: how to import secret gpg key (copied from one machine to another)?

Response: It is advised that it is necessary to add `--import` to the command line to import the private key and that according to the man page, the `--allow-secret-key-import flag` is an obsolete option.


Question: do personal hotspots use data?

Response:
Hotspots do consume data even though your device might show an active WiFi connection.
This could potentially result in very high charges.


Question: how do i report a security vulnerability about a trusted certificate authority?

Response:
When dealing with a serious claim involving vendor security issues, it is first advised to contact the vendor in question.
In parallel, reporting to the root store security teams at major corporations like Google, Microsoft, Apple, and Mozilla is crucial, as they design and maintain security controls.
For those less certain about proceedings or wishing anonymity, the Chromium security team offers assistance in reporting and coordinating these efforts.
Alternatively, contacting CERT is a solid option for guidance, confirmation of vulnerability assessments, and for documenting one's discovery.
Operating system and browser vendors are also relevant points of contact considering they manage root CA lists.
If necessary, individuals should compile evidence of the vulnerability, such as a certificate chain or session capture that demonstrates the fault, and publish it to platforms like GitHub or Pastebin to prevent repudiation.
For personal protection and representation in communications with vendors and the public, seeking a representative through the community, the Electronic Frontier Foundation (EFF), or a personal attorney is advisable.


Question: are programmers good at math?

Response:
Some say that in most instances, good programming and an interest in mathematics are distinct abilities, and proficiency in one does not necessitate competence in the other.
One programmer noted that the very worst very worst programmers they had ever worked with had PhD's in math.
Some prominent programmers, like Jeff Atwood, do not necessarily have a strong inclination towards mathematics.
While a fundamental understanding of algorithms is crucial for becoming a standout programmer, and a basic comfort with or knowledge of math will help you in your work, you don't necessarily need to excel in mathematics.
A lack of mathematical inclination does not preclude success in programming, though familiarity with principles like logic and geometry can enhance one's work with databases.
The idea that math is essential for programming is sometimes considered a myth, mainly propagated by academic environments, rather than by the reality of working as a programmer.
Some say that the level mathematical ability required depends completely on what you're programming.
But many believe math to be essential for programming, stating that mathematics is an abstract notation for modeling real world situations, which is exactly what programming is.
They add that high-level programming may not require extensive math; however, more in-depth understanding is mandatory for low-level programming.
Programming, they say, has firm mathematical roots, and comfort with numerical concepts is important, further advising that you have to either learn math, or create your own–either way, it is important to be good at it in some form or another.
The essence of being "good at math" may equate to the ability to construct and manipulate mental models rather than the memorization of facts, which is crucial for programming as well, proving to some that a programmer with good math skills will be a far better programmer than the one who lacks.
Mathematical knowledge can facilitate certain programming tasks, as seen in a Javascript acceleration and deceleration simulation using the Fibonacci sequence.
A comfort level with algebra seems almost non-negotiable for being a proficient programmer, but extensive math experience beyond that may not be frequently necessary.
Some say that it's pretty hard to be good at programming if you don't understand some basic concepts in Discrete Mathematics like set theory and Boolean logic.
Directly learning algebra from programming is not uncommon, as it helps in understanding algebraic expressions, and mathematics can give a valuable foundation for software developers.
Proficiency in mathematics can result in superior programming skills, as programming is essentially applied math: both fields reward clear, analytical thinking.
Likewise, interest in programming can boost mathematical ability, illustrating a practical application for math concepts in coding.
While some say that business programming might not involve intricate mathematics, they assert that the development of 3D graphics engines and developing data structures rely heavily on mathematical concepts.
But others counter that even business programming requirements necessitate some math skills, particularly databases, algorithms, and query processing, which are fundamentally mathematical.


Question: where in the file system are applications installed?

Response:
Apps on an Android device are stored in a few locations, with system apps typically housed in /data/app/.
On certain devices like the Xperia ray, the applications can be found in specific directories such as /mnt/asec/XXX-1/pkg.apk, where XXX is replaced by the Google Play ID of the app.
System apps might also be in places like /custpack/app's subdirectories, and normal apps are stored in internal memory at /data/app.
Apps downloaded from outside sources like Aptoide on a Kindle Fire are located in the downloads folder, while other apps are in the /system/app folder.


Question: how to move and overwrite subdirectories (and files) to parent directory?

Response:
You will have to copy them to the destination and then delete the source, using the commands 'cp -r *' followed by 'rm -rf *' as there is no direct way to merge directories utilizing the 'mv' command.
You can also use 'cp' and 'rm' without the need to transfer a large volume of data by creating hard links to files rather than copying their actual data—this is achieved via the command 'cp -rlf source destination' followed by 'rm -r source'.


Question: how does the sticky bit work?

Response:
The sticky bit used to apply to executable programs flagging the system to keep an image of the program in memory after the program finished running, but that is not obsolete and that in Linux, the application of the sticky bit is now confined to directories, not files.
It is a permission bit set in a directory intended to stop deletion of critical folders and their content by preventing unprivileged users (those who are not owners within that directory or root users) from deleting or renaming files in a directory.


Question: preserve bash history in multiple terminal windows

Response:
To preserve bash history in multiple terminal windows, first, add two lines to your ~/.bashrc:
```shopt -s histappend PROMPT_COMMAND="history -a;history -c;history -r;$PROMPT_COMMAND"```.
Additionally, you can use the `history -a` command to append the current session's history to the histfile and then use `history -r` on other terminals to read the histfile .
You can edit your BASH prompt to run "history -a" and "history -r":
```savePS1=$PS1 (in case you mess something up, which is almost guaranteed) PS1=$savePS1`history -a;history -r```.
Another approach involves writing a script to set a history file per session or task:
```# write existing history to the old file history -a # set new historyfile export HISTFILE="$1" export HISET=$1```.
You can also map the following to a hotkey:
```history | grep -v history >> ~/master_history.txt```.
Consider this solution:
```# Write history after each command _bash_history_append() { builtin history -a } PROMPT_COMMAND="_bash_history_append; $PROMPT_COMMAND"```.
If you prefer a simple version, you can use the following:
```shopt -s histappend PROMPT_COMMAND="history -a; history -c; history -r"```.
To maintain history in a file-per-tty, allowing multiple people to work on the same server, use this approach:
```shopt -s histappend PROMPT_COMMAND="history -a; history -c; history -r"```.
Another method involves storing the history of each session separately and recreating it on every prompt:
```export HISTFILESIZE= export HISTSIZE= export HISTTIMEFORMAT="[%F %T] " export HISTFILE=~/.bash_myhistory PROMPT_COMMAND="history -a; history -r; $PROMPT_COMMAND"```.
The following is also worth considering: export HISTFILESIZE= export HISTSIZE= export HISTTIMEFORMAT="[%F %T] " export HISTFILE=~/.bash_myhistory PROMPT_COMMAND="history -a; history -r; $PROMPT_COMMAND".
Finally, for a more hands-on approach, you can create a script to merge the on-disk ".bash_history" with the in-memory shell 'history'; here is the result: https://antofthy.gitlab.io/software/history_merge.bash.txt.


Question: internal keyboard and trackpad stop working after plugging in usb device

Response:
The intermittent problem can be attributed to a faulty cable that occasionally causes the connection to drop and reconnect.
A temporary workaround for this issue involves unplugging and re-plugging the phone multiple times until the trackpad and keyboard respond.
Moreover, removing or managing the Android File Transfer application on OS X has been reported to alleviate the issue for some users.


Question: enter a filename in the file open dialog

Response:
When using the Finder dialog box on a Mac, you can simply press ⇧⌘G to access the "Go to the folder" dialog, where you can insert the path of the desired file.
This dialog accepts Unix-style path expressions such as '~' for your home directory.
Moreover, the "Go to folder" dialog supports auto-completion by allowing you to type the first few characters of the name and then press TAB to complete the entry, which can significantly speed up the navigation process.
If you're trying to locate hidden files, pressing command+shift+. will reveal them.


Question: why does find -mtime +1 only return files older than 2 days?

Response:
When a file's age is calculated, it is rounded down to the nearest whole day, and "any fractional part if ignored", or put another way, fractional 24-hour periods are not taken into account—it's a simple truncation to the nearest whole number of days.
This behavior is dictated by the POSIX/SuS standard, which prescribes that the `find` command should work in this manner.
The argument to -mtime is interpreted as the number of whole days in the age of the file: -mtime +n means strictly greater than, -mtime -n means strictly less than.
Lastly, using -mtime N is a way to select files based on a range N ≤ A < N+1 days old, where "N" represents the number of whole days that have passed.


Question: how to use terminal to copy a file to the clipboard?

Response:
To replicate a file to a new location on a terminal, use the cp command: cp /path/to/file /path/to/destination.
Alternatively, the sequence of cat ~/Desktop/ded.html | pbcopy copies the file into the clipboard, and pbpaste > ~/Documents/ded.html pastes its contents into a specified document.
However, the command line lacks the capability to duplicate a file as performed in the Finder, with pbcopy and pbpaste being unsuitable for non-text files, which may become corrupted if an attempt is made to copy them in this manner.
However, you can explore the AppleScript and invoke it through the command line with osascript.


Question: what are the advantages and disadvantages of cryptographically signing commits and tags in git?

Response:
A git repository is susceptible to various forms of compromise, which is considered a normal risk and not a reason to avoid git.
There seems to be a majority consensus that signing commits is unnecessary, but signing tags is beneficial.
The key to the "sign every commit" debate probably has to do with the workflow being used.
Most people make a multitude of commits in their local repository, and then push that set and it should be sufficient to tag the final collection, assuming that all the changes are correct.
If you are working in an environment where lots of single commits are moving around, the distinction between a tag and a commit becomes less distinct and signing commits may become more useful.


Question: is there a keyboard shortcut to move a window from one monitor to another?

Response: Moom is an application that provides tools for window management, which includes the ability to create keyboard shortcuts for various window movements.


Question: why does unlocking the bootloader wipe phone?

Response:
When a device's bootloader is unlocked, it allows the flashing of unsigned images, which in turn makes rooting the device quite straightforward.
Carriers enforce locked bootloaders to ensure that if a handset is stolen, unlocking it will wipe all personal data, which prevents a tech-savvy thief from misusing the information or incurring costs for the victim through unsolicited use.


Question: when is double-quoting necessary?

Response: Double quotes are needed most of the time, specifically, wherever a list of words or a pattern is expected; they are optional in contexts where a raw string is expected by the parser.


Question: passing named arguments to shell scripts

Response:
The syntax closest to the example provided is `p_out='/some/path' arg_1='5' my_script`.
If you're comfortable with using single-letter arguments, you can utilize `my_script -p '/some/path' -a5` with the built-in getopts in bash.
However, with zsh, you would use zparseopts instead.


Question: can you connect airpods to apple watch series 3?

Response: The Airpods should automagically connect to the Watch once you set them up on your phone using iCloud, but if you need to pair them to the watch manually, you can do it like you would with any bluetooth headset.


Question: why should one not use the same asymmetric key for encryption as they do for signing?

Response:
Using the same key for encryption and signing, may enable attacks, depending on the particular public-key scheme you use, as an attacker can use this to decrypt our encrypted message.

The main reasons for using separate keys for signing and encryption are related to key management: it is useful in an organization where encryption key needs to be backed or kept in escrow in order to decrypt data once an employee/user of the organization is no longer available; unlike the encryption key, the signing key must never be used by anyone other than the employee/user, and does not and should not need to be kept in escrow, so different expiration times can used for the signing and encryption keys.

If you use different keys for different purposes, you can decide upon all questions of key management based upon the requirements of a single purpose, but if you use a single (master) key for multiple purposes, you may end up with conflicting requirements.


Question: is putty unix or linux?

Response: PuTTY, which has been ported to Unix and Unix-like systems, is known as pterm on these platforms.


Question: time machine ridiculously slow after el capitan upgrade

Response:
One solution involves changing the storage disk settings by going to Time Machine Preferences to removing the currently associated disk and then reconnecting to the NAS drive using its IP address via SMB protocol instead of AFP.
Additionally, you can verify I/O throttling via the Terminal through Spotlight, usually bound to  ⌘Space, and potentially increase the backup speed by altering system parameters to temporarily disable the low priority throttling.
It is then advised to re-enable the throttling after your backup finished successfully with the following command sudo sysctl debug.lowpri_throttle_enabled=1, which is also confirmed by another user.
Moreover, another approach was to discard all old backups, so one user dismounted the volume from the troublesome Mac, mounted the drive/network share from another computer (not a Mac), deleted the entire .sparsebundle directory, and then started the backup again; this created a new .sparsebundle and performed backing up at around 10 MB/sec.
If starting fresh is not preferred, alternative methods such as rebooting in Safe Mode or adjusting Spotlight indexing are suggested to be considered.


Question: should the variable be named id or id?

Response:
When considering the use of "ID" or "Id" across different coding practices, it's crucial to apply one approach consistently.
Microsoft specifically recommends using "Id" in the context of .NET class libraries.
When contrasting programming languages, such as Java’s conventions for naming classes versus those in C#, "ID" is recommended for Java, while "Id" should be used in C#.


Question: can i delete files or folders from /private/var/folders/?

Response:
In general, you can safely delete anything in /private/var/folders/ but not the folder itself.
Rumor has it that one should not delete /private/var/folders/zz, but if you want to be on the safe side, use cd /private/var/folders for i in *; do if [ "$i" != "zz".
From a general safety for the system integrity viewpoint,  anything withinin the hierarchy of /private/var/folders/* can be deleted, zz directory included, and system integrity should remain intact as temporary files will be repopulated after a reboot.
However, there could be some side-effects from wiping all data in these directories, including potential issues with applications that use files in these areas.
Quitting and restarting an actively cluttering app might often be enough to gain some space there.
On macOS Catalina (10.15), attempting to delete these files can be dangerous and lead to situations where the system may not restart, and recovering from a Time Machine backup can be problematic.
A safer alternative to deleting files could be to start the system in safe mode, which can clean up to 44GB of space.


Question: what are the practical differences between bash and zsh?

Response:
The main differences are in interactive configuration features.
While bash mainy reads .bashrc in non-login interactive shells,  .profile or .bash_profile in login shells, and .inputrc, Zsh reads mainly .zshrc and .zprofile.
The key bindings in each program, use completely different syntax.
Bash uses .inputrc and the bind builtin to bind keys to readline commands, while Zsh uses the bindkey builtin to bind keys to zle widgets.
In terms of arrays, Bash arrays are indexed from 0 to length-1 and Zsh's arrays are indexed from 1 to length.
Finally, in terms of commands, both programs handle well, but zsh's may be more precise.


Question: zip the contents of a folder without including the folder itself

Response:
The command `zip -r ../zipped_dir.zip` can be used to quickly and easily create a zipped directory from the current folder.
If you prefer not to include the 'root_folder' in the zipped file, use the `-j` option like this: `zip -r -j zipped_dir.zip folder/*`.
To avoid creating directories inside the zip file, you can use the `-D` flag as follows: `zip -r -D zipped.zip *`.
Alternatively, for creating a zip archive that includes the root directory along with all files and directories inside it, including hidden ones, the `7z` command would be `7z a zipped.zip ./rootDir/*` followed by `7z a zipped.zip ./rootDir/.*` or `7z a zipped.zip ./rootDir/{*,.*}` to explicitly add the hidden paths.


Question: reattach terminal tab to another window

Response:
To reattach a terminal tab to another window, first, in the window where you want to move the tab, go to View, and then to Show Tab Bar.
If you encounter issues with the tab bar, consider disabling the "Hide tab bar when there is only one tab" in Preferences under Appearance.
Alternatively, go to Preferences, uncheck the "Hide tab bar when there is only one tab," set the Tab position to the Bottom, and use your hotkey to show the Hotkey Window.
Then, click and drag the tab into the Hotkey Window's tab bar.
Also, you can hold down the Command + Shift + Option while dragging the body of the terminal.
Lastly, to complete the reattachment, click and drag the tab from one window onto the tab bar of the other window.


Question: what is the actual size of an ethernet mtu

Response: The Ethernet MTU is 1500 bytes.


Question: why is clean code suggesting avoiding protected variables?

Response:
Protected variables in programming should generally be used with caution as they can lead to "You Aren't Gonna Need It" (YAGNI) problems and can also introduce issues with the Liskov Substitution Principle (LSP).
Moreover, protected variables can violate the Open/Closed Principle (OCP) and tend to encourage inheritance-based design over composition, which can increase coupling and violate the Single Responsibility Principle (SRP).
Despite these potential issues, occasionally, a protected member may be the most appropriate choice for the design.
Similarly, protected variables can be problematic because they make it challenging to track where the variable is accessed or modified across multiple files, leading to inconsistencies.
Encapsulation is recommended over protected variables when their usage is not limited and clear.


Question: when will my phone get the android 2.3 update (gingerbread)?

Response:
A list of all known and rumored dates for devices' updates has been provided by Community Wiki.
For instance, the Commtiva z71, Geeksphone One and Geeksphone Zero will get the unofficial update to version 2.3.7 (CynogenMod 7.1) on October 11th, 2011.


Question: are ssl certificate port specific?

Response:
Certificates used for SSL do not have a standard method for including a port number, and such details related to the port are not typically checked by clients.
In essence, certificates are not designed to be specific to particular ports, as the concept of identity they convey does not extend to port numbers.


Question: where are efi variables stored?

Response: EFI settings are retained in NVRAM, which means swapping hard drives won't impact the EFI configuration.


Question: why are salted hashes more secure for password storage?

Response:
The salt is added before the hash, making the hash completely different for every salt.
This enhances security because when multiple users have the same password, they will have different hashes.
A large number of iterations in password hashing algorithms like PBKDF2 or Scrypt is to deliberately slow down attackers, which reduces the key space they can explore in a given time frame.
Simply salting MD5 hashes isn't sufficient in today's security environment; instead, one should use well-established security options like crypt, bcrypt, PBKDF2, or scrypt, which involve multiple rounds of hashing.
Salting prevents the cracking of multiple accounts with the same weak password and makes it hard for attackers to identify which passwords are easy to compromise.
A salted hash defeats rainbow table attacks because it makes the required rainbow table impractically large.
Unique salts per password hash compel attackers to target each password individually, preventing a wide-scale breach, as even similar passwords contain completely different hashes.
By a factor of 2N, the storage requirement and the time to compute a rainbow table are increased by a salt.
The presence of salt in password hashing adds a layer of protection against rainbow table attacks by requiring attackers to resort to brute-force methods.
While salts enhance security for medium-strength passwords, their effectiveness depends on the compromise of password hashes, which is already a severe security breach.
The primary benefit is evident when users reuse passwords across different systems, making medium-security passwords harder to reverse.
Even a moderately secure password, when coupled with a salt, can withstand extended brute-force attacks, providing users with an opportunity to change compromised passwords and enhance overall security.


Question: red pixels on mojave and catalina dark mode

Response:
This issue has potentially been resolved in macOS 11 Big Sur,  although it's not certain whether the solution will be applied to older versions like 10.15 or 10.14.
A temporary workaround that has helped some users is to put the problematic applications in fullscreen mode.
It is confirmed to be a software problem, reproducible on different MacBook models and LG USB-C type displays.
It is recommended to update software when available to fix this bug.


Question: roles to play when tailgaiting into a residential building

Response:
The classic ways to dupe people to letting you into a building include: have a prop that gives a visual indication why you're standing outside the door, such as a cigarette or e-Cig, lunch-bag, coffee, box of donuts; approach a door with your hands full, for example, with a huge gift wrapped box; pose as someone looking to pick someone else up, a family member needing to check on an elderly resident, or dress as a fire marshal, utilities inspector, law enforcement, building security, or process server.

You could also become a legitimate employee of doordash, and then order food to that building from yourself with instructions to go and find someone specific at the company you are targeting; just show the note to the receptionist and ask them to direct you.


Question: what are the names of the various versions of the android os, and how are these names chosen?

Response:
Starting from Android 1.5, each version has been assigned a specific codename.
These codenames follow an alphabetical sequence and are traditionally dessert items or sweet foods.
While some codenames represent multiple version numbers, others correspond to a single release, with no clear explanation for the variance.
Notably, versions 1.0 and 1.1 were not given a codename for public use; however, it's understood that internally, Android 1.1 was known as "Petit-Four".
The versions and their dessert-based codenames, such as Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice cream sandwich, Jelly bean, Kitkat, Lollipop, Marshmallow, Nougat, Oreo, and onwards, illustrate this alphabetical dessert theme.


Question: how do i set a user environment variable? (permanently, not session)

Response:
You have to put the declaration in the initialization files of your shell: for bash, you can use `.bash_profile (${HOME}/.bash_profile)` or .`bash_login` instead.
To add environment variables in bash, modifying the .bashrc file is often recommended.
You'll need to know which shell a user logs in with (`path="$(grep $USER /etc/passwd | cut -d ':' -f 7)" shell="$(basename -- "$path")" `) and which dot files it reads (`man $shell`).
Note that declaring a variable 'permanently' is specific to the session and the method varies depending on the shell.
Another method is to use: `echo 'export ABC + "123"'>> ~/.profile`.


Question: is there any option with ls command that i see only the directories?

Response:
You can list directories within the current working directory by using the command `ls -ld -- */`.
This command will output all the non-hidden directories, but it will also include symbolic links to directories.
If you're looking to list subdirectories in a different folder, you should execute `ls -ld /path/to/directory/*/`.
Remember, the `-l` option is not mandatory for this command to work.


Question: how to split the terminal into more than one view?

Response:
You can do it in screen using the terminal multiplexer, which allows vertical and horizontal splits with keyboard shortcuts and can unsplit and switch between different areas after starting new sessions.
Another option is splitvt, which is primarily used for splitting terminals.
Additionally, tmux is highlighted as a proficient terminal multiplexer for splitting screens, toggling between panes, and handling multiple windows with various layouts.
Terminator is recommended for users seeking more features, such as grid arrangements, tabs, drag and drop, and simultaneous typing across terminals, and it integrates well with Screen and Tmux.
Tmux is a Terminal Multiplexer with clear distinctions among sessions, windows, and panes.
Vertical Split for GNU Screen is available and provides functionality similar to the horizontal split command.
For those preferring ease of copy-pasting and efficient tab management within a window manager, terminator and tilix are recommended alternatives.
KDE's Konsole has built-in split view functionality alongside navigation through split views and tabs.
Lastly, Vim can serve as a basic terminal multiplexer with commands for opening split terminals.


Question: why does uncle bob suggest that coding standards shouldnt be written down if you can avoid it?

Response:
People tend to neglect reading documentation, and even if they do, following it consistently is uncommon.
Moreover, the practice of updating documentation is often overlooked.
Rather than relying solely on written practices, it's significantly more productive to build a culture that inherently incorporates these standards.
This approach ensures that coding standards reflect the reality of what practitioners actually do rather than an idealized set of rules that are rarely adhered to.


Question: is ping tcp or udp?

Response: The standard ping command operates without utilizing TCP or UDP protocols, instead, it relies on ICMP, specifically types 8 and 0 for echo messages and echo reply messages respectively.


Question: isnt inactive memory a waste of resources?

Response:
In Mac OS X memory management, "wired" memory is essential for system operations and is always retained in RAM, while "active" memory is currently being used by programs; "inactive" memory contains data that has been read from slower storage and which may be needed again soon by programs, and can improve performance for repeated tasks.
If a Mac has a fast solid-state drive (SSD), it can operate effectively with a smaller proportion of "free" and "inactive" memory before experiencing slowness, compared to a Mac with a slower hard drive.
However, in some cases, like with the latest version of Mountain Lion, users have reported issues where "inactive" memory is not being reclaimed efficiently when "free" memory is low, signaling a potential application issue or a bug within the system.


Question: how to get the complete and exact list of mounted filesystems in linux?

Response: Util-linux, as of version 2.18 released in July 2010, includes a feature,"findmnt", for displaying mounted file systems.


Question: why are shortcuts like x += y considered good practice?

Response:
Firstly, they contribute to readability by being more straightforward and directly describing functionality, making it easier to grasp when navigating through extensive code.
They provide a consistent way of expressing a particular programming construct.
In addition, these shortcuts are concise, involving fewer operators and less surface area, leading to a reduced chance of confusion.
Moreover, they are very useful when using a variable as an accumulator, enhancing readability, and don't have to evaluate its left operand twice.
When dealing with long names, the shortcuts make the code more compact.
They are considered a nice idiom, offering speed and quick adaptability.
Furthermore, the shortcuts prevent a whole class of errors, and their brevity facilitates code review, ensuring clarity about functionality.
Additionally, using such shortcuts makes the code easier to understand, eliminating the need for meticulous verification of long expressions and assisting the compiler in producing more efficient code.


Question: are fiber patch cables crossed?

Response: Fiber patch cables are designed to be crossed to ensure proper connectivity.


Question: can less retain colored output?

Response:
Use the -r or --raw-control-chars option with the `less` command.
If you want to make git output color codes even when the output is a pipe and not a terminal, you can use `git diff --color=always` combined with `less -r` or `less -R` for ANSI color codes only.
For a global setup, consider using `git config` to enable color ui and set `less -r` as your pager, which would include the configuration in your `~/.gitconfig` file.
Alternatively, set the environment variable `LESS` with the value 'r' in your `.bashrc`.
To force color output from commands like `tree` and `ls`, use them with `-C` or `--color` option, respectively, piped into `less -r`.
To ensure `git diff` retains color when piped into `less`, `unbuffer` from the expect package can be of help, especially with the `--no-pager` option to prevent hanging.


Question: how can i mount an ext4 file system on os x?

Response:
You can install OSXFUSE via the brew command line package manager: brew install homebrew/fuse/ext4fuse.
Alternatively, you can boot Linux VM swiftly on your OS X using Vagrant.
This requires an install of a VM provider, such as VirtualBox, and Vagrant either via .dmg file from the site or using brew cask.
For (High) Sierra For Sierra and High Sierra ext4fuse seems to work well, what's more it's read access only, so could be considered the preferable method.
If you should want to unmount, you can use the command: diskutil umount ${MOUNT_POINT}.


Question: what is /storage/emulated/0/?

Response: The directory /storage/emulated/0/ is presented through an emulated or virtual file system, specifically as /data/media/0/.


Question: displaying combined file size of selected files in finder

Response:
To display the combined file size of selected files in Finder, you can use ⌘+⌥+I instead of ⌘+I to see the information.
Another method is to select the files, right-click, hold the alt key, notice the menu options change, and then select 'Show Inspector'.


Question: is mac os x unix?

Response:
Yes, Mac OS X is Unix.
All releases of Mac OS X, except 10.7 Lion, have been certified as Unix by The Open Group.
The Unix certification for macOS is also detailed in Apple's Unix technology brief.
Furthermore, Mac OS X has been confirmed to be fully POSIX compliant.


Question: xfce how to lock screen?

Response:
To lock the screen in XFCE, you can use the default shortcut, which is ctrl-alt-del.
Another method is using the command line with the command $ xflock4.
Additionally, you can use 'xscreenlock' which is fairly ubiquitous.


Question: how to solve the issue that a terminal screen is messed up? (usually after a resizing)

Response:
Using the shortcut Ctrl+L may help as it has the function of clearing or redrawing the terminal screen, which varies with the program used.
Another approach involves enabling the checkwinsize option, which should automatically adjust the terminal size but may require a resize of the window or a maximize/minimize action for it to take effect.


Question: better colors so comments arent dark blue in vim?

Response:
In order to manually adjust comment colors in Vim, one approach is to use the command "hi Comment guifg=#ABCDEF", substituting ABCDEF with an appropriate color hex code.
The command "set background=dark" should be used to ensure a dark background in the terminal instead of the default light background setting.
You should add the respective commands to your ~/.vimrc file for a permanent configuration.
Additionally, you may need to set t_Co=256 in your vimrc file and adjust your terminal settings to support 256 colors to achieve the desired results.
If you want to create your gvim colors, there are online tools such as the one available at hmi-tech.in to help you customize and paste them into your vimrc file.


Question: disable command-w in the terminal

Response:
One approach is to set a prompt before closing in the preferences: Terminal Preferences → Settings → Shell.
Alternatively, in iTerm, you can go to Preferences > Keys, click the "+" in "Global Shortcut Keys," type Cmd-W, and select "Ignore" as the default action.
Another solution involves changing the shortcut for the "Close" command.
For iTerm2, navigate to iTerm2 → Preferences → Keys, and add a key mapping with "command + w" set to "ignore".
If you prefer a system-wide solution, you can go to System Preferences, select Keyboard, then Keyboard Shortcuts, and finally Application Shortcuts.
Add a new shortcut for "Terminal.app" with the command "Close Window" and assign a different shortcut like ⌘ControlW.


Question: 4-dial combination padlock: is it more secure to zero it out or to blindly spin the dials after locking?

Response:
Zeroing out the combination on a lock is a technique that is as secure as any other method, and has real-world security benefits.
Adopting a practice of either zeroing or following any other predetermined sequence for resetting locks could potentially offer a higher level of security over random scrambling, as consistent resetting behaviors might make it more difficult for an attacker to guess the pattern.
Nonetheless, in terms of physical protection and practicality, the position of the dial on combination locks is largely irrelevant since these locks can be easily bypassed by cutting or picking, and as such, they provide minimal delay to a determined attacker.
An alternative approach to enhance security might include either using both directions equally for zeroing or always rotating all to a single direction, to leave equal amount of fingerprints.
The recommendation when resetting a lock is to aim for zero knowledge of the correct combination for an attacker, to ensure there is no advantage gained from any resetting method that might be employed, whether it's zeroing, using a fixed value, or random scrambling.


Question: how to find out from the logs what caused system shutdown?

Response:
To investigate user logins and ascertain who may have been involved with a system halt, you can run the `last` command to check the login information for all users.
Additionally, system shutdowns can be tracked through the log files, particularly when they occur due to programmatically privileged requests or ACPI events.
In cases of overheating, logging details may be located in the `/var/log/syslog` file.
Moreover, the `/var/log/auth.log` file could also contain relevant information about system shutdowns.


Question: is ken thompsons compiler hack still a threat?

Response:
Despite the theoretical nature of a certain security threat, it remains unlikely in practice.
It is still possible, though, and one way to address the concern is by employing multiple compilers to ensure no hidden backdoors are introduced.
Alternatively, the threat never poses a real danger, as overcoming the associated challenges would be extremely sophisticated, making its occurrence improbable.
Moreover, without significant advances in self-directed AI programming, such an attack remains no threat.
There remains a small theoretical chance of occurrence, but verification techniques exist, such as the Diverse double-compiling method, which can offer assurances against compromised compilers.


Question: how to comment out multiple lines in shell script?

Response:
In shell scripts, the appropriate method to insert comments is by using the "#" symbol.
It is critical to not misuse other commands, like ":", for commenting, as it can lead to various unintended consequences, such as expansions and syntax errors.


Question: a modern and faster alternative to disk inventory x

Response:
OmniGroup provides OmniDisksweeper, a free utility that helps list files and folders by size for easy deletion.
Disk Inventory offers similar functionality and can be as fast or slow as other tools, recommending GrandPerspective as an updated alternative.
Daisy Disk is noted for its speed but is not free, and for faster, Linux-based tools, PhileSight is recommended.
MacOS has a built-in app called Storage Management, which is free and fast, offered by Apple for dealing with storage.
For those who prefer command-line tools, ncdu is highly recommended for its speed.


Question: can two bluetooth headphones connect to one iphone?

Response:
It is possible to do this in several ways: you can use a Bluetooth splitter; the JBL Synchros E40BT over the ear headphones sold at Crutchfield allow you to pair a "secondary" set to the first; and you can connect two SkyGenius headphones to one iPhone without any splitter using a function they call "ShareMe".

Apparently, Apple is rolling this capability out in a feature called Airplay.


Question: how to get rid of firewall accept incoming connections dialog?

Response: You can mitigate this issue by generating a code-signing certificate: you can create one in Keychain Access via the Certificate Assistant, which involves filling in your chosen certificate name and other details, selecting the self-signed root, setting a validity period of 10 years, and setting "Always trust" in the login keychain.


Question: can a cvv code be 000?

Response: 000 is a valid CVV code, but not one that banks use very often.


Question: how can programming ability be used to help people in poverty?

Response:
One can develop software to help doctors and teachers work more effectively with remote villages.
Using one's talent to earn money and donating a significant portion of it can also make an impact, as programmers often have the capacity to earn above their personal needs.
Contributing efforts to improve open-source projects, like Ubuntu Linux, directly supports those in poverty by providing free and accessible tools for managing their information needs.


Question: how do i set environment variables on os x?

Response:
To set an environment variable for use in a sh type shell, such as bash or zsh, you'll need to create .profile, .bash_profile, or .bashrc.
A .profile for environment variables can be created on an OSX system using the touch .profile command in a Terminal session, then editing the file with a text editor of your choice.
Alternatively, on OSX, you may use the launchctl setenv command followed by the variable name and value, ensuring that you restart the application/terminal to apply the change.