Question: is there a way to refresh a finder file listing?

Response:
There are a number of approaches, on is to use a simple AppleScript to instruct the Finder to tell the front window to update every item, which can then be saved and added to the Finder toolbar for quick access.
The easiest way to have the Finder refresh its listing is to enter a subfolder and click the back arrow to come back to the original folder.
Another approach is to change the view in Finder which seems to refresh the content of the Finder window; meaning, for example, going from Icon view to List.
Users can also hold the Option key and right-click on the Finder icon in the Dock to select 'Relaunch' for a full restart of the Finder.
Navigating into a subfolder and then clicking the back arrow to return or using the back arrow to go to the previous folder and then the forward arrow can also prompt a refresh.
For keyboard shortcuts, Command- or Command- followed by Command-[Down] can be used to quickly change folders, which in turn updates the folder view.


Question: can a computer virus be stored somewhere else than on the hard drive?

Response:
The short and unambiguous answer to the question regarding the presence of viruses beyond traditional computer hard drives is "yes".
Viruses are capable of hiding in various firmware, such as those in keyboards, mice, webcams, speakers, and even on the firmware of hard drives.
Executable files, DLLs, and drivers on the hard disk are common hiding spots for malware during operating system boot.
Other potential hiding spots include the BIOS or UEFI, and other forms of firmware on devices such as network cards or graphics cards.
Advanced persistent threats may manipulate management engines like IME, but doing so requires significant expertise and resources.
Peripheral devices with "embedded driver disks," like certain USB sticks, are among the common but overlooked places where malware may hide.
A USB device has also been known to act covertly as a keyboard to introduce malware to the host computer.
Additionally, it's worth noting that other storage devices connected to the PC, beyond hard drives, may harbor viruses.
Beyond computer-based storage, extraordinary research suggests that viruses can be stored in biological entities such as E coli bacteria or even human DNA, although this is a forward-looking and unconventional perspective on data storage and security.


Question: how do i edit a .plist file?

Response:
To edit plist files in the XML format, you can edit and create them in any text editor program like TextEdit.
In contrast, if the plist is in binary format, it requires conversion to XML before editing, which can be done via specific commands like 'plutil -convert xml1 file.plist'.
Programs like TextWrangler allow editing of binary .plist files directly, without needing to convert them beforehand.
According to one user,  Xcode is the best free option and if you're willing to go commercial, Plistinator will edit both binary and XML plist files.
On a terminal window, PlistBuddy offers the capability to read and modify plist files interactively or directly.
Lastly, free Visual Studio Code editor can open, edit and save plist files in binary format with the help of the Binary Plist extension.


Question: uninstall apps locked by phone vendor

Response:
To remove preinstalled apps from your phone, you must root your device, as they reside in a directory beyond regular user permissions.
After rooting, using Titanium Backup is one of the simplest ways to uninstall system apps.
However, ADB can also be used to remove applications if you prefer a method that doesn't involve marketplaces.
You can remove the app by using the command: `rm PackageName.apk pm uninstall class.name.of.package CyanogenMod`.


Question: how can i tell if my mac is keeping the clock updated properly?

Response:
To check your system time on macOS 10.14 Mojave, you should call sntp directly.
You can see the accuracy of your system clock by looking at the contents of the ntp.drift file.
Running pacemaker with the -a option allows you to adjust the frequency of time updates on your system.
To see if your time in macOS Sierra 10.12 or lower is correctly set, you should initially verify if your time is appropriately configured using the ntpq command, then you can test other servers to check if they render lower delays, and then check your pacemaker program.
To verify the accuracy of your system time to the second, you may refer to the official NIST time provided by time.gov.
For a detailed assessment of your time settings on macOS, you can run ntpdate in debug mode.
Similarly, running the ntpdate in Query mode on macOS High Sierra 10.13.2 may yield concise results.


Question: is the message you must change your passcode within 60 minutes valid / non-malware?

Response:
Your passcode is too obvious and needs to be changed.
This is typically the case if your device is enrolled under MDM and you receive a notification to update your passcode due to its simplicity.
To fix the issue with your passcode, go to the Settings app, select General, and then Profiles to delete any configuration profiles related to passcode control.
If you have any exchange mail accounts, disable them, as exchange servers can institute a passcode requirement.
Additionally, complex passcodes are generally more secure, and it's recommended to consider a more complicated passphrase.
It might be worth considering rolling back to a stock iOS for a while and choosing an entirely more complicated passphrase.
Furthermore, if you're experiencing continuous prompts to change your PIN, trying a more complex 9-digit PIN might resolve the issue, as too simple of a PIN can trigger such alerts.


Question: what are some disadvantages of using the same key?

Response:
Symmetric encryption utilizes the same key for both the encryption and decryption processes.
However, a notable limitation of symmetric encryption is the requirement of securely sharing this key between the encrypting and decrypting parties.
On the other hand, asymmetric encryption does not encounter this problem as the public key can be openly distributed without compromising confidentiality.
As for performance, asymmetric encryption tends to be slower than symmetric encryption, which generally restricts its use to encrypting a symmetric key for subsequent message encryption.
Additionally, a shared key in encryption does not provide non-repudiation because if a message is decrypted, it does not confirm the identity of the encryptor, leaving room to argue that the decryptor could have encrypted the message themselves.


Question: open finder window from current terminal location?

Response:
If you type 'open .' in Terminal, it will open the current directory in a Finder window.
Alternatively, you can execute the command open `pwd` to achieve the same result.


Question: what does ` (backquote/backtick) mean in commands?

Response:
In the context of commands, the backquote/backtick  means that whatever inside the backticks is interpreted as the result of that command and runs the contents of the enclosed string.
Consequently, everything you type between backticks is evaluated or executed by the shell before the main command.


Question: criticism and disadvantages of dependency injection

Response:
Dependency injection (DI) doesn't necessarily make automated testing easier as one might expect.
DI can also complicate code navigation, making it harder to trace through the code to find the implementations of interfaces.
While DI frameworks can reduce repetitive code for certain tasks, they often require a significant investment in learning to understand and use them effectively.


Question: what is photoanalysisd and why is it using 77% of my cpu?

Response:
Your iMac is currently processing the photos in your Photos library.
This might be occurring because you've recently imported or converted an existing Photos library from an earlier version of macOS.
If you have a large photo library, the processing can take some time.


Question: finding all large files in the root filesystem

Response:
To list all the files bigger than 100M on your system, you can use the command `find / -xdev -type f -size +100M`.
For directory disk usage analysis, `ncdu` is a helpful command.
If you are not running on a Linux system, you might instead need to use the command with suffixes like `-size +204800` or `-size +104857600c`, as the 'M' suffix is not POSIX-standard.
To obtain more detailed information about these files, you can enhance the command by adding `ls -la`, which will require sudo privileges to execute.


Question: umount: device is busy. why?

Response:
The problem was a stale loopback mount, which was resolved by deleting the stale loopback configurations with losetup.
Other issues include active screen sessions running in the background solved by killing the active shell sessions, a daemon running within a chroot environment (undetected by lsof and fuser) solved by using sudo ls -l /proc/*/root | grep chroot and an open tmux socket.
There were instances where bind and overlay mounts impeded the unmounting process, which required checking tab completion for the concerned mount-point.
Commonly, processes with open files are responsible for such issues, and using lsof or fuser commands can assist in identifying and terminating these processes to resolve the device busy error.


Question: how to know what packages are available with (home)brew?

Response:
To explore available packages with Homebrew, firstly, you can use the command `brew search` to list all available formulas or packages.
Additionally, you can browse the formulas directly on GitHub to discover the variety of packages Homebrew offers.
For those seeking a user-friendly alternative, there is BrewInstall, a cool website that provides the necessary commands for installing packages when their exact names are not known.
Moreover, Homebrew's website features an online package browser for easy exploration of available formulas.


Question: how can i download an apk file from the play store?

Response:
Downloading an APK file directly from the Play Store poses certain limitations, and traditional methods do not support direct downloads from market.android.com.
However, one option involves using the Android emulator and the Android Market to indirectly download the APK onto the emulator.
Another workaround is to access the Market site on a computer, prompting it to install the app, which may result in a successful download.
While there is no straightforward method, a Chrome extension, developed by redphoenix89, facilitates APK downloads, providing a practical solution.
Additionally, the Real APK Leecher program, written in Java, allows fetching APK files for free apps.
Online services like APK Downloader and its Chrome extension offer another avenue to download APKs from the Google Play Store.
A tool like Raccoon, a desktop Google Play client, present yet another alternative for downloading APK files directly from the Play Store.


Question: sort and count number of occurrence of lines

Response: To sort and count the number of line occurrences, you can use an associative array on "awk" and then optionally sort as follows: `$ awk ' { tot++ } END { for (i in tot) print tot,i } ' access.log, then sort output: 1 c.php 1 d.php 2 b.php 3 a.php.


Question: how to check if my hd is case sensitive or not?

Response:
To read the File System Personality using a terminal, execute the command 'diskutil info /'.
This command is also handy if you're using Disk Utility, which shows the same information in its info window.
The Terminal.app is the quickest way to perform this action by issuing 'diskutil info /Volumes/NAME-OF-VOLUME' or adding a grep command to filter for 'User Visible'.
If the ls command displays both files, abc1 and ABC2, then your drive is case insensitive.
A practical test to determine if your drive's file system is case insensitive is by using touch to create two files with names differing only by case and then utilizing ls to check if both appear.
Additionally, running 'diskutil info <device>' will clearly indicate the File System Personality.
Echoing text to a temporary file in a specific case format and then using cat to read it back is another method to verify if the file system is case-sensitive.
Lastly, using touch to create files with similar names with case variations can help test case sensitivity based on the number of files shown by ls.


Question: is dhcp the same thing as nat?

Response:
Apart from IP related things, and the word 'dynamic', the two have nothing in common.
Among other things, DHCP is a protocol for configuring hosts and assigns IP addresses to clients dynamically, while NAT mangles IP addresses.
In other words, DHCP assigns IP addresses to hosts in a private network, while NAT converts private addresses, such as such as 10.0.0.3, into public addresses, such as 209.113.65.5.
To be sure, NAT does not assign IP addresses to devices, but converts them to allow a host on a private network to communicate with a remote host.


Question: how to change facebook in game?

Response: You need to change the Facebook login in the app itself, so log out, then link it to your 2nd Facebook account by logging into it - again - within the app itself.


Question: are off brand iphone chargers bad?

Response: They are generally safe to use, but cheap cables may break.


Question: can ssl traffic be monitored?

Response:
If Websense is configured to log it, monitoring becomes possible, allowing visibility into the specific URLs visited and tracking the user's online activity.
While the possibility of monitoring SSL traffic exists, it necessitates certain setup procedures, indicating that it is not a straightforward task.
Particularly in a corporate context, companies can monitor SSL traffic.


Question: what is an integration test exactly?

Response:
An integration test is perceived as a feature test where all components of the system are real, including a real repository, database and user interface.
This type of test is an acceptance test and confirms that the system as a whole is operating correctly.
Integration tests demonstrate that the major parts of a system work well together, and can involve a component or components in your system in conversation with another "external" system.
They check the connection and correctness of data flow between two of more modules, typically requiring interaction with out-of-process elements like databases or external APIs.
Lastly, integration tests verify that components of a complex system, such as software, aircraft, or power plants, are working together as designed.


Question: difference between login shell and non-login shell?

Response:
In a GUI, when you start a shell in a new terminal, it's recognized as an interactive non-login shell and hence will not source files like the .profile, but it will source your .bashrc.
For a shell to be considered a "login shell," you would look at the first character of argument zero, which should be a '-' or should be started with the --login option.
However, in the case of the VSCode integrated terminal on a remote Linux VM, it was found that the environment variables set in /etc/profile.d/env_file.sh weren't picked up because the terminals were not initiated as login shells, indicated by the absence of the '-' in the output for `$0`.
To determine for sure if a shell is a login shell, it's necessary to check the output of both `echo $0` and `ps $(echo $$)`, looking for a '-' in front of 'bash' or for `/bin/bash -l` in the process status output.


Question: is ethernet port blinking really useful?

Response: Yes, the lights can be very helpful when diagnosing problems, especially when dealing with non-managed switches, or remote diagnosis with inexperienced users.


Question: can you still facetime if your number is blocked?

Response: No, blocking a number will block it for normal calls, FaceTime and FaceTime audio.


Question: why is my imessage texting from my email?

Response:
The Messages app on your iPhone is used to send messages to other devices, utilizing Apple's servers to determine the best method of delivery.
If the recipient uses an Apple device, the message is sent through the Apple network, thereby avoiding SMS charges.
For recipients not on Apple devices, such as Android phones, the message is transmitted through regular text messaging services, which may incur fees.
Messages are not sent via email; rather, your email, linked to your Apple ID, serves as an identifier that allows you to be contacted on devices that don't support phone numbers.


Question: are java pattern thread safe?

Response: Java Pattern objects are thread-safe.


Question: should we avoid object creation in java?

Response:
This depends on the specific application.
There is no way to avoid object creation in Java.
If you are writing a latency-sensitive application and wish to avoid GC pauses, or if you are in constrained memory situations, you may want to minimize the number of active objects created, as each object carries a small overhead (typically 8-16 bytes depending on JVM implementation).
Object avoidance in general is not condoned, but you should also avoid creating objects unnecessarily, and if you are creating the same object frequently, it is better to share that object.
Create as few objects as possible, however, avoiding object creation by maintaining your object pool is a bad idea.


Question: why is printf better than echo?

Response:
When discussing scripting, printf is favored for its capabilities with formatting outputs.
Echo commands lack the interpretative functionality that printf inherently possesses for certain escape sequences, such as new lines, without needing additional options.
However, echo faces portability issues due to variations in behavior across different shell implementations and operating systems; therefore, its reliability can be compromised when dealing with variable and uncontrolled data.
While printf is considered more reliable and consistent, especially for basic usage akin to echo, it has performance drawbacks, particularly in environments like Cygwin, where command execution overhead is significant.


Question: why are hard links to directories not allowed in unix/linux?

Response:
Allowing hard links to directories would break the directed acyclic graph structure of the filesystem (filesystem is organized as trees and a tree cannot have a cyclic reference), possibly creating infinite directory reference loops and dangling directory subtrees, which will confuse programs which traverse filesystem, such as making fsck and any other file tree walkers error prone.

With the exception of mount points, each directory has one and only one parent, enabling the use of '..': this algorithm relies on this fact, because if hard links to directories were allowed, which one of the multiple parents should .. point to?

Hardlink creation on directories would be unrevertable; for example, recursively deleting files in /dir2... would delete them from /dir1 too, risking data loss.

To resolve this, the system would have to traverse the entire file system until it finds the first pointer to the deleted directory, or the file system would have to maintain a list of all directories pointing to a hard linked directory; either would be a performance overhead and an extra complication for the file system meta data and/or code.


Question: ecdsa vs ecdh vs ed25519 vs curve25519

Response:
Ed25519 is noted for its significant practical advantage over (EC)DSA due to the latter's total failure in the event of a compromised random number generator, a situation that has occurred in the past.
ECDH and ECDSA are established cryptographic methods, with ECDH being a key exchange method and ECDSA a signature algorithm, both of which conceptually have been proven secure.
Ed25519 is a variant of EdDSA (Edwards version of ECDSA) that utilizes Curve25519 for signing.


Question: does it make sense to deploy ospf across metro ethernet?

Response:
You could very well run OSPF (or other IGP) on a multi-point metro-Ethernet service, and it should work very nicely.
OSPF over metroE works fine but you will need to make sure it fits your needs and you architect accordingly.


Question: how to switch between users on one terminal?

Response:
Use the `sudo` command with the `-u` flag to launch a new shell as the specified user.
Alternatively, the `su` command can be used to log in directly as a different user, requiring the user's password to do so.
For tasks where you want to remain in the original user's shell but execute a command as another user, you can use sudo with the `-u` flag followed by the command.
To ensure the terminal session cannot revert to the original user upon exit, `exec su - [username]` can be used.
On Ubuntu systems, `sudo su - username` allows login without the targeted user's password, assuming you have root privileges.
When running commands as a specific non-root user, such as in a MongoDB setup, launching a new shell as that user can facilitate the process.
If you need a simpler approach, `sudo -iu <your_username>` might work.
In cases where you have to run a command as another user with a password, use `su - UserB -c "ls -l /tmp"` and `su - UserB -c "ls -l /tmp"` if you don't know their password.
Lastly, the `sudo -u username command` comes in handy if you need to run just a single command.


Question: are all https sites legitimate?

Response:
HTTPS provides no guarantee that a website is not malicious.
Basically, it means that your connection to the page is encrypted by SSL, but not necessarily the content.
So, malicious JavaScript or viruses can be transferred over HTTPS as easily as over HTTP.
Therefore, it's best to avoid trusting website content just because it is delivered over HTTPS.


Question: why isnt java used for modern web application development?

Response:
Java is generally considered overkill for small web applications, typically being more suitable for larger systems such as those used by banks and insurance companies.
It is easier to find hosting for PHP compared to Java or ASP, which isn't a flaw of the languages but rather a reflection of market availability.
Java web applications are not typically associated with rapid development due to their structure and the arduous process of debugging and implementing a business logic layer.
Startups need to launch quickly, contradicted by the six-month timeline often required to release a Java web application, and the development process in Java is not as productive compared to frameworks like Rails/Django/Grails.
Java's earlier presence in web browsers through applets, which performed poorly and had security issues, has negatively impacted its perception in web development.
Java has the stigma of being unfun and too enterprise-oriented for the needs of startups, which prioritizes a rapid development cycle and the ability to make quick iterative changes.
In terms of cost and work involved, Java usually demands more effort and financial resources, and there's a perceived lack of synergy between the operating system and Java.
Startups may choose other technologies over Java because they are deemed "sexier" with a stronger open source community driving them.
Java doesn't have the "sexy" appeal of languages like Ruby for many modern web developers, often leading to a preference for languages that promise faster and easier development cycles.
Java web development frames can be difficult to learn, often unreasonable for the requirements, and the layer of abstraction can be painful to work with.
Startups, particularly those driven by under-30 visionaries, favor languages that allow them to program quickly and affordably, and they often choose non-mainstream languages as a natural filter for less committed developers.
Java is seen as complicated, with developers finding it easier and quicker to make changes in PHP compared to the restarts often required for Java applications, and the cost of hosting Java applications is also a concern.
Framework-based systems like Ruby on Rails provide an easier learning curve and faster setup than Java, which requires learning the language and additional frameworks or tools.
Java's syntax is criticized as too verbose and the development process is seen as cumbersome, especially when compared to the simplicity of other languages and frameworks.
The issue with Java in startups is about the trade-off between speed and scalability; startups need to move fast and iterate, which can be done more effectively with simpler languages and frameworks.
Java is seen as requiring a medium-sized team to see efficient implementation results, and the options in Java's ecosystem can be overwhelming, coupled with a lack of proper web hosting solutions.
Java is verbose and the community is seen as less innovative, with developers gravitating towards languages like Ruby, Python, or PHP, which are seen as more "friendly" and "fun".
To differentiate from the masses, developers learn new languages as Java is seen as the language of everyone, with other languages being more connected to modern web development.
Java is complex to learn and its ecosystem can be overwhelming, especially for beginners, whereas properly configured Java environments can be highly productive.
Java and J2EE may have been associated with long development cycles and heaviness, and alternatives in other languages are seen as offering a unified solution rather than a multitude of options.
Java is associated with a slower development time compared to languages like Python, and in web frameworks, Java's heavy resource requirements and lack of good shared hosting options are disadvantages.
The complexity often found in Java applications is seen as a result of the mindset of some developers within the Java community.
Java's verbosity and lack of certain modern language features can make development frustrating in comparison to dynamic languages that offer faster iterations in web development.  The "cool kids" in the developer community may use languages like Ruby because they solve problems in still simpler and time- and effort-saving ways, leaving Java due to its perceived difficulty and annoyance.
Java's lack of multiline string support and unsatisfactory web frameworks contribute to a challenging environment for creating web applications.
Java can be used efficiently and "hackily" to quickly build systems, but the inclination to overcomplicate projects can result from the extensive knowledge and tools available within the Java ecosystem.


Question: osx is repeatedly asking for login keychain password

Response:
One approach is to open the keychain at log-in and keep it open, but this is generally not recommended.
Alternatively, open the keychain, locate the specific applications, and configure them to have access.
Repairing the Keychain app could resolve certain issues that arise with it.
In cases where the default keychain needs to be reset, one would lose all saved passwords, but it can be a necessary step to fix certain problems.
Additionally, keychains typically lock after a period of inactivity or when the computer sleeps; however, these settings can be changed to prevent automatic locking.


Question: whats a good graphical sftp utility for os x?

Response:
Transmit, priced at $34, is an extremely well-built FTP Client with sFTP support, featuring a Mac-like interface to simplify and quickly upload, download and delete files over the internet.
Cyberduck, which is free, offers a robust FTP/SFTP browser with a user-friendly interface, good functionality and integration of technologies like Spotlight and Keychain.
RBrowser provides an interface similar to Finder and directory synchronization.
FileZilla is noted for its side-by-side interface, but is limited because it's not MacOSX-aware.
ExpanDrive acts like a USB drive plugged into your computer, allowing files to be opened, edited and saved remotely.
Flow is another option that is noted for its nice interface.
Finally, the newer implementation of Fuse for OSX is highly recommended, especially when used with SSHFS to connect to SSH drives automatically.


Question: ive rooted my phone. now what? what do i gain from rooting?

Response:
With root access, you can remount your /system/ directory as read-write, which allows you to remove unwanted carrier-shipped applications, among other things.
Rooting your Android device allows you to overcome manufacturer-imposed limitations, essentially giving you control over your device.
It also allows you to uninstall and/or backup stock or default apps that you don't use or don't want, besides those that violates user's privacy.
Moreover, rooting permits the moving of files and apps without restrictions, as well as more powerful program running capabilities like enhanced Tasker functionalities and better power management with specific apps.


Question: is vlan 1 the native vlan?

Response: Regarding default VLAN settings, Cisco and most vendors have VLAN 1 set as the native VLAN.


Question: how do you explain the necessity of nuke it from orbit to management and users?

Response:
Analogies comparing computer viruses to biological viruses can be used to illustrate how these threats work and their potential impacts.
Another method for illustration is to draw parallels with spy stories, explaining how compromised security systems are similar to compromised agents within a spy network, and how complete eradication is the only way to ensure security.
Some stakeholders are more persuaded by a straightforward explanation of the consequences in terms of tangible losses, such as dollars or hours of productivity, rather than evocative analogies.
A pragmatic approach that resonates with management includes providing a clear analysis of risk versus cost, offering choices without relying on biological or non-business analogies, and demonstrating these analyses in an easy-to-understand tabular format.
The notion of 'nuke it from orbit' as the most effective, yet costly, approach demonstrates the extent of measures that might be necessary for ensuring security, emphasizing the need to calculate potential costs and benefits in clear terms for business decisions.
Risk management tools can help underline the probability and impact of a security breach, facilitating a decision based on informed assessments.
Lastly, to impress upon management the severity and need for absolute measures, one can restate the famous quote from the movie "Aliens," emphasizing that certain drastic actions are the only way to be completely sure of security.


Question: this copy of the install os x el capitan application cant be verified. it may have been corrupted or tampered with during downloading

Response:
If you receive this error, it may not be a problem with the installer but rather an expired certificate.
On the other hand, it could be a result of a corrupted installer or a subtle issue of a reset internal clock in your machine.
To address this, open the terminal and set the date manually by typing `MMDDHHmmYY`.
If the problem persists, try setting the date to today's date.
If the install still fails, use `hdiutil` to verify the checksum.
Alternatively, you can download and install OS X El Capitan in SAFE MODE.
If you can't recall the installation date or guess it correctly, delete and reinstall the OS X El Capitan installer into your Applications folder.
If you're confident in the integrity of your installation media, you can use the terminal to bypass the error.
Connect to WiFi and run `ntpdate pool.ntp.org` to ensure the correct time setting.
Another solution is to set the time and date to 1 January 2014, and then run the installer.
For more information, refer to the article "Previously Downloaded OS X Installers No Longer Work".


Question: how to change your email name icloud?

Response: Log into iCloud.com, click Mail, and then at the bottom-left of the screen click on the Settings (gear) icon, click Preferences in the pop-up menu, then click Accounts, and change Full Name to how you would like your name to appear.


Question: colorizing your terminal and shell environment?

Response:
One method to enhance script readability is to set a bold or colored prompt using shell customization techniques.
ScriptEchoColor is a project that can be used to colorize script outputs, which is available at SourceForge.
Additionally, for Mac users, setting the TERM environment variable to xterm-256color is recommended if the terminal supports it.
Exploring the ZSH and its plugin, oh-my-zsh, is also advisable for powerful console features like theming your terminal.


Question: battery life and first time charging on li-ion batteries. myth?

Response:
Lithium-ion batteries do not require full charging, unlike lead-acid batteries, and it is better for the battery's longevity if they are not fully charged, as high voltages can stress the battery.
The advice from sellers regarding old batteries doesn’t apply to modern lithium-ion or lithium-polymer batteries; these are designed to be charged frequently and perform best when charged often.
Regarding the initial charge, it is important to fully charge the battery to ensure the proper formation of the SEI layer, which can influence the battery's long-term performance, a practice supported by research and not considered a myth.


Question: how can i create a symbolic link in terminal?

Response:
To create a symlink to replace a system directory (e.g. if you want to have /Users pointing to another disk drive), you need to disable System Integrity Protection.
if you're in GUI Land and don't want to enter Terminal Land, you can use SymbolicLinker.
The command is called ln; if used with the option -s it will create a symbolic link in the current directory: in -s /any/file/on/the/disk linked-file.
ln -s /some/dir/ ~/Desktop/dir: you can also create a symlink for directory using the same command ln -s "$(pwd)" ~/Desktop/dir to create symlink to the current directory.


Question: what happens when you mount over an existing folder with contents?

Response: When a hard drive is mounted over the existing /tmp directory, the contents of /tmp become hidden from view.


Question: why does my dock keep moving back to my other monitor?

Response:
You can summon the Dock on a different display by moving the cursor to the bottom of the desired display, and then continuing moving down.
Apple didn't account for the over/under monitor configuration, the overhang catches your cursor and summons the dock.


Question: turning power chime off

Response:
One approach to modify the MacBook's power connection chime is by creating an empty AIFF file to replace the default chime.
Alternatively, you can adjust the system settings: set ChimeOnNoHardware to true instead of setting ChimeOnAllHardware to false.
Additionally, there is a simple tool on all MacBooks after 2015 to quickly switch PowerChime https://git.io/nochime, which runs through curl without installation.


Question: whats wrong with comments that explain complex code?

Response:
While documenting work is generally considered good practice, comments often fail to update automatically along with the code, leading to inconsistencies, and comments don't make code easier to test.
Additionally, comments are always failures and since they cannot be executed, they cannot serve as substitutes for well-written code.
Moreover, relying on comments to convey the true functionality of the code may not be ideal, as comments unlike code are not always accurate representations of the code.
Furthermore, maintaining and updating comments as the code changes can be cumbersome, and there's a risk that individuals with varying language skills may misinterpret them.
Using comments as a shortcut to avoid improving the code itself is seen as lazy, a disservice, and disrespectful to those who maintain the code.


Question: remove particular characters from a variable using bash

Response:
Use `sed` with the command `sed 's/\.//g'` to strip periods from the text.
Additionally, bash's string manipulation capabilities are sufficient for such tasks without the need for external programs.
For example, when needing to extract only the numeric digits from a version string, you could employ `echo "$VERSION" | tr -cd [:digit:]` to accomplish this effectively.


Question: adb is not working in android studio?

Response:
Android Studio does not include ADB; instead, you need to get it through the Android SDK, which is typically set up the first time you run Android Studio version 0.9.x or newer.
When using a physical device with Android Studio, ensure that debugging mode is activated, which permits Android Studio to access the device.


Question: im doing 90% maintenance and 10% development, is this normal?

Response:
Doing 90% maintenance and 10% development, especially in the initial phases of a career, is a situation that many freshers face.
It might indicate a challenge in workload management and task prioritization by the management.
While your situation is a bit edgy, it is still considered normal, particularly for an entry-level position.
Embrace it as a building block for your future career, as entry-level employees often find themselves handling tasks that others might not prefer.


Question: how to check whether my intel-based mac is 32-bit or 64-bit

Response:
Go to the Apple Menu and select "About this Mac".
Alternatively, you can use the arch command without arguments to display the machine's architecture type.
To check the kernel version, launch System Profiler (renamed System Information in OS X 10.7) and click on the Software heading.
Another method is to run the command sysctl hw.cpu64bit_capable in a shell, which will indicate if the CPU can run 64-bit programs.
If your MacBook Pro is newer than a 2008 model, it will have a 64-bit processor and OS.
You can also run Activity Monitor and check the Kind column for the kernel_task process to see if it's running in 32-bit or 64-bit mode.
To run applications in the correct mode, you can look for the application in Activity Monitor.
Other quick checks include running getconf LONG_BIT or uname -m in the command line to display your system's bitness.
If you get x86_64 then you have 64bit OSx running.
If needed, sysctl or arch commands can also be used to check CPU architecture.


Question: should i use csrf protection on rest api endpoints?

Response:
No CSRF is possible with REST API endpoints that are truly stateless and do not use or accept data from cookies or sessions, as CSRF relies on "session riding".
However, CSRF protection is needed if cookies are used, especially for authentication purposes.
Even in environments that use integrated windows/kerberos authentication, where the browser might automatically provide credentials, CSRF protection is required.
Additionally, any authentication that enables the browser to autonomously include information in a request requires CSRF protection.
Specifically, CSRF protection is necessary only for the scope of the domain and path of the particular cookie.


Question: where can i find my crash logs?

Response:
To locate your crash logs, you can open the Console app, which is found in the Applications -> Utilities directory to display all system messages, including crash information.
Additionally, check the ~/Library/Logs or /Library/Logs directories to see if crash logs are stored there.
Specifically, crash logs may be present in the ~/Library/Logs/DiagnosticReports/ directory, where ~ represents your Home directory.


Question: are longer ethernet cables slower?

Response:
Having long cables does not necessarily slow down a network connection, but you should keep in mind the maximum length for copper cables is about 100 meters.
Although there's a very tiny extent of the effect, mostly the latency increases by one nanosecond per foot of cable, which is typically unnoticeable for most applications.
So, if the cable is within the standard maximum length, the slowdown is minor but can become noticeable as you approach that mark.
However, this delay in a local network setup is practically non-existent and the relevancy of cable length related delays becomes significant only over much greater distances, far surpassing typical Ethernet cable lengths.
Nevertheless, while the signal does weaken with increased cable length, causing potential data loss and retransmissions, it's important to note that the effect on speed is negligible until the signal becomes too weak.
But practically speaking, there's no significant impact on the speed of your connection due to the length of the cables used within their maximum specified range.
Finally, it's theorized that longer cable runs can reduce bandwidth and signal-to-noise ratio, affecting the potential capacity of a communication channel.


Question: how to connect 2 monitors to macbook pro 2018?

Response:
You can connect 3 x 4k-monitors to the 2018 15" MacBook Pro, using USB-C to DisplayPort cables to connect the monitors.

If you are using a dock that has multiple display outputs, note that the MacBook Pro 2018 only has two thunderbolt busses, but 4 ports (2 ports per bus), as a result, if you try to connect three external monitors, you will need to use different sides of the device; if you try to connect all three monitors into two ports on one side, it won't work.

One way to use a single cable solution or a dock station is to connect two screens using a single port each, and the third using a tethered dock, which can even provide power to charge the laptop.


Question: is there any way to set a macbook pro to not sleep when you close the lid?

Response:
One straightforward solution is to use InsomniaX, a menu bar utility; When activated, it keeps your laptop awake even when the lid is closed.
Alternatively, without relying on third-party software, Apple suggests connecting an external keyboard, mouse, or trackpad (USB or Bluetooth) to maintain wakefulness.
Another option is the macOS-nosleep-extension, providing an alternative to InsomniaX.
For users comfortable with the command line, the built-in caffeinate utility, available in Mavericks and Yosemite, serves the same purpose.


Question: is there a way to completely disable dock?

Response:
Completely disabling the Dock in macOS proves challenging, as turning it off entirely could potentially disrupt the operating system.
One suggestion to minimize its impact involves adjusting the Dock autohide delay to an extended duration, such as 1000 seconds, effectively reducing its visibility.
Additionally, you can modify the icon size to 1px, making the Dock practically invisible while still running in the background.


Question: quick directory navigation in the bash shell

Response:
To streamline your workflow on a bash command line, try using the "pushd -n" function.
Specifically by add the following entries to your ~/.bashrc file: pushd -n /Project/Warnest/docs/ and pushd -n ~/Dropbox/Projects/ds/test/.


Question: yosemite bluetooth audio is choppy/skips

Response:
If you're experiencing issues with com.apple.BluetoothAudioAgent and the common fixes aren't working, a reset of PRAM might resolve your problem.
Turn off the Mac, then turn it on and hold down the Command, Option, P, and R keys simultaneously; keep holding all four keys until you hear the startup sound play twice.


Question: can devices on different subnets communicate?

Response: Devices within different subnets have the capability to communicate with one another.


Question: how to comment multiple lines at once?

Response:
You can highlight them in Visual Block Mode, using / to jump to the endpoint, if necessary.

You can do it with the following commands: for commenting, :66,70s/^/#; for uncommenting, :66,70s/^#/ (for commenting lines from 66 to 70 (inclusive)).

There is a plugin, which offers an efficient way of commenting out, based on the file system being used.

Enter visual mode by pressing v, select the lines you like to comment (up/down arrow or j/k), enter :s/^/# / which translates to: in selection (:) replace beginning of line (^) with `# '.

You can use either NERDCommenter or use visual modes.


Question: texts are sending from email?

Response:
Your iPhone employs the Messages application to dispatch communications to other apparatuses.
Messages utilize an identifier, that is often your Apple ID, but the message is not transmitted via email.
This identifier function is particularly handy on devices without telephonic capabilities, allowing them to send messages using just an email address.


Question: hold cmd-q to quit from chrome

Response:
In Chrome's menu bar, select the option to uncheck "Warn before Quitting (⌘Q)" if you prefer the application not to warn you before it quits.
This setting is also accessible within Chrome's Preferences  (Cmd,) under the Appearance section.


Question: what is difference between find and ls?

Response:
The "ls" command is restricted to the current working directory, showing a detailed list sorted by modification time in reverse, only for files and directories that start with "file*".
On the other hand, the "find" command searches through all files and subdirectories for names beginning with "file*".


Question: what are pros and cons for macports, fink and homebrew?

Response:
MacPorts, unlike Homebrew, operates independently of MacOS libraries, making it less susceptible to future system updates.
It is also noted for its independence from Mac OS X, as MacPorts opts not to use many system libraries and software available in Mac OS X.
Also, MacPorts seems to actually be the "faster " option these days.
Further advantages include MacPorts' excellent support for legacy versions of macOS, with compatibility extending back to older systems like Tiger.
Homebrew, in contrast, only supports the OS versions that are currently supported by Apple, typically the last three releases.
However, Homebrew has gained significant popularity and is often preferred due to its use of the pre-installed MacOS libraries and the ease of installation it provides.


Question: what is the difference between a lan and wan port?

Response:
The differences between LANs and WANs tend to be at the physical and data-link layers.
WAN stands for Wide Area Network and this is the network that connects your router to your service provider.
The WAN port usually connects to a DSL modem, cable modem or fibre media converter.
LAN stands for Local Area Network and this is the network that connects the devices within your home/business to the router.
The LAN port or ports usually connect to PCs, printers etc. LAN ports can also connect to wireless APs to allow devices like laptops, smartphones, tablets to connect to the LAN.
Furthermore, a LAN is typically something completely within one premises, while a WAN is something that connects between geographically separate locations.
Also, because of the shorter distances involved, LANs tend to be built on Ethernet and other 802.3-family physical layers and data links.
Due to the technical hurdles associated with moving lots of data long distances reliably, WAN links tend to be lower bandwidth and higher latency than LAN links.


Question: is it possible to install an app and exclude some of its requested permissions?

Response:
Before Android 4.3, which is referred to as Jelly Bean, customizing app permissions was not an option without a custom ROM.
However, in Android versions 4.3 and 4.4, and partly in 5.x, a semi-hidden feature named App Ops allowed users to manage permissions more granularly via a third-party app, without needing root access or a custom ROM.
The custom ROM, CyanogenMod 7, has a feature for managing app permissions, which can be enabled through specific settings.
For devices running older Android versions, specifically below 4.2, LBE Privacy Guard was available to block specific permissions for individual apps.
In place of the LBE Privacy Guard, Xprivacy is now suggested, which also requires root access to function.
Through the use of the Xposed Framework alongside the App Settings Module, users can deny permissions to applications on their devices.


Question: how can i set up a keyboard shortcut for switching input source?

Response:
For input source toggling in System Preferences, navigate to Keyboard → Shortcuts → Input Sources and define a keyboard shortcut there.
If you are using Apple's Bangla keyboard, you can type English by holding down the Option/alt key, or with the Bangla Qwerty keyboard, do this by pressing the Caps Lock key.
Additionally, IMEShortcuts is a tool that lets you assign shortcuts to specific input methods, making it quicker to switch among them.


Question: how big should my time machine backup drive be?

Response:
For effective use of Time Machine, you'll need a drive that has 2 to 4 times the space of the data you wish to back up, though for lighter users, you might manage with 1.5 times the space.
The larger your backup drive, the more historical data Time Machine can retain, which has practical implications for how long your backups can be preserved.
In line with this, the actual volume of the drive is less significant than the volume of data you possess.
A 240 to 360GB drive could be enough if you only use 120GB of data.


Question: how to show all running launchctl daemons/agents?

Response: To retrieve a list of all jobs loaded into launchctl, you need to use the command sudo launchctl list.


Question: how to run find -exec?

Response:
Using the command `grep chrome`, you can search for occurrences of the word "chrome" in the current directory or recursively in all subdirectories.
An alternative method is to combine `find` with `grep` through an `-exec` command, such as `find . -exec grep chrome {} \;` or `find . -exec grep chrome {} +`, which will either perform a `grep` for each file found or process as many files as possible in one go.
Furthermore, you might use `find . | xargs grep 'chrome'` to produce a list of files containing "chrome", with the option to add `-ls` to only list the files rather than showing the lines within the files.
To specifically list files containing "chrome" without the lines, you can use the commands `grep -l "chrome" *` or `grep -r -l "chrome"`.
Lastly, the `find . -name "*.py" -print -exec fgrep hello {} \;` sequence is useful for locating `.py` files and searching for the string "hello" within each file, printing both the file names and the lines that contain the search term.


Question: should you keep a copy of all the code you write?

Response: Yes, you can retain the code you write, as well as entire projects.


Question: applications dont show up in spotlight

Response:
Removing the spotlight.plist in your user preferences may solve issues with re-indexing.
Loading the metadata plist also works.
However, in newer macOS versions, toggling the indexing feature off and on again often resolves re-indexing issues.


Question: write in ntfs using mavericks

Response:
One option is to use Paragon's NTFS for Mac® OS X 11.
Alternatively, a combination of macfuse-core-10.5-2.1.9 and ntfs-3g-2010.10.2-macosx has been reported to enable writing to an NTFS drive on OS X Mavericks.
Installing NTFS-FREE for OS X Mountain Lion 10.8.2 software and rebooting the Mac is another viable solution, as reported to work on OS X Mavericks.
For those who prefer using Homebrew and Cask, the installation process can be initiated by installing Homebrew and Cask if not already present.
Using MacPorts is also an option, involving commands such as sudo port install fuse4x ntfs-3g and sudo ntfs-3g /dev/disk2s1 /Volumes/ntfsmountpoint.
Another alternative is to download a free driver, such as the one provided by Seagate.
This solution may be particularly suitable for users of OS X 10.11 El Capitan, where installing the latest osxfuse (3.x.x) is recommended for compatibility.


Question: is there a keyboard shortcut to bring up finder?

Response:
By default, Finder doesn't have a built-in keyboard shortcut.
However, tools like Keyboard Maestro can be utilized to create one.
You can add a Launch Application action and select Finder from /System/Library/CoreServices/.
Additionally, the sliding in or out animation can be linked to a hotkey combination.
On Yosemite, you can press option ⌥+command ⌘+spacebar to open a new Smart Finder window.
Another shortcut, alt + command + <space>, allows you to search for files directly in Finder mode.
If you want to open Finder with specific files or folders, Spotlight can be used; simply press ⌘+Space to activate Spotlight, then type the name of the file or folder you want to open.
There are also native keyboard shortcuts to open specific Finder windows: shift+⌘+C for the Computer folder, shift+⌘+D for the Desktop folder, shift+⌘+H for the Home folder, shift+⌘+O for the Documents folder, shift+⌘+A for Applications folder, and shift+alt+L for Downloads folder.
Alternatively, you can cycle through the apps using ⌘+TAB, highlight Finder, and then hold option ⌥ before releasing ⌘ to open a new Finder window.


Question: can the iphone x zoom?

Response:
As of iOS 14 beta 3, the Zoomed View feature is supported on iPhone XS Max and iPhone XR.
Prior to this update, the feature was not supported.


Question: can tls work without certificates?

Response:
TLS itself could do encryption without certificates.
Additionally, you can have SSL/TLS without certificates.


Question: how are globals any different from a database?

Response:
Databases serve a different purpose than global variables.
While databases are designed for storing and managing large quantities of organized data, global variables fulfill specific niches within the application.
The difference between them becomes apparent in their intended use cases; databases model different data than global variables, and each is suited for particular tasks.
Global state in an application lacks the strong consistency guarantees provided by a database.
Moreover, how they are employed differs, as databases are typically used for storing and searching extensive data, while global variables may serve in-process or operational functions.
One critical distinction concerning global variables is that they form hidden and unprotected lines of communication.
Additionally, using a database is much more like using explicit state than using global variables.
Despite the potential for a database to represent a global state, it doesn't have to be all the time.
In a sense, the distinction between global variables and a database is similar to the distinction between private and public members of an object.
The globals are the private variables, and the database is the public fields.
The key distinction here is one of assumed responsibility.


Question: do contacts get notified when you join whatsapp?

Response: Your contacts are not automatically notified when you join Whatsapp, but they will see your name if they look at their WhatsApp contacts list.


Question: do you know other android keypad commands (dialer codes)?

Response:
The code *#*#4636#*#* can provide information on your phone and battery, including phone information, battery information, battery history, and usage statistics.
Using the code *#*#7780#*#*, you can perform a factory data reset, which will remove Google account settings, system and application data, and downloaded apps, though not the system software or SD card contents.
For camera information, *#*#34971539#*#* will give you options like updating camera firmware and checking the camera firmware version.
An app called "SGS Tools" is freely available on the market, offering a collection of these commands.
Android secret codes like 4636 (for debug information), 8351/8350 (voice call debug), and 36245 (email debug) are consistently applicable across all devices.
It's important to note that each Android device may have a different set of secret codes, usually defined by the applications installed.


Question: where are twrp file stored?

Response:
The backup for TWRP on an LG G2 device is usually located in the directory `./TWRP/BACKUPS/` on the root of the SD card.
For a Verizon model of the LG G2, the backup can be found at `root/data/media/0/TWRP/BACKUPS/`; however, accessing this requires a root explorer file manager.
Similarly, the backup may be found in the path `/data/media/0/TWRP/(backups folder)` and can be accessed using software like Droid Explorer, which also allows system files and folders to be transferred.


Question: to sufficiently protect against krack is patching the client, the ap, or both, required?

Response:
To comprehensively secure a network from particular attacks, both the client and the access point must receive patches.
However, there are conditions under which it may be sufficient to only patch the access point to protect your clients, such as when the access point is used to mitigate attacks on unpatched clients, or when it has client-like functionalities, including acting as a repeater, supporting fast roaming, or being involved in station-to-station traffic.
While it may be possible to prevent attacks by just patching the AP alone in certain scenarios, ideally, patching the client is advised for optimal security.
Nevertheless, for ordinary home users, the primary focus should be on updating the WiFi client for laptops and smartphones, as this can often be adequate for protection.
Lastly, patching the access point will not prevent attacks against vulnerable clients, and neither will patching all clients prevent attacks against vulnerable access points, so there may be conditions where you need to at least patch only the access points, only the client, or both of them.


Question: apple id has not been used?

Response:
To utilize your Apple ID with the App Store for the first time, ensure that you set both the billing and shipping addresses in your account information.
Additionally, initiating iTunes on a Mac and signing in through the account menu can help resolve the issue.
However, patience may be required as it might take multiple attempts.


Question: what is id in top?

Response: In top, "id" refers to "time spent in idle operations".


Question: why hasnt a faster, better language than c come out?

Response:
Fortran is known to be faster than C for numerical tasks due to how it manages memory references.
Moreover, there exist languages that surpass C's speed, including Fortran for its aliasing rules, as well as specialized assembly-like and mathematical languages that excel in their respective domains, like APL with built-in support for Vector processing units.
While C once dominated various programming niches, contemporary languages often outperform C within their specific areas, such as C++ and Java in application development or domain-specific languages like Matlab in scientific computing.


Question: copying the current directorys path to the clipboard

Response:
Next to the name of the folder in the Finder is an icon depicting that folder: this icon can be dragged to anywhere you need to accept a path.
This coupled with pbcopy and pbpaste should fit the bill for getting arbitrary paths to text format and then into your clipboard.
Or just use Launchbar to push files around without caring so much about recording a specific folder.
Another simple method is to invoke DTerm on the Finder window and run: pwd | pbcopy.
You can also do: Command + I, then copy information under Where; Command+C then Command+V, or use Automator.
Take into account that Option+Command+C will copy the path for selected folder or file to the clipboard.
Another method is Command+I for Info, Command+A, Command+X to cut the path to clipboard, then Command+W.
If you use Alfred, you can select the items, press ⌥⌘\, and select Copy path to Clipboard.
One of the easiest ways is to Get Info on the folder or file, then in the middle "General" section, you can select and copy (command + C) the path.
The MacYourself tip Copy file or folder path to the clipboard in Mac OS X Lion works on 10.7.4.
One user suggests that is more efficient to simply drag-and-drop the file into a text field, which will automatically insert the file's path.


Question: how to automatically login to captive portals on os x?

Response:
You can rename the app to a different title, allowing password management via a preferred web browser and compatible extensions such as 1password.
Specificaly, one can rename /System/Library/CoreServices/Captive Network Assistant.app into /System/Library/CoreServices/No More Captive Network Assistant.app.
Additionally, the NetworkAutoLogin project by Tyilo facilitates automated login to Captive Portal Networks by injecting pre-determined credentials through a configuration file.


Question: command line: how do you rotate a pdf file 90 degrees?

Response:
To rotate a PDF file clockwise, the command "pdftk input.pdf cat 1-endeast output output.pdf" can be used; for anti-clockwise rotation, "pdftk input.pdf cat 1-endwest output output.pdf" can be used.
For Debian and Ubuntu systems, an alternative is using pdfjam with the command "pdfjam --landscape --angle 90 input.pdf" for a clockwise rotation.
To automatically orient a PDF to be upright, the Ghostscript command "gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -dAutoRotatePages=/All -sOutputFile="$outputFile" "$file"" is applicable.


Question: i included emoji in my password and now i cant log in to my account on yosemite

Response:
Apple has made changes in macOS 10.11 El Capitan that prevent the use of emoji in the password entry field, so you would need to reset your password.
Alternatively, adjusting your Keyboard Preferences can help resolve input issues, allowing you to add Unicode Hex Input and utilize a wide range of Unicode and Emoji characters.


Question: copying iso file to usb drive in os x?

Response:
An option is to drag and drop the unmounted USB partition into the destination.
Another approach involves making the ISO file into a special DMG file and then uploading it.
The easiest way involves using the terminal to execute commands to prepare the bootable USB stick.
Additionally, you can utilize open-source tools like UNetbootin for this purpose, and there are step-by-step tutorials available, such as the one provided by Ubuntu.


Question: exit vim more quickly

Response:
Shiftzz (that is, ZZ, in uppercase) in normal or command mode saves the current file and exits or closes the current window/tab (which is the same as :x but not :wq, which is one key more, and writes the file even if it hasn't been modified).

To exit unconditionally without changing anything, use: ZQ (same as :q!).

Alternatively, just Q for 'Quit', if you haven't made any edits, which only requires one shifted keystroke (i.e. Shift and Q),or :q! which wipes out all edits and allows you to exit from vi.; and you could add to your .vimrc file: " allow quit via single keypress (Q) map Q :qa<CR>, and if you have saved buffers, it will prompt you before exiting.

Create a custom mapping for frequently used tasks, for example, nnoremap <leader><leader> :xa<cr>; if the <leader> is set to comma by let mapleader = "," then hitting comma twice will be a quick way of quitting vim.

A simple and convenient solution for quit and save from vim - is: Ctrl + X shortcut (just add this code to .vimrc file: "Fast quit and save from normal and insert mode :map <C-X> <ESC>:x<CR> :imap <C-X> <ESC>:x<CR>.

You could try nno : ; nno ; : vno : ; vno ; (if you use fFtT this will take some getting used to, but now quitting's just ;x to save if needed, ;q to not save.

Ctrl + s to save, ctrl + d to save and exit, ctrl + q to exit discarding changes.


Question: ctrl + alt + delete: mac equivalent?

Response:
The keyboard shortcut to bring up the Force Quit Applications window on a Mac is ⌘ + ⌥ + ⎋ (Command + Option + Escape).

Unfaithful answer with Insertions:

When you need to force quit an application on a Mac, the required keyboard shortcut is ⌘ + ⌥ + ⎋, which can also be referred to as Command + Option + Escape.  This will result in the Force Quit Applications window appearing, where you can select the unresponsive program.

Unfaithful answer with Substitution:

To prompt the Force Quit Applications window and select programs to close on a Mac, use the shortcut ⌘ + ⌥ + ⎋, which is the same as Command + Option + Escape.


Question: how umount device is busy?

Response:
When faced with difficulties unmounting a volume, it may be due to another volume mounted on top of the one you're attempting to unmount.
Another potential problem is if you're logged into it multiple times, with at least one instance being in a directory within the desired unmount point.
Additionally, the inability to unmount may be because of processes that have open files on the mount point.


Question: how do i convert an epoch timestamp to a human readable format on the cli?

Response:
One approach to convert an epoch timestamp to "hrf" is to use the command: `date -d @1190000000` and replace the 1190000000 with your specific epoch.
For a custom date format using GNU date, the command is: `date -d @1234567890 +'%Y-%m-%d %H:%M:%S'`.
Alternatively, you can use GNU awk with the command: `awk 'BEGIN { print strftime("%Y-%m-%d %H:%M:%S", 1234567890); }'`.
With the zsh shell, you could use the strftime builtin: `strftime format epochtime` to output the date denoted by epochtime in the specified format.


Question: windowserver high cpu on yosemite

Response:
To address high CPU usage in WindowServer, disabling the "Display have separate Spaces" and logging off and on again may resolve the issue.
Moreover, changing "Displays have separate Spaces" to off and disabling the Dashboard in Mission Control might be helpful.
Removing Google Chrome from the system has also been found to lead to performance improvements.
Eliminating menu bar items that frequently update graphics can further reduce CPU strain.
Disabling tray animations or performing a full reboot can provide temporary relief from sluggish performance.
Switching the system's appearance from dark mode to bright mode has significantly reduced WindowServer load for some.
Disconnecting a second screen, rebooting, then reconnecting, along with closing Google Chrome, may help.
Upgrading the operating system to OS X 10.10.2 has resolved issues for others, allowing for smoother functions and reducing the need for frequent reboots.
Removing specific menu bar items such as iStat Menus and Little Snitch has also led to improvements.
Lastly, using an eGPU can address performance problems for MacBook Pro 16'' (2019) models when dealing with external monitors.


Question: how api works in website?

Response: A Web API is just an Interface to allow access to your system such as a website via standard HTTP request methods.


Question: what is the difference between tcp and tls?

Response:
TLS is purpose-built to provide a secure channel over a reliable transport layer as it does not handle transport errors, lost packets or other disturbances that may occur with IP.
While TLS itself does not impose a requirement on the transport protocol to be TCP, TCP is generally chosen as the reliable protocol for internet operations.


Question: is there a legitimate reason i should be required to use my companys computer? (byod prohibited)

Response:
Standard corporate security policies generally disallow personal devices on company networks for security reasons.
Companies are better positioned to enforce security procedures on their hardware.
To prevent security risks and data leaks, it's advised to consult with the IT Security department regarding these policies.
Controlling software licenses also plays a critical role in ensuring legal compliance and practical management of resources.
Companies may impose restrictions on using personal computers to monitor productivity and protect against economic espionage or other malicious activities.
Legally, they may need to install employee monitoring software, which is simpler on company-owned equipment.
Moreover, companies have hardware standards that facilitate security settings, use of technology, and software requirements.


Question: how can i protect myself from this kind of clipboard abuse?

Response:
Use the intermediate-text editor approach instead of editing directly in a terminal, an intermediate text editor like Notepad++ or Emacs is utilized to assemble and finalize the text before copying it to the terminal.
Never use the terminal pasting functionality to paste things into vim/emacs, because it is akin to executing a batch of commands.
It has been advised that pasting unsafe data into terminals is not safe, and even though there are plugins meant for safe pasting, they may have been compromised.
Nevertheless, it is safe to use Vim's specific command 'set mouse=a' for pasting with the middle mouse button.
Employ a background application to consistently monitor and automatically sanitize clipboard contents, removing potentially harmful control characters.
Another solution is, running the web browser in a virtual machine to prevent mindlessly pasting potentially dangerous content from the web into a terminal, given that the virtual machine's clipboard is not synchronized with the host.


Question: should i contact the manufacturer if their product allows access to other users location information?

Response:
In your situation, it is advisable to inform the company of the vulnerability with caution.
It's essential because the problematic ID you discovered allows for tracking and potentially stalking by exploiting the static nature of these IDs, posing a significant privacy risk.
Suggesting improvements such as implementing expiring or regenerable user IDs could benefit the company and its users, helping to prevent potential harm such as stalking or pranks.
Anonymously reporting these issues may protect you from negative repercussions from the company while still ensuring they are aware of the security flaw.


Question: can gid and uid be same?

Response:
As a general rule, the UID and GID are equal for ordinary users, but this is not always the case.
In fact, the UID is only equal to the GID by default if no separate ordinary groups are added and if no groups are explicitly specified during the creation of a user.
So, in short, they are not always the same, but can be.


Question: how can i delete a word backward at the command line (bash and zsh)?

Response:
"Alt+Backspace" is a functioning shortcut for deleting the previous word in bash and zsh shells.
An alternative method in some environments is the use of Ctrl+W, which is recognized as the standard command to kill the last word you typed.
For Mac users, this action can be performed by pressing "Fn+Delete".
Additionally, terminal emulators may have their own specific shortcuts, and sometimes you can customize them within your settings or by modifying files like "~/.inputrc".
It’s even possible to configure the 'stty' command to change the default key bindings for word deletion or line deletion.


Question: amount of simple operations that is safely out of reach for all humanity?

Response:
The computational limit set by Landauer's principle is approximately 6.32×10^68 elementary computations, or 2^225.2.
When considering the total world energy consumption and diverting it entirely to computation, we reach a limit close to 5×10^36, which resembles 2^122.
With optimistic technological progress factored in, we may achieve a grand total of 2^138 elementary operations for a decade-long computation using Earth's total resources by the year 2040.


Question: how can i save tabs in iterm 2 so they restore the next time the app is run?

Response:
In iTerm2, you have the ability to save and restore window arrangements using the shortcuts ⇧ ⌘ S for saving and ⇧ ⌘ R for restoring.
To enable 'Session Restoration' in iTerm 2.9 beta or iTerm3 beta, you should open Preferences, select the General tab, navigate to Startup, change the setting to 'Use System window restoration setting', and afterwards, restart the program.
iTerm2 version 2.1.4 features a setting under Profiles that allows reusing the previous session's directory.
iTermocil can be utilized in iTerm2 to create pre-configured layouts that include a specified directory and the execution of predetermined commands.


Question: bash: what does >| do?

Response:
The >| operator is a specialized form of the > redirect operator, distinct from pipe operations and is associated with the 'noclobber' shell option, which prevents existing files from being overwritten by redirection.
You can explicitly override the setting of noclobber with the >| redirection operator.


Question: how to change default alarm tone galaxy s6?

Response:
While android doesn't provide a way to change the default alarm tone, there is a way.
Via the ES File Explorer, navigate to /system/media/audio/alarms, then click on the file you want, and in the "Open with" prompt, select "ES Media Player".
Now, open the menu in the top right, and pick "Set ringtone".
Finally, in the dialog that appears, choose "Set alarm" and you're done.
You can also do this using Zedge, which allows default alarm tones to be set to one of your choice.


Question: why would i tar a single file?

Response:
Tarring a single file offers advantages, as .tar.gz stores more meta-data, including UNIX permissions, compared to .gz.
This setup facilitates easy expansion for storing multiple files.
Additionally, tarring a single file is useful for copying while preserving the timestamp, a detail often overlooked in downloads.
This practice aligns with the standard approach of compressing files to enhance download speed.


Question: in bash, when to alias, when to script, and when to write a function?

Response:
In determining whether to use an alias or, script, or function in shell scripting, individual preference plays a significant role.
One should begin with an alias for simplicity (if you only need to add an argument at the front of a single command, for example) an alias will work, advance to a function when complexity increases, and resort to a script for standalone and reusable tasks.
Some say aliases are only suitable for simple text replacements, with no arguments/parameters, functions, a well-defined concept of a few lines of code, are easy to write/use, full shell scripting capability, only available inside bash with one command and some parameters, and scripts have several commands and no parameters and are more or less like functions (or a collections of functions) but available (callable) outside of bash as well.
For changes that should persist within the current shell environment, functions are the appropriate choice as they execute within the same process, avoiding the overhead of creating a new shell that occurs with scripts.
In multi-user environments, scripts are favored for their reliability across different contexts, as aliases and functions might depend on a specific shell context or user environment.
Scripts are primarily used to assemble different software components into more complex functionalities, while functions act as pre-loaded scripts for enhancing modularity and reusability in bash scripts.
Scripts can be invoked in various ways and used by multiple programs, and read from files each time they are called, contrasting with aliases and functions which are stored in and restricted to the current shell's memory.
For modifications requiring administrative privileges, like editing system files, scripts are necessary since they can be executed with 'sudo'.
Aliases and functions require less memory and execute faster, though they necessitate load time as the shell must interpret them before showing the prompt.
If speed is essential, one should consider an alias or function, but if a task needs to function outside the favored shell or takes arguments, scripting is advisable.
Lastly, while aliases and functions serve different purposes and can co-exist, aliases are limited to interactive sessions and are not nestable like functions.


Question: in linux, how to delete all files except the pattern *.txt?

Response:
To delete all files except those with a '.txt' extension, you have multiple command options. You can apply the "find" command with specific parameters.
You can make use of bash's extended globbing or employ zsh's extendedglob capability.
Another approach involves using inverted grep in conjunction with xargs.
Furthermore, there is a simple command, rm $(ls -I "*.txt" ), that achieves file deletion while excluding '.txt' files.


Question: why qt is not popular?

Response:
One reason why Qt may not be as popular is that it doesn't always conform to the look of native programs.
Licensing has historically been a factor, and until 2005, those wanting to release free software for Windows tended to avoid Qt.
Also, until 2000, people who cared strongly about open source did not use Qt.
Another drawback is its compatibility issues with templates and the preprocessor.
The language bindings of Qt may not be sufficient for all mainstream languages, making it less appropriate for the job and some programmers will simply never have given it a go.
Additionally, Qt can be less productive and prone to errors due to its lack of automatic memory management and limited introspection.
Some find it to be heavyweight for certain applications, especially when dealing with licensing requirements that may not align with common licenses.
For those focused on specific architectures, alternatives like C#/.NET for Windows or Java for cross-platform apps might be more preferred.
The fact that Qt is based around C++ may also contribute to its lesser popularity, as fewer people use C++ for desktop apps, and it requires a separate compilation step.
Qt's signal slot mechanisms have been criticized for inefficiency, and there are limitations in the signals provided for certain widgets.
Lastly, the complexity of Qt could be a deterrent for some developers.


Question: restricting command+tab options to only apps that are in the current space

Response: To switch between applications within the same virtual desktop space, you can use the keyboard shortcut control+F4, or ⌃F4 on a Mac.


Question: is there a way for me to run adb shell as root without typing in su?

Response:
One approach for executing scripts as root without typing 'su' on an Android phone is to write the script directly on the device and then use 'adb' to execute it, like in the command: adb shell sh /sdcard/myscript.sh.
Additionally, if your Android device is rooted, it's possible to run commands using su -c, which runs the specified command with root permissions.
For enhancing security, you can install the adbd Insecure.


Question: what is the difference between a hash and a checksum?

Response:
They are essentially the same thing in that they are both used to verify the integrity of data, with checksums tending to be smaller than hash functions.
They are both deterministic and can map a variable sized data to a fixed size.
They can both be used to check for sameness of data, for example a downloaded file compared to the source file, although with different guarantees.
A checksum (such as CRC32) is used to prevent accidental changes, while a hash function is used to map data to other data.
Finally, If you want to detect random errors then a checksums would be the most appropriate, while hashes are better to compare large data sets.


Question: how to switch between different chrome windows with keyboard shortcuts?

Response:
For quick switching between Chrome windows on a Mac, ⌘ Cmd+` can be used for some OS X versions, although in certain cases other combinations like ⌘ Cmd-F1 might be necessary.
To specifically alternate between distinct Chrome users, ⌘ Cmd-Shift-M is the designated shortcut.
For a visual display of all Chrome windows, Control-↓ is an option, after which you can navigate through them using the arrow keys.
Additionally, Alt+PageUp and Alt+PageDown will be introduced for navigating between Chrome windows in the upcoming 15.01 version of TabIt - NewTab extension.
And if dealing with previously maximized Chrome windows, Control key + left or right arrow keys can switch between the two.


Question: what certificates are needed for multi-level subdomains?

Response: It is advisable to adhere to RFC 6125, while DigiCert, WildCard, and ssl certificates are unique in allowing you to secure ANY subdomain of your domain, or you could use a certificate from StartSSL.


Question: is there a quick way to lock my mac?

Response:
Go to "System Preferences" then "Security" under "General" to change your preferences.
If you enable screen locking within the screen saver pref pane you can put the computer to sleep and lock at the same time by pressing ⌘+⌥+F12.
⇧+⌘+⌥+Q will perform a quick logout.
Via the Expose system preferences panel you can set a "hot corner" of your monitor that activates your screen saver.
Go to settings -> Mission control and then over to HotCorners on the bottom left corner where there are 4 corner settings: choose anyone of them according to your feasibility as put to sleep.
Another option is to enable Fast User Switching in the Login Options pane of the Accounts preferences panel.
You can also use  ⌥+⌘+⏏ to put your Mac to sleep.
Control-Command-Q locks your screen on High Sierra.
If you don't need to remote control the Mac, MacLoc is a simple and effective solution.
If you want to be able to remote control:  launch the application Keychain Access, press ⌘ to open up the Preferences window, tick the Show Status in Menu Bar, click the newly appeared lock icon in the menu bar, then click Lock Screen.
Another idea is to use a free tool like the BetterTouchTool to configure you track pad so that a four finger swipe left locks your Mac.
Alternatively, configure Lock as ⌃+⌘+L or you can specify whatever you want.
Try using a keyboard shortcut (such as CTRL-OPT-L or Command+Option+Shift+L) and use Automator to make a screen lock service.
If you're using Alfred, just invoke Alfred and start typing "lock".
Control-Shift-Power (⏏ or ⌽) also works, as does just clicking the Apple menu at the top left of the screen, and then pressing Lock Screen (^⌘Q).
Deskshade, QuickLock, Lock Me Now and Padlock are examples of programs that lock the screen.


Question: how to open files via terminal

Response: To open a file with the default application from the command line, you should type "open" followed by the file name or path; if you want the file to open in a specific application, put "-a" followed by the application's name in quotes between open and the file.


Question: is centos exactly the same as rhel?

Response:
CentOS is derived from the Red Hat Enterprise Linux (RHEL) distribution, offering an enterprise-class computing platform, maintaining 100% binary compatibility with its upstream source, Red Hat.
Unlike RHEL, with CentOS, users do not pay for commercial support from RedHat, and updates are generally available for RedHat first before being released to CentOS; Other than that they are the same.
CentOS closely mirrors RHEL except for the branding and support, with library versions are the same, ensuring compatibility of binaries and administration tools that are configured similarly.
The release notes on the CentOS pages will reveal a list of RPMs that differ from Red Hat, mostly related to branding or the update mechanism that is proprietary to Red Hat.
CentOS is described as more flexible compared to other clone projects and offers various advantages such as a growing community, responsiveness of developers, and multiple free support avenues, positioning CentOS as the community counterpart to Red Hat, akin to the relationship between Linux Mint and Ubuntu.
As a community project that is developed, maintained, and supported by and for its users, CentOS is divergent from Red Hat Enterprise Linux in terms of build environments, QA processes, kernels and other open source components, and the additional software that is not part of the Red Hat Enterprise Linux codebase, maintained by the CentOS Project.
Nonetheless, there are vital differences such as the lack of certified cryptographic protection on CentOS as required by government networks, and the fact that Common Vulnerabilities and Exposures (CVEs) are not tested on CentOS, making it unsuitable for certain secure network environments.


Question: what un(der)-documented features have you stumbled upon in mountain lion?

Response:
A 'Do Not Disturb' mode can be activated in the Notification Center to silence notifications for the day, while the Centre itself can be toggled with click-and-hold.
Also, notifications can be quickly dismissed with a two-finger swipe.
In the Dock, an accidental Dock icon removal prevention feature has been added, requiring a minimum distance and duration before an icon is deleted.
Also, bouncing application icons in the Dock can be silenced simply by hovering over them, while the Dock's aesthetics have also been slightly improved.
If an application is iCloud-savvy, its Open dialog has an iCloud tab.
Furthermore, Safari now supports tab sharing across Mac devices with the same iCloud account.
Also, in Safari, renaming bookmarks has been made quicker, the Reading List can now cache content for offline use and PDF navigation has been enhanced.
For Finder, customization of the sidebar through drag-and-drop is available again.
Also, a three-finger tap can be used to trigger QuickLook for items in the Finder, plus direct video/audio encoding from Finder is now an option.
Quick Look also allows zooming in on PDFs through touchscreen gestures or mouse actions.
The Mac App Store can be navigated forward and backward using two-finger swipe gestures, similar to Safari.
Meanwhile, software Updates now come through the App Store, while the Store updates come with new reopening and skipping options for apps.
Also, the Preview app has gotten a new 'Edit' toolbar and week numbers can now be displayed in Calendar app.
Furthermore, taking app screenshots without shadow is an available option and full screen apps can be used on a screen other than the primary one by dragging the app to the desired screen and activating full screen mode.
Now, downloads and file copies come with an inline progress bar that indicates progress made, while enhancements to Launchpad include a search bar on top and the display of download progress on the Launchpad icon.
Also, Zoom and Mission Control/Launchpad integration has been improved.
Other changes include, new kinetic photo-based screen savers were introduced, allowing users to choose images from several stock image categories or their own collections.
Also, photo navigation in screensavers is possible using keyboard arrows.
Chess can be played over the internet via Game Center.
You can force the system to ask to keep changes when closing documents, thus providing more control over document saving.
The 'Save As' functionality has returned, accessible through the keyboard shortcut: option-shift-command-S, or by pressing the OPTION key while the file menu is pulled down.
Internet Sharing supports WPA2 encryption enhancing security.
New date picker interfaces are integrated into date entry fields.
Web Sharing for individual users can be re-enabled through Terminal commands.
AirPlay Everywhere feature enables streaming audio from the Mac to devices like Apple TV and Airport Express.
Scrollbars become wider when hovered over to facilitate easier grabbing.
In-app file manipulation options are expanded for efficiency.
Applications are now expressly listed as 32-bit or not in the 'Get Info' dialogue window.
Dictation is available wherever text can be input, but requires an internet connection.
Managing Dashboard widgets is streamlined with a new interface and a search bar.
Document auto-locking feature has been removed.
Show scrollbars functionality without scrolling has been added for multi-touch devices.
The estimated battery time remaining option has been removed from the battery menu bar item.
Users will now receive prompts for address book access.
Accessibility settings can be accessed quickly with the keyboard shortcut: ⌥+⌘+F5.
Multiple Time Machine Backup Destinations can be set.
The kernel is exclusively 64-bit and Kernel security is improved through ASLR.
Clipboard content persists through reboots.


Question: can i connect an android phone to an external monitor, keyboard and mouse?

Response:
To meet these needs, the Motorola 'Atrix' phone is a device that has been recently showcased, with its release anticipated for later in the year.
Samsung Galaxy S can connect to a TV through the use of a Micro USB to HDMI cable.
Samsung also offers a dock for the Galaxy Tab, which enables it to connect to a full-size keyboard, positioning the screen similarly to that of a laptop.
Additionally, various Android devices, including the Galaxy Tab, have video or HDMI out features, and Bluetooth can be used for keyboard connections.
The Asus EEE Pad Transformer is another device that aligns with user requirements and is currently available.
You can find demonstrations online, like the one for Ubuntu for Android, showing how an Android phone can be turned into a fully functional desktop while simultaneously functioning as an Android phone.
The Samsung Galaxy Nexus setup allows for the use of Bluetooth peripherals and an external monitor, providing a simple solution without the need for special drivers or applications.


Question: can i change the brightness on a secondary display?

Response:
Controlling the brightness on external displays for Macs is typically managed using the physical buttons or menus found on the display itself.
However, if using an Apple Cinema Display, you can adjust the brightness by connecting the display's USB cable to your Mac, which will then allow a "Brightness" slider to appear in the "Displays" System Preferences.
For Apple Cinema displays, the brightness can also be adjusted through the "Displays" preference pane, and the settings will appear on both the main display and the MacBook Pro, enabling separate brightness adjustments.
Additionally, on Apple displays, pressing Control+F1 or Control+F2 can adjust the brightness on a secondary display, providing that the USB cable is connected to the MacBook Pro, which enables the keyboard shortcuts.
Connecting only one Thunderbolt display at a time to the MacBook Pro allows you to adjust its brightness before reconnecting both, however, this method excludes displaying a brightness slider for both screens.
For a dual display arrangement where the second screen's USB is connected to the first screen, Ctrl+F1 and Ctrl+F2 can adjust the brightness of the second screen without the need for disconnection.
Using the command cmd+F1 can mirror the displays to duplicate brightness levels, and repeating this command allows each screen to be adjusted separately.
This mirroring technique can also be used for adjusting brightness when working with an extended desktop setup on an MBP connected to an LED or Thunderbolt display.
Finally, there are software solutions available, such as the free "Brightness Slider" on the App Store, and a program called "Brightness Control" that allows for dimming multiple external monitors.


Question: is public wi-fi a threat nowadays?

Response:
Public WiFi remains unsecure and without the use of protection like VPNs, it is open to various risks.
By being on the same local network as others, you could be exposed to potential attackers.
Any public network connection you make exposes you to certain risks, and even with tools like VPNs, local network threats remain if user errors happen.
There are numerous threats associated with public WiFi, such as Man in the Middle attacks, unencrypted networks, malware distribution, snooping and sniffing, and malicious hotspots.
Even with technologies like HTTPS or VPN, leaks can occur, and these technologies only provide a false sense of security.
Finally, public WiFi hotspots are inherently untrustworthy, but so is the wider internet, where various entities may eavesdrop on your connections.


Question: how can i find broken symlinks

Response:
Add the -L flag to your command will allow you do get rid of the grep: $ find -L . -type l.
Additionally, the symlinks command can identify various characteristics of symlinks, like whether they are dangling or not.
However, some caution against using find -L because it follows all the symlinks, which can lead to searching through unintended directories such as /usr/share, potentially causing significant delays and other issues.
Alternative approaches include using "find . -xtype l", which performs a test on a dereferenced link, and to detect broken symlinks without traversing into other filesystems, the command "find . -type l ! -exec test -e {} \; -print" can be used.
This approach is considered safe and portable and even detects cyclic symlinks.
For those looking for a quick check, running "find -L . -type l | xargs symlinks" will provide information on a per-found-file basis.
For specific cases, such as not traversing outside a known directory, one might use "find -L $path -maxdepth 1 -type l".
Meanwhile, for a simple, easy-to-remember method, the use of "find . | xargs file | grep -i "broken symbolic link"" or "find . -print0 | xargs -0 file | grep -i "broken symbolic link"' to handle NULL terminators might suffice.
For zsh (Z Shell) users, a specific command, "rm -v" is available to remove broken symlinks.


Question: how can i list all user accounts in the terminal?

Response:
An approach is to execute ls /users if no user home directories were moved.
Another method involves using dscl . list /Users | grep -v '^_'.
Additionally, executing `ls *` in the /Users directory will enumerate all local users registered on the system.


Question: can you see how many times you called someone on iphone?

Response:
You can do so by opening the Phone app and tapping Recents, then on the "i" icon next to the contact you want to check.
Subsequently, a list of calls will appear with information about them.


Question: is ipod classic still supported?

Response:
The iPod Classic is no longer supported by the software updates from Apple, and as such, cannot interface with the newer iTunes versions.
In contrast, the older iPods, generally, have compatibility issues with the latest iTunes update.
However, there are instances where the older iPod models might still function correctly with the current versions of iTunes on compatible hardware and software environments.
When support for the iPod classic is unavailable, using a third-party music manager is the recommended solution as the iPod classic support is discontinued in the recent updates of iTunes.


Question: if someone blocks you can they still facetime you?

Response: No, blocking a number will block it for normal calls, FaceTime and FaceTime audio.


Question: what is a tainted kernel in linux?

Response:
A kernel becomes tainted when it enters a condition that is not supported by the community, often leading to disabled debugging functions and ignored bug reports related to that kernel.
Loading a non-GPL-compatible module or unsigned module will trigger a taint flag in the kernel, which can be checked through kernel logs or specific runtime queries.


Question: finding the pid of the process using a specific port?

Response:
In modern Linux systems, the `ss` command is considered the appropriate tool for retrieving network socket information.
To obtain the desired output when dealing with processes, one should elevate privileges with `sudo`.
Tools such as `lsof` and `fuser` offer alternative methods for accessing network and process information, with `lsof` revealing listening ports and `fuser` providing the user, PID, and command associated with a particular TCP port.
When trying to view the PID of a process using `netstat`, running the command with `sudo` might be necessary.


Question: why are statements in many programming languages terminated by semicolons?

Response:
The syntax of many programming languages is modeled after C which uses the semicolon as a statement terminator.
Another reason the semicolon was chosen is possibly because of its use in English "to indicate interdependent statements" or to separate items in a list of statements.
It is a method that makes it easy to parse individual program statements while still remaining close to normal English punctuation.
ALGOL introduced the semicolon to separate programming statements and it seems that every subsequent block-structured language followed ALGOL's lead and used semicolon to separate or terminate statements.
ALGOL picked a specific terminator which would allow a statement to flow over several lines and picked one that was visible and easily noticed by human readers.
The semicolon is easy to type, less confusing, and it adds meaning to a character with limited meaning in a less complicated manner because special cases don't really exist with its use.
Additionally, there was a need for an explicit statement-terminator other than a carriage-return/new-line and semicolons are convenient because they're not commonly used in logical or mathematical statements, avoiding conflicts within code.
Despite its origins in ALGOL 60 primarily as a statement separator, PL/I, which was the IBM's successor to line-oriented Fortran, decided to make the semicolon a statement terminator rather than a separator, which was well-received by programmers, influencing its extensive use in modern languages.


Question: torvalds quote about good programmer

Response:
According to Torvalds, a good programmer places significant emphasis on the overall high-level design, prioritizing data structures and their relationships over implementation details.
Understanding the intricacies of how data flows within a system is considered crucial by Torvalds, highlighting the importance of grasping these concepts for effective problem-solving.
In his perspective, a programmer's ability to comprehend the things that will solve the problems they are facing is crucial.
Torvalds contends that it is the mastery of data structures that truly sets apart a skilled programmer.


Question: whats the purpose of dh parameters?

Response:
When static Diffie Hellman (DH) is used (as opposed to Ephemeral Diffie Hellman (EDH)), the DH parameters are set for the server and can actually be embedded in a certificate, so they are public.

The purpose of the DH parameters is to exchange a secret (a large prime integer belonging to a prime order group) that will be used to encrypt a transcript of messages within a session, where each party sets a private key that is combined with the secret to create a public key, enabling encrypted messages to be exchanged and then de-encrypted.

The DH parameters are set for the server and can actually be embedded in a certificate, so they are public; with Ephemeral DH, the session key (exchanged at the beginning of the session) is deleted upon session termination.


Question: why was ~ chosen to represent the home directory?

Response: The practice of using tilde to denote the current user's home directory on Unix-like operating systems originates from the Lear-Siegler ADM-3A terminal, which was commonly used in the 1970s.