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Stack Overflow

Questions tagged [linux]

NOTICE: All Linux questions must be related to programming; those that aren't will be closed. Use this tag only if your question relates to programming using Linux APIs or Linux-specific behavior, not just because you happen to run your code on Linux. If you need Linux support, you can try https://unix.stackexchange.com or the specific Linux distribution's Stack Exchange site like https://askubuntu.com or https://elementaryos.stackexchange.com/

GNU/Linux is a Unix-like computer operating system which consists of necessary user-space libraries and programs provided by GNU in Cambridge, Massachusetts and a kernel, developed by Linus Torvalds in Helsinki, Finland.

The GNU/Linux naming controversy is a dispute among members of the free and open-source software community over how to refer to the computer operating system commonly called .

Design

A GNU/Linux-based system is a modular Unix-like operating system. It derives much of its basic design from principles established in Unix during the 1970s and 1980s. Such a system uses a monolithic kernel that handles process control, networking, and peripheral and file system access. Device drivers are either integrated directly with the kernel or added as modules loaded while the system is running.

Separate projects that interface with the kernel provide much of the system's higher-level functionality. The GNU user land is an important part of most GNU/Linux-based systems, providing the most common implementation of the C library, a popular shell, and many of the common Unix tools which carry out many basic operating system tasks. The graphical user interface (or GUI) used by most GNU/Linux systems is built on top of an implementation of the X Window System.

Tag Usage

The tag on Stack Overflow is generally used for questions about:

  • programming against the APIs supplied by the operating system
  • the implementation of the kernel
  • programming tools and techniques for use on a Linux-based system.

Notable questions that probably don't belong are:

  • questions about using a desktop or laptop GNU/Linux system are better directed towards Super User, Unix & Linux, Ask Ubuntu, or Elementary OS if they're specifically about those distributions.
  • questions about administering GNU/Linux systems for other users and networking GNU/Linux systems in a context more complicated than a minimal home network are better directed towards Server Fault.

Many questions about GNU/Linux can also be properly tagged as , but some features are specific to GNU/Linux and are not found on other Unix™ and Unix-like operating systems. If you have questions about a specific distribution and version (e.g., , it may not be necessary to use this tag for that question.

A fair number of questions are questions about the command shell (bash by default on many systems), and are probably better tagged with and/or the particular shell you are interested in (, , , etc.).

Questions about the internals of the Linux kernel or regarding writing Linux kernel modules should be tagged .

Free Linux and GNU/Linux Books

Common GNU/Linux distributions

Distrowatch aggregates new release notices from these and hundreds of other GNU/Linux distributions, Phoronix keeps track of new GNU/Linux features and GNU/Linux Performance.

Other resources

Related tags

226061 questions
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Specify the from user when sending email using the mail command

Does anyone know how to change the from user when sending email using the mail command? I have looked through the man page and can not see how to do this. We are running Redhat Linux 5.
Joel Cunningham
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PGP: Not enough random bytes available. Please do some other work to give the OS a chance to collect more entropy

Setup : Ubuntu Server on Virtual Machine with 6 cores and 3GB of RAM. when I am trying to generate a asymmetric key pair via GPG like this gpg --gen-key . I get the following error : Not enough random bytes available. Please do some other work to…
user1524529
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4 answers

How to set system wide umask?

I am working in a lab where we are running Linux (Debian and Ubuntu). Usernames and group names are handled by NIS and yp. We have some common users that everybody has access to that run the experiments and then we each have our own users in…
HansHarhoff
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How to skip saturday and sunday in a cron expression?

Hi I want to create a cron expression excluding saturday and sunday.
Rakesh Sabbani
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69
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17 answers

64 bit ntohl() in C++?

The man pages for htonl() seem to suggest that you can only use it for up to 32 bit values. (In reality, ntohl() is defined for unsigned long, which on my platform is 32 bits. I suppose if the unsigned long were 8 bytes, it would work for 64 bit…
Tom
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69
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2 answers

What does a dot before the variable name in struct mean?

looking at the linux kernel source, I found this: static struct tty_operations serial_ops = { .open = tiny_open, .close = tiny_close, .write = tiny_write, .write_room = tiny_write_room, .set_termios = tiny_set_termios, }; I've never seen…
c0de
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69
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4 answers

ImageMagick not authorized to convert PDF to an image

I have a program, in which I need to convert a PDF to an image using Image Magick. I do that using the subprocess package: cmd = 'magick convert -density 300 '+pdfFile+'['+str(rangeTuple[0])+'-'+str(rangeTuple[1])+'] -depth 8 '+'temp.tiff'…
Mooncrater
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3 answers

What is the difference between -I and -L in makefile?

What is the usage of the -I and -L flags in a makefile?
MainID
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69
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Parsing secrets from AWS secrets manager using AWS cli

I am retrieving secrets I have stored in AWS secrets manager with the AWS cli like this: aws secretsmanager get-secret-value --secret-id secrets Which returns arn:aws:secretsmanager:secret:my_secrets my_secrets {"API_KEY":"ABCDEFGHI"} …
Moddaman
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69
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1 answer

In SSHD Configuration what does "MaxStartups 10:30:60" mean?

Problem Is: Some SFTP connections are failing in customer environment But using sample code if i test with same server no connection is failed. may be in customer envi many parallel sftp connection started at a time. I Want…
Syedsma
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69
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2 answers

select vs poll vs epoll

I am designing a new server which needs to support thousands of UDP connections (somewhere around 100,000 sessions). Any input or suggestions on which one to use?
ravi
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PM2 command not found

I installed node.js and npm to my centOS 7 server. But i have problems with pm2. Actually real problem is i don't have experiences in linux and i don't know how to change path. Here is folder structure. * bin * code * error_docs * httpdocs * lib64 *…
kenarsuleyman
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How to increase thread priority in pthreads?

I am using pthread in Linux. I would like to increase the thread priority by setting the parameters sched_param.priority. However, I could not find much info from the net regarding the range of the thread priority I could set, or about the…
Steveng
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3 answers

Get all modules/packages used by a python project

I have a python GUI application. And now I need to know what all libraries the application links to. So that I can check the license compatibility of all the libraries. I have tried using strace, but strace seems to report all the packages even if…
user2109788
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69
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7 answers

CLI pdf viewer for linux

Hey, for quite a while now, I am looking for a pdf viewer for the command line. As I like to work without X on Linux, and often work on a remote machine, I would like to have a tool to read pdfs. There are quite a lot of really good graphical…
bitmask
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