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I want to check out the source code for commands such as ps. It seems to be impossible to search LXR (linux.no) for "ps". Where do I find it?

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Ps belongs to procps-ng, git repository is here

To fetch it,

git clone git://gitorious.org/procps/procps.git

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Sure, but where is it in the source tree? – TheLegassis Sep 19 '12 at 1:44
@TheLegassis it's a userland tool, what you looking for? – warl0ck Sep 19 '12 at 1:46
Hi warl0ck, so I am interested in how it gets included in every Linux build I used. Is it precompiled? I would like to take a look at the source code and modify it – TheLegassis Sep 19 '12 at 1:50
@TheLegassis yes, procps reads from /proc, proc-ps – warl0ck Sep 19 '12 at 11:08
@TheLegassis I think the answer to your question about how ps gets included in Linux distributions (not really builds as such) is simply that the people distribution operating systems based on Linux, such as Red Hat, Debian, Ubuntu etc have chosen to include it. They give you a copy of ps alongside the Linux kernel and lots of other software. – bdsl Oct 16 '15 at 14:08

Check procps or procps-ng (the latter is used by Debian/Fedora/openSUSE/Arch and other distros).

procps is the package that has a bunch of small useful utilities that give information about processes using the /proc filesystem. The package includes the programs ps, top, vmstat, w, kill, free, slabtop, and skill.

which looks unmaintained and was forked into procps-ng

Debian, Fedora and openSUSE fork of procps. For more information about the former upstream see http://procps.sourceforge.net.

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Renan, I understand.. but where would I find this in Linux source tree? – TheLegassis Sep 19 '12 at 1:42
@TheLegassis it is not in the Linux source tree (it's userland, not kernel stuff). To get the source code go to the links I gave. – Renan Sep 19 '12 at 2:18
Alright, how does ps get the process information? Through /proc directory or does it use a system call? – TheLegassis Sep 19 '12 at 2:21
For that type of question, it would be best to just look at the source. – Jim Paris Sep 19 '12 at 3:01
If you want to know how programs obtain information about the system you can use strace. – Kotte Sep 19 '12 at 6:36

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