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easily strace all your apache processes

Terminal - easily strace all your apache processes
ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace
2011-03-14 21:45:22
User: px
Functions: awk grep ps xargs
5
easily strace all your apache processes

This one-liner will use strace to attach to all of the currently running apache processes output and piped from the initial "ps auxw" command into some awk.

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
straceprocessname(){ x=( $(pgrep "$@") ); [[ ${x[@]} ]] || return 1; strace -vf ${x[@]/#/-p }; }
2009-12-03 00:04:39
User: sputnick
Functions: return strace
3

Especially for sysadmins when they don't want to waste time to add -p flag on the N processes of a processname.

In the old school, you did ;

pgrep processname

and typing strace -f -p 456 -p 678 -p 974...

You can add -f argument to the function. That way, the function will deal with pgrep to match the command-line.

Example :

processname -f jrockit
ps h --ppid $(cat /var/run/apache2.pid) | awk '{print"-p " $1}' | xargs sudo strace
2012-03-21 01:59:41
Functions: awk cat ps sudo xargs
2

Like the original version except it does not include the parent apache process or the grep process and adds "sudo" so it can be run by user.

ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace -f
2013-02-19 19:14:57
User: msealand
Functions: awk grep ps strace xargs
1

This version also attaches to new processes forked by the parent apache process. That way you can trace all current and *future* apache processes.

ps -C apache o pid= | sed 's/^/-p /' | xargs strace

Know a better way?

If you can do better, submit your command here.

What others think

Why the inclusion of the the time of the running process only to use awk to separate out on the fs (:) to get the pid? On CentOS (tested on 5.5) this provides the same results:

ps auxw | grep sbin/httpd | awk '{print $2}' | awk ' {print "-p "$1}' | xargs strace
Comment by mrlinsky 189 weeks and 2 days ago

Actually, this works as well on the same test env:

ps auxw | grep sbin/httpd | awk '{print"-p " $2}' | xargs strace
Comment by mrlinsky 189 weeks and 2 days ago

Thanks @mrlinsky, I will update the command. I just put together a few bits and forgot to get rid of the extras while I tested it. :)

Comment by px 189 weeks and 2 days ago

there, i shortened it for ya'll from 4 command pipe to 3.

strace $(pidof httpd | sed 's/\([0-9]*\)/\-p \1/g')
Comment by layer3switch 189 weeks and 2 days ago

@layer3switch, thank you kindly.

Comment by px 189 weeks and 1 day ago

Shorter: sh -c "strace -p{$(pgrep -d, apache)}"

Comment by akg240 189 weeks and 1 day ago

@akg240, that wouldn't work for fork() process as there is no way of knowing which calls are attached to which pid. the whole point of separate "-p" per pid is to associate calls per pid. also "sh -c" must include following string enclosed using single quote, not double quote.

Comment by layer3switch 189 weeks ago

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