[Solved]Sending Characters to a process

pepeapepepe · 2009-09-10 17:55:48

Hi,

I'm trying to stop (nicely) a xterm running a ncmpc from another termial. For scrpiting purposes.

So i thought it would be enought to send a 'q' character trought stdin.

this is what i'm testing

pc -C ncmpc # to grab the PID

once i've got the PID i try

echo -n q > /proc/PID/fd/0

but the progrma doesn't exits. (it prints the q on stdout)

Could somebody give advice on how to do this?

1) is this the best way ?(maybe kill -STOP PID is not bad if ncmpc handles it well)

2) or how do i echo the q?

regards

Last edited by pepeapepepe (2009-09-10 19:06:29)

Procyon · 2009-09-10 18:32:07

fd/1 doesn't work either.

killall ncmpc should work

With gdb you can run C code in the application, like ungetch('q')
$ gdb ncmpc PID
(gdb) call ungetch('q')
(gdb) detach

I'm not sure if there's a more convenient way for a bash script, but with a gdb script file it seems to work
call ungetch('q')
detach
quit

and run
gdb ncmpc $(pgrep ncmpc) --command=gdbsendq.txt

pepeapepepe · 2009-09-10 19:08:24

ok,

it worked fine,
that's a cool gdb feature i didn't knew about

thaks

Arch Linux