grep'ping the ps output....

[Eric Schuele]

Hello,

I am sure this is quite trivial, but...

I have need to determine if an app (firefox, or anything really) is 
already running before I perform some action.  So I grep the ps output. 
  However sometimes (many times) that which I'm searching for is present 
in the output because I am presently grep'ing for it.  But it is not 
always there.  It seems to be a bit inconsistent. (See below).

I was wondering if someone could explain why it is sometimes there and 
not other times.  And how I should correctly go about detecting if the 
process is running before I perform my action.

Thanks,
Eric


%ps | grep firefox^M^M
   703  v0  I      0:00.00 /bin/sh /usr/X11R6/bin/firefox^M
   722  v0  I      0:00.00 /bin/sh /usr/X11R6/lib/firefox/run-mozilla.sh 
/usr/X1^
M
   734  v0  S      0:10.92 /usr/X11R6/lib/firefox/firefox-bin^M
%ps | grep firefox^M^M
   703  v0  I      0:00.00 /bin/sh /usr/X11R6/bin/firefox^M
   722  v0  I      0:00.00 /bin/sh /usr/X11R6/lib/firefox/run-mozilla.sh 
/usr/X1^
M
   734  v0  S      0:10.92 /usr/X11R6/lib/firefox/firefox-bin^M
  1230  p1  RV     0:00.00 grep firefox (csh)^M
%^M^M
%ps | grep firefox^M^M
   703  v0  I      0:00.00 /bin/sh /usr/X11R6/bin/firefox^M
   722  v0  I      0:00.00 /bin/sh /usr/X11R6/lib/firefox/run-mozilla.sh 
/usr/X1^
M
   734  v0  S      0:10.92 /usr/X11R6/lib/firefox/firefox-bin^M
  1232  p1  R+     0:00.00 grep firefox^M
%ps | grep firefox^M^M
   703  v0  I      0:00.00 /bin/sh /usr/X11R6/bin/firefox^M
   722  v0  I      0:00.00 /bin/sh /usr/X11R6/lib/firefox/run-mozilla.sh 
/usr/X1^
M
   734  v0  S      0:10.92 /usr/X11R6/lib/firefox/firefox-bin^M
%ps | grep firefox^M^M
   703  v0  I      0:00.00 /bin/sh /usr/X11R6/bin/firefox^M
   722  v0  I      0:00.00 /bin/sh /usr/X11R6/lib/firefox/run-mozilla.sh 
/usr/X1^
M
   734  v0  S      0:10.92 /usr/X11R6/lib/firefox/firefox-bin^M
  1236  p1  R+     0:00.00 grep firefox^M
%ps | grep firefox^M^M
   703  v0  I      0:00.00 /bin/sh /usr/X11R6/bin/firefox^M
   722  v0  I      0:00.00 /bin/sh /usr/X11R6/lib/firefox/run-mozilla.sh 
/usr/X1^
M
   734  v0  S      0:10.92 /usr/X11R6/lib/firefox/firefox-bin^M

-- 
Regards,
Eric