Good day all,

I am trying to write a bash script to show all processes of java, however i would like it to display in the below manner.

 ps -p $PID -o pid,vsz=MEMORY -o user,group=GROUP -o comm,args=ARGS

The problem with the above is that it only show one particular PID.

So I want to ps aux|grep j\[a\]va get the PID of each and then run each PID in the above command.


 root@reinhardt-VirtualBox:/home/reinhardt# ps -p 1959 -o pid,vsz=MEMORY -o user,group=GROUP -o comm,args=ARGS
 1959  13648 root     root     grep            grep --color=auto java

I would guess some sort of loop will be made like for loop?


Not in a place where I can test this, but this should work. read is a standard part of shell scripting, it places something from stdin (which can be a stream, or a device such as /dev/tty) into a variable. Then you just do a while loop

ps auwwx | gawk '/[j]ava/{print $1}' | while read PID
    ps -p $PID -o pid,vsz=MEMORY -o user,group=GROUP -o comm,args=ARGS

Or more simply, if your UNIX has pgrep:

pgrep java | while read PID
    ps -p $PID -o pid,vsz=MEMORY -o user,group=GROUP -o comm,args=ARGS

Sometimes you can use xargs in cases like these. Remember that by default, xargs puts a group of arguments at the end of the command. So you need to feed it one at a time (with -n1) and place the PID where you want, with -i:

pgrep java | xargs -n1 -i{} ps -p {} -o pid,vsz=MEMORY -o user,group=GROUP -o comm,args=ARGS

(again, apologies if I get the -i syntax wrong, I can't test now. Check manpage if this blows up)

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  • Awesome, tried the 1st piece of code, 2 problems, it said gawk is not known. I then took out the g and then the script ran through the loop, however i am not sure if the PID is inserted into the $PID. I get "error: process ID list syntax error" – Reinhardt Ratkas van Rooyen Oct 28 '14 at 15:33
  • Oh and the last one is working perfectly! – Reinhardt Ratkas van Rooyen Oct 28 '14 at 15:36
  • @ReinhardtRatkasvanRooyen is this on a Mac? My assumption was Linux, therefore gawk. – Rich Homolka Oct 28 '14 at 16:28
  • This is linux, Ubuntu 13 – Reinhardt Ratkas van Rooyen Oct 29 '14 at 7:35

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