> -----Original Message----- > From: redhat-list-bounces@xxxxxxxxxx > [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Steve Buehler > Sent: Monday, March 14, 2005 3:35 PM > To: General Red Hat Linux discussion list > Subject: RE: shell script to count httpd processes > > At 01:43 PM 3/14/2005, you wrote: > > > I am trying to create a shell script with /bin/sh that will count > > > how many httpd processes are running at the time. > > > This is how it would look as a perl script: > > > ---start of script--- > > > #!/usr/bin/perl > > > $count = 0; > > > @hits = (`ps -afe | grep httpd | grep -v grep`); > > > foreach $entry (@hits) { > > > $count++; > > > } > > > print "$count\n"; > > > ---end of script--- > > > > > > I am trying to do this in an sh script. Partly for > learning partly > > > because I want to do some other things to, but can only > know how to > > > do them in a shell script. Any help would be greatly appreciated. > > > >The following shell script should do the trick: > > > >--- start of script --- > >#!/bin/bash > > > >COUNT=`ps -aef | grep httpd | grep -c -v grep` > > > >echo $COUNT > >--- end of script --- > > > >If the reason for your question is to understand how to use > a for loop, > >the following script will also work: > > > >--- start of script --- > >#!/bin/bash > >PROCIDLIST=`ps -aef | grep httpd | grep -v grep | awk > '{print $2}'` for > >PROCID in $PROCIDLIST do > > COUNT=$((COUNT+1)) > >done > > > >echo $COUNT > >--- end of script > > > >Please note there is another syntax for the 'for' command, > which looks > >like the following: > >---- > >for (( statement1; statement2; statement3)) do > > statement block > >done > >---- > >The above 'for' syntax works like the 'for' statement in C. > > Steve, Brian and Michael. > Thank you all for your responses. I had tried the > wc -l option and couldn't get it to work. Figured it was > because it was for files. It was just because I tried it in > every way but the correct way. > Michael > You gave me just what I was looking for. A little > knowledge of the for loop. Was hoping for a loop that would > actually count the lines and not the words though. But your > awk command helped me there. I will continue hunting for an > answer to my "learning question" where I am just trying to > find out how to count whole lines in a shell script variable. > with a loop internally to the script without the wc command. > Thanks > Steve > > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list > Steve, If you want to know how to read one line at a time from a variable and feed that line to your for loop, you can use the following script: --- start of script --- #!/bin/bash COUNT=0 IFS=$'\n' PROCIDLIST=`ps -aef | grep httpd | grep -v grep | awk '{print $2}'` for PROCID in $PROCIDLIST do COUNT=$((COUNT+1)) done echo $COUNT --- end of script --- The IFS variable tells the shell script how to delimit words in a variable. It is usually set to the following: IFS=$' \t\n' in other words, spaces, tabs, and newlines usually delimit words in a variable. In the above script, I have changed it to just have newlines delimit words. Michael -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
