On 17 October 2011 20:45, Mike Wright <mike.wright@xxxxxxxxxxxxxx> wrote: > On 10/17/2011 12:39 PM, Mike Wright wrote: >> Hi all, >> >> I'm trying to write a bash script and having problems. >> >> If I execute this: >> >> ps x | grep mongod | wc -l >> >> it returns a value. >> >> OTOH, if I execute this: >> >> LINES = ps x | grep mongod | wc -l >> >> it returns "command not found". >> >> How does one assign the output of a command to an environment variable? > > Aaargh! Doesn't like the spaces around the = sign. > > LINES=`ps x | grep mongod | wc -l` is a way to write it. > There's quite a good explanation of that somewhere, I think in the bash manual. It boils down to: X=A is an assignment (to X) X =A is a command (run X, argument, '=A') X= A is an assignment (X="") followed by a command (A) run with that assignment in effect (normally you need to export the value for it to affect the child process). Exercise left for the reader as to what X = A is. -- imalone -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
