Brent Barker wrote:
my man page (1) for "grep" states:
Normally, exit status is 0 if selected lines are found and 1
otherwise.
But the exit status is 2 if an error occurred, unless the -q or
--quiet
or --silent option is used and a selected line is found.
I'm using grep in a script, found here:
#!/bin/bash
if echo "$1" | grep /
then
echo "returned 1"
else
echo "returned 0"
fi
It seems that grep returns 1 if it finds the pattern, 0 if it does
not. This seems to be contrary to what is said in the man page. The
behavior is the same if I add the -q option.
Your assumptions are wrong. 0 is considered "success", anything else is
considered failure. So your script above will echo "returned 1" when
grep actually returns 0, and will echo "returned 0" when grep returns
anything other than 0. Try this instead:
echo "$1" | grep / ; echo "returned $?"
This will display the actual return value, be it 0, 1, 2, 67*, or any
other number. (*I don't think grep ever returns 67 :-). But some other
program might.)
--
Matthew
Obscurity: +5
