grep is inconsistently defaulting to grep -P?
- by Sammitch
I have a script that does some housekeeping that works perfectly well when invoked from an interactive shell, but did nothing when invoked by cron. To troubleshoot this I started a shell with a 'blank' environment with the command:
env -i /bin/bash --noprofile --norc
Using this blank env I've dug into my script and found that the following grep will not match any files:
grep -il "^ws_status\s*=\s*[\"']remove[\"']$"
However, when run from an interactive shell the command will return the filenames of the matching files.
As a note, the expression is matching lines like: WS_STATUS = "remove"
Through trial-and-error I discovered that adding -P to the options [Perl regex] the command started working normally in the 'blank' shell. However, I have no idea why my login shell appears to be defaulted to grep -P.
There is only one grep binary, /bin/grep
There are no aliases defined for grep=pgrep or grep="grep -P"
There is no env variable GREP_OPTIONS defined.
What's the deal here?
Note: OS is RHEL v5.10, Bash is v3.2.25, grep is v2.5.1
