I am trying to search the file dep/playlist for 'ohn'. Then, I would like to take this result and apply it to a new grep command that searches the file employee list end then echoes the results on screen. The code below isn't behaving as expected.
grep ohn dep/playlist > search
grep $(cat search) employeelist > newlist
cat newlist
Thanks,
Tim
You need to tell grep to obtain the patterns from a file, use the -f option:
-f FILE, --file=FILE
Obtain patterns from FILE, one per line. The empty file
contains zero patterns, and therefore matches nothing. (-f is
specified by POSIX.)
So the command would look like:
grep -f search employeelist > newlist
Using process substitution you could obviate the need of a temporary file. So the two grep commands could be written into one as:
grep -f <(grep ohn dep/playlist) employeelist > newlist
grep ohn dep/playlist | xargs -I name grep name employeelist
This searches dep/playlist for 'ohn', and then upon finding a result, that result is then used in grep X employeelist, where X is the result from the first grep.
-n 1 option to xargs.