Shell script to search for a pattern in a file using if else

Question

This is my script, I want to find a pattern in a file. I know the exit status of grep -q '<Pattern>' '<file>' && echo $? is 0 if pattern is found. But I am getting if: Expression Syntax error.

 if ( (grep -q '<Pattern>' '<file>' && echo $?)==0  ) then
 echo "Pattern found"
 else
 echo "Pattern not found"
 endif

I don't know tcsh, but in bash and POSIX sh, you'd just do `if grep -q '' ''; then`. — Benjamin W., Aug 28 '18 at 14:44
I'd do that in `tcsh` as well: `sh -c 'if grep -q "" ""; then ... '` :) — chepner, Aug 28 '18 at 15:27
BTW, the `shell` tag is generally focused on POSIX-family shells; better to stick to `csh` and `tcsh` tags here, to avoid pulling in a bunch of folks who consider any use of csh [severely](http://www.faqs.org/faqs/unix-faq/shell/csh-whynot/) [misguided](http://www.grymoire.com/unix/CshTop10.txt). — Charles Duffy, Aug 28 '18 at 16:35

score 2 · Accepted Answer · answered Aug 28 '18 at 16:33

I think you want this:

if ( { grep -q '<Pattern>' '<file>' } ) then
 echo "Pattern found"
else
 echo "Pattern not found"
endif

Note the curly braces around command and the spaces between braces and command.

See the man tcsh, Expressions:

Command exit status

Commands can be executed in expressions and their exit status returned by enclosing them in braces ('{}'). Remember that the braces should be separated from the words of the command by spaces.

Shell script to search for a pattern in a file using if else

1 Answers1