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When running a command from a shell, its exit status is made available through the special shell parameter, $?. Top Best Answer 0 Mark this reply as the best answer?(Choose carefully, this can't be changed) Yes | No Saving... Exit immediately with zero status if any match is found, even if an error was detected. chrism01 View Public Profile View LQ Blog View Review Entries View HCL Entries Find More Posts by chrism01 12-17-2007, 06:45 PM #6 unSpawn Moderator Registered: May 2001 Posts: 29,332 check over here

up vote 14 down vote favorite How can I reduce the following bash script? It prints the filename (because there was at least one match), and IMMEDIATELY EXITS. LinuxQuestions.org > Forums > Non-*NIX Forums > Programming How to check grep status when find elements return 0 User Name Remember Me? That's because the status value immediately becomes the status of echo, overwriting the interesting one from grep. --- Top Best Answer 0 Mark this reply as the best answer?(Choose carefully, this http://www.gnu.org/software/grep/manual/html_node/Exit-Status.html

Grep Exit Code Always 0

However, currently I have problem where grep would also grab the 150 and 156 as well. More generally, [ "`cmd`" ] would return true if cmd outputs at least one non-empty line on stdout (with potential problems if it outputs NUL bytes). Need a better layout, so that blank space can be utilized Does being engaged (to be married) carry any legal significance?

That comment would have made sense for [ `grep PATTERN file.txt ` ], but as hinted in the comment, [ "`grep -n PATTERN file.txt`" ] would be better if PATTERN may more hot questions question feed about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation Science I've been poking around at it, but I don't see what it sees. Grep In If Statement Shell Script Ramesh Reddy replied Jun 19, 2012 $?

As such, Tgr's bash solution wouldn't work, and I didn't want to expand the complexity as in Christopher Neylan's answer. Grep Always Return 0 Then, ignore the return status, take the command output (which we forced to be empty), apply word splitting and file glob expansion (resulting in no arguments at all), then run the Remove advertisements Sponsored Links frans View Public Profile Find all posts by frans #7 03-09-2010 Franklin52 Moderator Join Date: Feb 2007 Last Activity: 15 December 2016, 7:28 http://unix.stackexchange.com/questions/294371/how-to-obtain-grep-exit-status-into-a-variable If you'd like to contribute content, let us know.

bash shell command-line grep return-status share|improve this question edited Jul 7 at 11:03 rems4e 1033 asked Jul 7 at 8:07 omri gilhar 212 1 Look up command substitution. –123 Jul Grep Exit Code 0 and you'll see what happens. What is so wrong with thinking of real numbers as infinite decimals? See my answer. –Robpol86 Jul 21 '15 at 21:27 add a comment| up vote 6 down vote You actually don't need to use exit at all.

Grep Always Return 0

Bharathi xxxxxx replied Jun 14, 2012 I tried both options. I'm really just looking for a slicker way to do this thing that seems like it should be easy. Grep Exit Code Always 0 That fixed it. Grep If Statement Top White Papers and Webcasts Popular Big Data and the CMO: An Introduction to the Challenge and ...

Not the answer you're looking for? check my blog Though here of course it's if grep -q PATTERN file.txt you want. –Stéphane Chazelas Sep 17 at 6:47 add a comment| Your Answer draft saved draft discarded Sign up or i use it for a quick syntax check on js files: find src/js/ -name \*js -exec node \{\} \; 2>&1 | grep -B 5 SyntaxError || exit 0 && exit 1; Thanks. -Jason ahjiefreak View Public Profile View LQ Blog View Review Entries View HCL Entries Find More Posts by ahjiefreak 12-17-2007, 09:07 AM #2 bigearsbilly Senior Member Registered: Bash If Grep True

In the days before I learned about pgrep, I wrote this function to automate the above command: psg () { local -a patterns=() (( $# == 0 )) && set -- I did say in the question that I would award it to the tightest code. How do manufacturers detune engines? this content On my system, it's /usr/bin/[. (Well, technically, your shell probably has it built-in, but that's an optimization.

Try saying you are not clear about status, or echo, or stdout, or stderr, or ${ } syntax, or whatever. Grep Silent variable: grep -P "STATUS: (?!Perfect)" recess.txt exit $((1-$?)) (But note that grep may also return 2, so it's not clear what you'd want to occur in such cases.) share|improve this answer kinzlaw Linux - General 1 03-11-2006 03:38 AM Multi-line return from grep into an array?

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So personally I gave up on grep for this and used awk. Code Coverage Calculation - Seems to be including code in test methods How do I select an extra row for each row in the result set in SQL? Thanks! Grep Invert Exit Code Code Coverage Calculation - Seems to be including code in test methods What happened to Obi-Wan's lightsaber after he was killed by Darth Vader?

MATCHES="$( grep Pattern MyLog.log )" if [[ "${MATCHES}" -gt 0 ]]; then You got one or more. You could try adding set -xv at the top of your scipt which will show you in detail exactly what it's doing (kind of a debug mode) chrism01 View Public So, if you wanted to check that the pattern is matched 3 or more times, you would do: if [ "$(grep -c "^$1" schemas.txt)" -ge 3 ]; then ... have a peek at these guys Platonic Truth and 1st Order Predicate Logic Why study finite-dimensional vector spaces in the abstract if they are all isomorphic to R^n?

Coprimes up to N Did Malcolm X say that Islam has shown him that a blanket indictment of all white people is wrong? Exit immediately with zero status if any match is found, even if an error was detected. What is the most secured SMTP authentication type? 8-year-old received tablet as gift, but he does not have the self-control or maturity to own a tablet more hot questions question feed Word that means "to fill the air with a bad smell"? 3% personal loan online.

Do you say prefix K for airport codes in the US when talking with ATC? You're now being signed in. Why study finite-dimensional vector spaces in the abstract if they are all isomorphic to R^n? It works the same way, [ returns a zero exit code for true, a non-zero exit code for false. (test is the same thing as [, except for the closing ])

Since you’re a new learner, I’d strongly recommend that you start with a good book and/or online tutorial to get the basics. Wayne Willcox replied Jun 19, 2012 Which is NOT the return code. All Rights Reserved. Recommendations of external resources are discouraged on Stack Exchange sites but I’d suggest Lhunath and GreyCat’s Bash Guide.

rose_bud4201 Programming 2 06-14-2005 05:11 PM undefined refrence return status link error azucarmom Programming 7 03-30-2005 12:15 PM All times are GMT -5. bigearsbilly View Public Profile View LQ Blog View Review Entries View HCL Entries Find More Posts by bigearsbilly 12-17-2007, 09:08 AM #3 colucix LQ Guru Registered: Sep 2003 Location: grep -q -i 'pattern' file; then # do things (pattern was not found) fi share|improve this answer edited Jul 7 at 13:45 answered Jul 7 at 8:43 Kusalananda 9,1001549 add a more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed

So, since grep -q itself is returning a true/false value, it is unnecessary and problematic to use the command [ also? –Lauren Sep 18 '12 at 19:19 1 @Lauren You share|improve this answer edited Jul 7 at 8:47 answered Jul 7 at 8:35 Anthony Geoghegan 3,5431839 add a comment| up vote 2 down vote You've told bash to set the variable This is what happens: Code: $ s=`echo 'abc def'|grep 'xxx'` $ echo $? 1 $ s=`echo 'abc def'|grep 'abc'` $ echo $? 0 Remove advertisements Sponsored Links Franklin52 all together: if grep -q -i 'pattern' file; then # do things (pattern was found) else # do other things (pattern was not found) fi or, if you just want to

However, if the -q or --quiet or --silent option is used and a line is selected, the exit status is 0 even if an error occurred. if [ grep -q ^$1 schemas.txt ] then echo "Schema already exists. It knows it has done all it can with that file.