#51160 [Com]: Exec family of functions runs a script piped into 'head' too until script end

ID: 51160 Comment by: binarycleric at gmail dot com Reported By: poehler at interworx dot com Status: Open Bug Type: *General Issues Operating System: CentOS 5.4 PHP Version: 5.2.13 New Comment: Just wanted to confirm that this also occurs on Mac OS 10.6 using version PHP 5.3.0. Previous Comments: ------------------------------------------------------------------------ [2010-02-26 21:15:40] poehler at interworx dot com Description: ------------ See reproduce code and expected / actual result sections for details. Short story is when exec'ing with a pipe to 'head', we're getting unexpected results. I'm aware this may be 'correct' behavior, by some definition, but for the life of me I can't figure out where this behavior is documented, if that is the case. So if that is the case, please point me in the right direction, if you could be so kind. Reproduce code: --------------- test.sh: ================= #!/bin/sh for i in 1 2 3 4 5 do echo "Welcome $i times" sleep 1 done ================== test.php: ================== <? passthru( '/bin/sh test.sh | head -n1' ); ================== Expected result: ---------------- Here is the output of running the same command at the shell, which is correct. ================== [root@me]# time /bin/sh test.sh | head -n1 Welcome 1 times real 0m1.030s user 0m0.002s sys 0m0.027s ================== And I would expect identical (save minor timing differences) when test.php is run. Actual result: -------------- [root@me]# php test.php Welcome 1 times test.sh: line 5: echo: write error: Broken pipe test.sh: line 5: echo: write error: Broken pipe test.sh: line 5: echo: write error: Broken pipe test.sh: line 5: echo: write error: Broken pipe real 0m5.191s user 0m0.002s sys 0m0.038s Note that this took 5 seconds instead of 1. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=51160&edit=1