PHP System Call Always Fails

Question

(Seemingly) no matter what command I try to run with PHP's system function, the command always does nothing and then fails with exit code 1. For example,

system("echo 'this should definitely work'", $retval);

sets $retval = 1. So does

system("dir", $retval);

as well as running an executable that I've written; when I run

vfmt -h cat.v

from cmd.exe the command works and returns with exit code 0, but running

system("vfmt -h cat.v", $retval);

again sets $retval = 1. This vfmt.exe file is in the same directory as the src.php script that is attempting these system calls.

I am nearly at my wit's end trying to figure out what's wrong. What could possibly be causing this issue?

Answer 1

You should check your php.ini for line like the next:

disable_functions =exec,passthru,shell_exec,system,proc_open,popen,curl_exec,curl_multi_exec,parse_ini_file,show_source
                   ^^^^          ^^^^^^^^^^^^^^^^^^

and such.

Also check your "safe mode" status, (php ver. < 5.4) if you have enabled it you can only execute files within the safe_mode_exec_dir and so on...

More information in the doc and for the execution of commands here and especially for system here.