用于执行exec的PHP脚本

Question

I am writing a PHP script to upload a file that execute other c files by using system calls fork() , and exec() , and execl() . Unfortunately execl() function did not work.
In more details, the PHP script , execute exec() function as:

$output =shell_exec('./app/p1';
echo "<pre>$output</pre>"; ) 

to execute p1 which is the executable file of p1.c, and the p1.c program calls execl() as:

execl("./p2", "./p2", "a.param","test.txt", NULL); 

to execute p2 which is the executable file of p2.c. As the result execl() in p1.c is not executed, and p2.c is not executed. Any suggestions.

Answer 1

As stated in shell_exec documentation , this function is only enabled if safe_mode is disabled in PHP configuration.

To disable it, (only for PHP prior to 5.4 ), you must include the following line in php.ini :

safe_mode = Off

Another possible problem could come from current path. You're calling the binnaries using relative paths ( ./app/p1 and ./p2 ). Are you sure that these binnaries are in the current working directory?

To get rid of this problem, simply use the file's full path in both cases.