如何从php编译GCC

Question

I tried this function from php with :

exec("gcc testC.c -o runner.out 2>&1",$output,$status);

but when I print $output I get this error :(:

gcc: error trying to exec 'cc1': execvp: No such file or directory

If I run

exec("/usr/bin/gcc testing/pruebaC.c -o testing/frommm.out 2>&1",$output,$status);

I get that

collect2: fatal error: cannot find 'ld'

My user :

groups vagrant
vagrant : vagrant root adm cdrom sudo dip www-data plugdev lpadmin sambashare

My gcc directory

/usr/bin$ ls -l gcc
lrwxrwxrwx 1 root vagrant 7 Apr  7  2014 gcc -> gcc-4.8

If I run from terminal all work, I can compile and execute but from PHP I cant :(

Answer 1

I'm not sure what happened in the comments, but I've figured out the root of the problem and I'm answering this just to clarify for any future readers.

@zneak is right. If you try and echo $_ENV["PATH"] and receive nothing in response, this means that PHP is executing gcc and any other executables without looking for them in a PATH variable. As a result, it sometimes can't find any of them. @Marco interpreted as echoing the PATH variable in bash, and executed echo $PATH instead. However, these two variables are separate, and often the PHP PATH is unset while the bash PATH is.

In order to fix this issue, you'll have to define PATH for PHP in its environment variables. If you're unsure what to put, refer to the PATH variable defined in bash. For example, my current Laravel project has the line

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

at the bottom of it's .env file, and now executing just gcc (without giving the full path /usr/bin/gcc) works correctly.