PHP: exec command not working; sh: command not found

When using PHP exec command, if you find sh: Command not found , error in your web server logs, you have to export the full path of that command.

Assuming, that command in /opt/local/bin, change the command to

 $cmd ='export PATH=$PATH:/opt/local/bin; myCommand 2>&1';  
 echo exec($cmd,$out);  

To debug PHP exec command, Read this

For example:
For the PHP code:

 $cmd = "gmake";  
 echo exec($cmd,$out);  

There will be no output. In your web server error log, your will have :

 sh: gmake: command not found  

To fix this, we need to export the PATH of the gmake.

Go to your terminal, find where your command is located, In this example:

 $ which gmake  
 /opt/local/bin/gmake  

So, modify you PHP code as following:

 $cmd ='export PATH=$PATH:/opt/local/bin; gmake 2>&1';  
 echo exec($cmd,$out) ;

This will output, on your web page

 gmake: *** No targets specified and no makefile found. Stop.