php man page for escapeshellcmd

ESCAPESHELLCMD(3)							 1							 ESCAPESHELLCMD(3)

escapeshellcmd - Escape shell metacharacters

SYNOPSIS
       string escapeshellcmd (string  $command)

DESCRIPTION
       escapeshellcmd(3)  escapes  any	characters in a string that might be used to trick a shell command into executing arbitrary commands. This
       function should be used to make sure that any data coming from user input is escaped before this data is passed to the exec(3) or system(3)
       functions, or to the backtick operator.

	Following characters are preceded by a backslash: #&;`|*?~<>^()[]{}$, x0A and xFF.  ' and " are escaped only if they are not paired. In
       Windows, all these characters plus % are replaced by a space instead.

PARAMETERS
	      o $command
		- The command that will be escaped.

RETURN VALUES
	The escaped string.

EXAMPLES
       Example #1

	      escapeshellcmd(3) example

	      <?php
	      // We allow arbitrary number of arguments intentionally here.
	      $command = './configure '.$_POST['configure_options'];

	      $escaped_command = escapeshellcmd($command);

	      system($escaped_command);
	      ?>

       Warning

	      escapeshellcmd(3) should be used on the whole command string, and it still allows the attacker to pass  arbitrary  number  of  argu-
	      ments. For escaping a single argument escapeshellarg(3) should be used instead.

SEE ALSO
       escapeshellarg(3), exec(3), popen(3), system(3), backtick operator.

PHP Documentation Group 													 ESCAPESHELLCMD(3)