string escapeshellcmd(string command);EscapeShellCmd() 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() or system() functions, or to the backtick operator. A standard use would be:
system(EscapeShellCmd($cmd))
See also exec(), popen(), system(), and the backtick operator.