LXXXI. Program Execution functions

Those functions provides means to executes commands on the system itself, and means secure such commands. Those functions are also closely related to the backtick operator.

Table of Contents
escapeshellarg -- escape a string to be used as a shell argument
escapeshellcmd -- escape shell metacharacters
exec -- Execute an external program
passthru --  Execute an external program and display raw output
proc_close --  Close a process opened by proc_open and return the exit code of that process.
proc_open --  Execute a command and open file pointers for input/output
shell_exec --  Execute command via shell and return complete output as string
system -- Execute an external program and display output