passthru
(PHP 4, PHP 5, PHP 7, PHP 8)
passthru — Execute an external program and display raw output
Description
$command, int &$result_code = null): ?bool
The passthru() function is similar to the
exec() function in that it executes a
command. This function
should be used in place of exec() or
system() when the output from the Unix command
is binary data which needs to be passed directly back to the
browser. A common use for this is to execute something like the
pbmplus utilities that can output an image stream directly. By
setting the Content-type to image/gif and
then calling a pbmplus program to output a gif, you can create
PHP scripts that output images directly.
Parameters
-
command -
The command that will be executed.
-
result_code -
If the
result_codeargument is present, the return status of the Unix command will be placed here.
Return Values
Returns null on success or false on failure.
Notes
When allowing user-supplied data to be passed to this function, use escapeshellarg() or escapeshellcmd() to ensure that users cannot trick the system into executing arbitrary commands.
Note:
If a program is started with this function, in order for it to continue running in the background, the output of the program must be redirected to a file or another output stream. Failing to do so will cause PHP to hang until the execution of the program ends.
See Also
- exec() - Execute an external program
- system() - Execute an external program and display the output
- popen() - Opens process file pointer
- escapeshellcmd() - Escape shell metacharacters
- backtick operator
