popen
(PHP 4, PHP 5)
popen — Opens process file pointer
Description
resource popen
( string $command
, string $mode
)
Parameters
-
command
-
The command
-
mode
-
The mode
Return Values
Returns a file pointer identical to that returned by
fopen(), except that it is unidirectional (may
only be used for reading or writing) and must be closed with
pclose(). This pointer may be used with
fgets(), fgetss(), and
fwrite().
If an error occurs, returns FALSE.
Examples
Example #1 popen() example
<?php
$handle = popen("/bin/ls", "r");
?>
If the command to be executed could not be found, a valid
resource is returned. This may seem odd, but makes sense; it
allows you to access any error message returned by the shell:
Example #2 popen() example
<?php
error_reporting(E_ALL);
/* Add redirection so we can get stderr. */
$handle = popen('/path/to/spooge 2>&1', 'r');
echo "'$handle'; " . gettype($handle) . "\n";
$read = fread($handle, 2096);
echo $read;
pclose($handle);
?>
Notes
Note:
If you're looking for bi-directional support (two-way), use
proc_open().
Note: When
safe mode is enabled, you can only
execute files within the safe_mode_exec_dir.
For practical reasons, it is currently not allowed to have ..
components in the path to the executable.
WarningWith safe mode enabled,
the command string is escaped with escapeshellcmd(). Thus,
echo y | echo x becomes echo y \| echo x.
