resource popen(string $command, string $mode)
With safe mode enabled, the command string is escaped with escapeshellcmd(). Thus, echo y | echo x becomes echo y \| echo x.
Opens a pipe to a process executed by forking the command given by
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(). When the mode is 'r', the returned file pointer equals to the STDOUT of the command, when the mode is 'w', the returned file pointer equals to the STDIN of the command.
If an error occurs, returns
- string $command: The command
- string $mode: The mode
Example #1 popen() example
$handle = popen("/bin/ls", "r");
Example #2 popen() example
/* Add redirection so we can get stderr. */
$handle = popen('/path/to/executable 2>&1', 'r');
echo "'$handle'; " . gettype($handle) . "\n";
$read = fread($handle, 2096);
- If you're looking for bi-directional support (two-way), use proc_open().
- 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.