popen
(PHP 4, PHP 5)
popen — Opens process file pointer
說明
Opens a pipe to a process executed by forking the command given by command.
參數
- command
-
The command
- mode
-
The mode
Return值
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.
範例
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);
?>
註釋
Note: If you're looking for bi-directional support (two-way), use proc_open().
Note: 在啟用了安全模式時，只能執行在 safe_mode_exec_dir 之內的執行檔。為實用起見目前不能在執行檔的路徑中包含 .. 元素。
在啟用了安全模式時，命令字串會被 escapeshellcmd() 跳脫。所以 echo y | echo x 就成了 echo "y | echo x"。