# posix_getsid

(PHP 4, PHP 5, PHP 7)

posix_getsid — Get the current sid of the process

### 说明

posix_getsid ( int `$pid` ) : int

Return the session id of the process `pid`. The session id of a process is the process group id of the session leader.

### 参数

`pid`

  The process identifier. If set to 0, the current process is assumed. If an invalid `pid` is specified, then `FALSE` is returned and an error is set which can be checked with posix_get_last_error().

### 返回值

Returns the identifier, as an integer.

### 范例

Example #1 Example use of posix_getsid()

    <?php
    $pid = posix_getpid();
    echo posix_getsid($pid); //8805
    ?>

### 参见

- posix_getpgid() - Get process group id for job control
- posix_setsid() - Make the current process a session leader
- POSIX man page GETSID(2)