HP-UX Reference (11i v2 03/08) - 2 System Calls (vol 5)

setsid(2) setsid(2)

NAME

setsid - create session and set process group ID

SYNOPSIS

#include <unistd.h>

pid_t setsid(void);

DESCRIPTION

If the calling process is not a process group leader,

setsid() creates a new session. The calling process

becomes the session leader of this new session, it becomes the process group leader of a new process

group, and it has no controlling terminal. The process group ID of the calling process is set equal to the

process ID of the calling process. The calling process is the only process in the new process group, and

the only process in the new session.

RETURN VALUE

Upon successful completion,

setsid() returns the value of the new process group ID of the calling pro-

cess. Otherwise, it returns a value of −1

, and sets errno to indicate the error.

ERRORS

setsid() fails, no changes occur and errno (see errno (2)) is set to one of the following values:

[EPERM] The calling process is already a process group leader or the process group ID of a

process other than the calling process matches the process ID of the calling process.

AUTHOR

setsid() was developed by HP and AT&T.