getsid (2)

#include <unistd.h>

pid_t getsid(pid_t pid);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

getsid():

_XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

|| /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L

getsid(0) returns the session ID of the calling process. getsid(p) returns the session ID of the process with process ID p. (The session ID of a process is the process group ID of the session leader.)

On success, a session ID is returned. On error, (pid_t) -1 will be returned, and errno is set appropriately.

EPERM

A process with process ID p exists, but it is not in the same session as the calling process, and the implementation considers this an error.

ESRCH

No process with process ID p was found.

This system call is available on Linux since version 2.0.

SVr4, POSIX.1-2001.

Linux does not return EPERM.

getpgid(2), setsid(2), credentials(7)

This page is part of release 3.74 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man-pages/.