getsid (2)

NAME

getsid - get session ID

SYNOPSIS

#include <sys/types.h>
 
#include <unistd.h>
pid_t getsid(pid_t pid);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getsid():
_XOPEN_SOURCE >= 500
 

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

DESCRIPTION

getsid(0) returns the session ID of the calling process. getsid() returns the session ID of the process with process ID pid. If pid is 0, getsid() returns the session ID of the calling process.

RETURN VALUE

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

ERRORS

EPERM
A process with process ID pid 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 pid was found.

VERSIONS

This system call is available on Linux since version 2.0.

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, SVr4.

NOTES

Linux does not return EPERM.
See credentials(7) for a description of sessions and session IDs.

SEE ALSO

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

Information

Source
Linux kernel
OS/version
Linux
Source updated
September 15, 2017
Page created
February 9, 2018
Page generated
December 2, 2018