NAME

getsid - get session ID

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#include <unistd.h>

pid_t getsid(pid_t pid);

getsid():

    _XOPEN_SOURCE >= 500
        || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L

DESCRIPTION

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 is returned, and errno is set to indicate the error.

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

Linux does not return EPERM.

STANDARDS

POSIX.1-2024.

HISTORY

SVr4, SUSv1, Linux 2.0, POSIX.1-2001 XSI, POSIX.1-2008.

NOTES

See credentials(7) for a description of sessions and session IDs.

SEE ALSO

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