NAME

       getsid - get session ID

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #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() 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.1-2008.

HISTORY

       POSIX.1-2001, SVr4.  Linux 2.0.

NOTES

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

SEE ALSO

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