Manpages - getsid.2

getsid - get session ID

  #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

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.

On success, a session ID is returned. On error, (pid_t) -1 is returned, and errno is set to indicate the error.

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.

This system call is available on Linux since version 2.0.

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

Linux does not return EPERM.

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

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

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