2:getsid

From Linux Man Pages

      getsid - get session ID
      

Contents 1 SYNOPSIS 2 DESCRIPTION 3 ERRORS 4 CONFORMING TO 5 NOTES 6 RELATED 7 CATEGORY

SYNOPSIS

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

DESCRIPTION

      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 error, (pid_t) -1
      will be returned, and errno is set appropriately.

ERRORS

      EPERM  A  process  with  process  ID  p exists, but it is not in the same session as the current process, and the
             implementation considers this an error.
 
      ESRCH  No process with process ID p was found.

CONFORMING TO

      SVr4, POSIX.1-2001.

NOTES

      Linux does not return EPERM.
 
      Linux has this system call since Linux 1.3.44.  There is libc support since libc 5.2.19.
 
      To get the prototype  under  glibc,  define  both  _XOPEN_SOURCE  and  _XOPEN_SOURCE_EXTENDED,  or  use  "#define
      _XOPEN_SOURCE n" for some integer n larger than or equal to 500.

RELATED

      getpgid(2), setsid(2), feature_test_macros(7)

CATEGORY