tcgetsid(3) — Linux manual page

tcgetsid(3)             Library Functions Manual             tcgetsid(3)

NAME

       tcgetsid - get session ID

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #define _XOPEN_SOURCE 500        /* See feature_test_macros(7) */
       #include <termios.h>

       pid_t tcgetsid(int fd);

DESCRIPTION

       The function tcgetsid() returns the session ID of the current
       session that has the terminal associated to fd as controlling
       terminal.  This terminal must be the controlling terminal of the
       calling process.

RETURN VALUE

       When fd refers to the controlling terminal of our session, the
       function tcgetsid() will return the session ID of this session.
       Otherwise, -1 is returned, and errno is set to indicate the
       error.

ERRORS

       EBADF  fd is not a valid file descriptor.

       ENOTTY The calling process does not have a controlling terminal,
              or it has one but it is not described by fd.

ATTRIBUTES

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ tcgetsid()                          │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       POSIX.1-2008.

HISTORY

       glibc 2.1.  POSIX.1-2001.

       This function is implemented via the TIOCGSID ioctl(2), present
       since Linux 2.1.71.

SEE ALSO

       getsid(2)

COLOPHON

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Linux man-pages 6.9.1          2024-05-02                    tcgetsid(3)

Pages that refer to this page: setsid(2), TIOCSPGRP(2const), credentials(7)

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