tcgetsid - Man Page

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).

InterfaceAttributeValue
tcgetsid()Thread safetyMT-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)

Referenced By

credentials(7), procenv(1), setsid(2).

2023-10-31 Linux man-pages 6.7