tcgetpgrp - Man Page

get the foreground process group ID

Prolog

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

Synopsis

#include <unistd.h>

pid_t tcgetpgrp(int fildes);

Description

The tcgetpgrp() function shall return the value of the process group ID of the foreground process group associated with the terminal.

If there is no foreground process group, tcgetpgrp() shall return a value greater than 1 that does not match the process group ID of any existing process group.

The tcgetpgrp() function is allowed from a process that is a member of a background process group; however, the information may be subsequently changed by a process that is a member of a foreground process group.

Return Value

Upon successful completion, tcgetpgrp() shall return the value of the process group ID of the foreground process associated with the terminal. Otherwise, -1 shall be returned and errno set to indicate the error.

Errors

The tcgetpgrp() function shall fail if:

EBADF

The fildes argument is not a valid file descriptor.

ENOTTY

The calling process does not have a controlling terminal, or the file is not the controlling terminal.

The following sections are informative.

Examples

None.

Application Usage

None.

Rationale

None.

Future Directions

None.

See Also

setsid(), setpgid(), tcsetpgrp()

The Base Definitions volume of POSIX.1-2017, <sys_types.h>, <unistd.h>

Referenced By

tcsetpgrp(3p), unistd.h(0p).

2017 IEEE/The Open Group POSIX Programmer's Manual