tcgetpgrp3p
Get the foreground process group id
Usage
#include <unistd.h>
pid_t tcgetpgrp(int fildes);
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.
Overview
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.