tcgetpgrp.3c (2010 09)

t
tcgetpgrp(3C) tcgetpgrp(3C)
NAME
tcgetpgrp( ) - get foreground process group id
SYNOPSIS
#include <unistd.h>
pid_t tcgetpgrp(int fildes);
DESCRIPTION
tcgetpgrp() returns the value of the process group ID of the foreground process group associated with
the terminal referenced by fildes .
tcgetpgrp() is allowed from a process that is a member of a back-
ground process group (see termio (7)); however, the information can be subsequently changed by a process
that is a member of a foreground process group.
RETURN VALUE
Upon successful completion,
tcgetpgrp() returns the value of the process group ID of the foreground
process group associated with the terminal referenced by fildes . Otherwise,
tcgetpgrp() returns a
value of −1 and sets
errno to indicate the error.
ERRORS
tcgetpgrp() fails if any of the following conditions are encountered:
[EACCES] The file associated with fildes is the controlling terminal of the calling process, how-
ever, there is no foreground process group defined for the controlling terminal.
[EBADF] fildes is not a valid file descriptor.
[ENOTTY] The file associated with fildes is not the controlling terminal or the calling process
does not have a controlling terminal.
WARNINGS
The error [EACCES], which is returned if the controlling terminal has no foreground process group,
might not be returned in future releases, depending on the course taken by the POSIX standard. Port-
able applications therefore should not rely on this error condition.
SEE ALSO
setpgid(2), setsid(2), tcsetpgrp(3C), thread_safety(5), termio(7).
STANDARDS CONFORMANCE
tcgetpgrp(): AES, SVID3, XPG3, XPG4, FIPS 151-2, POSIX.1
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1