tcgetpgrp, tcsetpgrp — get and set terminal foreground process group
#include <unistd.h>
pid_t
tcgetpgrp( |
int fd); |
int
tcsetpgrp( |
int fd, |
pid_t pgrp); |
The function tcgetpgrp()
returns the process group ID of the foreground process group
on the terminal associated to fd, which must be the
controlling terminal of the calling process.
The function tcsetpgrp()
makes the process group with process group ID pgrp the foreground process
group on the terminal associated to fd, which must be the
controlling terminal of the calling process, and still be
associated with its session. Moreover, pgrp must be a (nonempty)
process group belonging to the same session as the calling
process.
If tcsetpgrp() is called by
a member of a background process group in its session, and
the calling process is not blocking or ignoring SIGTTOU, a SIGTTOU signal is sent to all members of
this background process group.
When fd refers to
the controlling terminal of the calling process, the function
tcgetpgrp() will return the
foreground process group ID of that terminal if there is one,
and some value larger than 1 that is not presently a process
group ID otherwise. When fd does not refer to the
controlling terminal of the calling process, −1 is
returned, and errno is set to
indicate the error.
When successful, tcsetpgrp()
returns 0. Otherwise, it returns −1, and errno is set to indicate the error.
fd is not a
valid file descriptor.
pgrp has an
unsupported value.
The calling process does not have a controlling
terminal, or it has one but it is not described by
fd, or, for
tcsetpgrp(), this
controlling terminal is no longer associated with the
session of the calling process.
pgrp has a
supported value, but is not the process group ID of a
process in the same session as the calling process.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
tcgetpgrp(), tcsetpgrp() |
Thread safety | MT-Safe |