tcsetpgrp - set the foreground process group ID
int tcsetpgrp(int fildes, pid_t pgid_id);
If the process has a controlling terminal, tcsetpgrp() shall set the foreground process group ID associated with the terminal to pgid_id. The application shall ensure that the file associated with fildes is the controlling terminal of the calling process and the controlling terminal is currently associated with the session of the calling process. The application shall ensure that the value of pgid_id matches a process group ID of a process in the same session as the calling process.
Attempts to use tcsetpgrp() from a process which is a member of a background process group on a fildes associated with its controlling terminal shall cause the process group to be sent a SIGTTOU signal. If the calling thread is blocking SIGTTOU signals or the process is ignoring SIGTTOU signals, the process shall be allowed to perform the operation, and no signal is sent.
Upon successful completion, 0 shall be returned. Otherwise, -1 shall be returned and errno set to indicate the error.
The tcsetpgrp() function shall fail if:
- The fildes argument is not a valid file descriptor.
- This implementation does not support the value in the pgid_id argument.
- The process group of the writing process is orphaned, the calling thread is not blocking SIGTTOU, and the process is not ignoring SIGTTOU.
- The calling process does not have a controlling terminal, or the file is not the controlling terminal, or the controlling terminal is no longer associated with the session of the calling process.
- The value of pgid_id is a value supported by the implementation, but does not match the process group ID of a process in the same session as the calling process.
XBD <sys/types.h>, <unistd.h>
First released in Issue 3. Included for alignment with the POSIX.1-1988 standard.
In the SYNOPSIS, the inclusion of <sys/types.h> is no longer required.
The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:
The requirement to include <sys/types.h> has been removed. Although <sys/types.h> was required for conforming implementations of previous POSIX specifications, it was not required for UNIX applications.
In the DESCRIPTION and ERRORS sections, text previously conditional on _POSIX_JOB_CONTROL is now mandated. This is a FIPS requirement.
The normative text is updated to avoid use of the term "must" for application requirements.
The Open Group Corrigendum U047/4 is applied.
POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0655  and XSH/TC1-2008/0656  are applied.
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