| TCGETPGRP(3) | Library Functions Manual | TCGETPGRP(3) | 
tcgetpgrp — get
    foreground process group ID
Standard C Library (libc, -lc)
#include
    <unistd.h>
pid_t
  
  tcgetpgrp(int fildes);
The
    tcgetpgrp()
    function returns the value of the process group ID of the foreground process
    group associated with the terminal device. If there is no foreground process
    group, tcgetpgrp() returns an invalid process
  ID.
If an error occurs, tcgetpgrp() returns -1
    and the global variable errno is set to indicate the
    error, as follows:
#include
    <sys/types.h> #include
    <unistd.h>
The include file
    <sys/types.h> is
  necessary.
The tcgetpgrp() function is expected to be
    compliant with the IEEE Std 1003.1-1988
    (“POSIX.1”) specification.
| June 4, 1993 | macOS 15.6 |