getppid

GETPID(2)                     System Calls Manual                    GETPID(2)

NAME
     getpid, getppid — get parent or calling process identification

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     pid_t
     getpid(void);

     pid_t
     getppid(void);

DESCRIPTION
     The getpid() system call returns the process ID of the calling process.
     Though the ID is guaranteed to be unique, it should NOT be used for
     constructing temporary file names, for security reasons; see mkstemp(3)
     instead.

     The getppid() system call returns the process ID of the parent of the
     calling process.

ERRORS
     The getpid() and getppid() system calls are always successful, and no
     return value is reserved to indicate an error.

SEE ALSO
     fork(2), getpgrp(2), kill(2), setpgid(2), setsid(2), exec(3)

STANDARDS
     The getpid() and getppid() system calls are expected to conform to
     ISO/IEC 9945-1:1990 (“POSIX.1”).

HISTORY
     The getpid() function appeared in Version 7 AT&T UNIX.

                               December 15, 2015