getpid, getpgrp, getppid - Gets the process ID, process group ID, parent
pid_t getpid( void );
pid_t getpgrp( void );
pid_t getppid( void );
Application developers may want to specify an #include statement for
<<sys/types.h>> before the one for <<unistd.h>> if programs are being developed
for multiple platforms. The additional #include statement is not required
on Tru64 UNIX systems or by ISO or X/Open standards, but may be required on
other vendors' systems that conform to these standards.
Interfaces documented on this reference page conform to industry standards
getpid(), getpgrp(), getppid(): POSIX.1, XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about indus-
try standards and associated tags.
The getpid() function returns the process ID of the calling process.
The getpgrp() function returns the process group ID of the calling process.
The getppid() function returns the parent process ID of the calling pro-
cess. When a process is created, its parent process ID is the process ID
of its parent process. If a parent process exits, the parent process IDs
of its child processes are changed to the process ID of the init program.
System calls: fork(2), kill(2), setpgid(2), setsid(2), wait(2)