getpgid

Small Linux executable around the getpgid(2) system call to get Process Group ID

It can be used e.g. to kill a whole process tree spawned from and including the script itself by calling

sedsid kill -9 -$(getpgid)

from inside the script. There is no more need to remember all child PIDs to kill them separately.

Dependencies

This is solely dependent on glibc>=2.12

Building

git clone https://github.com/wilriker/getpgid.git
cd getpgid
make
make install

It will be installed to

/usr/bin/getpgid

You can use

make PREFIX=/path/to/dir install

to customize the installation location.

Usage

Either use

getpgid

without any parameters. This will return the PGID of ggetpgid. This basically only makes sense when called from inside a script. It is also possible to provide a PID

getpgid <PID>

that will return the PGID for a valid PID.

Return codes and output

getpgid will return

0: Success together with PGID on stdout
1: PID was provided but not a valid number together with an error message on stderr
2: PGID could not be determinded due to e.g. invalid PID or missing permissions together with error message on stderr