`<process.h>`

`_c_exit`	Perform _exit cleanup without terminating the program.
`_cexit`	Perform exit cleanup without terminating the program.
`execl, execle, execlp, execlpe, execv, execve, execvp, execvpe`	Loads and runs other programs.
`getpid`	Gets the process ID of a program.
`spawnl, spawnle, spawnlp, spawnlpe, spawnv, spawnve, spawnvp, spawnvpe`	Creates and runs child processes.