prctl - operations on a process
int prctl(int option, unsigned long arg2, unsigned long arg3 , unsigned long arg4, unsigned long arg5);
prctl is called with a first argument describing what to do (with values defined in <linux/prctl.h>), and further parameters with a significance depending on the first one. The first argument can be:
- (since Linux 2.1.57) Set the parent process death signal of the current process to arg2 (either a signal value in the range 1..maxsig, or 0 to clear). This is the signal that the current process will get when its parent dies. This value is cleared upon a fork().
- (since Linux 2.3.15) Read the current value of the parent process death signal into the (int *) arg2.
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
- The value of option is not recognized, or it is PR_SET_PDEATHSIG and arg2 is not zero or a signal number.
This call is Linux-specific. IRIX has a prctl system call (also introduced in Linux 2.1.44 as irix_prctl on the MIPS architecture), with prototype
ptrdiff_t prctl(int option, int arg2, int arg3);
and options to get the maximum number of processes per user, get the maximum number of processors the calling process can use, find out whether a specified process is currently blocked, get or set the maximum stack size, etc., etc.
The prctl() systemcall was introduced in Linux 2.1.57. There is no prctl() library call as yet.