minix/nbsd_include/sys/wait.h
2011-02-21 13:13:55 +00:00

64 lines
2.1 KiB
C

#ifndef _SYS_WAIT_H_
#define _SYS_WAIT_H_
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/featuretest.h>
/* The <sys/wait.h> header contains macros related to wait(). The value
* returned by wait() and waitpid() depends on whether the process
* terminated by an exit() call, was killed by a signal, or was stopped
* due to job control, as follows:
*
* High byte Low byte
* +---------------------+
* exit(status) | status | 0 |
* +---------------------+
* killed by signal | 0 | signal |
* +---------------------+
* stopped (job control) | signal | 0177 |
* +---------------------+
*/
/*
* Macros to test the exit status returned by wait
* and extract the relevant values.
*/
#define _LOW(v) ( (v) & 0377)
#define _HIGH(v) ( ((v) >> 8) & 0377)
#define WIFEXITED(s) (_LOW(s) == 0) /* normal exit */
#define WEXITSTATUS(s) (_HIGH(s)) /* exit status */
#define WTERMSIG(s) (_LOW(s) & 0177) /* sig value */
#define WIFSIGNALED(s) ((((unsigned int)(s)-1) & 0xFFFFU) < 0xFFU) /* signaled */
#define WIFSTOPPED(s) (_LOW(s) == 0177) /* stopped */
#define WSTOPSIG(s) (_HIGH(s) & 0377) /* stop signal */
/*
* Option bits for the third argument of waitpid. WNOHANG causes the
* wait to not hang if there are no stopped or terminated processes, rather
* returning an error indication in this case (pid==0). WUNTRACED
* indicates that the caller should receive status about untraced children
* which stop due to signals. If children are stopped and a wait without
* this option is done, it is as though they were still running... nothing
* about them is returned.
*/
#define WNOHANG 0x00000001 /* don't hang in wait */
#define WUNTRACED 0x00000002 /* tell about stopped,
untraced children */
/* POSIX extensions and 4.2/4.3 compatibility: */
/*
* Tokens for special values of the "pid" parameter to waitpid.
*/
#define WAIT_ANY (-1) /* any process */
#define WAIT_MYPGRP 0 /* any process in my process group */
__BEGIN_DECLS
pid_t wait(int *);
pid_t waitpid(pid_t, int *, int);
__END_DECLS
#endif /* !_SYS_WAIT_H_ */