source: branches/minix3-book/include/sys/wait.h@ 25

Last change on this file since 25 was 4, checked in by Mattia Monga, 14 years ago

Importazione sorgenti libro

File size: 1.3 KB
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1/* The <sys/wait.h> header contains macros related to wait(). The value
2 * returned by wait() and waitpid() depends on whether the process
3 * terminated by an exit() call, was killed by a signal, or was stopped
4 * due to job control, as follows:
5 *
6 * High byte Low byte
7 * +---------------------+
8 * exit(status) | status | 0 |
9 * +---------------------+
10 * killed by signal | 0 | signal |
11 * +---------------------+
12 * stopped (job control) | signal | 0177 |
13 * +---------------------+
14 */
15
16#ifndef _WAIT_H
17#define _WAIT_H
18
19#ifndef _TYPES_H
20#include <sys/types.h>
21#endif
22
23#define _LOW(v) ( (v) & 0377)
24#define _HIGH(v) ( ((v) >> 8) & 0377)
25
26#define WNOHANG 1 /* do not wait for child to exit */
27#define WUNTRACED 2 /* for job control; not implemented */
28
29#define WIFEXITED(s) (_LOW(s) == 0) /* normal exit */
30#define WEXITSTATUS(s) (_HIGH(s)) /* exit status */
31#define WTERMSIG(s) (_LOW(s) & 0177) /* sig value */
32#define WIFSIGNALED(s) (((unsigned int)(s)-1 & 0xFFFF) < 0xFF) /* signaled */
33#define WIFSTOPPED(s) (_LOW(s) == 0177) /* stopped */
34#define WSTOPSIG(s) (_HIGH(s) & 0377) /* stop signal */
35
36/* Function Prototypes. */
37_PROTOTYPE( pid_t wait, (int *_stat_loc) );
38_PROTOTYPE( pid_t waitpid, (pid_t _pid, int *_stat_loc, int _options) );
39
40#endif /* _WAIT_H */
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