sys/wait.h - declarations for waiting
#include <sys/wait.h>
The <sys/wait.h> header defines the following symbolic constants for use with waitpid():
- WNOHANG
- Do not hang if no status is available, return immediately.
- WUNTRACED
- Report status of stopped child process.
and the following macros for analysis of process status values:
- WEXITSTATUS()
Return exit status. - WIFCONTINUED()
True if child has been continued - WIFEXITED()
True if child exited normally. - WIFSIGNALED()
True if child exited due to uncaught signal. - WIFSTOPPED()
True if child is currently stopped. - WSTOPSIG()
Return signal number that caused process to stop. - WTERMSIG()
Return signal number that caused process to terminate. The following symbolic constants are defined as possible values for the options argument to waitid():
- WEXITED
- Wait for processes that have exited.
- WSTOPPED
- Status will be returned for any child that has stopped upon receipt of a signal.
- WCONTINUED
- Status will be returned for any child that was stopped and has been continued.
- WNOHANG
- Return immediately if there are no children to wait for.
- WNOWAIT
- Keep the process whose status is returned in infop in a waitable state.
The type idtype_t is defined as an enumeration type whose possible values include at least the following:
P_ALL P_PID P_PGIDThe id_t type is defined as described in <sys/types.h>.
The siginfo_t type is defined as described in <signal.h>.
The rusage structure is defined as described in <sys/resource.h>.
The pid_t type is defined as described in <sys/types.h>.
Inclusion of the <sys/wait.h> header may also make visible all symbols from <signal.h> and <sys/resource.h>.
The following are declared as functions and may also be defined as macros. Function prototypes must be provided for use with an ISO C compiler.
pid_t wait(int *); pid_t wait3(int *, int, struct rusage *); int waitid(idtype_t, id_t, siginfo_t *, int); pid_t waitpid(pid_t, int *, int);
None.
None.
wait(), waitid(). <sys/resource.h>, <sys/types.h>.