NAME

sys/wait.h - declarations for waiting

SYNOPSIS

#include <sys/wait.h>

DESCRIPTION

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_PGID

The 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);

APPLICATION USAGE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

wait(), waitid(). <sys/resource.h>, <sys/types.h>.