wait(3) - Plan 9 from User Space

From adc93f6097615f16d57e8a24a256302f2144ec4e Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 17:37:50 +0000 Subject: cut out the html - they're going to cause diffing problems. --- man/man3/wait.html | 170 ----------------------------------------------------- 1 file changed, 170 deletions(-) delete mode 100644 man/man3/wait.html (limited to 'man/man3/wait.html') diff --git a/man/man3/wait.html b/man/man3/wait.html deleted file mode 100644 index 84322bc2..00000000 --- a/man/man3/wait.html +++ /dev/null @@ -1,170 +0,0 @@ - -wait(3) - Plan 9 from User Space - - - - -

WAIT(3) WAIT(3) -

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-

NAME
- -
- - await, awaitnohang, awaitfor, wait, waitnohang, waitfor, waitpid - – wait for a process to exit
- -
-

SYNOPSIS
- -
- - #include <u.h> - #include <libc.h> - - - Waitmsg* wait(void) - - - Waitmsg* waitnohang(void) - - - Waitmsg* waitfor(int pid) - - - int waitpid(void) - - - int await(char *s, int n) - - - int awaitnohang(char *s, int n) - - - int awaitfor(int pid, char *s, int n) - -
-

DESCRIPTION
- -
- - Wait causes a process to wait for any child process (see fork(2) - and rfork(3)) to exit. It returns a Waitmsg holding information - about the exited child. A Waitmsg has this structure:
- -
- - typedef - struct Waitmsg - { - - - - int pid; /* of loved one */ - ulong time[3]; /* of loved one & descendants */ - char *msg; - - - } Waitmsg; - - - - -
- Pid is the child’s process id. The time array contains the time - the child and its descendants spent in user code, the time spent - in system calls, and the child’s elapsed real time, all in units - of milliseconds. Msg contains the message that the child specified - in exits(3). For a normal exit, msg[0] is zero, otherwise msg -is the exit string prefixed by the process name, a blank, the - process id, and a colon. -
- - If there are no more children to wait for, wait returns immediately, - with return value nil. -
- - The Waitmsg structure is allocated by malloc(3) and should be - freed after use. For programs that only need the pid of the exiting - program, waitpid returns just the pid and discards the rest of - the information. -
- - Waitnohang is like wait but does not block if there are no more - children to wait for. Instead it returns immediately and sets - errstr. -
- - Waitfor is like wait but waits for a particular pid. -
- - The underlying calls are await, awaitnohang, and awaitfor, which - fill in the n-byte buffer s with a textual representation of the - pid, times, and exit string. There is no terminal NUL. The return - value is the length, in bytes, of the data. -
- - The filled-in buffer may be parsed (after appending a NUL) using - tokenize (see getfields(3)); the resulting fields are, in order, - pid, the three times, and the exit string, which will be '' for - normal exit. If the representation is longer than n bytes, it - is truncated but, if possible, properly formatted. The information - that - does not fit in the buffer is discarded, so a subsequent call - to await will return the information about the next exiting child, - not the remainder of the truncated message. In other words, each - call to await returns the information about one child, blocking - if necessary if no child has exited. If the calling process has - no - living children, await returns −1.
- -
-

SOURCE
- -
- - /usr/local/plan9/src/lib9/wait.c - - - /usr/local/plan9/src/lib9/await.c - -
-

SEE ALSO
- -
- - rfork(3), exits(3),
- -
-

DIAGNOSTICS
- -
- - These routines set errstr.
- -
-

BUGS
- -
- - To avoid name conflicts with the underlying system, wait, waitpid, - and waitfor are preprocessor macros defined as p9wait, p9waitpid, - and p9waitfor; see intro(3).
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- -

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