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-rw-r--r--man2/wait.258
1 files changed, 29 insertions, 29 deletions
diff --git a/man2/wait.2 b/man2/wait.2
index cbd851e..e15ca87 100644
--- a/man2/wait.2
+++ b/man2/wait.2
@@ -26,7 +26,7 @@
.\" 2005-05-10, mtk, __W* flags can't be used with waitid()
.\" 2008-07-04, mtk, removed erroneous text about SA_NOCLDSTOP
.\"
-.TH wait 2 2023-05-03 "Linux man-pages 6.05.01"
+.TH wait 2 2023-10-31 "Linux man-pages 6.7"
.SH NAME
wait, waitpid, waitid \- wait for process to change state
.SH LIBRARY
@@ -35,21 +35,21 @@ Standard C library
.SH SYNOPSIS
.nf
.B #include <sys/wait.h>
-.PP
+.P
.BI "pid_t wait(int *_Nullable " "wstatus" );
.BI "pid_t waitpid(pid_t " pid ", int *_Nullable " wstatus ", int " options );
-.PP
+.P
.BI "int waitid(idtype_t " idtype ", id_t " id \
", siginfo_t *" infop ", int " options );
/* This is the glibc and POSIX interface; see
NOTES for information on the raw system call. */
.fi
-.PP
+.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
-.PP
+.P
.BR waitid ():
.nf
Since glibc 2.26:
@@ -70,7 +70,7 @@ In the case of a terminated child, performing a wait allows
the system to release the resources associated with the child;
if a wait is not performed, then the terminated child remains in
a "zombie" state (see NOTES below).
-.PP
+.P
If a child has already changed state, then these calls return immediately.
Otherwise, they block until either a child changes state or
a signal handler interrupts the call (assuming that system calls
@@ -90,13 +90,13 @@ children terminates.
The call
.I wait(&wstatus)
is equivalent to:
-.PP
+.P
.in +4n
.EX
waitpid(\-1, &wstatus, 0);
.EE
.in
-.PP
+.P
The
.BR waitpid ()
system call suspends execution of the calling thread until a
@@ -109,7 +109,7 @@ waits only for terminated children, but this behavior is modifiable
via the
.I options
argument, as described below.
-.PP
+.P
The value of
.I pid
can be:
@@ -131,7 +131,7 @@ equal to that of the calling process at the time of the call to
meaning wait for the child whose process ID is equal to the
value of
.IR pid .
-.PP
+.P
The value of
.I options
is an OR of zero or more of the following constants:
@@ -151,9 +151,9 @@ even if this option is not specified.
.BR WCONTINUED " (since Linux 2.6.10)"
also return if a stopped child has been resumed by delivery of
.BR SIGCONT .
-.PP
+.P
(For Linux-only options, see below.)
-.PP
+.P
If
.I wstatus
is not NULL,
@@ -233,7 +233,7 @@ The
.BR waitid ()
system call (available since Linux 2.6.9) provides more precise
control over which child state changes to wait for.
-.PP
+.P
The
.I idtype
and
@@ -266,7 +266,7 @@ as the caller's process group at the time of the call.
Wait for any child;
.I id
is ignored.
-.PP
+.P
The child state changes to wait for are specified by ORing
one or more of the following flags in
.IR options :
@@ -281,7 +281,7 @@ Wait for children that have been stopped by delivery of a signal.
Wait for (previously stopped) children that have been
resumed by delivery of
.BR SIGCONT .
-.PP
+.P
The following flags may additionally be ORed in
.IR options :
.TP
@@ -292,7 +292,7 @@ As for
.B WNOWAIT
Leave the child in a waitable state; a later wait call
can be used to again retrieve the child status information.
-.PP
+.P
Upon successful return,
.BR waitid ()
fills in the following fields of the
@@ -337,7 +337,7 @@ Set to one of:
.B CLD_CONTINUED
(child continued by
.BR SIGCONT ).
-.PP
+.P
If
.B WNOHANG
was specified in
@@ -355,7 +355,7 @@ waitable state, zero out the
.I si_pid
field before the call and check for a nonzero value in this field
after the call returns.
-.PP
+.P
POSIX.1-2008 Technical Corrigendum 1 (2013) adds the requirement that when
.B WNOHANG
is specified in
@@ -382,7 +382,7 @@ not all implementations follow the POSIX.1 specification on this point.
.BR wait ():
on success, returns the process ID of the terminated child;
on failure, \-1 is returned.
-.PP
+.P
.BR waitpid ():
on success, returns the process ID of the child whose state has changed;
if
@@ -391,7 +391,7 @@ was specified and one or more child(ren) specified by
.I pid
exist, but have not yet changed state, then 0 is returned.
On failure, \-1 is returned.
-.PP
+.P
.BR waitid ():
returns 0 on success or
if
@@ -404,7 +404,7 @@ on failure, \-1 is returned.
.\" returns the PID of the child. Either this is a bug, or it is intended
.\" behavior that needs to be documented. See my Jan 2009 LKML mail
.\" "waitid() return value strangeness when infop is NULL".
-.PP
+.P
On failure, each of these calls sets
.I errno
to indicate the error.
@@ -465,7 +465,7 @@ is equal to
.BR wait ()
is actually a library function that (in glibc) is implemented as a call to
.BR wait4 (2).
-.PP
+.P
On some architectures, there is no
.BR waitpid ()
system call;
@@ -473,7 +473,7 @@ system call;
instead, this interface is implemented via a C library
wrapper function that calls
.BR wait4 (2).
-.PP
+.P
The raw
.BR waitid ()
system call takes a fifth argument, of type
@@ -507,7 +507,7 @@ are adopted by
operation);
.BR init (1)
automatically performs a wait to remove the zombies.
-.PP
+.P
POSIX.1-2001 specifies that if the disposition of
.B SIGCHLD
is set to
@@ -536,7 +536,7 @@ Note that even though the default disposition of
is "ignore", explicitly setting the disposition to
.B SIG_IGN
results in different treatment of zombie process children.)
-.PP
+.P
Linux 2.6 conforms to the POSIX requirements.
However, Linux 2.4 (and earlier) does not:
if a
@@ -565,7 +565,7 @@ of another thread, even when the latter belongs to the same thread group.
However, POSIX prescribes such functionality, and since Linux 2.4
a thread can, and by default will, wait on children of other threads
in the same thread group.
-.PP
+.P
The following Linux-specific
.I options
are for use with children created using
@@ -596,7 +596,7 @@ type ("clone" or "non-clone").
Do not wait for children of other threads in
the same thread group.
This was the default before Linux 2.4.
-.PP
+.P
Since Linux 4.7,
.\" commit bf959931ddb88c4e4366e96dd22e68fa0db9527c
.\" prevents cases where an unreapable zombie is created if
@@ -636,9 +636,9 @@ using the integer supplied on the command line as the exit status.
The parent process executes a loop that monitors the child using
.BR waitpid (),
and uses the W*() macros described above to analyze the wait status value.
-.PP
+.P
The following shell session demonstrates the use of the program:
-.PP
+.P
.in +4n
.EX
.RB "$" " ./a.out &"