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Removed BSD prototype from synopsis. 

Various rewordings.
This commit is contained in:
Michael Kerrisk 2007-02-02 06:26:31 +00:00
parent e2ba4f8ea7
commit 5a7f195c23
1 changed files with 20 additions and 29 deletions
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49
man3/usleep.3
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@ -28,18 +28,12 @@
.\" Modified 2001-04-01 by aeb
.\" Modified 2003-07-23 by aeb
.\"
.TH USLEEP 3 2003-07-23 "" "Linux Programmer's Manual"
.TH USLEEP 3 2007-02-01 "" "Linux Programmer's Manual"
.SH NAME
usleep \- suspend execution for microsecond intervals
.SH SYNOPSIS
.nf
/* BSD version */
.B "#include <unistd.h>"
.sp
.BI "void usleep(unsigned long " usec );
.sp
/* SUSv2 version */
.B "#define _XOPEN_SOURCE 500"
.B "#define _XOPEN_SOURCE 500 /* Or: #define _BSD_SOURCE */"
.br
.B "#include <unistd.h>"
.sp
@ -51,7 +45,7 @@ The \fBusleep\fP() function suspends execution of the calling process for
by any system activity or by the time spent processing the call or by the
granularity of system timers.
.SH "RETURN VALUE"
None (BSD). Or: 0 on success, \-1 on error (SUSv2).
0 on success, \-1 on error.
.SH ERRORS
.TP
EINTR
@ -62,8 +56,17 @@ EINVAL
(On systems where that is considered an error.)
.SH "CONFORMING TO"
4.3BSD, POSIX.1-2001.
The SUSv2 version returns int, and this is also the prototype
used by glibc 2.2.2.
POSIX.1-2001 declares this function obsolete; use
.BR nanosleep (2)
instead.
On the original BSD implementation,
and in glibc before version 2.2.2, the return type of this function is
.IR void .
The POSIX version returns
.IR int ,
and this is also the prototype used since glibc 2.2.2.
Only the EINVAL error return is documented by SUSv2.
.SH NOTES
The type
@ -77,19 +80,11 @@ if they never mention this type explicitly. Use
.sp
#include <unistd.h>
\&...
unsigned int usecs;
\&...
usleep(usecs);
.sp
unsigned int usecs;
\&.
usleep(usecs);
.fi
.RE
This type is defined by
.I <sys/types.h>
included by
.I <unistd.h>
but glibc defines it only when _XOPEN_SOURCE has a value not less than 500,
or both _XOPEN_SOURCE and _XOPEN_SOURCE_EXTENDED are defined.
.\" useconds_t also gives problems on HP-UX 10.
.LP
The interaction of this function with the SIGALRM signal, and with
other timer functions such as
@ -104,17 +99,13 @@ other timer functions such as
.BR timer_settime (),
.BR ualarm ()
is unspecified.
.LP
This function is obsolete. Use
.BR nanosleep (2)
or
.BR setitimer (2)
instead.
.SH "SEE ALSO"
.BR alarm (2),
.BR getitimer (2),
.BR nanosleep (2),
.BR select (2),
.BR setitimer (2),
.BR ualarm (3),
.BR sleep (3),
.BR feature_test_macros (7)
.BR feature_test_macros (7),
.BR time (7)