des_crypt.3: Minor wording fix in VERSIONS

[thirdparty/man-pages.git] / man3 / memchr.3

diff --git a/man3/memchr.3 b/man3/memchr.3
index 6caf862e75f370e688b2118b20b1b4926d6ae67c..5258868e6eac1f098c9ca63f801c1d7fa7886d6b 100644 (file)
--- a/man3/memchr.3
+++ b/man3/memchr.3
@@ -2,6 +2,7 @@
 .\" and Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk
 .\"     <mtk.manpages@gmail.com>
 .\"
+.\" %%%LICENSE_START(VERBATIM)
 .\" Permission is granted to make and distribute verbatim copies of this
 .\" manual provided the copyright notice and this permission notice are
 .\" preserved on all copies.
@@ -21,81 +22,87 @@
 .\"
 .\" Formatted or processed versions of this manual, if unaccompanied by
 .\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
 .\"
 .\" Modified Mon Apr 12 12:49:57 1993, David Metcalfe
 .\" Modified Sat Jul 24 18:56:22 1993, Rik Faith (faith@cs.unc.edu)
 .\" Modified Wed Feb 20 21:09:36 2002, Ian Redfern (redferni@logica.com)
 .\" 2008-07-09, mtk, add rawmemchr()
 .\"
-.TH MEMCHR 3  2009-04-21 "" "Linux Programmer's Manual"
+.TH MEMCHR 3  2019-03-06 "" "Linux Programmer's Manual"
 .SH NAME
 memchr, memrchr, rawmemchr \- scan memory for a character
 .SH SYNOPSIS
 .nf
 .B #include <string.h>
-
+.PP
 .BI "void *memchr(const void *" s ", int " c ", size_t " n );
-
+.PP
 .BI "void *memrchr(const void *" s ", int " c ", size_t " n );
-
+.PP
 .BI "void *rawmemchr(const void *" s ", int " c );
 .fi
-.sp
+.PP
 .in -4n
 Feature Test Macro Requirements for glibc (see
 .BR feature_test_macros (7)):
 .in
-.sp
+.PP
+.BR memrchr (),
 .BR rawmemchr ():
 _GNU_SOURCE
 .SH DESCRIPTION
 The
 .BR memchr ()
-function scans the first \fIn\fP bytes of the memory
-area pointed to by \fIs\fP for the character \fIc\fP.
-The first byte to
-match \fIc\fP (interpreted as an unsigned character) stops the operation.
+function scans the initial
+.I n
+bytes of the memory
+area pointed to by
+.I s
+for the first instance of
+.IR c .
+Both
+.I c
+and the bytes of the memory area pointed to by
+.I s
+are interpreted as
+.IR "unsigned char" .
 .PP
 The
 .BR memrchr ()
 function is like the
 .BR memchr ()
 function,
-except that it searches backwards from the end of the \fIn\fP bytes
-pointed to by \fIs\fP instead of forwards from the beginning.
-
+except that it searches backward from the end of the
+.I n
+bytes pointed to by
+.I s
+instead of forward from the beginning.
+.PP
 The
 .BR rawmemchr ()
 function is similar to
 .BR memchr ():
 it assumes (i.e., the programmer knows for certain)
-that the character
+that an instance of
 .I c
-lies somewhere in the string
+lies somewhere in the memory area starting at the location pointed to by
 .IR s ,
-and so performs an optimized search
-for the character
+and so performs an optimized search for
 .IR c
-(i.e., no checking for the terminating null byte, or use of an argument,
-.IR n ,
-to limit the range of the search).
-If the character
+(i.e., no use of a count argument to limit the range of the search).
+If an instance of
 .I c
-is not in the string
-.IR s ,
-then
-.BR rawmemchr ()
-may proceed to search beyond the end of the string,
-and the result is unspecified.
-The folowing call is a fast means of locating a string's
+is not found, the results are unpredictable.
+The following call is a fast means of locating a string's
 terminating null byte:
+.PP
 .in +4n
-.nf
-
-char *p = rawmemchr(s,\ \(aq\\0\(aq);
-.fi
+.EX
+char *p = rawmemchr(s,\ \(aq\e0\(aq);
+.EE
 .in
-.SH "RETURN VALUE"
+.SH RETURN VALUE
 The
 .BR memchr ()
 and
@@ -103,7 +110,7 @@ and
 functions return a pointer
 to the matching byte or NULL if the character does not occur in
 the given memory area.
-
+.PP
 The
 .BR rawmemchr ()
 function returns a pointer to the matching byte, if one is found.
@@ -111,24 +118,39 @@ If no matching byte is found, the result is unspecified.
 .SH VERSIONS
 .BR rawmemchr ()
 first appeared in glibc in version 2.1.
-
+.PP
 .BR memrchr ()
 first appeared in glibc in version 2.2.
-.SH "CONFORMING TO"
-The
-.BR memchr ()
-function conforms to SVr4, 4.3BSD, C89, C99, POSIX.1-2001.
-
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lbw32 lb lb
+l l l.
+Interface      Attribute       Value
+T{
+.BR memchr (),
+.BR memrchr (),
+.BR rawmemchr ()
+T}     Thread safety   MT-Safe
+.TE
+.SH CONFORMING TO
+.BR memchr ():
+POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.
+.PP
 The
 .BR memrchr ()
 function is a GNU extension, available since glibc 2.1.91.
-
+.PP
 The
 .BR rawmemchr ()
 function is a GNU extension, available since glibc 2.1.
-.SH "SEE ALSO"
+.SH SEE ALSO
+.BR bstring (3),
 .BR ffs (3),
 .BR index (3),
+.BR memmem (3),
 .BR rindex (3),
 .BR strchr (3),
 .BR strpbrk (3),