man3/wcsspn.3

   1 '\" t
   2 .\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
   3 .\"
   4 .\" SPDX-License-Identifier: GPL-2.0-or-later
   5 .\"
   6 .\" References consulted:
   7 .\"   GNU glibc-2 source code and manual
   8 .\"   Dinkumware C library reference http://www.dinkumware.com/
   9 .\"   OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
  10 .\"   ISO/IEC 9899:1999
  11 .\"
  12 .TH wcsspn 3 (date) "Linux man-pages (unreleased)"
  13 .SH NAME
  14 wcsspn \- get length of a prefix wide-character substring
  15 .SH LIBRARY
  16 Standard C library
  17 .RI ( libc ", " \-lc )
  18 .SH SYNOPSIS
  19 .nf
  20 .B #include <wchar.h>
  21 .PP
  22 .BI "size_t wcsspn(const wchar_t *" wcs ", const wchar_t *" accept );
  23 .fi
  24 .SH DESCRIPTION
  25 The
  26 .BR wcsspn ()
  27 function is the wide-character equivalent of the
  28 .BR strspn (3)
  29 function.
  30 It determines the length of the longest initial segment of
  31 .I wcs
  32 which consists entirely of wide-characters listed in
  33 .IR accept .
  34 In other
  35 words, it searches for the first occurrence in the wide-character string
  36 .I wcs
  37 of a wide-character not contained in the wide-character string
  38 .IR accept .
  39 .SH RETURN VALUE
  40 The
  41 .BR wcsspn ()
  42 function returns the number of
  43 wide characters in the longest
  44 initial segment of
  45 .I wcs
  46 which consists entirely of wide-characters listed
  47 in
  48 .IR accept .
  49 In other words, it returns the position of the first
  50 occurrence in the wide-character string
  51 .I wcs
  52 of a wide-character not
  53 contained in the wide-character string
  54 .IR accept ,
  55 or
  56 .I wcslen(wcs)
  57 if there is none.
  58 .SH ATTRIBUTES
  59 For an explanation of the terms used in this section, see
  60 .BR attributes (7).
  61 .TS
  62 allbox;
  63 lbx lb lb
  64 l l l.
  65 Interface       Attribute       Value
  66 T{
  67 .na
  68 .nh
  69 .BR wcsspn ()
  70 T}      Thread safety   MT-Safe
  71 .TE
  72 .sp 1
  73 .SH STANDARDS
  74 C11, POSIX.1-2008.
  75 .SH HISTORY
  76 POSIX.1-2001, C99.
  77 .SH SEE ALSO
  78 .BR strspn (3),
  79 .BR wcscspn (3)