From 8d71c7b0e4f76dce251a121e07dff8212bed73f8 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Thu, 14 Mar 1996 11:20:23 +0000 Subject: Thu Mar 14 06:01:07 1996 Roland McGrath * string/strnlen.c: New file. * string/Makefile (routines): Add strnlen. * string/string.h [__USE_GNU] (strnlen): Declare new function. [__OPTIMIZE__]: Define extern inline implementation of it. --- string/Makefile | 5 +++-- string/string.h | 17 +++++++++++++++++ string/strnlen.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 50 insertions(+), 2 deletions(-) create mode 100644 string/strnlen.c (limited to 'string') diff --git a/string/Makefile b/string/Makefile index 1fa63c24d2..5901c36594 100644 --- a/string/Makefile +++ b/string/Makefile @@ -1,4 +1,4 @@ -# Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. +# Copyright (C) 1991, 92, 93, 94, 95, 96 Free Software Foundation, Inc. # This file is part of the GNU C Library. # The GNU C Library is free software; you can redistribute it and/or @@ -24,7 +24,8 @@ subdir := string headers := string.h strings.h memory.h endian.h bytesex.h routines := strcat strchr strcmp strcoll strcpy strcspn strdup \ - strerror _strerror strlen strncat strncmp strncpy \ + strerror _strerror strlen strnlen \ + strncat strncmp strncpy \ strrchr strpbrk strsignal strspn strstr strtok \ strxfrm memchr memcmp memmove memset \ bcopy bzero ffs stpcpy stpncpy \ diff --git a/string/string.h b/string/string.h index 95dcba0041..49b29fd168 100644 --- a/string/string.h +++ b/string/string.h @@ -127,9 +127,26 @@ extern __ptr_t memmem __P ((__const __ptr_t __haystack, size_t __haystacklen, __const __ptr_t __needle, size_t __needlelen)); #endif + /* Return the length of S. */ extern size_t strlen __P ((__const char *__s)); +#ifdef __USE_GNU +/* Find the length of STRING, but scan at most MAXLEN characters. + If no '\0' terminator is found in that many characters, return MAXLEN. */ +extern size_t strnlen __P ((__const char *__string, size_t __maxlen)); + +#ifdef __OPTIMIZE__ +extern __inline size_t +strnlen (__const char *__string, size_t __maxlen) +{ + __const char *__end = memchr (__string, '\0', __maxlen); + return __end ? __end - __string : __maxlen; +} +#endif +#endif + + /* Return a string describing the meaning of the `errno' code in ERRNUM. */ extern char *strerror __P ((int __errnum)); #ifdef __USE_REENTRANT diff --git a/string/strnlen.c b/string/strnlen.c new file mode 100644 index 0000000000..eb01a63692 --- /dev/null +++ b/string/strnlen.c @@ -0,0 +1,30 @@ +/* Find the length of STRING, but scan at most MAXLEN characters. +Copyright (C) 1996 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include + +/* Find the length of STRING, but scan at most MAXLEN characters. + If no '\0' terminator is found in that many characters, return MAXLEN. */ + +size_t +strnlen (const char *string, size_t maxlen) +{ + const char *end = memchr (string, '\0', maxlen); + return end ? end - string : maxlen; +} -- cgit v1.2.3