1 /* -*- linux-c -*- ------------------------------------------------------- *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
6 * This file is part of the Linux kernel, and is made available under
7 * the terms of the GNU General Public License version 2.
9 * ----------------------------------------------------------------------- */
12 * Very basic string functions
17 int strcmp(const char *str1, const char *str2)
19 const unsigned char *s1 = (const unsigned char *)str1;
20 const unsigned char *s2 = (const unsigned char *)str2;
33 int strncmp(const char *cs, const char *ct, size_t count)
41 return c1 < c2 ? -1 : 1;
49 size_t strnlen(const char *s, size_t maxlen)
52 while (*es && maxlen) {
60 unsigned int atou(const char *s)
64 i = i * 10 + (*s++ - '0');
68 /* Works only for digits and letters, but small and fast */
69 #define TOLOWER(x) ((x) | 0x20)
71 static unsigned int simple_guess_base(const char *cp)
74 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
84 * simple_strtoull - convert a string to an unsigned long long
85 * @cp: The start of the string
86 * @endp: A pointer to the end of the parsed string will be placed here
87 * @base: The number base to use
90 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
92 unsigned long long result = 0;
95 base = simple_guess_base(cp);
97 if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
100 while (isxdigit(*cp)) {
103 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
106 result = result * base + value;
116 * strlen - Find the length of a string
117 * @s: The string to be sized
119 size_t strlen(const char *s)
123 for (sc = s; *sc != '\0'; ++sc)
129 * strstr - Find the first substring in a %NUL terminated string
130 * @s1: The string to be searched
131 * @s2: The string to search for
133 char *strstr(const char *s1, const char *s2)
143 if (!memcmp(s1, s2, l2))