diff options
Diffstat (limited to 'lib/string.c')
| -rw-r--r-- | lib/string.c | 207 |
1 files changed, 172 insertions, 35 deletions
diff --git a/lib/string.c b/lib/string.c index b19b87af65a3..e5878de4f101 100644 --- a/lib/string.c +++ b/lib/string.c @@ -22,7 +22,10 @@ #include <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> -#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/bug.h> +#include <linux/errno.h> #ifndef __HAVE_ARCH_STRNICMP /** @@ -36,25 +39,21 @@ int strnicmp(const char *s1, const char *s2, size_t len) /* Yes, Virginia, it had better be unsigned */ unsigned char c1, c2; - c1 = c2 = 0; - if (len) { - do { - c1 = *s1; - c2 = *s2; - s1++; - s2++; - if (!c1) - break; - if (!c2) - break; - if (c1 == c2) - continue; - c1 = tolower(c1); - c2 = tolower(c2); - if (c1 != c2) - break; - } while (--len); - } + if (!len) + return 0; + + do { + c1 = *s1++; + c2 = *s2++; + if (!c1 || !c2) + break; + if (c1 == c2) + continue; + c1 = tolower(c1); + c2 = tolower(c2); + if (c1 != c2) + break; + } while (--len); return (int)c1 - (int)c2; } EXPORT_SYMBOL(strnicmp); @@ -246,13 +245,17 @@ EXPORT_SYMBOL(strlcat); #undef strcmp int strcmp(const char *cs, const char *ct) { - signed char __res; + unsigned char c1, c2; while (1) { - if ((__res = *cs - *ct++) != 0 || !*cs++) + c1 = *cs++; + c2 = *ct++; + if (c1 != c2) + return c1 < c2 ? -1 : 1; + if (!c1) break; } - return __res; + return 0; } EXPORT_SYMBOL(strcmp); #endif @@ -266,14 +269,18 @@ EXPORT_SYMBOL(strcmp); */ int strncmp(const char *cs, const char *ct, size_t count) { - signed char __res = 0; + unsigned char c1, c2; while (count) { - if ((__res = *cs - *ct++) != 0 || !*cs++) + c1 = *cs++; + c2 = *ct++; + if (c1 != c2) + return c1 < c2 ? -1 : 1; + if (!c1) break; count--; } - return __res; + return 0; } EXPORT_SYMBOL(strncmp); #endif @@ -330,20 +337,33 @@ EXPORT_SYMBOL(strnchr); #endif /** - * strstrip - Removes leading and trailing whitespace from @s. + * skip_spaces - Removes leading whitespace from @str. + * @str: The string to be stripped. + * + * Returns a pointer to the first non-whitespace character in @str. + */ +char *skip_spaces(const char *str) +{ + while (isspace(*str)) + ++str; + return (char *)str; +} +EXPORT_SYMBOL(skip_spaces); + +/** + * strim - Removes leading and trailing whitespace from @s. * @s: The string to be stripped. * * Note that the first trailing whitespace is replaced with a %NUL-terminator * in the given string @s. Returns a pointer to the first non-whitespace * character in @s. */ -char *strstrip(char *s) +char *strim(char *s) { size_t size; char *end; size = strlen(s); - if (!size) return s; @@ -352,12 +372,9 @@ char *strstrip(char *s) end--; *(end + 1) = '\0'; - while (*s && isspace(*s)) - s++; - - return s; + return skip_spaces(s); } -EXPORT_SYMBOL(strstrip); +EXPORT_SYMBOL(strim); #ifndef __HAVE_ARCH_STRLEN /** @@ -520,6 +537,35 @@ bool sysfs_streq(const char *s1, const char *s2) } EXPORT_SYMBOL(sysfs_streq); +/** + * strtobool - convert common user inputs into boolean values + * @s: input string + * @res: result + * + * This routine returns 0 iff the first character is one of 'Yy1Nn0'. + * Otherwise it will return -EINVAL. Value pointed to by res is + * updated upon finding a match. + */ +int strtobool(const char *s, bool *res) +{ + switch (s[0]) { + case 'y': + case 'Y': + case '1': + *res = true; + break; + case 'n': + case 'N': + case '0': + *res = false; + break; + default: + return -EINVAL; + } + return 0; +} +EXPORT_SYMBOL(strtobool); + #ifndef __HAVE_ARCH_MEMSET /** * memset - Fill a region of memory with the given value @@ -648,7 +694,7 @@ EXPORT_SYMBOL(memscan); */ char *strstr(const char *s1, const char *s2) { - int l1, l2; + size_t l1, l2; l2 = strlen(s2); if (!l2) @@ -665,6 +711,31 @@ char *strstr(const char *s1, const char *s2) EXPORT_SYMBOL(strstr); #endif +#ifndef __HAVE_ARCH_STRNSTR +/** + * strnstr - Find the first substring in a length-limited string + * @s1: The string to be searched + * @s2: The string to search for + * @len: the maximum number of characters to search + */ +char *strnstr(const char *s1, const char *s2, size_t len) +{ + size_t l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + while (len >= l2) { + len--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} +EXPORT_SYMBOL(strnstr); +#endif + #ifndef __HAVE_ARCH_MEMCHR /** * memchr - Find a character in an area of memory. @@ -687,3 +758,69 @@ void *memchr(const void *s, int c, size_t n) } EXPORT_SYMBOL(memchr); #endif + +static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) +{ + while (bytes) { + if (*start != value) + return (void *)start; + start++; + bytes--; + } + return NULL; +} + +/** + * memchr_inv - Find an unmatching character in an area of memory. + * @start: The memory area + * @c: Find a character other than c + * @bytes: The size of the area. + * + * returns the address of the first character other than @c, or %NULL + * if the whole buffer contains just @c. + */ +void *memchr_inv(const void *start, int c, size_t bytes) +{ + u8 value = c; + u64 value64; + unsigned int words, prefix; + + if (bytes <= 16) + return check_bytes8(start, value, bytes); + + value64 = value; +#if defined(ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 + value64 *= 0x0101010101010101; +#elif defined(ARCH_HAS_FAST_MULTIPLIER) + value64 *= 0x01010101; + value64 |= value64 << 32; +#else + value64 |= value64 << 8; + value64 |= value64 << 16; + value64 |= value64 << 32; +#endif + + prefix = (unsigned long)start % 8; + if (prefix) { + u8 *r; + + prefix = 8 - prefix; + r = check_bytes8(start, value, prefix); + if (r) + return r; + start += prefix; + bytes -= prefix; + } + + words = bytes / 8; + + while (words) { + if (*(u64 *)start != value64) + return check_bytes8(start, value, 8); + start += 8; + words--; + } + + return check_bytes8(start, value, bytes % 8); +} +EXPORT_SYMBOL(memchr_inv); |