diff options
author | Stephen Rothwell <sfr@canb.auug.org.au> | 2011-05-10 11:53:54 +1000 |
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committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2011-05-10 11:53:54 +1000 |
commit | 24b9fe4ee4f962d012a850c49dcc087afdf6716a (patch) | |
tree | 4dcce04b06402bd179a4fa2ee546846601fa94e1 /lib | |
parent | 42d24dab029d92b3a10cbed809097285d0194b33 (diff) | |
parent | bd8c7d496d270f9fbb4d10be3d5ff97df7ee9d26 (diff) |
Merge branch 'quilt/rr'
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Makefile | 3 | ||||
-rw-r--r-- | lib/bsearch.c | 53 | ||||
-rw-r--r-- | lib/string.c | 29 |
3 files changed, 84 insertions, 1 deletions
diff --git a/lib/Makefile b/lib/Makefile index ef0f28571156..4b49a249064b 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -21,7 +21,8 @@ lib-y += kobject.o kref.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ - string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o + string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o \ + bsearch.o obj-y += kstrtox.o obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o diff --git a/lib/bsearch.c b/lib/bsearch.c new file mode 100644 index 000000000000..5b54758e2afb --- /dev/null +++ b/lib/bsearch.c @@ -0,0 +1,53 @@ +/* + * A generic implementation of binary search for the Linux kernel + * + * Copyright (C) 2008-2009 Ksplice, Inc. + * Author: Tim Abbott <tabbott@ksplice.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; version 2. + */ + +#include <linux/module.h> +#include <linux/bsearch.h> + +/* + * bsearch - binary search an array of elements + * @key: pointer to item being searched for + * @base: pointer to first element to search + * @num: number of elements + * @size: size of each element + * @cmp: pointer to comparison function + * + * This function does a binary search on the given array. The + * contents of the array should already be in ascending sorted order + * under the provided comparison function. + * + * Note that the key need not have the same type as the elements in + * the array, e.g. key could be a string and the comparison function + * could compare the string with the struct's name field. However, if + * the key and elements in the array are of the same type, you can use + * the same comparison function for both sort() and bsearch(). + */ +void *bsearch(const void *key, const void *base, size_t num, size_t size, + int (*cmp)(const void *key, const void *elt)) +{ + size_t start = 0, end = num; + int result; + + while (start < end) { + size_t mid = start + (end - start) / 2; + + result = cmp(key, base + mid * size); + if (result < 0) + end = mid; + else if (result > 0) + start = mid + 1; + else + return (void *)base + mid * size; + } + + return NULL; +} +EXPORT_SYMBOL(bsearch); diff --git a/lib/string.c b/lib/string.c index f71bead1be3e..01fad9b203e1 100644 --- a/lib/string.c +++ b/lib/string.c @@ -535,6 +535,35 @@ 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 |