tools/lib/string.c

   1 /*
   2  *  linux/tools/lib/string.c
   3  *
   4  *  Copied from linux/lib/string.c, where it is:
   5  *
   6  *  Copyright (C) 1991, 1992  Linus Torvalds
   7  *
   8  *  More specifically, the first copied function was strtobool, which
   9  *  was introduced by:
  10  *
  11  *  d0f1fed29e6e ("Add a strtobool function matching semantics of existing in kernel equivalents")
  12  *  Author: Jonathan Cameron <jic23@cam.ac.uk>
  13  */
  14
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <errno.h>
  18 #include <linux/string.h>
  19 #include <linux/compiler.h>
  20
  21 /**
  22  * memdup - duplicate region of memory
  23  *
  24  * @src: memory region to duplicate
  25  * @len: memory region length
  26  */
  27 void *memdup(const void *src, size_t len)
  28 {
  29         void *p = malloc(len);
  30
  31         if (p)
  32                 memcpy(p, src, len);
  33
  34         return p;
  35 }
  36
  37 /**
  38  * strtobool - convert common user inputs into boolean values
  39  * @s: input string
  40  * @res: result
  41  *
  42  * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
  43  * Otherwise it will return -EINVAL.  Value pointed to by res is
  44  * updated upon finding a match.
  45  */
  46 int strtobool(const char *s, bool *res)
  47 {
  48         switch (s[0]) {
  49         case 'y':
  50         case 'Y':
  51         case '1':
  52                 *res = true;
  53                 break;
  54         case 'n':
  55         case 'N':
  56         case '0':
  57                 *res = false;
  58                 break;
  59         default:
  60                 return -EINVAL;
  61         }
  62         return 0;
  63 }
  64
  65 /**
  66  * strlcpy - Copy a C-string into a sized buffer
  67  * @dest: Where to copy the string to
  68  * @src: Where to copy the string from
  69  * @size: size of destination buffer
  70  *
  71  * Compatible with *BSD: the result is always a valid
  72  * NUL-terminated string that fits in the buffer (unless,
  73  * of course, the buffer size is zero). It does not pad
  74  * out the result like strncpy() does.
  75  *
  76  * If libc has strlcpy() then that version will override this
  77  * implementation:
  78  */
  79 size_t __weak strlcpy(char *dest, const char *src, size_t size)
  80 {
  81         size_t ret = strlen(src);
  82
  83         if (size) {
  84                 size_t len = (ret >= size) ? size - 1 : ret;
  85                 memcpy(dest, src, len);
  86                 dest[len] = '\0';
  87         }
  88         return ret;
  89 }