Jetpack/kernel/kernel-4.9/tools/lib/string.c

90 lines
1.9 KiB
C

/*
* linux/tools/lib/string.c
*
* Copied from linux/lib/string.c, where it is:
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* More specifically, the first copied function was strtobool, which
* was introduced by:
*
* d0f1fed29e6e ("Add a strtobool function matching semantics of existing in kernel equivalents")
* Author: Jonathan Cameron <jic23@cam.ac.uk>
*/
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <linux/string.h>
#include <linux/compiler.h>
/**
* memdup - duplicate region of memory
*
* @src: memory region to duplicate
* @len: memory region length
*/
void *memdup(const void *src, size_t len)
{
void *p = malloc(len);
if (p)
memcpy(p, src, len);
return p;
}
/**
* 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;
}
/**
* strlcpy - Copy a C-string into a sized buffer
* @dest: Where to copy the string to
* @src: Where to copy the string from
* @size: size of destination buffer
*
* Compatible with *BSD: the result is always a valid
* NUL-terminated string that fits in the buffer (unless,
* of course, the buffer size is zero). It does not pad
* out the result like strncpy() does.
*
* If libc has strlcpy() then that version will override this
* implementation:
*/
size_t __weak strlcpy(char *dest, const char *src, size_t size)
{
size_t ret = strlen(src);
if (size) {
size_t len = (ret >= size) ? size - 1 : ret;
memcpy(dest, src, len);
dest[len] = '\0';
}
return ret;
}