btrfs-progs/common/string-utils.c

150 lines
3.8 KiB
C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include "kerncompat.h"
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <ctype.h>
#include "common/string-utils.h"
#include "common/messages.h"
#include "common/parse-utils.h"
int string_is_numerical(const char *str)
{
if (!str)
return 0;
if (!(*str >= '0' && *str <= '9'))
return 0;
while (*str >= '0' && *str <= '9')
str++;
if (*str != '\0')
return 0;
return 1;
}
int string_has_prefix(const char *str, const char *prefix)
{
for (; ; str++, prefix++)
if (!*prefix)
return 0;
else if (*str != *prefix)
return (unsigned char)*prefix - (unsigned char)*str;
}
/*
* strncpy_null - strncpy with null termination
* @dest: the target array
* @src: the source string
* @n: maximum bytes to copy (size of *dest)
*
* Like strncpy, but ensures destination is null-terminated.
*
* Copies the string pointed to by src, including the terminating null
* byte ('\0'), to the buffer pointed to by dest, up to a maximum
* of n bytes. Then ensure that dest is null-terminated.
*/
char *strncpy_null(char *dest, const char *src, size_t n)
{
strncpy(dest, src, n);
if (n > 0)
dest[n - 1] = '\0';
return dest;
}
/*
* Print a string and escape characters (in a C way) that could break the line.
* Returns the length of the escaped characters. Unprintable characters are
* escaped as octals. Usable for paths or text-like data like xattrs.
*/
int string_print_escape_special_len(const char *str, size_t str_len)
{
size_t i;
int len = 0;
for (i = 0; i < str_len; i++) {
char c = str[i];
len++;
switch (c) {
case '\a': putchar('\\'); putchar('a'); len++; break;
case '\b': putchar('\\'); putchar('b'); len++; break;
case '\e': putchar('\\'); putchar('e'); len++; break;
case '\f': putchar('\\'); putchar('f'); len++; break;
case '\n': putchar('\\'); putchar('n'); len++; break;
case '\r': putchar('\\'); putchar('r'); len++; break;
case '\t': putchar('\\'); putchar('t'); len++; break;
case '\v': putchar('\\'); putchar('v'); len++; break;
case ' ': putchar('\\'); putchar(' '); len++; break;
case '\\': putchar('\\'); putchar('\\'); len++; break;
default:
if (!isprint(c)) {
printf("\\%c%c%c",
'0' + ((c & 0300) >> 6),
'0' + ((c & 070) >> 3),
'0' + (c & 07));
len += 3;
} else {
putchar(c);
}
}
}
return len;
}
/*
* This function should be only used when parsing command arg, it won't return
* error to its caller and rather exit directly just like usage().
*/
u64 arg_strtou64(const char *str)
{
u64 value;
int ret;
ret = parse_u64(str, &value);
if (ret == -ERANGE) {
error("%s is too large", str);
exit(1);
} else if (ret == -EINVAL) {
if (str[0] == '-')
error("%s: negative value is invalid", str);
else
error("%s is not a valid numeric value", str);
exit(1);
}
return value;
}
u64 arg_strtou64_with_suffix(const char *str)
{
u64 value;
int ret;
ret = parse_u64_with_suffix(str, &value);
if (ret == -ERANGE) {
error("%s is too large", str);
exit(1);
} else if (ret == -EINVAL) {
error("%s is not a valid numeric value with supported size suffixes", str);
exit(1);
} else if (ret < 0) {
errno = -ret;
error("failed to parse string '%s': %m", str);
exit(1);
}
return value;
}