lib/parser.c: add match_wildcard() function

match_wildcard function is a simple implementation of wildcard
matching algorithm. It only supports two usual wildcardes:
    '*' - matches zero or more characters
    '?' - matches one character
This algorithm is safe since it is non-recursive.

Signed-off-by: Du, Changbin <changbin.du@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Du, Changbin 2014-01-23 15:54:12 -08:00 коммит произвёл Linus Torvalds
Родитель 0d9dfc23f4
Коммит aace05097a
2 изменённых файлов: 52 добавлений и 0 удалений

Просмотреть файл

@ -29,5 +29,6 @@ int match_token(char *, const match_table_t table, substring_t args[]);
int match_int(substring_t *, int *result);
int match_octal(substring_t *, int *result);
int match_hex(substring_t *, int *result);
bool match_wildcard(const char *pattern, const char *str);
size_t match_strlcpy(char *, const substring_t *, size_t);
char *match_strdup(const substring_t *);

Просмотреть файл

@ -192,6 +192,56 @@ int match_hex(substring_t *s, int *result)
return match_number(s, result, 16);
}
/**
* match_wildcard: - parse if a string matches given wildcard pattern
* @pattern: wildcard pattern
* @str: the string to be parsed
*
* Description: Parse the string @str to check if matches wildcard
* pattern @pattern. The pattern may contain two type wildcardes:
* '*' - matches zero or more characters
* '?' - matches one character
* If it's matched, return true, else return false.
*/
bool match_wildcard(const char *pattern, const char *str)
{
const char *s = str;
const char *p = pattern;
bool star = false;
while (*s) {
switch (*p) {
case '?':
s++;
p++;
break;
case '*':
star = true;
str = s;
if (!*++p)
return true;
pattern = p;
break;
default:
if (*s == *p) {
s++;
p++;
} else {
if (!star)
return false;
str++;
s = str;
p = pattern;
}
break;
}
}
if (*p == '*')
++p;
return !*p;
}
/**
* match_strlcpy: - Copy the characters from a substring_t to a sized buffer
* @dest: where to copy to
@ -235,5 +285,6 @@ EXPORT_SYMBOL(match_token);
EXPORT_SYMBOL(match_int);
EXPORT_SYMBOL(match_octal);
EXPORT_SYMBOL(match_hex);
EXPORT_SYMBOL(match_wildcard);
EXPORT_SYMBOL(match_strlcpy);
EXPORT_SYMBOL(match_strdup);