Changeset 65ed8f4 in mainline for uspace/lib/posix/fnmatch.c

Timestamp:

2011-06-30T23:25:23Z (13 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

517cedc0

Parents:

9067152

Message:

Add unfinished and untested implementation of fnmatch() (work in progress)

File:

• uspace/lib/posix/fnmatch.c (modified) (2 diffs)

uspace/lib/posix/fnmatch.c

@@ -38 +38 @@
 #include "fnmatch.h"
 
+#include "stdlib.h"
+#include "string.h"
+#include "ctype.h"
+
+#define INVALID_PATTERN -1
+
+/* Type for collating element, simple identity with characters now,
+ * but may be extended for better locale support.
+ */
+typedef int _coll_elm_t;
+
+#define COLL_ELM_INVALID -1
+
+static _coll_elm_t _coll_elm_get(const char* str)
+{
+        if (str[0] == '\0' || str[1] != '\0') {
+                return COLL_ELM_INVALID;
+        }
+        return str[0];
+}
+
+static _coll_elm_t _coll_elm_char(int c)
+{
+        return c;
+}
+
+/**
+ *
+ * @param elm
+ * @param pattern
+ * @return 0 if the element doesn't match, or the number of characters matched.
+ */
+static int _coll_elm_match(_coll_elm_t elm, const char *str)
+{
+        return elm == *str;
+}
+
+static int _coll_elm_between(_coll_elm_t first, _coll_elm_t second,
+    const char *str)
+{
+        return *str >= first && *str <= second;
+}
+
+/** Read a string delimited by [? and ?].
+ *
+ * @param pattern Pointer to the string to read from. Its position is moved
+ *    to the first character after the closing ].
+ * @param seq The character on the inside of brackets.
+ * @param buf Read buffer.
+ * @param buf_sz Read buffer's size. If the buffer is not large enough for
+ *    the entire string, the string is cut with no error indication.
+ * @return
+ */
+static bool _get_delimited(
+    const char **pattern, int seq,
+    char *buf, size_t buf_sz, int flags)
+{
+        const bool noescape = (flags & FNM_NOESCAPE) != 0;
+        const bool pathname = (flags & FNM_PATHNAME) != 0;
+
+        const char *p = *pattern;
+        assert(p[0] == '[' && p[1] == seq /* Caller should ensure this. */);
+        p += 2;
+
+        while (true) {
+                if (*p == seq && *(p + 1) == ']') {
+                        /* String properly ended, return. */
+                        *pattern = p + 2;
+                        *buf = '\0';
+                        return true;
+                }
+                if (!noescape && *p == '\\') {
+                        p++;
+                }
+                if (*p == '\0') {
+                        /* String not ended properly, invalid pattern. */
+                        return false;
+                }
+                if (pathname && *p == '/') {
+                        /* Slash in a pathname pattern is invalid. */
+                        return false;
+                }
+                if (buf_sz > 1) {
+                        /* Only add to the buffer if there is space. */
+                        *buf = *p;
+                        buf++;
+                        buf_sz--;
+                }
+                p++;
+        }
+}
+
+/************** CHARACTER CLASSES ****************/
+
+#define MAX_CLASS_OR_COLL_LEN 6
+
+struct _char_class {
+        const char *name;
+        int (*func) (int);
+};
+
+/* List of supported character classes. */
+static const struct _char_class _char_classes[] = {
+        { "alnum", isalnum },
+        { "alpha", isalpha },
+        { "blank", posix_isblank },
+        { "cntrl", posix_iscntrl },
+        { "digit", isdigit },
+        { "graph", posix_isgraph },
+        { "lower", islower },
+        { "print", posix_isprint },
+        { "punct", posix_ispunct },
+        { "space", isspace },
+        { "upper", isupper },
+        { "xdigit", posix_isxdigit }
+};
+
+static int _class_compare(const void *key, const void *elem)
+{
+        const struct _char_class *class = elem;
+        return posix_strcmp((const char *) key, class->name);
+}
+
+static bool _is_in_class (const char *cname, int c)
+{
+        /* Search for class in the array of supported character classes. */
+        const struct _char_class *class = posix_bsearch(cname, _char_classes,
+            sizeof(_char_classes) / sizeof(struct _char_class),
+            sizeof(struct _char_class), _class_compare);
+
+        if (class == NULL) {
+                /* No such class supported - treat as an empty class. */
+                return false;
+        } else {
+                /* Class matched. */
+                return class->func(c);
+        }
+}
+
+static int _match_char_class(const char **pattern, const char *str, int flags)
+{
+        char class[MAX_CLASS_OR_COLL_LEN + 1];
+
+        if (!_get_delimited(pattern, ':', class, sizeof(class), flags)) {
+                return INVALID_PATTERN;
+        }
+
+        return _is_in_class(class, *str);
+}
+
+/************** END CHARACTER CLASSES ****************/
+
+static _coll_elm_t _next_coll_elm(const char **pattern, int flags)
+{
+        const char *p = *pattern;
+        const bool noescape = (flags & FNM_NOESCAPE) != 0;
+        const bool pathname = (flags & FNM_PATHNAME) != 0;
+
+        if (*p == '[') {
+                if (*(p + 1) == '.') {
+                        char buf[MAX_CLASS_OR_COLL_LEN + 1];
+                        if (!_get_delimited(pattern, '.', buf, sizeof(buf), flags)) {
+                                return COLL_ELM_INVALID;
+                        }
+                        return _coll_elm_get(buf);
+                }
+
+                if (*(p + 1) == '=') {
+                        char buf[MAX_CLASS_OR_COLL_LEN + 1];
+                        if (!_get_delimited(pattern, '=', buf, sizeof(buf), flags)) {
+                                return COLL_ELM_INVALID;
+                        }
+                        return _coll_elm_get(buf);
+                }
+        }
+
+        if (!noescape && *p == '\\') {
+                p++;
+        }
+        if (pathname && *p == '/') {
+                return COLL_ELM_INVALID;
+        }
+
+        *pattern = p + 1;
+        return _coll_elm_char(*p);
+}
+
+/**
+ *
+ */
+static int _match_bracket_expr(const char **pattern, const char *str, int flags)
+{
+        const bool pathname = (flags & FNM_PATHNAME) != 0;
+        const bool special_period = (flags & FNM_PERIOD) != 0;
+        const char *p = *pattern;
+        bool negative = false;
+        int matched = 0;
+
+        #define _matched(match) { \
+                int _match = match; \
+                if (_match < 0) { \
+                        /* Invalid pattern */ \
+                        return _match; \
+                } else if (matched == 0 && _match > 0) { \
+                        /* First match */ \
+                        matched = _match; \
+                } \
+        }
+
+        assert(*p == '[');  /* calling code should ensure this */
+        p++;
+
+        if (*str == '\0' || (pathname && *str == '/') ||
+            (pathname && special_period && *str == '.' && *(str - 1) == '/')) {
+                /* No bracket expression matches end of string,
+                 * slash in pathname match or initial period with FNM_PERIOD
+                 * option.
+                 */
+                return 0;
+        }
+
+        if (*p == '^' || *p == '!') {
+                negative = true;
+                p++;
+        }
+
+        if (*p == ']') {
+                /* When ']' is first, treat it as a normal character. */
+                _matched(*str == ']');
+                p++;
+        }
+        
+        _coll_elm_t current_elm = COLL_ELM_INVALID;
+        
+        while (*p != ']') {
+                if (*p == '-' && *(p + 1) != ']' &&
+                    current_elm != COLL_ELM_INVALID) {
+                        /* Range expression. */
+                        p++;
+                        _coll_elm_t end_elm = _next_coll_elm(&p, flags);
+                        if (end_elm == COLL_ELM_INVALID) {
+                                return INVALID_PATTERN;
+                        }
+                        _matched(_coll_elm_between(current_elm, end_elm, str));
+                        continue;
+                }
+        
+                if (*p == '[' && *(p + 1) == ':') {
+                        current_elm = COLL_ELM_INVALID;
+                        _matched(_match_char_class(&p, str, flags));
+                        continue;
+                }
+                
+                current_elm = _next_coll_elm(&p, flags);
+                if (current_elm == COLL_ELM_INVALID) {
+                        return INVALID_PATTERN;
+                }
+                _matched(_coll_elm_match(current_elm, str));
+        }
+
+        /* No error occured - update pattern pointer. */
+        *pattern = p + 1;
+
+        if (matched == 0) {
+                /* No match found */
+                return negative;
+        } else {
+                /* Matched 'match' characters. */
+                return negative ? 0 : matched;
+        }
+
+        #undef _matched
+}
+
+/**
+ *
+ */
+static bool _partial_match(const char **pattern, const char **string, int flags)
+{
+        /* Only a single *-delimited subpattern is matched here.
+         * So in this function, '*' is understood as the end of pattern.
+         */
+
+        const bool pathname = (flags & FNM_PATHNAME) != 0;
+        const bool special_period = (flags & FNM_PERIOD) != 0;
+        const bool noescape = (flags & FNM_NOESCAPE) != 0;
+        const char *s = *string;
+        const char *p = *pattern;
+
+        for (; *p != '*'; p++) {
+                if (*p == '[') {
+                        /* Bracket expression. */
+                        int matched = _match_bracket_expr(&p, s, flags);
+                        if (matched == 0) {
+                                /* Doesn't match. */
+                                return false;
+                        }
+                        if (matched == INVALID_PATTERN) {
+                                /* Fall through to match [ as an ordinary
+                                 * character.
+                                 */
+                        } else {
+                                s += matched;
+                                continue;
+                        }
+                }
+
+                if (*p == '?') {
+                        /* Wildcard match. */
+                        if (*s == '\0' || (pathname && *s == '/') ||
+                            (special_period && pathname && *s == '.' &&
+                            *(s - 1) == '/')) {
+                                return false;
+                        }
+                        p++;
+                        s++;
+                        continue;
+                }
+
+                if (!noescape && *p == '\\') {
+                        /* Escaped character. */
+                        p++;
+                }
+
+                if (*p == *s) {
+                        /* Exact match. */
+                        if (*s == '\0') {
+                                break;
+                        }
+                        continue;
+                }
+
+                /* Nothing matched. */
+                return false;
+        }
+
+        /* Entire pattern matched. */
+        *pattern = p;
+        *string = s;
+        return true;
+}
+
+static bool _full_match(const char *pattern, const char *string, int flags)
+{
+        const bool special_period = (flags & FNM_PERIOD) != 0;
+
+        if (special_period && *string == '.') {
+                /* Initial dot must be matched by an explicit dot in pattern. */
+                if (*pattern != '.') {
+                        return false;
+                }
+                pattern++;
+                string++;
+        }
+
+        if (*pattern != '*') {
+                if (!_partial_match(&pattern, &string, flags)) {
+                        /* The initial match must succeed. */
+                        return false;
+                }
+        }
+
+        while (*pattern != '\0') {
+                assert(*pattern == '*');
+
+                while (*pattern == '*') {
+                        pattern++;
+                }
+
+                /* Try to match every possible offset. */
+                while (*string != '\0') {
+                        if (_partial_match(&pattern, &string, flags)) {
+                                break;
+                        }
+                        string++;
+                }
+        }
+
+        return *string == '\0';
+}
+
 /**
  * Filename pattern matching.
@@ -48 +429 @@
 int posix_fnmatch(const char *pattern, const char *string, int flags)
 {
-        // TODO
-        not_implemented();
+        bool result = _full_match(pattern, string, flags);
+        return result ? 0 : FNM_NOMATCH;
 }