/* HTML parser for Wget.
- Copyright (C) 1998, 2000, 2003 Free Software Foundation, Inc.
+ Copyright (C) 1998-2006 Free Software Foundation, Inc.
This file is part of GNU Wget.
GNU Wget is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or (at
+the Free Software Foundation; either version 3 of the License, or (at
your option) any later version.
GNU Wget is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with Wget; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+along with Wget. If not, see <http://www.gnu.org/licenses/>.
In addition, as a special exception, the Free Software Foundation
gives permission to link the code of its release of Wget with the
#include <stdio.h>
#include <stdlib.h>
-#ifdef HAVE_STRING_H
-# include <string.h>
-#else
-# include <strings.h>
-#endif
+#include <string.h>
#include <assert.h>
#include "wget.h"
char *contents; /* pointer to the contents. */
int size; /* size of the pool. */
int tail; /* next available position index. */
- int resized; /* whether the pool has been resized
+ bool resized; /* whether the pool has been resized
using malloc. */
char *orig_contents; /* original pool contents, usually
P->contents = (initial_storage); \
P->size = (initial_size); \
P->tail = 0; \
- P->resized = 0; \
+ P->resized = false; \
P->orig_contents = P->contents; \
P->orig_size = P->size; \
} while (0)
P->contents = P->orig_contents; \
P->size = P->orig_size; \
P->tail = 0; \
- P->resized = 0; \
+ P->resized = false; \
} while (0)
/* Used for small stack-allocated memory chunks that might grow. Like
if (ga_newsize != (sizevar)) \
{ \
if (resized) \
- basevar = (type *)xrealloc (basevar, ga_newsize * sizeof (type)); \
+ basevar = xrealloc (basevar, ga_newsize * sizeof (type)); \
else \
{ \
void *ga_new = xmalloc (ga_newsize * sizeof (type)); \
memcpy (ga_new, basevar, (sizevar) * sizeof (type)); \
(basevar) = ga_new; \
- resized = 1; \
+ resized = true; \
} \
(sizevar) = ga_newsize; \
} \
} while (0)
\f
-#define AP_DOWNCASE 1
-#define AP_PROCESS_ENTITIES 2
-#define AP_TRIM_BLANKS 4
+/* Test whether n+1-sized entity name fits in P. We don't support
+ IE-style non-terminated entities, e.g. "<foo" -> "<foo".
+ However, "<foo" will work, as will "<!foo", "<", etc. In
+ other words an entity needs to be terminated by either a
+ non-alphanumeric or the end of string. */
+#define FITS(p, n) (p + n == end || (p + n < end && !ISALNUM (p[n])))
+
+/* Macros that test entity names by returning true if P is followed by
+ the specified characters. */
+#define ENT1(p, c0) (FITS (p, 1) && p[0] == c0)
+#define ENT2(p, c0, c1) (FITS (p, 2) && p[0] == c0 && p[1] == c1)
+#define ENT3(p, c0, c1, c2) (FITS (p, 3) && p[0]==c0 && p[1]==c1 && p[2]==c2)
+
+/* Increment P by INC chars. If P lands at a semicolon, increment it
+ past the semicolon. This ensures that e.g. "<foo" is converted
+ to "<foo", but "<,foo" to "<,foo". */
+#define SKIP_SEMI(p, inc) (p += inc, p < end && *p == ';' ? ++p : p)
+
+/* Decode the HTML character entity at *PTR, considering END to be end
+ of buffer. It is assumed that the "&" character that marks the
+ beginning of the entity has been seen at *PTR-1. If a recognized
+ ASCII entity is seen, it is returned, and *PTR is moved to the end
+ of the entity. Otherwise, -1 is returned and *PTR left unmodified.
+
+ The recognized entities are: <, >, &, &apos, and ". */
+
+static int
+decode_entity (const char **ptr, const char *end)
+{
+ const char *p = *ptr;
+ int value = -1;
+
+ if (++p == end)
+ return -1;
+
+ switch (*p++)
+ {
+ case '#':
+ /* Process numeric entities "&#DDD;" and "&#xHH;". */
+ {
+ int digits = 0;
+ value = 0;
+ if (*p == 'x')
+ for (++p; value < 256 && p < end && ISXDIGIT (*p); p++, digits++)
+ value = (value << 4) + XDIGIT_TO_NUM (*p);
+ else
+ for (; value < 256 && p < end && ISDIGIT (*p); p++, digits++)
+ value = (value * 10) + (*p - '0');
+ if (!digits)
+ return -1;
+ /* Don't interpret 128+ codes and NUL because we cannot
+ portably reinserted them into HTML. */
+ if (!value || (value & ~0x7f))
+ return -1;
+ *ptr = SKIP_SEMI (p, 0);
+ return value;
+ }
+ /* Process named ASCII entities. */
+ case 'g':
+ if (ENT1 (p, 't'))
+ value = '>', *ptr = SKIP_SEMI (p, 1);
+ break;
+ case 'l':
+ if (ENT1 (p, 't'))
+ value = '<', *ptr = SKIP_SEMI (p, 1);
+ break;
+ case 'a':
+ if (ENT2 (p, 'm', 'p'))
+ value = '&', *ptr = SKIP_SEMI (p, 2);
+ else if (ENT3 (p, 'p', 'o', 's'))
+ /* handle &apos for the sake of the XML/XHTML crowd. */
+ value = '\'', *ptr = SKIP_SEMI (p, 3);
+ break;
+ case 'q':
+ if (ENT3 (p, 'u', 'o', 't'))
+ value = '\"', *ptr = SKIP_SEMI (p, 3);
+ break;
+ }
+ return value;
+}
+#undef ENT1
+#undef ENT2
+#undef ENT3
+#undef FITS
+#undef SKIP_SEMI
+
+enum {
+ AP_DOWNCASE = 1,
+ AP_DECODE_ENTITIES = 2,
+ AP_TRIM_BLANKS = 4
+};
/* Copy the text in the range [BEG, END) to POOL, optionally
performing operations specified by FLAGS. FLAGS may be any
- combination of AP_DOWNCASE, AP_PROCESS_ENTITIES and AP_TRIM_BLANKS
+ combination of AP_DOWNCASE, AP_DECODE_ENTITIES and AP_TRIM_BLANKS
with the following meaning:
* AP_DOWNCASE -- downcase all the letters;
- * AP_PROCESS_ENTITIES -- process the SGML entities and write out
- the decoded string. Recognized entities are <, >, &, ",
-   and the numerical entities.
+ * AP_DECODE_ENTITIES -- decode the named and numeric entities in
+ the ASCII range when copying the string.
* AP_TRIM_BLANKS -- ignore blanks at the beginning and at the end
- of text. */
+ of text, as well as embedded newlines. */
static void
convert_and_copy (struct pool *pool, const char *beg, const char *end, int flags)
{
int old_tail = pool->tail;
- int size;
- /* First, skip blanks if required. We must do this before entities
- are processed, so that blanks can still be inserted as, for
- instance, ` '. */
+ /* Skip blanks if required. We must do this before entities are
+ processed, so that blanks can still be inserted as, for instance,
+ ` '. */
if (flags & AP_TRIM_BLANKS)
{
while (beg < end && ISSPACE (*beg))
while (end > beg && ISSPACE (end[-1]))
--end;
}
- size = end - beg;
- if (flags & AP_PROCESS_ENTITIES)
+ if (flags & AP_DECODE_ENTITIES)
{
/* Grow the pool, then copy the text to the pool character by
character, processing the encountered entities as we go
never lengthen it. */
const char *from = beg;
char *to;
+ bool squash_newlines = !!(flags & AP_TRIM_BLANKS);
POOL_GROW (pool, end - beg);
to = pool->contents + pool->tail;
while (from < end)
{
- if (*from != '&')
- *to++ = *from++;
- else
+ if (*from == '&')
{
- const char *save = from;
- int remain;
-
- if (++from == end)
- goto lose;
- remain = end - from;
-
- /* Process numeric entities "&#DDD;" and "&#xHH;". */
- if (*from == '#')
- {
- int numeric = 0, digits = 0;
- ++from;
- if (*from == 'x')
- {
- ++from;
- for (; from < end && ISXDIGIT (*from); from++, digits++)
- numeric = (numeric << 4) + XDIGIT_TO_NUM (*from);
- }
- else
- {
- for (; from < end && ISDIGIT (*from); from++, digits++)
- numeric = (numeric * 10) + (*from - '0');
- }
- if (!digits)
- goto lose;
- numeric &= 0xff;
- *to++ = numeric;
- }
-#define FROB(x) (remain >= (sizeof (x) - 1) \
- && 0 == memcmp (from, x, sizeof (x) - 1) \
- && (*(from + sizeof (x) - 1) == ';' \
- || remain == sizeof (x) - 1 \
- || !ISALNUM (*(from + sizeof (x) - 1))))
- else if (FROB ("lt"))
- *to++ = '<', from += 2;
- else if (FROB ("gt"))
- *to++ = '>', from += 2;
- else if (FROB ("amp"))
- *to++ = '&', from += 3;
- else if (FROB ("quot"))
- *to++ = '\"', from += 4;
- /* We don't implement the proposed "Added Latin 1"
- entities (except for nbsp), because it is unnecessary
- in the context of Wget, and would require hashing to
- work efficiently. */
- else if (FROB ("nbsp"))
- *to++ = 160, from += 4;
+ int entity = decode_entity (&from, end);
+ if (entity != -1)
+ *to++ = entity;
else
- goto lose;
-#undef FROB
- /* If the entity was followed by `;', we step over the
- `;'. Otherwise, it was followed by either a
- non-alphanumeric or EOB, in which case we do nothing. */
- if (from < end && *from == ';')
- ++from;
- continue;
-
- lose:
- /* This was not an entity after all. Back out. */
- from = save;
- *to++ = *from++;
+ *to++ = *from++;
}
+ else if ((*from == '\n' || *from == '\r') && squash_newlines)
+ ++from;
+ else
+ *to++ = *from++;
}
/* Verify that we haven't exceeded the original size. (It
shouldn't happen, hence the assert.) */
AC_S_DASH4,
AC_S_QUOTE1,
AC_S_IN_QUOTE,
- AC_S_QUOTE2,
+ AC_S_QUOTE2
} state = AC_S_BANG;
if (beg == end)
return NULL;
}
\f
-/* Return non-zero of the string inside [b, e) are present in hash
- table HT. */
+/* Return true if the string containing of characters inside [b, e) is
+ present in hash table HT. */
-static int
+static bool
name_allowed (const struct hash_table *ht, const char *b, const char *e)
{
char *copy;
if (!ht)
- return 1;
+ return true;
BOUNDED_TO_ALLOCA (b, e, copy);
return hash_table_get (ht, copy) != NULL;
}
MAPFUN will be called with two arguments: pointer to an initialized
struct taginfo, and MAPARG.
- ALLOWED_TAG_NAMES should be a NULL-terminated array of tag names to
- be processed by this function. If it is NULL, all the tags are
- allowed. The same goes for attributes and ALLOWED_ATTRIBUTE_NAMES.
+ ALLOWED_TAGS and ALLOWED_ATTRIBUTES are hash tables the keys of
+ which are the tags and attribute names that this function should
+ use. If ALLOWED_TAGS is NULL, all tags are processed; if
+ ALLOWED_ATTRIBUTES is NULL, all attributes are returned.
(Obviously, the caller can filter out unwanted tags and attributes
just as well, but this is just an optimization designed to avoid
- unnecessary copying for tags/attributes which the caller doesn't
- want to know about. These lists are searched linearly; therefore,
- if you're interested in a large number of tags or attributes, you'd
- better set these to NULL and filter them out yourself with a
- hashing process most appropriate for your application.) */
+ unnecessary copying of tags/attributes which the caller doesn't
+ care about.) */
void
map_html_tags (const char *text, int size,
struct attr_pair attr_pair_initial_storage[8];
int attr_pair_size = countof (attr_pair_initial_storage);
- int attr_pair_resized = 0;
+ bool attr_pair_resized = false;
struct attr_pair *pairs = attr_pair_initial_storage;
if (!size)
int nattrs, end_tag;
const char *tag_name_begin, *tag_name_end;
const char *tag_start_position;
- int uninteresting_tag;
+ bool uninteresting_tag;
look_for_tag:
POOL_REWIND (&pool);
if (!name_allowed (allowed_tags, tag_name_begin, tag_name_end))
/* We can't just say "goto look_for_tag" here because we need
the loop below to properly advance over the tag's attributes. */
- uninteresting_tag = 1;
+ uninteresting_tag = true;
else
{
- uninteresting_tag = 0;
+ uninteresting_tag = false;
convert_and_copy (&pool, tag_name_begin, tag_name_end, AP_DOWNCASE);
}
SKIP_WS (p);
if (*p == '\"' || *p == '\'')
{
- int newline_seen = 0;
+ bool newline_seen = false;
char quote_char = *p;
attr_raw_value_begin = p;
ADVANCE (p);
comes first. Such a tag terminated at `>'
is discarded. */
p = attr_value_begin;
- newline_seen = 1;
+ newline_seen = true;
continue;
}
else if (newline_seen && *p == '>')
goto look_for_tag;
attr_raw_value_end = p; /* <foo bar="baz"> */
/* ^ */
- operation = AP_PROCESS_ENTITIES;
+ operation = AP_DECODE_ENTITIES;
if (flags & MHT_TRIM_VALUES)
operation |= AP_TRIM_BLANKS;
}
goto backout_tag;
attr_raw_value_begin = attr_value_begin;
attr_raw_value_end = attr_value_end;
- operation = AP_PROCESS_ENTITIES;
+ operation = AP_DECODE_ENTITIES;
}
}
else
taginfo.attrs = pairs;
taginfo.start_position = tag_start_position;
taginfo.end_position = p + 1;
- /* Ta-dam! */
- (*mapfun) (&taginfo, maparg);
+ mapfun (&taginfo, maparg);
ADVANCE (p);
}
goto look_for_tag;
int main ()
{
int size = 256;
- char *x = (char *)xmalloc (size);
+ char *x = xmalloc (size);
int length = 0;
int read_count;
int tag_counter = 0;
{
length += read_count;
size <<= 1;
- x = (char *)xrealloc (x, size);
+ x = xrealloc (x, size);
}
map_html_tags (x, length, test_mapper, &tag_counter, 0, NULL, NULL);
projects / wget / blobdiff