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/*
* File: dpip.c
*
* Copyright 2005-2007 Jorge Arellano Cid <jcid@dillo.org>
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
*/
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "../dlib/dlib.h"
#include "dpip.h"
#include "d_size.h"
static const char Quote = '\'';
/*
* Basically the syntax of a dpip tag is:
*
* "<"[*alpha] *(<name>"="Quote<escaped_value>Quote) " "Quote">"
*
* 1.- No space is allowed around the "=" sign between a name and its value.
* 2.- The Quote character is not allowed in <name>.
* 3.- Attribute values stuff Quote as QuoteQuote.
*
* e.g. (with ' as Quote):
*
* <a='b' b='c' '> OK
* <dpi a='b i' b='12' '> OK
* <a='>' '> OK
* <a='ain''t no doubt' '> OK
* <a='ain''t b=''no'' b='' doubt' '> OK
* <a = '>' '> Wrong
*
* Notes:
*
* Restriction #1 is for easy finding of end of tag (EOT=Space+Quote+>).
* Restriction #2 can be removed, but what for? ;)
* The functions here provide for this functionality.
*/
typedef enum {
SEEK_NAME,
MATCH_NAME,
SKIP_VALUE,
SKIP_QUOTE,
FOUND
} DpipTagParsingState;
/* ------------------------------------------------------------------------- */
/*
* Printf like function for building dpip commands.
* It takes care of dpip escaping of its arguments.
* NOTE : It ONLY accepts string parameters, and
* only one %s per parameter.
*/
char *a_Dpip_build_cmd(const char *format, ...)
{
va_list argp;
char *p, *q, *s;
Dstr *cmd;
/* Don't allow Quote characters in attribute names */
if (strchr(format, Quote))
return NULL;
cmd = dStr_sized_new(64);
dStr_append_c(cmd, '<');
va_start(argp, format);
for (p = q = (char*)format; *q; ) {
p = strstr(q, "%s");
if (!p) {
dStr_append(cmd, q);
break;
} else {
/* Copy format's part */
while (q != p)
dStr_append_c(cmd, *q++);
q += 2;
dStr_append_c(cmd, Quote);
/* Stuff-copy of argument */
s = va_arg (argp, char *);
for ( ; *s; ++s) {
dStr_append_c(cmd, *s);
if (*s == Quote)
dStr_append_c(cmd, *s);
}
dStr_append_c(cmd, Quote);
}
}
va_end(argp);
dStr_append_c(cmd, ' ');
dStr_append_c(cmd, Quote);
dStr_append_c(cmd, '>');
p = cmd->str;
dStr_free(cmd, FALSE);
return p;
}
/*
* Task: given a tag, its size and an attribute name, return the
* attribute value (stuffing of ' is removed here).
*
* Return value: the attribute value, or NULL if not present or malformed.
*/
char *a_Dpip_get_attr_l(char *tag, size_t tagsize, const char *attrname)
{
uint_t i, n = 0, found = 0;
char *p, *q, *start, *val = NULL;
DpipTagParsingState state = SEEK_NAME;
if (!tag || !tagsize || !attrname || !*attrname)
return NULL;
for (i = 1; i < tagsize && !found; ++i) {
switch (state) {
case SEEK_NAME:
if (tag[i] == attrname[0] && (tag[i-1] == ' ' || tag[i-1] == '<')) {
n = 1;
state = MATCH_NAME;
} else if (tag[i] == Quote && tag[i-1] == '=')
state = SKIP_VALUE;
break;
case MATCH_NAME:
if (tag[i] == attrname[n])
++n;
else if (tag[i] == '=' && !attrname[n])
state = FOUND;
else
state = SEEK_NAME;
break;
case SKIP_VALUE:
if (tag[i] == Quote)
state = (tag[i+1] == Quote) ? SKIP_QUOTE : SEEK_NAME;
break;
case SKIP_QUOTE:
state = SKIP_VALUE;
break;
case FOUND:
found = 1;
break;
}
}
if (found) {
p = start = tag + i;
while ((q = strchr(p, Quote)) && q[1] == Quote)
p = q + 2;
if (q && q[1] == ' ') {
val = dStrndup(start, (uint_t)(q - start));
for (p = q = val; (*q = *p); ++p, ++q)
if (*p == Quote && p[1] == p[0])
++p;
}
}
return val;
}
/*
* Task: given a tag and an attribute name, return its value.
* Return value: the attribute value, or NULL if not present or malformed.
*/
char *a_Dpip_get_attr(char *tag, const char *attrname)
{
return (tag ? a_Dpip_get_attr_l(tag, strlen(tag), attrname) : NULL);
}
/* ------------------------------------------------------------------------- */
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