chiark / gitweb /
Add global unihash table; use universal hashing instead of CRC.
[mLib] / url.c
CommitLineData
0f2a8846 1/* -*-c-*-
2 *
78b1464e 3 * $Id: url.c,v 1.4 2001/06/22 19:36:18 mdw Exp $
0f2a8846 4 *
5 * Parsing and construction of url-encoded name/value pairs
6 *
7 * (c) 1999 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
19 * mLib is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
28 */
29
30/*----- Revision history --------------------------------------------------*
31 *
32 * $Log: url.c,v $
78b1464e 33 * Revision 1.4 2001/06/22 19:36:18 mdw
34 * Include @<ctype.h>@.
35 *
000b4322 36 * Revision 1.3 2001/01/20 12:06:21 mdw
37 * Be more conservative in base-64 encoding.
38 *
d16e1bac 39 * Revision 1.2 1999/09/03 08:02:05 mdw
40 * Make `#' a special character which needs escaping.
41 *
0f2a8846 42 * Revision 1.1 1999/06/01 09:49:48 mdw
43 * New files for url-encoding and decoding.
44 *
45 */
46
47/*----- Header files ------------------------------------------------------*/
48
78b1464e 49#include <ctype.h>
0f2a8846 50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53
54#include "dstr.h"
55#include "url.h"
56
57/*----- Main code ---------------------------------------------------------*/
58
59/* --- @url_initenc@ --- *
60 *
61 * Arguments: @url_ectx *ctx@ = pointer to context block
62 *
63 * Returns: ---
64 *
65 * Use: Initializes a URL encoding context.
66 */
67
68void url_initenc(url_ectx *ctx)
69{
70 ctx->f = 0;
71}
72
73/* --- @encode@ --- *
74 *
75 * Arguments: @dstr *d@ = pointer to output string
76 * @const char *p@ = pointer to thing to encode
77 *
78 * Returns: ---
79 *
80 * Use: Encodes the input string into the output string.
81 */
82
83static void encode(dstr *d, const char *p)
84{
85 while (*p) {
86 switch (*p) {
87 case ' ':
88 DPUTC(d, '+');
89 break;
90 default:
000b4322 91 if (isalnum((unsigned char)*p))
0f2a8846 92 DPUTC(d, *p);
93 else
000b4322 94 dstr_putf(d, "%%%02x", *p);
0f2a8846 95 break;
96 }
97 p++;
98 }
99}
100
101/* --- @url_enc@ --- *
102 *
103 * Arguments: @url_ectx *ctx@ = pointer to encoding context
104 * @dstr *d@ = pointer to output string
105 * @const char *name@ = pointer to name
106 * @const char *value@ = pointer to value
107 *
108 * Returns: ---
109 *
110 * Use: Writes an assignment between @name@ and @value@ to the
111 * output string, encoding the values properly.
112 */
113
114void url_enc(url_ectx *ctx, dstr *d, const char *name, const char *value)
115{
116 if (ctx->f & URLF_SEP)
117 DPUTC(d, '&');
118 encode(d, name);
119 DPUTC(d, '=');
120 encode(d, value);
121 DPUTZ(d);
122 ctx->f |= URLF_SEP;
123}
124
125/* --- @url_initdec@ --- *
126 *
127 * Arguments: @url_dctx *ctx@ = pointer to context block
128 * @const char *p@ = string to read data from
129 *
130 * Returns: ---
131 *
132 * Use: Initializes a URL decoding context.
133 */
134
135void url_initdec(url_dctx *ctx, const char *p)
136{
137 ctx->p = p;
138}
139
140/* --- @decode@ --- *
141 *
142 * Arguments: @dstr *d@ = pointer to output string
143 * @const char *p@ = pointer to input data
144 * @int eq@ = whether to stop at `=' characters
145 *
146 * Returns: Pointer to next available character.
147 *
148 * Use: Does a URL decode.
149 */
150
151static const char *decode(dstr *d, const char *p, int eq)
152{
153 if (!*p)
154 return (0);
155 for (;;) {
156 switch (*p) {
157 case '=':
158 if (eq)
159 return (p);
160 DPUTC(d, *p);
161 break;
162 case 0:
163 case '&':
164 return (p);
165 case '+':
166 DPUTC(d, ' ');
167 break;
168 case '%': {
169 unsigned int ch;
170 int n;
171 int x = sscanf(p + 1, "%2x%n", &ch, &n);
172 if (x == 1) {
173 DPUTC(d, ch);
174 p += n;
175 break;
176 }
177 }
178 default:
179 DPUTC(d, *p);
180 break;
181 }
182 p++;
183 }
184}
185
186/* --- @url_dec@ --- *
187 *
188 * Arguments: @url_dctx *ctx@ = pointer to decode context
189 * @dstr *n@ = pointer to output string for name
190 * @dstr *v@ = pointer to output string for value
191 *
192 * Returns: Nonzero if it read something, zero if there's nothing left
193 *
194 * Use: Decodes the next name/value pair from a urlencoded string.
195 */
196
197int url_dec(url_dctx *ctx, dstr *n, dstr *v)
198{
199 const char *p = ctx->p;
200 size_t l = n->len;
201
202again:
203 if ((p = decode(n, p, 1)) == 0 || *p == 0)
204 return (0);
205 if (*p != '=') {
206 p++;
207 n->len = l;
208 goto again;
209 }
210 p++;
211 if ((p = decode(v, p, 0)) == 0)
212 return (0);
213 DPUTZ(n);
214 DPUTZ(v);
215 ctx->p = p;
216 return (1);
217}
218
219/*----- That's all, folks -------------------------------------------------*/