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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: url.c,v 1.2 1999/09/03 08:02:05 mdw Exp $ |
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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 $ |
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33 | * Revision 1.2 1999/09/03 08:02:05 mdw |
34 | * Make `#' a special character which needs escaping. |
35 | * |
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36 | * Revision 1.1 1999/06/01 09:49:48 mdw |
37 | * New files for url-encoding and decoding. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <stdio.h> |
44 | #include <stdlib.h> |
45 | #include <string.h> |
46 | |
47 | #include "dstr.h" |
48 | #include "url.h" |
49 | |
50 | /*----- Main code ---------------------------------------------------------*/ |
51 | |
52 | /* --- @url_initenc@ --- * |
53 | * |
54 | * Arguments: @url_ectx *ctx@ = pointer to context block |
55 | * |
56 | * Returns: --- |
57 | * |
58 | * Use: Initializes a URL encoding context. |
59 | */ |
60 | |
61 | void url_initenc(url_ectx *ctx) |
62 | { |
63 | ctx->f = 0; |
64 | } |
65 | |
66 | /* --- @encode@ --- * |
67 | * |
68 | * Arguments: @dstr *d@ = pointer to output string |
69 | * @const char *p@ = pointer to thing to encode |
70 | * |
71 | * Returns: --- |
72 | * |
73 | * Use: Encodes the input string into the output string. |
74 | */ |
75 | |
76 | static void encode(dstr *d, const char *p) |
77 | { |
78 | while (*p) { |
79 | switch (*p) { |
80 | case ' ': |
81 | DPUTC(d, '+'); |
82 | break; |
83 | default: |
84 | if (*p >= 33 && *p < 127) |
85 | DPUTC(d, *p); |
86 | else |
87 | case '&': |
88 | case '+': |
89 | case '=': |
90 | case '%': |
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91 | case '#': |
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92 | dstr_putf(d, "%%%02x", *p); |
93 | break; |
94 | } |
95 | p++; |
96 | } |
97 | } |
98 | |
99 | /* --- @url_enc@ --- * |
100 | * |
101 | * Arguments: @url_ectx *ctx@ = pointer to encoding context |
102 | * @dstr *d@ = pointer to output string |
103 | * @const char *name@ = pointer to name |
104 | * @const char *value@ = pointer to value |
105 | * |
106 | * Returns: --- |
107 | * |
108 | * Use: Writes an assignment between @name@ and @value@ to the |
109 | * output string, encoding the values properly. |
110 | */ |
111 | |
112 | void url_enc(url_ectx *ctx, dstr *d, const char *name, const char *value) |
113 | { |
114 | if (ctx->f & URLF_SEP) |
115 | DPUTC(d, '&'); |
116 | encode(d, name); |
117 | DPUTC(d, '='); |
118 | encode(d, value); |
119 | DPUTZ(d); |
120 | ctx->f |= URLF_SEP; |
121 | } |
122 | |
123 | /* --- @url_initdec@ --- * |
124 | * |
125 | * Arguments: @url_dctx *ctx@ = pointer to context block |
126 | * @const char *p@ = string to read data from |
127 | * |
128 | * Returns: --- |
129 | * |
130 | * Use: Initializes a URL decoding context. |
131 | */ |
132 | |
133 | void url_initdec(url_dctx *ctx, const char *p) |
134 | { |
135 | ctx->p = p; |
136 | } |
137 | |
138 | /* --- @decode@ --- * |
139 | * |
140 | * Arguments: @dstr *d@ = pointer to output string |
141 | * @const char *p@ = pointer to input data |
142 | * @int eq@ = whether to stop at `=' characters |
143 | * |
144 | * Returns: Pointer to next available character. |
145 | * |
146 | * Use: Does a URL decode. |
147 | */ |
148 | |
149 | static const char *decode(dstr *d, const char *p, int eq) |
150 | { |
151 | if (!*p) |
152 | return (0); |
153 | for (;;) { |
154 | switch (*p) { |
155 | case '=': |
156 | if (eq) |
157 | return (p); |
158 | DPUTC(d, *p); |
159 | break; |
160 | case 0: |
161 | case '&': |
162 | return (p); |
163 | case '+': |
164 | DPUTC(d, ' '); |
165 | break; |
166 | case '%': { |
167 | unsigned int ch; |
168 | int n; |
169 | int x = sscanf(p + 1, "%2x%n", &ch, &n); |
170 | if (x == 1) { |
171 | DPUTC(d, ch); |
172 | p += n; |
173 | break; |
174 | } |
175 | } |
176 | default: |
177 | DPUTC(d, *p); |
178 | break; |
179 | } |
180 | p++; |
181 | } |
182 | } |
183 | |
184 | /* --- @url_dec@ --- * |
185 | * |
186 | * Arguments: @url_dctx *ctx@ = pointer to decode context |
187 | * @dstr *n@ = pointer to output string for name |
188 | * @dstr *v@ = pointer to output string for value |
189 | * |
190 | * Returns: Nonzero if it read something, zero if there's nothing left |
191 | * |
192 | * Use: Decodes the next name/value pair from a urlencoded string. |
193 | */ |
194 | |
195 | int url_dec(url_dctx *ctx, dstr *n, dstr *v) |
196 | { |
197 | const char *p = ctx->p; |
198 | size_t l = n->len; |
199 | |
200 | again: |
201 | if ((p = decode(n, p, 1)) == 0 || *p == 0) |
202 | return (0); |
203 | if (*p != '=') { |
204 | p++; |
205 | n->len = l; |
206 | goto again; |
207 | } |
208 | p++; |
209 | if ((p = decode(v, p, 0)) == 0) |
210 | return (0); |
211 | DPUTZ(n); |
212 | DPUTZ(v); |
213 | ctx->p = p; |
214 | return (1); |
215 | } |
216 | |
217 | /*----- That's all, folks -------------------------------------------------*/ |