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1 | /* -*-c-*- |
2 | * |
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3 | * Character scanners |
4 | * |
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5 | * (c) 1999 Straylight/Edgeware |
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6 | */ |
7 | |
8 | /*----- Licensing notice --------------------------------------------------* |
9 | * |
10 | * This file is part of the `fw' port forwarder. |
11 | * |
12 | * `fw' is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License as published by |
14 | * the Free Software Foundation; either version 2 of the License, or |
15 | * (at your option) any later version. |
16 | * |
17 | * `fw' is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU General Public License for more details. |
21 | * |
22 | * You should have received a copy of the GNU General Public License |
23 | * along with `fw'; if not, write to the Free Software Foundation, |
24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
25 | */ |
26 | |
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27 | /*----- Header files ------------------------------------------------------*/ |
28 | |
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29 | #include <stdio.h> |
30 | #include <stdlib.h> |
31 | #include <string.h> |
32 | |
33 | #include <mLib/dstr.h> |
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34 | #include <mLib/sub.h> |
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35 | |
36 | #include "scan.h" |
37 | |
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38 | /*----- File scanner source -----------------------------------------------*/ |
39 | |
40 | /* --- File scanner block --- */ |
41 | |
42 | typedef struct fscan { |
43 | scansrc ss; |
44 | FILE *fp; |
45 | unsigned f; |
46 | } fscan; |
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47 | |
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48 | /* --- @scan@ --- */ |
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49 | |
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50 | static int fscan_scan(scansrc *ss) |
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51 | { |
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52 | fscan *fs = (fscan *)ss; |
53 | int ch = getc(fs->fp); |
54 | if (ch == '\n') |
55 | fs->ss.line++; |
56 | return (ch); |
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57 | } |
58 | |
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59 | /* --- @destroy@ --- */ |
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60 | |
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61 | static void fscan_destroy(scansrc *ss) |
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62 | { |
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63 | fscan *fs = (fscan *)ss; |
64 | if (!(fs->f & SCF_NOCLOSE)) |
65 | fclose(fs->fp); |
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66 | xfree(fs->ss.src); |
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67 | DESTROY(fs); |
68 | } |
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69 | |
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70 | /* --- File scanner operations --- */ |
71 | |
72 | static scansrc_ops fscan_ops = { fscan_scan, fscan_destroy }; |
73 | |
74 | /* --- @scan_file@ --- * |
75 | * |
76 | * Arguments: @FILE *fp@ = pointer to file descriptor |
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77 | * @const char *name@ = pointer to source file name |
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78 | * @unsigned f@ = flags |
79 | * |
80 | * Returns: A scanner source. |
81 | * |
82 | * Use: Creates a new scanner source for reading from a file. |
83 | */ |
84 | |
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85 | scansrc *scan_file(FILE *fp, const char *name, unsigned f) |
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86 | { |
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87 | fscan *fs = CREATE(fscan); |
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88 | fs->ss.ops = &fscan_ops; |
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89 | fs->ss.src = xstrdup(name); |
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90 | fs->ss.line = 1; |
91 | fs->fp = fp; |
92 | fs->f = f; |
93 | return (&fs->ss); |
94 | } |
95 | |
96 | /*---- Argv scanner source ------------------------------------------------*/ |
97 | |
98 | /* --- Argv scanner block --- */ |
99 | |
100 | typedef struct avscan { |
101 | scansrc ss; |
102 | char **av; |
103 | char *p; |
104 | } avscan; |
105 | |
106 | /* --- @scan@ --- */ |
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107 | |
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108 | static int avscan_scan(scansrc *ss) |
109 | { |
110 | avscan *as = (avscan *)ss; |
111 | int ch; |
112 | if (!as->p) |
113 | ch = EOF; |
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114 | else if ((ch = (unsigned char)*as->p++) == 0) { |
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115 | as->ss.line++; |
116 | as->p = *as->av++; |
117 | ch = '\n'; |
118 | } |
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119 | return (ch); |
120 | } |
121 | |
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122 | /* --- @destroy@ --- */ |
123 | |
124 | static void avscan_destroy(scansrc *ss) |
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125 | { |
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126 | avscan *as = (avscan *)ss; |
127 | DESTROY(as); |
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128 | } |
129 | |
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130 | /* --- Argv scanner operations --- */ |
131 | |
132 | static scansrc_ops avscan_ops = { avscan_scan, avscan_destroy }; |
133 | |
134 | /* --- @scan_argv@ --- * |
135 | * |
136 | * Arguments: @char **av@ = pointer to argument array (null terminated) |
137 | * |
138 | * Returns: A scanner source. |
139 | * |
140 | * Use: Creates a new scanner source for reading from an @argv@ |
141 | * array. |
142 | */ |
143 | |
144 | scansrc *scan_argv(char **av) |
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145 | { |
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146 | avscan *as = CREATE(avscan); |
147 | as->ss.ops = &avscan_ops; |
148 | as->ss.src = "<argv>"; |
149 | as->ss.line = 1; |
150 | as->p = *av++; |
151 | as->av = av; |
152 | return (&as->ss); |
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153 | } |
154 | |
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155 | /*----- End-of-file sentinel block ----------------------------------------*/ |
156 | |
157 | /* --- @scan@ --- */ |
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158 | |
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159 | static int eof_scan(scansrc *ss) |
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160 | { |
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161 | return (EOF); |
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162 | } |
163 | |
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164 | /* --- @destroy@ --- */ |
165 | |
166 | static void eof_destroy(scansrc *ss) |
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167 | { |
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168 | ; |
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169 | } |
170 | |
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171 | /* --- Eof scanner operations --- */ |
172 | |
173 | static scansrc_ops eof_ops = { eof_scan, eof_destroy }; |
174 | |
175 | /* --- The end of file marker --- */ |
176 | |
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177 | static scansrc scan_eof = { &scan_eof, &eof_ops, "<eof>", 0, DSTR_INIT }; |
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178 | |
179 | /*----- General scanner handling ------------------------------------------*/ |
180 | |
181 | /* --- @scan@ --- * |
182 | * |
183 | * Arguments: @scanner *sc@ = pointer to main scanner context |
184 | * |
185 | * Returns: Character read, or end-of-file. |
186 | * |
187 | * Use: Scans a character from a source of characters. |
188 | */ |
189 | |
190 | int scan(scanner *sc) |
191 | { |
192 | int ch; |
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193 | if (sc->head->pushback.len) |
194 | ch = sc->head->pushback.buf[--sc->head->pushback.len]; |
195 | else { |
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196 | scansrc *ss = sc->head; |
197 | if (ss == &scan_eof) |
198 | ch = EOF; |
199 | else if ((ch = ss->ops->scan(ss)) == EOF) { |
200 | sc->head = ss->next; |
201 | if (sc->head == &scan_eof) |
202 | sc->tail = &sc->head; |
203 | ss->ops->destroy(ss); |
204 | ch = '\n'; |
205 | } |
206 | } |
207 | return (ch); |
208 | } |
209 | |
210 | /* --- @unscan@ --- * |
211 | * |
212 | * Arguments: @scanner *sc@ = pointer to main scanner context |
213 | * @int ch@ = character to unscan |
214 | * |
215 | * Returns: --- |
216 | * |
217 | * Use: Scans a character from a source of characters. |
218 | */ |
219 | |
220 | void unscan(scanner *sc, int ch) |
221 | { |
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222 | DPUTC(&sc->head->pushback, ch); |
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223 | } |
224 | |
225 | /* --- @scan_push@ --- * |
226 | * |
227 | * Arguments: @scanner *sc@ = pointer to main scanner context |
228 | * @scansrc *ss@ = souorce to push |
229 | * |
230 | * Returns: --- |
231 | * |
232 | * Use: Pushes a scanner source onto the front of the queue. |
233 | */ |
234 | |
235 | void scan_push(scanner *sc, scansrc *ss) |
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236 | { |
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237 | ss->next = sc->head; |
238 | if (sc->head == &scan_eof) |
239 | sc->tail = &ss->next; |
240 | sc->head = ss; |
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241 | dstr_create(&ss->pushback); |
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242 | ss->tok = 0; |
243 | ss->t = 0; |
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244 | } |
245 | |
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246 | /* --- @scan_add@ --- * |
247 | * |
248 | * Arguments: @scanner *sc@ = pointer to main scanner context |
249 | * @scansrc *ss@ = souorce to push |
250 | * |
251 | * Returns: --- |
252 | * |
253 | * Use: Adds a scanner source onto the end of the queue. |
254 | */ |
255 | |
256 | void scan_add(scanner *sc, scansrc *ss) |
257 | { |
258 | ss->next = &scan_eof; |
259 | *sc->tail = ss; |
260 | sc->tail = &ss->next; |
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261 | dstr_create(&ss->pushback); |
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262 | ss->tok = 0; |
263 | ss->t = 0; |
264 | } |
265 | |
266 | /* --- @scan_create@ --- * |
267 | * |
268 | * Arguments: @scanner *sc@ = scanner context to initialize |
269 | * |
270 | * Returns: --- |
271 | * |
272 | * Use: Initializes a scanner block ready for use. |
273 | */ |
274 | |
275 | void scan_create(scanner *sc) |
276 | { |
277 | sc->head = &scan_eof; |
278 | sc->tail = &sc->head; |
279 | dstr_create(&sc->d); |
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280 | sc->wbegin = sc->wcont = 0; |
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281 | } |
282 | |
283 | /* --- @scan_destroy@ --- * |
284 | * |
285 | * Arguments: @scanner *sc@ = pointer to scanner context |
286 | * |
287 | * Returns: --- |
288 | * |
289 | * Use: Destroys a scanner and all the sources attached to it. |
290 | */ |
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291 | |
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292 | void scan_destroy(scanner *sc) |
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293 | { |
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294 | scansrc *ss = sc->head; |
295 | while (ss != &scan_eof) { |
296 | scansrc *sss = ss; |
297 | ss = ss->next; |
298 | if (sss->tok) |
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299 | xfree(sss->tok); |
300 | dstr_destroy(&sss->pushback); |
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301 | sss->ops->destroy(sss); |
302 | } |
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303 | dstr_destroy(&sc->d); |
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304 | if (scan_eof.tok) |
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305 | xfree(scan_eof.tok); |
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306 | scan_eof.tok = 0; |
307 | sc->head = &scan_eof; |
308 | sc->tail = &sc->head; |
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309 | } |
310 | |
311 | /*----- That's all, folks -------------------------------------------------*/ |