| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Character scanners |
| 4 | * |
| 5 | * (c) 1999 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of the `fwd' port forwarder. |
| 11 | * |
| 12 | * `fwd' 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 | * `fwd' 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 `fwd'; if not, write to the Free Software Foundation, |
| 24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | */ |
| 26 | |
| 27 | #include "fwd.h" |
| 28 | |
| 29 | /*----- File scanner source -----------------------------------------------*/ |
| 30 | |
| 31 | /* --- File scanner block --- */ |
| 32 | |
| 33 | typedef struct fscan { |
| 34 | scansrc ss; |
| 35 | FILE *fp; |
| 36 | unsigned f; |
| 37 | } fscan; |
| 38 | |
| 39 | /* --- @scan@ --- */ |
| 40 | |
| 41 | static int fscan_scan(scansrc *ss) |
| 42 | { |
| 43 | fscan *fs = (fscan *)ss; |
| 44 | int ch = getc(fs->fp); |
| 45 | if (ch == '\n') |
| 46 | fs->ss.line++; |
| 47 | return (ch); |
| 48 | } |
| 49 | |
| 50 | /* --- @destroy@ --- */ |
| 51 | |
| 52 | static void fscan_destroy(scansrc *ss) |
| 53 | { |
| 54 | fscan *fs = (fscan *)ss; |
| 55 | if (!(fs->f & SCF_NOCLOSE)) |
| 56 | fclose(fs->fp); |
| 57 | xfree(fs->ss.src); |
| 58 | DESTROY(fs); |
| 59 | } |
| 60 | |
| 61 | /* --- File scanner operations --- */ |
| 62 | |
| 63 | static scansrc_ops fscan_ops = { fscan_scan, fscan_destroy }; |
| 64 | |
| 65 | /* --- @scan_file@ --- * |
| 66 | * |
| 67 | * Arguments: @FILE *fp@ = pointer to file descriptor |
| 68 | * @const char *name@ = pointer to source file name |
| 69 | * @unsigned f@ = flags |
| 70 | * |
| 71 | * Returns: A scanner source. |
| 72 | * |
| 73 | * Use: Creates a new scanner source for reading from a file. |
| 74 | */ |
| 75 | |
| 76 | scansrc *scan_file(FILE *fp, const char *name, unsigned f) |
| 77 | { |
| 78 | fscan *fs = CREATE(fscan); |
| 79 | fs->ss.ops = &fscan_ops; |
| 80 | fs->ss.src = xstrdup(name); |
| 81 | fs->ss.line = 1; |
| 82 | fs->fp = fp; |
| 83 | fs->f = f; |
| 84 | return (&fs->ss); |
| 85 | } |
| 86 | |
| 87 | /*---- Argv scanner source ------------------------------------------------*/ |
| 88 | |
| 89 | /* --- Argv scanner block --- */ |
| 90 | |
| 91 | typedef struct avscan { |
| 92 | scansrc ss; |
| 93 | char **av; |
| 94 | char *p; |
| 95 | } avscan; |
| 96 | |
| 97 | /* --- @scan@ --- */ |
| 98 | |
| 99 | static int avscan_scan(scansrc *ss) |
| 100 | { |
| 101 | avscan *as = (avscan *)ss; |
| 102 | int ch; |
| 103 | if (!as->p) |
| 104 | ch = EOF; |
| 105 | else if ((ch = (unsigned char)*as->p++) == 0) { |
| 106 | as->ss.line++; |
| 107 | as->p = *as->av++; |
| 108 | ch = '\n'; |
| 109 | } |
| 110 | return (ch); |
| 111 | } |
| 112 | |
| 113 | /* --- @destroy@ --- */ |
| 114 | |
| 115 | static void avscan_destroy(scansrc *ss) |
| 116 | { |
| 117 | avscan *as = (avscan *)ss; |
| 118 | DESTROY(as); |
| 119 | } |
| 120 | |
| 121 | /* --- Argv scanner operations --- */ |
| 122 | |
| 123 | static scansrc_ops avscan_ops = { avscan_scan, avscan_destroy }; |
| 124 | |
| 125 | /* --- @scan_argv@ --- * |
| 126 | * |
| 127 | * Arguments: @char **av@ = pointer to argument array (null terminated) |
| 128 | * |
| 129 | * Returns: A scanner source. |
| 130 | * |
| 131 | * Use: Creates a new scanner source for reading from an @argv@ |
| 132 | * array. |
| 133 | */ |
| 134 | |
| 135 | scansrc *scan_argv(char **av) |
| 136 | { |
| 137 | avscan *as = CREATE(avscan); |
| 138 | as->ss.ops = &avscan_ops; |
| 139 | as->ss.src = "<argv>"; |
| 140 | as->ss.line = 1; |
| 141 | as->p = *av++; |
| 142 | as->av = av; |
| 143 | return (&as->ss); |
| 144 | } |
| 145 | |
| 146 | /*----- End-of-file sentinel block ----------------------------------------*/ |
| 147 | |
| 148 | /* --- @scan@ --- */ |
| 149 | |
| 150 | static int eof_scan(scansrc *ss) |
| 151 | { |
| 152 | return (EOF); |
| 153 | } |
| 154 | |
| 155 | /* --- @destroy@ --- */ |
| 156 | |
| 157 | static void eof_destroy(scansrc *ss) |
| 158 | { |
| 159 | ; |
| 160 | } |
| 161 | |
| 162 | /* --- Eof scanner operations --- */ |
| 163 | |
| 164 | static scansrc_ops eof_ops = { eof_scan, eof_destroy }; |
| 165 | |
| 166 | /* --- The end of file marker --- */ |
| 167 | |
| 168 | static scansrc scan_eof = { &scan_eof, &eof_ops, "<eof>", 0, DSTR_INIT }; |
| 169 | |
| 170 | /*----- General scanner handling ------------------------------------------*/ |
| 171 | |
| 172 | /* --- @scan@ --- * |
| 173 | * |
| 174 | * Arguments: @scanner *sc@ = pointer to main scanner context |
| 175 | * |
| 176 | * Returns: Character read, or end-of-file. |
| 177 | * |
| 178 | * Use: Scans a character from a source of characters. |
| 179 | */ |
| 180 | |
| 181 | int scan(scanner *sc) |
| 182 | { |
| 183 | int ch; |
| 184 | if (sc->head->pushback.len) |
| 185 | ch = sc->head->pushback.buf[--sc->head->pushback.len]; |
| 186 | else { |
| 187 | scansrc *ss = sc->head; |
| 188 | if (ss == &scan_eof) |
| 189 | ch = EOF; |
| 190 | else if ((ch = ss->ops->scan(ss)) == EOF) { |
| 191 | sc->head = ss->next; |
| 192 | if (sc->head == &scan_eof) |
| 193 | sc->tail = &sc->head; |
| 194 | ss->ops->destroy(ss); |
| 195 | ch = '\n'; |
| 196 | } |
| 197 | } |
| 198 | return (ch); |
| 199 | } |
| 200 | |
| 201 | /* --- @unscan@ --- * |
| 202 | * |
| 203 | * Arguments: @scanner *sc@ = pointer to main scanner context |
| 204 | * @int ch@ = character to unscan |
| 205 | * |
| 206 | * Returns: --- |
| 207 | * |
| 208 | * Use: Scans a character from a source of characters. |
| 209 | */ |
| 210 | |
| 211 | void unscan(scanner *sc, int ch) |
| 212 | { |
| 213 | DPUTC(&sc->head->pushback, ch); |
| 214 | } |
| 215 | |
| 216 | /* --- @scan_push@ --- * |
| 217 | * |
| 218 | * Arguments: @scanner *sc@ = pointer to main scanner context |
| 219 | * @scansrc *ss@ = souorce to push |
| 220 | * |
| 221 | * Returns: --- |
| 222 | * |
| 223 | * Use: Pushes a scanner source onto the front of the queue. |
| 224 | */ |
| 225 | |
| 226 | void scan_push(scanner *sc, scansrc *ss) |
| 227 | { |
| 228 | ss->next = sc->head; |
| 229 | if (sc->head == &scan_eof) |
| 230 | sc->tail = &ss->next; |
| 231 | sc->head = ss; |
| 232 | dstr_create(&ss->pushback); |
| 233 | ss->tok = 0; |
| 234 | ss->t = 0; |
| 235 | } |
| 236 | |
| 237 | /* --- @scan_add@ --- * |
| 238 | * |
| 239 | * Arguments: @scanner *sc@ = pointer to main scanner context |
| 240 | * @scansrc *ss@ = souorce to push |
| 241 | * |
| 242 | * Returns: --- |
| 243 | * |
| 244 | * Use: Adds a scanner source onto the end of the queue. |
| 245 | */ |
| 246 | |
| 247 | void scan_add(scanner *sc, scansrc *ss) |
| 248 | { |
| 249 | ss->next = &scan_eof; |
| 250 | *sc->tail = ss; |
| 251 | sc->tail = &ss->next; |
| 252 | dstr_create(&ss->pushback); |
| 253 | ss->tok = 0; |
| 254 | ss->t = 0; |
| 255 | } |
| 256 | |
| 257 | /* --- @scan_create@ --- * |
| 258 | * |
| 259 | * Arguments: @scanner *sc@ = scanner context to initialize |
| 260 | * |
| 261 | * Returns: --- |
| 262 | * |
| 263 | * Use: Initializes a scanner block ready for use. |
| 264 | */ |
| 265 | |
| 266 | void scan_create(scanner *sc) |
| 267 | { |
| 268 | sc->head = &scan_eof; |
| 269 | sc->tail = &sc->head; |
| 270 | dstr_create(&sc->d); |
| 271 | sc->wbegin = sc->wcont = 0; |
| 272 | } |
| 273 | |
| 274 | /* --- @scan_destroy@ --- * |
| 275 | * |
| 276 | * Arguments: @scanner *sc@ = pointer to scanner context |
| 277 | * |
| 278 | * Returns: --- |
| 279 | * |
| 280 | * Use: Destroys a scanner and all the sources attached to it. |
| 281 | */ |
| 282 | |
| 283 | void scan_destroy(scanner *sc) |
| 284 | { |
| 285 | scansrc *ss = sc->head; |
| 286 | while (ss != &scan_eof) { |
| 287 | scansrc *sss = ss; |
| 288 | ss = ss->next; |
| 289 | if (sss->tok) |
| 290 | xfree(sss->tok); |
| 291 | dstr_destroy(&sss->pushback); |
| 292 | sss->ops->destroy(sss); |
| 293 | } |
| 294 | dstr_destroy(&sc->d); |
| 295 | if (scan_eof.tok) |
| 296 | xfree(scan_eof.tok); |
| 297 | scan_eof.tok = 0; |
| 298 | sc->head = &scan_eof; |
| 299 | sc->tail = &sc->head; |
| 300 | } |
| 301 | |
| 302 | /*----- That's all, folks -------------------------------------------------*/ |