3 * $Id: scan.c,v 1.7 2004/04/08 01:36:25 mdw Exp $
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the `fw' port forwarder.
14 * `fw' is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * `fw' 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 General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with `fw'; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Header files ------------------------------------------------------*/
35 #include <mLib/dstr.h>
40 /*----- File scanner source -----------------------------------------------*/
42 /* --- File scanner block --- */
44 typedef struct fscan
{
52 static int fscan_scan(scansrc
*ss
)
54 fscan
*fs
= (fscan
*)ss
;
55 int ch
= getc(fs
->fp
);
61 /* --- @destroy@ --- */
63 static void fscan_destroy(scansrc
*ss
)
65 fscan
*fs
= (fscan
*)ss
;
66 if (!(fs
->f
& SCF_NOCLOSE
))
72 /* --- File scanner operations --- */
74 static scansrc_ops fscan_ops
= { fscan_scan
, fscan_destroy
};
76 /* --- @scan_file@ --- *
78 * Arguments: @FILE *fp@ = pointer to file descriptor
79 * @const char *name@ = pointer to source file name
80 * @unsigned f@ = flags
82 * Returns: A scanner source.
84 * Use: Creates a new scanner source for reading from a file.
87 scansrc
*scan_file(FILE *fp
, const char *name
, unsigned f
)
89 fscan
*fs
= CREATE(fscan
);
90 fs
->ss
.ops
= &fscan_ops
;
91 fs
->ss
.src
= xstrdup(name
);
98 /*---- Argv scanner source ------------------------------------------------*/
100 /* --- Argv scanner block --- */
102 typedef struct avscan
{
110 static int avscan_scan(scansrc
*ss
)
112 avscan
*as
= (avscan
*)ss
;
116 else if ((ch
= (unsigned char)*as
->p
++) == 0) {
124 /* --- @destroy@ --- */
126 static void avscan_destroy(scansrc
*ss
)
128 avscan
*as
= (avscan
*)ss
;
132 /* --- Argv scanner operations --- */
134 static scansrc_ops avscan_ops
= { avscan_scan
, avscan_destroy
};
136 /* --- @scan_argv@ --- *
138 * Arguments: @char **av@ = pointer to argument array (null terminated)
140 * Returns: A scanner source.
142 * Use: Creates a new scanner source for reading from an @argv@
146 scansrc
*scan_argv(char **av
)
148 avscan
*as
= CREATE(avscan
);
149 as
->ss
.ops
= &avscan_ops
;
150 as
->ss
.src
= "<argv>";
157 /*----- End-of-file sentinel block ----------------------------------------*/
161 static int eof_scan(scansrc
*ss
)
166 /* --- @destroy@ --- */
168 static void eof_destroy(scansrc
*ss
)
173 /* --- Eof scanner operations --- */
175 static scansrc_ops eof_ops
= { eof_scan
, eof_destroy
};
177 /* --- The end of file marker --- */
179 static scansrc scan_eof
= { &scan_eof
, &eof_ops
, "<eof>", 0, DSTR_INIT
};
181 /*----- General scanner handling ------------------------------------------*/
185 * Arguments: @scanner *sc@ = pointer to main scanner context
187 * Returns: Character read, or end-of-file.
189 * Use: Scans a character from a source of characters.
192 int scan(scanner
*sc
)
195 if (sc
->head
->pushback
.len
)
196 ch
= sc
->head
->pushback
.buf
[--sc
->head
->pushback
.len
];
198 scansrc
*ss
= sc
->head
;
201 else if ((ch
= ss
->ops
->scan(ss
)) == EOF
) {
203 if (sc
->head
== &scan_eof
)
204 sc
->tail
= &sc
->head
;
205 ss
->ops
->destroy(ss
);
212 /* --- @unscan@ --- *
214 * Arguments: @scanner *sc@ = pointer to main scanner context
215 * @int ch@ = character to unscan
219 * Use: Scans a character from a source of characters.
222 void unscan(scanner
*sc
, int ch
)
224 DPUTC(&sc
->head
->pushback
, ch
);
227 /* --- @scan_push@ --- *
229 * Arguments: @scanner *sc@ = pointer to main scanner context
230 * @scansrc *ss@ = souorce to push
234 * Use: Pushes a scanner source onto the front of the queue.
237 void scan_push(scanner
*sc
, scansrc
*ss
)
240 if (sc
->head
== &scan_eof
)
241 sc
->tail
= &ss
->next
;
243 dstr_create(&ss
->pushback
);
248 /* --- @scan_add@ --- *
250 * Arguments: @scanner *sc@ = pointer to main scanner context
251 * @scansrc *ss@ = souorce to push
255 * Use: Adds a scanner source onto the end of the queue.
258 void scan_add(scanner
*sc
, scansrc
*ss
)
260 ss
->next
= &scan_eof
;
262 sc
->tail
= &ss
->next
;
263 dstr_create(&ss
->pushback
);
268 /* --- @scan_create@ --- *
270 * Arguments: @scanner *sc@ = scanner context to initialize
274 * Use: Initializes a scanner block ready for use.
277 void scan_create(scanner
*sc
)
279 sc
->head
= &scan_eof
;
280 sc
->tail
= &sc
->head
;
282 sc
->wbegin
= sc
->wcont
= 0;
285 /* --- @scan_destroy@ --- *
287 * Arguments: @scanner *sc@ = pointer to scanner context
291 * Use: Destroys a scanner and all the sources attached to it.
294 void scan_destroy(scanner
*sc
)
296 scansrc
*ss
= sc
->head
;
297 while (ss
!= &scan_eof
) {
302 dstr_destroy(&sss
->pushback
);
303 sss
->ops
->destroy(sss
);
305 dstr_destroy(&sc
->d
);
309 sc
->head
= &scan_eof
;
310 sc
->tail
= &sc
->head
;
313 /*----- That's all, folks -------------------------------------------------*/