mdw@git.distorted.org.uk Git - fwd/blob - scan.c

   1 /* -*-c-*-
   2  *
   3  * $Id: scan.c,v 1.1 1999/07/01 08:56:23 mdw Exp $
   4  *
   5  * Character scanners
   6  *
   7  * (c) 1999 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  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.
  18  *
  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.
  23  *
  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.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: scan.c,v $
  32  * Revision 1.1  1999/07/01 08:56:23  mdw
  33  * Initial revision
  34  *
  35  */
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include "config.h"
  40
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44
  45 #include <mLib/dstr.h>
  46
  47 #include "scan.h"
  48
  49 /*----- Main code ---------------------------------------------------------*/
  50
  51 /* --- Generic scanner setup --- */
  52
  53 static void scan_init(scanner *sc, scan_ops *ops, const char *src)
  54 {
  55   sc->ops = ops;
  56   sc->line = 1;
  57   sc->src = src;
  58   dstr_create(&sc->d);
  59 }
  60
  61 /* --- @argv@ scanner --- */
  62
  63 static int argv_scan(void *p)
  64 {
  65   scan_argvctx *c = p;
  66   int ch;
  67
  68   if (c->ch != EOF) {
  69     ch = c->ch;
  70     c->ch = EOF;
  71   } else if (*c->p)
  72     ch = *c->p++;
  73   else if (*c->pp) {
  74     c->p = *c->pp++;
  75     ch = '\n';
  76   } else
  77     ch = EOF;
  78
  79   return (ch);
  80 }
  81
  82 static void argv_unscan(int ch, void *p)
  83 {
  84   scan_argvctx *c = p;
  85   c->ch = ch;
  86 }
  87
  88 void scan_argvinit(scan_argvctx *c, char **pp)
  89 {
  90   static struct scan_ops ops = { argv_scan, argv_unscan };
  91   c->p = *pp++;
  92   c->pp = pp;
  93   c->ch = EOF;
  94   scan_init(&c->sc, &ops, "<args>");
  95 }
  96
  97 /* --- File scanner --- */
  98
  99 static int file_scan(void *p)
 100 {
 101   scan_filectx *c = p;
 102   return (getc(c->fp));
 103 }
 104
 105 static void file_unscan(int ch, void *p)
 106 {
 107   scan_filectx *c = p;
 108   ungetc(ch, c->fp);
 109 }
 110
 111 void scan_fileinit(scan_filectx *c, FILE *fp, const char *file)
 112 {
 113   static struct scan_ops ops = { file_scan, file_unscan };
 114   c->fp = fp;
 115   scan_init(&c->sc, &ops, file);
 116 }
 117
 118 /* --- Miscellaneous functions --- */
 119
 120 void scan_destroy(void *p)
 121 {
 122   scanner *sc = p;
 123   dstr_destroy(&sc->d);
 124 }
 125
 126 /*----- That's all, folks -------------------------------------------------*/