in.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "xroff.h"
   5
   6 struct inbuf {
   7         char path[64];          /* for file buffers */
   8         FILE *fin;
   9         char *buf;              /* for string buffers */
  10         char **args;
  11         int pos;
  12         int len;
  13         int backed;
  14         int nl;                 /* read \n, if the previous char was not */
  15         struct inbuf *prev;
  16 };
  17
  18 static struct inbuf *buf;
  19 static char files[NFILES][PATHLEN];
  20 static int nfiles;
  21 static int cfile;
  22 static int in_last;
  23
  24 static char **args_init(char **args);
  25 static void args_free(char **args);
  26
  27 static void in_new(void)
  28 {
  29         struct inbuf *next = malloc(sizeof(*next));
  30         memset(next, 0, sizeof(*next));
  31         next->backed = -1;
  32         next->prev = buf;
  33         buf = next;
  34 }
  35
  36 void in_push(char *s, char **args)
  37 {
  38         int len = strlen(s);
  39         in_new();
  40         buf->buf = malloc(len + 1);
  41         buf->len = len;
  42         strcpy(buf->buf, s);
  43         buf->args = args ? args_init(args) : NULL;
  44 }
  45
  46 void in_pushnl(char *s, char **args)
  47 {
  48         in_push(s, args);
  49         buf->nl = 1;
  50 }
  51
  52 void in_source(char *path)
  53 {
  54         FILE *fin = path && path[0] ? fopen(path, "r") : stdin;
  55         if (fin) {
  56                 in_new();
  57                 buf->fin = fin;
  58                 if (path)
  59                         snprintf(buf->path, sizeof(buf->path) - 1, "%s", path);
  60         }
  61 }
  62
  63 void in_queue(char *path)
  64 {
  65         if (nfiles < NFILES)
  66                 snprintf(files[nfiles++], PATHLEN - 1, "%s", path ? path : "");
  67 }
  68
  69 static void in_pop(void)
  70 {
  71         struct inbuf *old = buf;
  72         buf = buf->prev;
  73         if (old->args)
  74                 args_free(old->args);
  75         if (old->fin && old->path[0])
  76                 fclose(old->fin);
  77         free(old->buf);
  78         free(old);
  79 }
  80
  81 static int in_nextfile(void)
  82 {
  83         while (!buf && cfile < nfiles)
  84                 in_source(files[cfile++]);
  85         return !buf;
  86 }
  87
  88 static int in_read(void)
  89 {
  90         int c;
  91         while (buf || !in_nextfile()) {
  92                 if (buf->nl-- > 0 && in_last != '\n')
  93                         return '\n';
  94                 if (buf->buf && buf->pos < buf->len)
  95                         break;
  96                 if (!buf->buf && (c = getc(buf->fin)) >= 0)
  97                         return c;
  98                 in_pop();
  99         }
 100         if (!buf)
 101                 return -1;
 102         /* replacing \\ with \ only for buffers inserted via in_push() */
 103         if (buf->buf[buf->pos] == '\\' && buf->buf[buf->pos + 1] == '\\')
 104                 buf->pos++;
 105         return buf->buf[buf->pos++];
 106 }
 107
 108 int in_next(void)
 109 {
 110         int c;
 111         if (!buf && in_nextfile())
 112                 return -1;
 113         c = buf->backed;
 114         if (c >= 0)
 115                 buf->backed = -1;
 116         else
 117                 c = in_read();
 118         in_last = c;
 119         return c;
 120 }
 121
 122 void in_back(int c)
 123 {
 124         if (buf)
 125                 buf->backed = c;
 126 }
 127
 128 char *in_arg(int i)
 129 {
 130         struct inbuf *cur = buf;
 131         while (cur && !cur->args)
 132                 cur = cur->prev;
 133         return cur && cur->args && cur->args[i - 1] ? cur->args[i - 1] : "";
 134 }
 135
 136 char *in_filename(void)
 137 {
 138         struct inbuf *cur = buf;
 139         while (cur && !cur->fin)
 140                 cur = cur->prev;
 141         return cur && cur->path[0] ? cur->path : "-";
 142 }
 143
 144 static char **args_init(char **args)
 145 {
 146         char **out = malloc(NARGS * sizeof(*out));
 147         int i;
 148         for (i = 0; i < NARGS; i++) {
 149                 out[i] = NULL;
 150                 if (args[i]) {
 151                         int len = strlen(args[i]) + 1;
 152                         out[i] = malloc(len);
 153                         memcpy(out[i], args[i], len);
 154                 }
 155         }
 156         return out;
 157 }
 158
 159 static void args_free(char **args)
 160 {
 161         int i;
 162         for (i = 0; i < NARGS; i++)
 163                 if (args[i])
 164                         free(args[i]);
 165         free(args);
 166 }