in.c

   1 /* input stream management */
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include "roff.h"
   6
   7 struct inbuf {
   8         char path[64];          /* for file buffers */
   9         FILE *fin;
  10         char *buf;              /* for string buffers */
  11         char **args;
  12         int unbuf[8];           /* unread characters */
  13         int un;                 /* number of unread characters */
  14         int pos;
  15         int len;
  16         int lnum;               /* file line number */
  17         int nl;                 /* read \n, if the previous char was not */
  18         struct inbuf *prev;
  19 };
  20
  21 static struct inbuf *buf;
  22 static char files[NFILES][PATHLEN];
  23 static int nfiles;
  24 static int cfile;
  25 static int in_last[2] = {'\n'}; /* the last chars returned from in_next() */
  26
  27 static char **args_init(char **args);
  28 static void args_free(char **args);
  29
  30 static void in_new(void)
  31 {
  32         struct inbuf *next = malloc(sizeof(*next));
  33         memset(next, 0, sizeof(*next));
  34         next->prev = buf;
  35         buf = next;
  36 }
  37
  38 void in_push(char *s, char **args)
  39 {
  40         int len = strlen(s);
  41         in_new();
  42         buf->buf = malloc(len + 1);
  43         buf->len = len;
  44         strcpy(buf->buf, s);
  45         buf->args = args ? args_init(args) : NULL;
  46 }
  47
  48 void in_pushnl(char *s, char **args)
  49 {
  50         in_push(s, args);
  51         buf->nl = 1;
  52 }
  53
  54 void in_so(char *path)
  55 {
  56         FILE *fin = path && path[0] ? fopen(path, "r") : stdin;
  57         if (fin) {
  58                 in_new();
  59                 buf->fin = fin;
  60                 buf->lnum = 1;
  61                 if (path)
  62                         snprintf(buf->path, sizeof(buf->path), "%s", path);
  63         }
  64 }
  65
  66 void in_lf(char *path, int lnum)
  67 {
  68         struct inbuf *cur = buf;
  69         while (cur && !cur->fin)
  70                 cur = cur->prev;
  71         if (path)
  72                 snprintf(cur->path, sizeof(cur->path), "%s", path);
  73         cur->lnum = lnum;
  74 }
  75
  76 void in_queue(char *path)
  77 {
  78         if (nfiles < NFILES)
  79                 snprintf(files[nfiles++], PATHLEN - 1, "%s", path ? path : "");
  80 }
  81
  82 static void in_pop(void)
  83 {
  84         struct inbuf *old = buf;
  85         buf = buf->prev;
  86         if (old->args)
  87                 args_free(old->args);
  88         if (old->fin && old->fin != stdin)
  89                 fclose(old->fin);
  90         free(old->buf);
  91         free(old);
  92 }
  93
  94 void in_nx(char *path)
  95 {
  96         while (buf)
  97                 in_pop();
  98         if (path)
  99                 in_so(path);
 100 }
 101
 102 void in_ex(void)
 103 {
 104         while (buf)
 105                 in_pop();
 106         cfile = nfiles;
 107 }
 108
 109 static int in_nextfile(void)
 110 {
 111         while (!buf && cfile < nfiles)
 112                 in_so(files[cfile++]);
 113         return !buf;
 114 }
 115
 116 static int in_read(void)
 117 {
 118         int c;
 119         while (buf || !in_nextfile()) {
 120                 if (buf->un)
 121                         return buf->unbuf[--buf->un];
 122                 if (buf->nl-- > 0 && in_last[0] != '\n')
 123                         return '\n';
 124                 if (buf->buf && buf->pos < buf->len)
 125                         break;
 126                 if (!buf->buf && (c = getc(buf->fin)) >= 0) {
 127                         if (c == '\n')
 128                                 buf->lnum++;
 129                         return c;
 130                 }
 131                 in_pop();
 132         }
 133         return buf ? (unsigned char) buf->buf[buf->pos++] : -1;
 134 }
 135
 136 int in_next(void)
 137 {
 138         int c = in_read();
 139         if (c >= 0) {
 140                 in_last[1] = in_last[0];
 141                 in_last[0] = c;
 142         }
 143         return c;
 144 }
 145
 146 void in_back(int c)
 147 {
 148         if (c < 0)
 149                 return;
 150         in_last[0] = in_last[1];
 151         if (buf)
 152                 buf->unbuf[buf->un++] = c;
 153 }
 154
 155 int in_top(void)
 156 {
 157         return buf && buf->un ? buf->unbuf[buf->un - 1] : -1;
 158 }
 159
 160 char *in_arg(int i)
 161 {
 162         struct inbuf *cur = buf;
 163         while (cur && !cur->args)
 164                 cur = cur->prev;
 165         return cur && cur->args && cur->args[i - 1] ? cur->args[i - 1] : "";
 166 }
 167
 168 int in_nargs(void)
 169 {
 170         struct inbuf *cur = buf;
 171         int n = 0;
 172         while (cur && !cur->args)
 173                 cur = cur->prev;
 174         while (cur && cur->args && cur->args[n])
 175                 n++;
 176         return n;
 177 }
 178
 179 char *in_filename(void)
 180 {
 181         struct inbuf *cur = buf;
 182         while (cur && !cur->fin)
 183                 cur = cur->prev;
 184         return cur && cur->path[0] ? cur->path : "-";
 185 }
 186
 187 int in_lnum(void)
 188 {
 189         struct inbuf *cur = buf;
 190         while (cur && !cur->fin)
 191                 cur = cur->prev;
 192         return cur->lnum;
 193 }
 194
 195 static char **args_init(char **args)
 196 {
 197         char **out = malloc(NARGS * sizeof(*out));
 198         int i;
 199         for (i = 0; i < NARGS; i++) {
 200                 out[i] = NULL;
 201                 if (args[i]) {
 202                         int len = strlen(args[i]) + 1;
 203                         out[i] = malloc(len);
 204                         memcpy(out[i], args[i], len);
 205                 }
 206         }
 207         return out;
 208 }
 209
 210 static void args_free(char **args)
 211 {
 212         int i;
 213         for (i = 0; i < NARGS; i++)
 214                 if (args[i])
 215                         free(args[i]);
 216         free(args);
 217 }