gnu/lib/libdialog/rc.c

   1 /*
   2  *  rc.c -- routines for processing the configuration file
   3  *
   4  *  AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  as published by the Free Software Foundation; either version 2
   9  *  of the License, or (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  *  $DragonFly: src/gnu/lib/libdialog/rc.c,v 1.2 2005/06/04 13:42:28 eirikn Exp $
  21  */
  22
  23 #include <dialog.h>
  24 #include "dialog.priv.h"
  25 #include "colors.h"
  26 #include "rc.h"
  27
  28
  29 static unsigned char *attr_to_str(int fg, int bg, int hl);
  30 static int str_to_attr(unsigned char *str, int *fg, int *bg, int *hl);
  31 static int parse_line(unsigned char *line, unsigned char **var, unsigned char **value);
  32
  33
  34 /*
  35  * Create the configuration file
  36  */
  37 void dialog_create_rc(unsigned char *filename)
  38 {
  39   int i;
  40   FILE *rc_file;
  41
  42   if ((rc_file = fopen(filename, "wt")) == NULL) {
  43     fprintf(stderr, "\nError opening file for writing in create_rc().\n");
  44     exit(-1);
  45   }
  46
  47   fprintf(rc_file, "#\
  48 \n# Run-time configuration file for dialog\
  49 \n#\
  50 \n# Automatically generated by \"dialog --create-rc <file>\"\
  51 \n#\
  52 \n#\
  53 \n# Types of values:\
  54 \n#\
  55 \n# Number     -  <number>\
  56 \n# String     -  \"string\"\
  57 \n# Boolean    -  <ON|OFF>\
  58 \n# Attribute  -  (foreground,background,highlight?)\
  59 \n#\n\n");
  60
  61   /* Print an entry for each configuration variable */
  62   for (i = 0; i < VAR_COUNT; i++) {
  63     fprintf(rc_file, "\n# %s\n", vars[i].comment);    /* print comment */
  64     switch (vars[i].type) {
  65       case VAL_INT:
  66         fprintf(rc_file, "%s = %d\n", vars[i].name, *((int *) vars[i].var));
  67         break;
  68       case VAL_STR:
  69         fprintf(rc_file, "%s = \"%s\"\n", vars[i].name, (unsigned char *) vars[i].var);
  70         break;
  71       case VAL_BOOL:
  72         fprintf(rc_file, "%s = %s\n", vars[i].name, *((bool *) vars[i].var) ? "ON" : "OFF");
  73         break;
  74       case VAL_ATTR:
  75         fprintf(rc_file, "%s = %s\n", vars[i].name, attr_to_str(((int *) vars[i].var)[0], ((int *) vars[i].var)[1], ((int *) vars[i].var)[2]));
  76         break;
  77     }
  78   }
  79
  80   fclose(rc_file);
  81 }
  82 /* End of create_rc() */
  83
  84
  85 /*
  86  * Parse the configuration file and set up variables
  87  */
  88 int parse_rc(void)
  89 {
  90   int i, l = 1, parse, fg, bg, hl;
  91   unsigned char str[MAX_LEN+1], *var, *value, *tempptr;
  92   FILE *rc_file = NULL;
  93
  94   /*
  95    *
  96    *  At start, 'dialog' determines the settings to use as follows:
  97    *
  98    *  a) if environment variable DIALOGRC is set, it's value determines the
  99    *     name of the configuration file.
 100    *
 101    *  b) if the file in (a) can't be found, use the file $HOME/.dialogrc
 102    *     as the configuration file.
 103    *
 104    *  c) if the file in (b) can't be found, use compiled in defaults.
 105    *
 106    */
 107
 108   if ((tempptr = getenv("DIALOGRC")) != NULL)
 109     rc_file = fopen(tempptr, "rt");
 110
 111   if (tempptr == NULL || rc_file == NULL) {    /* step (a) failed? */
 112     /* try step (b) */
 113     if ((tempptr = getenv("HOME")) == NULL)
 114       return 0;    /* step (b) failed, use default values */
 115
 116     if (tempptr[0] == '\0' || lastch(tempptr) == '/')
 117       sprintf(str, "%s%s", tempptr, DIALOGRC);
 118     else
 119       sprintf(str, "%s/%s", tempptr, DIALOGRC);
 120
 121     if ((rc_file = fopen(str, "rt")) == NULL)
 122       return 0;    /* step (b) failed, use default values */
 123   }
 124
 125   /* Scan each line and set variables */
 126   while (fgets(str, MAX_LEN, rc_file) != NULL) {
 127     if (lastch(str) != '\n') {    /* ignore rest of file if line too long */
 128       fprintf(stderr, "\nParse error: line %d of configuration file too long.\n", l);
 129       fclose(rc_file);
 130       return -1;    /* parse aborted */
 131     }
 132     else {
 133       lastch(str) = '\0';
 134       parse = parse_line(str, &var, &value);    /* parse current line */
 135
 136       switch (parse) {
 137         case LINE_BLANK:    /* ignore blank lines and comments */
 138         case LINE_COMMENT:
 139           break;
 140         case LINE_OK:
 141           /* search table for matching config variable name */
 142           for (i = 0; i < VAR_COUNT && strcmp(vars[i].name, var); i++);
 143
 144           if (i == VAR_COUNT) {    /* no match */
 145             fprintf(stderr, "\nParse error: unknown variable at line %d of configuration file.\n", l);
 146             return -1;    /* parse aborted */
 147           }
 148           else {    /* variable found in table, set run time variables */
 149             switch (vars[i].type) {
 150               case VAL_INT:
 151                 *((int *) vars[i].var) = atoi(value);
 152                 break;
 153               case VAL_STR:
 154                 if (!isquote(value[0]) || !isquote(lastch(value)) || strlen(value) < 2) {
 155                   fprintf(stderr, "\nParse error: string value expected at line %d of configuration file.\n", l);
 156                   return -1;    /* parse aborted */
 157                 }
 158                 else {
 159                   /* remove the (") quotes */
 160                   value++;
 161                   lastch(value) = '\0';
 162                   strcpy((unsigned char *) vars[i].var, value);
 163                 }
 164                 break;
 165               case VAL_BOOL:
 166                 if (!strcasecmp(value, "ON"))
 167                   *((bool *) vars[i].var) = TRUE;
 168                 else if (!strcasecmp(value, "OFF"))
 169                   *((bool *) vars[i].var) = FALSE;
 170                 else {
 171                   fprintf(stderr, "\nParse error: boolean value expected at line %d of configuration file.\n", l);
 172                   return -1;    /* parse aborted */
 173                 }
 174                 break;
 175               case VAL_ATTR:
 176                 if (str_to_attr(value, &fg, &bg, &hl) == -1) {
 177                   fprintf(stderr, "\nParse error: attribute value expected at line %d of configuration file.\n", l);
 178                   return -1;    /* parse aborted */
 179                 }
 180                 ((int *) vars[i].var)[0] = fg;
 181                 ((int *) vars[i].var)[1] = bg;
 182                 ((int *) vars[i].var)[2] = hl;
 183                 break;
 184             }
 185           }
 186           break;
 187         case LINE_ERROR:
 188           fprintf(stderr, "\nParse error: syntax error at line %d of configuration file.\n", l);
 189           return -1;    /* parse aborted */
 190       }
 191     }
 192
 193     l++;    /* next line */
 194   }
 195
 196   fclose(rc_file);
 197   return 0;    /* parse successful */
 198 }
 199 /* End of parse_rc() */
 200
 201
 202 /*
 203  * Convert an attribute to a string representation like this:
 204  *
 205  * "(foreground,background,highlight)"
 206  */
 207 static unsigned char *attr_to_str(int fg, int bg, int hl)
 208 {
 209   int i;
 210   static unsigned char str[MAX_LEN+1];
 211
 212   strcpy(str, "(");
 213   /* foreground */
 214   for (i = 0; fg != color_names[i].value; i++);
 215   strcat(str, color_names[i].name);
 216   strcat(str, ",");
 217
 218   /* background */
 219   for (i = 0; bg != color_names[i].value; i++);
 220   strcat(str, color_names[i].name);
 221
 222   /* highlight */
 223   strcat(str, hl ? ",ON)" : ",OFF)");
 224
 225   return str;
 226 }
 227 /* End of attr_to_str() */
 228
 229
 230 /*
 231  * Extract the foreground, background and highlight values from an attribute
 232  * represented as a string in this form:
 233  *
 234  * "(foreground,background,highlight)"
 235  */
 236 static int str_to_attr(unsigned char *str, int *fg, int *bg, int *hl)
 237 {
 238   int i = 0, j, get_fg = 1;
 239   unsigned char tempstr[MAX_LEN+1], *part;
 240
 241   if (str[0] != '(' || lastch(str) != ')')
 242     return -1;    /* invalid representation */
 243
 244   /* remove the parenthesis */
 245   strcpy(tempstr, str + 1);
 246   lastch(tempstr) = '\0';
 247
 248   *fg = 0;      /* fix compiler warning */
 249
 250   /* get foreground and background */
 251
 252   while (1) {
 253     /* skip white space before fg/bg string */
 254     while (whitespace(tempstr[i]) && tempstr[i] != '\0') i++;
 255     if (tempstr[i] == '\0')
 256       return -1;    /* invalid representation */
 257     part = tempstr + i;    /* set 'part' to start of fg/bg string */
 258
 259     /* find end of fg/bg string */
 260     while(!whitespace(tempstr[i]) && tempstr[i] != ',' && tempstr[i] != '\0') i++;
 261
 262     if (tempstr[i] == '\0')
 263       return -1;    /* invalid representation */
 264     else if (whitespace(tempstr[i])) {   /* not yet ',' */
 265       tempstr[i++] = '\0';
 266
 267       /* skip white space before ',' */
 268       while(whitespace(tempstr[i]) && tempstr[i] != '\0') i++;
 269
 270       if (tempstr[i] != ',')
 271         return -1;    /* invalid representation */
 272     }
 273
 274     tempstr[i++] = '\0';    /* skip the ',' */
 275     for (j = 0; j < COLOR_COUNT && strcasecmp(part, color_names[j].name); j++);
 276     if (j == COLOR_COUNT)    /* invalid color name */
 277       return -1;
 278     if (get_fg) {
 279       *fg = color_names[j].value;
 280       get_fg = 0;    /* next we have to get the background */
 281     }
 282     else {
 283       *bg = color_names[j].value;
 284       break;
 285     }
 286   }   /* got foreground and background */
 287
 288
 289   /* get highlight */
 290
 291   /* skip white space before highlight string */
 292   while (whitespace(tempstr[i]) && tempstr[i] != '\0') i++;
 293   if (tempstr[i] == '\0')
 294     return -1;    /* invalid representation */
 295   part = tempstr + i;    /* set 'part' to start of highlight string */
 296
 297   /* trim trailing white space from highlight string */
 298   i = strlen(part) - 1;
 299   while(whitespace(part[i])) i--;
 300   part[i+1] = '\0';
 301
 302   if (!strcasecmp(part, "ON"))
 303     *hl = TRUE;
 304   else if (!strcasecmp(part, "OFF"))
 305     *hl = FALSE;
 306   else
 307     return -1;    /* invalid highlight value */
 308
 309   return 0;
 310 }
 311 /* End of str_to_attr() */
 312
 313
 314 /*
 315  * Parse a line in the configuration file
 316  *
 317  * Each line is of the form:  "variable = value". On exit, 'var' will contain
 318  * the variable name, and 'value' will contain the value string.
 319  *
 320  * Return values:
 321  *
 322  * LINE_BLANK   - line is blank
 323  * LINE_COMMENT - line is comment
 324  * LINE_OK      - line is ok
 325  * LINE_ERROR   - syntax error in line
 326  */
 327 static int parse_line(unsigned char *line, unsigned char **var, unsigned char **value)
 328 {
 329   int i = 0;
 330
 331   /* ignore white space at beginning of line */
 332   while(whitespace(line[i]) && line[i] != '\0') i++;
 333
 334   if (line[i] == '\0')    /* line is blank */
 335     return LINE_BLANK;
 336   else if (line[i] == '#')    /* line is comment */
 337     return LINE_COMMENT;
 338   else if (line[i] == '=')    /* variables names can't strart with a '=' */
 339     return LINE_ERROR;
 340
 341   /* set 'var' to variable name */
 342   *var = line + i++;    /* skip to next character */
 343
 344   /* find end of variable name */
 345   while(!whitespace(line[i]) && line[i] != '=' && line[i] != '\0') i++;
 346
 347   if (line[i] == '\0')    /* syntax error */
 348     return LINE_ERROR;
 349   else if (line[i] == '=')
 350     line[i++] = '\0';
 351   else {
 352     line[i++] = '\0';
 353
 354     /* skip white space before '=' */
 355     while(whitespace(line[i]) && line[i] != '\0') i++;
 356
 357     if (line[i] != '=')    /* syntax error */
 358       return LINE_ERROR;
 359     else
 360       i++;    /* skip the '=' */
 361   }
 362
 363   /* skip white space after '=' */
 364   while(whitespace(line[i]) && line[i] != '\0') i++;
 365
 366   if (line[i] == '\0')
 367     return LINE_ERROR;
 368   else
 369     *value = line + i;    /* set 'value' to value string */
 370
 371   /* trim trailing white space from 'value' */
 372   i = strlen(*value) - 1;
 373   while(whitespace((*value)[i])) i--;
 374   (*value)[i+1] = '\0';
 375
 376   return LINE_OK;    /* no syntax error in line */
 377 }
 378 /* End of parse_line() */