configfile.c

   1 /* configfile.c: parsing of config files
   2  *
   3  * Copyright (C) 2008 Lars Hjemli
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include <ctype.h>
  10 #include <stdio.h>
  11 #include "configfile.h"
  12
  13 static int next_char(FILE *f)
  14 {
  15         int c = fgetc(f);
  16         if (c == '\r') {
  17                 c = fgetc(f);
  18                 if (c != '\n') {
  19                         ungetc(c, f);
  20                         c = '\r';
  21                 }
  22         }
  23         return c;
  24 }
  25
  26 static void skip_line(FILE *f)
  27 {
  28         int c;
  29
  30         while ((c = next_char(f)) && c != '\n' && c != EOF)
  31                 ;
  32 }
  33
  34 static int read_config_line(FILE *f, char *line, const char **value, int bufsize)
  35 {
  36         int i = 0, isname = 0;
  37
  38         *value = NULL;
  39         while (i < bufsize - 1) {
  40                 int c = next_char(f);
  41                 if (!isname && (c == '#' || c == ';')) {
  42                         skip_line(f);
  43                         continue;
  44                 }
  45                 if (!isname && isspace(c))
  46                         continue;
  47
  48                 if (c == '=' && !*value) {
  49                         line[i] = 0;
  50                         *value = &line[i + 1];
  51                 } else if (c == '\n' && !isname) {
  52                         i = 0;
  53                         continue;
  54                 } else if (c == '\n' || c == EOF) {
  55                         line[i] = 0;
  56                         break;
  57                 } else {
  58                         line[i] = c;
  59                 }
  60                 isname = 1;
  61                 i++;
  62         }
  63         line[i + 1] = 0;
  64         return i;
  65 }
  66
  67 int parse_configfile(const char *filename, configfile_value_fn fn)
  68 {
  69         static int nesting;
  70         int len;
  71         char line[256];
  72         const char *value;
  73         FILE *f;
  74
  75         /* cancel deeply nested include-commands */
  76         if (nesting > 8)
  77                 return -1;
  78         if (!(f = fopen(filename, "r")))
  79                 return -1;
  80         nesting++;
  81         while ((len = read_config_line(f, line, &value, sizeof(line))) > 0)
  82                 fn(line, value);
  83         nesting--;
  84         fclose(f);
  85         return 0;
  86 }
  87