C语言实现的配置文件读取功能

winston

1. 首先声明, 代码主要是从Linux udev程序中提取出来的.
2.  支持的配置文件格式如下：

3. #comment
4. var_name1 = "XXX"                  #comment
5. var_name2 = "QQQ"                #comment
7. 3. config_file.h
9. #include <stdint.h>
10. #include <stdio.h>
11. #include
12. <syslog.h>
13. #define    MAX_PATH_LEN         (512)
14. #define    MAX_FILE_NAME_LEN   
15. (128)

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/* 将配置文件中的配置项解析后存放到全局数组中 */
int parse_config_file(char *path_to_config_file);   

/* 从全局数组中读取一个个配置项。例如  get_config_var("var_name1");  */
char * get_config_var(char *var_name);  
4.  config_file.c

3. #include <string.h>
4. #include <sys/types.h>
5. #include
6. <sys/socket.h>
7. #include <unistd.h>
8. #include
9. <stdio.h>
10. #include <stdlib.h>
11. #include
12. <netinet/in.h>
13. #include <arpa/inet.h>
14. #include
15. <errno.h>
16. #include <ctype.h>
17. #include <syslog.h>
18. #include <fcntl.h>
19. #include
20. <sys/resource.h>
21. #include <signal.h>
22. #include "config_file.h"
23. #define    MAX_VAR_NUM          (16)
24. #define    MAX_VAR_NAME_LEN     
25. (128)
26. #define    MAX_VAR_VALUE_LEN    (MAX_PATH_LEN)
28. #define COMMENT_CHARACTER   '#'
29. #define LINE_SIZE    (768)
31. char ga_variables[MAX_VAR_NUM][MAX_VAR_NAME_LEN + 1];
32. char
33. ga_values[MAX_VAR_NUM][MAX_VAR_VALUE_LEN + 1];
34. int  g_var_num = 0;
35. void get_dir_path_of_file(char *file, char *dir_path)
36. {
37. char
38. *temp;
39.     strncpy(dir_path, file, MAX_PATH_LEN);
40.     temp =
41. strrchr(dir_path, '/');
42.     temp[0] = '\0';
43. }
44. void remove_trailing_chars(char *path, char c)
45. {
46. size_t len;
47. len = strlen(path);
48. while (len > 0 && path[len-1] ==
49. c)
50.   path[--len] = '\0';
51. }
52. int get_key(char **line, char **key, char **value)
53. {
54. char
55. *linepos;
56. char *temp;
57. linepos = *line;
58. if (!linepos)
59.     {   
60.   return -1;
61.     }
62. /* skip whitespace */
63. while (isspace(linepos[0]))
64.   linepos++;
65. if (linepos[0] == '\0')
66.     {   
67.   return -1;
68.     }
69. /* get the key */
70. *key = linepos;
71. while (1)
72. {
73.   linepos++;
74.   if (linepos[0] == '\0')
75.         {
76.    return
77. -1;
78.         }
79.   if (isspace(linepos[0]))
80.    break;
81.   if (linepos[0]
82. == '=')
83.    break;
84. }
85. /* terminate key */
86. linepos[0] = '\0';
87. while (1) {
88.   linepos++;
89.   if (linepos[0] == '\0')
90.         
91. {
92.    return -1;
93.         }
94.   if
95. (isspace(linepos[0]))
96.    continue;
97.   if (linepos[0] ==
98. '=')
99.    continue;
100.         break;
101. }
103. /* get the value*/
104. if (linepos[0] == '"')
105.     {   
107.   linepos++;
108.     }
109. else
110.     {
111.   return -1;
112.     }
113. *value
114. = linepos;
115. temp = strchr(linepos, '"');
116. if (!temp)
117.     {
118.   return -1;
119.    
120. }
121.    
122. temp[0] = '\0';
123. return 0;
124. }
126. int parse_config_file(char *path_to_config_file)
127. {
128. char
129. line[LINE_SIZE + 2];
130. char *bufline;
131. char *linepos;
132. char
133. *variable;
134. char *value;
135. char *buf;
136. size_t bufsize;
137. size_t
138. cur;
139. size_t count;
140. int lineno;
141. int retval = 0;
142.     FILE *cfg_file = fopen(path_to_config_file, "r");
143. if (NULL ==
144. cfg_file)
145.     {
146.   ErrSysLog("can't open '%s' as config file: %s",
147. path_to_config_file, strerror(errno));
148.   goto EXIT;
149. }
150. /* loop through the whole file */
151. lineno = 0;
152. cur = 0;
153. while
154. (NULL != fgets(line, sizeof(line), cfg_file))
155.    
156. {
157.   lineno++;
158.   bufline = line;
159.   count = strlen(line);
160.   if (count > LINE_SIZE)
161.         {
162.    ErrSysLog("line too long,
163. conf line skipped %s, line %d", path_to_config_file,
164. lineno);
165.    continue;
166.   }
167.   /* eat the whitespace */
168.   while ((count > 0) &&
169. isspace(bufline[0]))
170.         
171. {
172.    bufline++;
173.    count--;
174.   }
175.   if (count ==
176. 0)
177.    continue;
178.   /* see if this is a comment */
179.   if (bufline[0] ==
180. COMMENT_CHARACTER)
181.    continue;
182.   memcpy(line, bufline, count);
183.   line[count] = '\0';
184.   linepos = line;
185.   retval = get_key(&linepos, &variable,
186. &value);
187.   if (retval != 0)
188.         {
189.    ErrSysLog("error parsing
190. %s, line %d:%d", path_to_config_file, lineno,
191. (int)(linepos-line));
192.    continue;
193.   }
194.         if (g_var_num >= MAX_VAR_NUM)
195.         {
196.    ErrSysLog("too
197. many vars in  %s, line %d:%d", path_to_config_file, lineno,
198. (int)(linepos-line));
199.    continue;
200.   }
201.         if (strlen(variable) > MAX_VAR_NAME_LEN)
202.         
203. {
204.    ErrSysLog("var name to long %s, line %d:%d", path_to_config_file,
205. lineno, (int)(linepos-line));
206.    continue;
207.   }
208.         if (strlen(value) > MAX_VAR_VALUE_LEN)
209.         
210. {
211.    ErrSysLog("value to long %s, line %d:%d", path_to_config_file, lineno,
212. (int)(linepos-line));
213.    continue;
214.   }
215.   strncpy(ga_variables[g_var_num], variable,
216. sizeof(ga_variables[g_var_num]));
217.         remove_trailing_chars(value,
218. '/');
219.   strncpy(ga_values[g_var_num], value,
220. sizeof(ga_values[g_var_num]));
221.         g_var_num++;
222.         continue;
223. }
224. EXIT:
225. fclose(cfg_file);
226. return g_var_num;
227. }
228. char * get_config_var(char *var_name)
229. {
230.     int i;
231. for(i = 0; i
232. < g_var_num; i++)
233.     {
234.   if (strcasecmp(ga_variables[i], var_name) ==
235. 0)
236.         {
237.    return ga_values[i];
238.   }
239.     }
240.     ErrSysLog("get %s failed", var_name);
241. return NULL;
242.    
244. }
245. void print_all_vars()
246. {
247.     int i;
248.     ErrPrintf("g_var_num == %d",
249. g_var_num);
250. for(i = 0; i < g_var_num; i++)
251.     {
252.         printf("%s
253. = %s\n", ga_variables[i], ga_values[i]);
254.     }
255.    
256.    
257. }

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作者：crazycoder8848 发表于2011-12-23 0:32:27 原文链接