C语言实现的配置文件读取功能
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：
#comment
var_name1 = "XXX" #comment
var_name2 = "QQQ" #comment
3. config_file.h
#include <stdint.h>
#include <stdio.h>
#include
<syslog.h>
#define MAX_PATH_LEN (512)
#define MAX_FILE_NAME_LEN
(128)
/* 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
#include <string.h>
#include <sys/types.h>
#include
<sys/socket.h>
#include <unistd.h>
#include
<stdio.h>
#include <stdlib.h>
#include
<netinet/in.h>
#include <arpa/inet.h>
#include
<errno.h>
#include <ctype.h>
#include <syslog.h>
#include <fcntl.h>
#include
<sys/resource.h>
#include <signal.h>
#include "config_file.h"
#define MAX_VAR_NUM (16)
#define MAX_VAR_NAME_LEN
(128)
#define MAX_VAR_VALUE_LEN (MAX_PATH_LEN)
#define COMMENT_CHARACTER '#'
#define LINE_SIZE (768)
char ga_variables;
char
ga_values;
intg_var_num = 0;
void get_dir_path_of_file(char *file, char *dir_path)
{
char
*temp;
strncpy(dir_path, file, MAX_PATH_LEN);
temp =
strrchr(dir_path, '/');
temp = '\0';
}
void remove_trailing_chars(char *path, char c)
{
size_t len;
len = strlen(path);
while (len > 0 && path ==
c)
path[--len] = '\0';
}
int get_key(char **line, char **key, char **value)
{
char
*linepos;
char *temp;
linepos = *line;
if (!linepos)
{
return -1;
}
/* skip whitespace */
while (isspace(linepos))
linepos++;
if (linepos == '\0')
{
return -1;
}
/* get the key */
*key = linepos;
while (1)
{
linepos++;
if (linepos == '\0')
{
return
-1;
}
if (isspace(linepos))
break;
if (linepos
== '=')
break;
}
/* terminate key */
linepos = '\0';
while (1) {
linepos++;
if (linepos == '\0')
{
return -1;
}
if
(isspace(linepos))
continue;
if (linepos ==
'=')
continue;
break;
}
/* get the value*/
if (linepos == '"')
{
linepos++;
}
else
{
return -1;
}
*value
= linepos;
temp = strchr(linepos, '"');
if (!temp)
{
return -1;
}
temp = '\0';
return 0;
}
int parse_config_file(char *path_to_config_file)
{
char
line;
char *bufline;
char *linepos;
char
*variable;
char *value;
char *buf;
size_t bufsize;
size_t
cur;
size_t count;
int lineno;
int retval = 0;
FILE *cfg_file = fopen(path_to_config_file, "r");
if (NULL ==
cfg_file)
{
ErrSysLog("can't open '%s' as config file: %s",
path_to_config_file, strerror(errno));
goto EXIT;
}
/* loop through the whole file */
lineno = 0;
cur = 0;
while
(NULL != fgets(line, sizeof(line), cfg_file))
{
lineno++;
bufline = line;
count = strlen(line);
if (count > LINE_SIZE)
{
ErrSysLog("line too long,
conf line skipped %s, line %d", path_to_config_file,
lineno);
continue;
}
/* eat the whitespace */
while ((count > 0) &&
isspace(bufline))
{
bufline++;
count--;
}
if (count ==
0)
continue;
/* see if this is a comment */
if (bufline ==
COMMENT_CHARACTER)
continue;
memcpy(line, bufline, count);
line = '\0';
linepos = line;
retval = get_key(&linepos, &variable,
&value);
if (retval != 0)
{
ErrSysLog("error parsing
%s, line %d:%d", path_to_config_file, lineno,
(int)(linepos-line));
continue;
}
if (g_var_num >= MAX_VAR_NUM)
{
ErrSysLog("too
many vars in%s, line %d:%d", path_to_config_file, lineno,
(int)(linepos-line));
continue;
}
if (strlen(variable) > MAX_VAR_NAME_LEN)
{
ErrSysLog("var name to long %s, line %d:%d", path_to_config_file,
lineno, (int)(linepos-line));
continue;
}
if (strlen(value) > MAX_VAR_VALUE_LEN)
{
ErrSysLog("value to long %s, line %d:%d", path_to_config_file, lineno,
(int)(linepos-line));
continue;
}
strncpy(ga_variables, variable,
sizeof(ga_variables));
remove_trailing_chars(value,
'/');
strncpy(ga_values, value,
sizeof(ga_values));
g_var_num++;
continue;
}
EXIT:
fclose(cfg_file);
return g_var_num;
}
char * get_config_var(char *var_name)
{
int i;
for(i = 0; i
< g_var_num; i++)
{
if (strcasecmp(ga_variables, var_name) ==
0)
{
return ga_values;
}
}
ErrSysLog("get %s failed", var_name);
return NULL;
}
void print_all_vars()
{
int i;
ErrPrintf("g_var_num == %d",
g_var_num);
for(i = 0; i < g_var_num; i++)
{
printf("%s
= %s\n", ga_variables, ga_values);
}
}
作者：crazycoder8848 发表于2011-12-23 0:32:27 原文链接
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