正文
c语言实现配置文件的读写
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配置文件的格式如下：
key1 = value1
key2 = value2
.
.
.
名值对以一个=链接，一条记录以换行符分割
头文件：
#include<stdio.h>
#include<stdlib.h>
#include <string.h>
函数原型：
void trim(char *strIn, char *strOut);//去除字符串首位空格 void getValue(char * keyAndValue, char * key, char * value);
//根据key得到value int writeCFG(const char *filename/*in*/, const char *key/*in*/, const char *value/*in*/);
//写入配置文件 void readCFG(const char *filename/*in*/, const char *key/*in*/, const char **value/*out*/);
//读取配置文件
函数实现：
void trim(char *strIn, char *strOut){
char *start, *end, *temp;//定义去除空格后字符串的头尾指针和遍历指针
temp = strIn;
while (*temp == ' '){
++temp;
}
start = temp; //求得头指针
temp = strIn + strlen(strIn) - ; //得到原字符串最后一个字符的指针(不是'\0')
while (*temp == ' '){
--temp;
}
end = temp; //求得尾指针
for(strIn = start; strIn <= end; ){
*strOut++ = *strIn++;
}
*strOut = '\0';
}
void getValue(char * keyAndValue, char * key, char * value){
char *p = keyAndValue;
p = strstr(keyAndValue, key);
if(p == NULL){
//printf("没有key\n");
return ;
}
p += strlen(key);
trim(p, value);
p = strstr(value, "=");
if(p == NULL){
printf("没有=\n");
return;
}
p+= strlen("=");
trim(p, value);
p = strstr(value, "=");
if(p != NULL){
printf("多余的=\n");
return;
}
p = value;
trim(p, value);
}
int writeCFG(const char *filename/*in*/, const char *key/*in*/, const char *value/*in*/){
FILE *pf = NULL;
char ftemp[flen] = {}, fline[] = {}, *fp; //文件缓存数组
long fsize = ;
int reg = ;
int exit = ;
int i = ;
pf = fopen(filename, "r+");
if(pf == NULL){
pf = fopen(filename, "w+");
}
//获得文件大小
fseek(pf, , SEEK_END); // 将文件指针指向末尾
fsize = ftell(pf);
if(fsize > flen){
printf("文件不能超过8k\n");
reg = -;
goto end;
}
fseek(pf, , SEEK_SET); //将文件指针指向开头
//一行一行的读，如果存在key则修改value存到缓存数组中
while(!feof(pf)){
fgets(fline, , pf);
if(strstr(fline, key) != NULL && exit == )
strcpy(fline, "");
if(strstr(fline, key) != NULL && exit == ){ //判断key是否存在
exit = ;
sprintf(fline,"%s = %s\n", key, value);
}
printf("fline = %s\n", fline);
strcat(ftemp, fline);
}
if(exit != ){//如果不存在则把key value写入到最后一行
sprintf(fline,"%s = %s\n", key, value);
strcat(ftemp, fline);
}
if(pf != NULL){
fclose(pf);
pf = fopen(filename, "w+");
fp = (char *)malloc(sizeof(char) * strlen(ftemp) + );
strcpy(fp, ftemp);
fp[strlen(fp) - ] = EOF;
fputs(fp, pf);
if(fp != NULL){
free(fp);
fp = NULL;
}
fclose(pf);
}
end :
if(pf != NULL)
fclose(pf);
//重新创建一个以filename命名的文件
return reg;
}
void readCFG(const char *filename/*in*/, const char *key/*in*/, const char **value/*out*/){
FILE *pf = NULL;
char line[] = {}, vtemp[] = {};
pf = fopen(filename, "r"); //以只读方式打开
while(!feof(pf)){
fgets(line, , pf);
getValue(line, key, vtemp);
if(strlen(vtemp) != )
break;
}
if(strlen(vtemp) != ){
*value = (char *)malloc(sizeof(char) * strlen(vtemp) + );
strcpy(*value, vtemp);
}
else
*value = NULL;
if(pf != NULL)
fclose(pf);
}
测试：
#define filename "c:/cfg.ini"
void menu(){
printf("===========================\n");
printf("1 写入配置文件\n");
printf("2 读取配置文件\n");
printf("0 退出程序");
printf("===========================\n");
} int tWrite(){ char key[] = {}, value[] = {}; printf("请输入key:");
scanf("%s", key);
printf("请输入value:");
scanf("%s", value);
printf("\n您输入的是：%s = %s\n", key, value); return writeCFG(filename/*in*/,key/*in*/,value/*in*/);
} void tRead(){
char key[] = {}, *value; printf("请输入key:");
scanf("%s", key); readCFG(filename/*in*/,key/*in*/, &value/*out*/);
if(value == NULL){
printf("没有key\n");
return ;
}
printf("\nvalue = %s\n", value); if(value != NULL){
free(value);
value = NULL;
} }
int main(){ int choose; while(){
choose = ;
menu();
printf("请输入选择:");
scanf("%d", &choose);
switch(choose){
case :
if(tWrite() == -)
return -;
break;
case :
tRead();
break;
case :
return ;
default:
return ;
}
}
system("pause");
return ;
}
运行结果：
