老子叫李单纯
c语言读取配置文件，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 #include #include
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：
1 void trim(char *strin, char *strout){
2
3 char *start, *end, *temp;//定义去除空格后字符串的头尾指针和遍历指针
4
5 temp = strin;
6
7 while (*temp == ' '){
8 ++temp;
9 }
10
11 start = temp; //求得头指针
12
13 temp = strin + strlen(strin) - 1; //得到原字符串最后一个字符的指针(不是'\0')
14
15 while (*temp == ' '){
16 --temp;
17 }
18
19 end = temp; //求得尾指针
20
21
22 for(strin = start; strin <= end; ){
23 *strout++ = *strin++;
24 }
25
26 *strout = '\0';
27 }
28
29 void getvalue(char * keyandvalue, char * key, char * value){
30
31 char *p = keyandvalue;
32
33 p = strstr(keyandvalue, key);
34 if(p == null){
35 //printf("没有key\n");
36 return ;
37 }
38
39 p += strlen(key);
40 trim(p, value);
41
42 p = strstr(value, "=");
43 if(p == null){
44 printf("没有=\n");
45 return;
46 }
47 p+= strlen("=");
48 trim(p, value);
49
50 p = strstr(value, "=");
51 if(p != null){
52 printf("多余的=\n");
53 return;
54 }
55 p = value;
56 trim(p, value);
57
58 }
59 int writecfg(const char *filename/*in*/, const char *key/*in*/, const char *value/*in*/){
60
61 file *pf = null;
62 char ftemp[flen] = {0}, fline[1024] = {0}, *fp; //文件缓存数组
63 long fsize = 0;
64 int reg = 0;
65 int exit = 0;
66 int i = 0;
67
68 pf = fopen(filename, "r+");
69 if(pf == null){
70 pf = fopen(filename, "w+");
71 }
72 //获得文件大小
73 fseek(pf, 0, seek_end); // 将文件指针指向末尾
74 fsize = ftell(pf);
75 if(fsize > flen){
76 printf("文件不能超过8k\n");
77 reg = -1;
78 goto end;
79 }
80 fseek(pf, 0, seek_set); //将文件指针指向开头
81
82 //一行一行的读，如果存在key则修改value存到缓存数组中
83 while(!feof(pf)){
84 fgets(fline, 1024, pf);
85 if(strstr(fline, key) != null && exit == 1)
86 strcpy(fline, "");
87 if(strstr(fline, key) != null && exit == 0){ //判断key是否存在
88 exit = 1;
89 sprintf(fline,"%s = %s\n", key, value);
90 }
91
92 printf("fline = %s\n", fline);
93 strcat(ftemp, fline);
94
95 }
96 if(exit != 1){//如果不存在则把key value写入到最后一行
97 sprintf(fline,"%s = %s\n", key, value);
98 strcat(ftemp, fline);
99 }
100 if(pf != null){
101 fclose(pf);
102 pf = fopen(filename, "w+");
103 fp = (char *)malloc(sizeof(char) * strlen(ftemp) + 1);
104 strcpy(fp, ftemp);
105 fp[strlen(fp) - 1] = eof;
106 fputs(fp, pf);
107 if(fp != null){
108 free(fp);
109 fp = null;
110 }
111 fclose(pf);
112 }
113 end :
114 if(pf != null)
115 fclose(pf);
116 //重新创建一个以filename命名的文件
117 return reg;
118 }
119
120 void readcfg(const char *filename/*in*/, const char *key/*in*/, const char **value/*out*/){
121
122 file *pf = null;
123 char line[1024] = {0}, vtemp[1024] = {0};
124
125 pf = fopen(filename, "r"); //以只读方式打开
126
127 while(!feof(pf)){
128 fgets(line, 1024, pf);
129 getvalue(line, key, vtemp);
130 if(strlen(vtemp) != 0)
131 break;
132 }
133 if(strlen(vtemp) != 0){
134 *value = (char *)malloc(sizeof(char) * strlen(vtemp) + 1);
135 strcpy(*value, vtemp);
136 }
137 else
138 *value = null;
139 if(pf != null)
140 fclose(pf);
141 }
测试：
1 #define filename "c:/cfg.ini"
2 void menu(){
3 printf("===========================\n");
4 printf("1 写入配置文件\n");
5 printf("2 读取配置文件\n");
6 printf("0 退出程序");
7 printf("===========================\n");
8 }
9
10 int twrite(){
11
12 char key[1024] = {0}, value[1024] = {0};
13
14 printf("请输入key:");
15 scanf("%s", key);
16 printf("请输入value:");
17 scanf("%s", value);
18 printf("\n您输入的是：%s = %s\n", key, value);
19
20 return writecfg(filename/*in*/,key/*in*/,value/*in*/);
21 }
22
23 void tread(){
24 char key[1024] = {0}, *value;
25
26 printf("请输入key:");
27 scanf("%s", key);
28
29 readcfg(filename/*in*/,key/*in*/, &value/*out*/);
30 if(value == null){
31 printf("没有key\n");
32 return ;
33 }
34 printf("\nvalue = %s\n", value);
35
36 if(value != null){
37 free(value);
38 value = null;
39 }
40
41 }
42 int main(){
43
44 int choose;
45
46 while(1){
47 choose = 0;
48 menu();
49 printf("请输入选择:");
50 scanf("%d", &choose);
51 switch(choose){
52 case 1:
53 if(twrite() == -1)
54 return -1;
55 break;
56 case 2:
57 tread();
58 break;
59 case 0:
60 return 0;
61 default:
62 return 0;
63 }
64 }
65 system("pause");
66 return 0;
67 }
运行结果：
