c语言实现名值对通过key查找value

需求、例如:

1、" key1 = value1 " 通过"key1"从该字符串中查找出"value",value去除前后空格

2、" key1 == value1 " 、" key1 = = value1 " 双等于号不合法

头文件:

#include<stdlib.h>
#include<stdio.h>
#include<string.h>

 

函数原型:

void trim(char *strIn /*in*/, char *strOut /*out*/);

void getValue(char * keyAndValue  /*in*/, char * key  /*in*/, char * value /*out*/);

实现方法:

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) - 1; //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);

}

测试:

void main(){

    char *keyAndValue = " key1 = kkkki";
    
    char *key = "key1";

    char value[100] = {0};

    getValue(keyAndValue, key, value);

    printf("value = *%s*\n", value);
    system("pause");
}