C语言工具函数

/*************************************************
*函数功能：根据步长分割字符串
*参数str：待处理的字符串
*参数step：步长
*返回值：返回处理得到的字符串
*备注：调用需包含string.h
*************************************************/
char *strsplit(char *str,short step)
{
    char bstr[1024] = {0};//转换缓冲区
    static char *str_ptr = NULL;
    static short idx = 0;

    if(str) {str_ptr = str;idx = 0;}
    else if(!str_ptr) {return NULL;}
    if(idx>strlen(str_ptr)) {return NULL;}
    strncpy(bstr,str_ptr+idx,step);
    idx += step;

    return bstr;
}

/************************************************/
//用例：按步长4分割字符串，并转换成ASCII字符输出
/************************************************/
#include <stdio.h>
#include <string.h>

char *strsplit(char *str,short step)
{
    char bstr[1024] = {0};//转换缓冲区
    static char *str_ptr = NULL;
    static short idx = 0;

    if(str) {str_ptr = str;idx = 0;}
    else if(!str_ptr) {return NULL;}
    if(idx>strlen(str_ptr)) {return NULL;}
    strncpy(bstr,str_ptr+idx,step);
    idx += step;

    return bstr;
}

int main()
{
    char str[] = "00630065006E007400650072002C0061002C0031003200330034003500360023";
    char str_tmp[80] = {0};
    short idx = 0;
    char *token;

    printf("%s
",str);

    token = strsplit(str,4);
    while(token != NULL)
    {
        char ch[5]={0};
        sscanf(token,"%X",ch);
        strcat(str_tmp,ch);
        token = strsplit(NULL,4);
    }

    printf("
%s
",str_tmp);
    return 0;
}

/*************************************************
*函数功能：使用newstr替换oldstr，若newstr为空，则表示删除
*参数str：待处理的字符串
*参数oldstr：旧字符串
*参数newstr：新字符串（可传NULL）
*返回值：返回处理得到的字符串
*备注：调用需包含string.h
*************************************************/
char *strrpc(char *str,char *oldstr,char *newstr)
{
    char bstr[1024] = {0};//转换缓冲区
    int i = 0;

    if(!str||!oldstr) return NULL;
    for(i=0;i<strlen(str);i++)
    {
        if(!strncmp(str+i,oldstr,strlen(oldstr)))
        {//查找目标字符串
            if(newstr!=NULL) {strcat(bstr,newstr);}//newstr参数若为NULL,则表示删除字符串
            i += strlen(oldstr)-1;
        }else{
            strncat(bstr,str+i,1);//保存一字节进缓冲区
        }
    }

    strcpy(str,bstr);
    return bstr;
}

/************************************************/
//用例：将FF0C替换成002C，并删除00
/************************************************/
#include <stdio.h>
#include <string.h>

char *strrpc(char *str,char *oldstr,char *newstr)
{
    char bstr[1024] = {0};//转换缓冲区
    int i = 0;

    if(!str||!oldstr) return NULL;
    for(i=0;i<strlen(str);i++)
    {
        if(!strncmp(str+i,oldstr,strlen(oldstr)))
        {//查找目标字符串
            if(newstr!=NULL) {strcat(bstr,newstr);}//newstr参数若为NULL,则表示删除字符串
            i += strlen(oldstr)-1;
        }else{
            strncat(bstr,str+i,1);//保存一字节进缓冲区
        }
    }

    strcpy(str,bstr);
    return bstr;
}

int main()
{
    char str[] = "00630065006E007400650072FF0C0061FF0C0031003200330034003500360023";
    char str_tmp[80] = {0};

    printf("%s
",str);

    strrpc(str,"FF0C","002C");
    strrpc(str,"00",NULL);

    printf("
%s
",str);

    return 0;
}

char* strtrim(char str_arr[], short str_len)
{
    char* ptr = NULL;
    short loop = 0;
    
    if(!str_arr||!str_len) {return NULL;}

    ptr = (char*)str_arr + str_len;
    while(isspace(*ptr))
    {//先从尾部剔除空白符
        *ptr = '';
        ptr--;
    }    
    
    ptr = (char*)str_arr;
    while(isspace(*ptr))
    {//再从头部剔除空白符
        *ptr = '';
        ptr++;
    }
    if(ptr == (char*)str_arr) {return str_arr;}
    
    for(loop=0; loop<str_len; loop++)
    {
        *(str_arr+loop) = *ptr;
        if(*(ptr++) == '') {break;}
    }
    return str_arr;
}

int GetValFromStrByKey(void* str,void* key,void* val,short val_len,char* delimiter,char* tailed)
{
    char* head_ptr = NULL;
    char* tail_ptr = NULL;
    
    if(!str||!key||!val) {return 0;}
    if(!delimiter) {delimiter = "=";}
    if(!tailed) {tailed = "
";}
    
    //匹配键名
    if((head_ptr = strstr((char*)str, (char*)key)) == NULL) {return 0;}

    //根据键名获取其后的键值
    if((head_ptr = strstr((char*)head_ptr, (char*)delimiter)) != NULL)
    {//键名与键值间的连接符，如:NUM = 123456中,键名为NUM,键值为123456,二者间的连接符为=
        head_ptr += strlen(delimiter);
        if((tail_ptr = strstr((char*)head_ptr, (char*)tailed)) != NULL)
        {//考虑到字符串中可能有多个键值对存在，因此约定键值对间以tailed做分隔符
            short str_len = (char*)tail_ptr-(char*)head_ptr;
            
            if(str_len >= val_len) {str_len = val_len-1;}//若值长度太长，则仅截取到val可存的长度
            memset((char*)val, 0x00, val_len);
            memcpy((char*)val, (char*)head_ptr, str_len);
            
            return 1;
        }
    }
    return 0;
}