源码备份

C

#include<stdio.h>
#include<windows.h>
void strTonum( );
void Tran(double gps);
int main()
{
    while(1)
    {
    }
    return 0;
}
void strTonum()
{
    //116.575594,40.052042
        //116°34'32.1384"
        char str[22];
        printf("GPS:\n\n");
        scanf("%s",&str);
        //经度
        char longitude_str[12] = {0};
        //纬度
        char latitude_str[11] = {0};
        double longitude_num = 0;
        double latitude_num = 0;
        snprintf(longitude_str,11,str); 
        strncpy(latitude_str,str+11,9);
        //字符串转数字 
        longitude_num = atof(longitude_str);
        latitude_num = atof(latitude_str);
}
void Tran(double gps)
{
    int du =  (int)(gps);
    int fen = (int)((gps - du)*60);
    float miao = ((gps - du)*60 - fen)*60;
    char gsp_str[30] = {0};
    int j = 0;
    j = sprintf(gsp_str,"%d,",du);
    j+= sprintf(gsp_str+j,"%d,",fen);
    j+=  sprintf(gsp_str+j,"%f",miao);
    printf("\n");
    printf("%s\n\n",gsp_str);
//  printf("\n");
}

C语言中没有从某位置开始指定长度子字符串的函数（还是我没找到？），只有从头开始截取的strncat和strncpy，
以strncpy为例：
char dest[4] = {""};
char src[] = {"123456789"};
strncpy(dest, src, 3);
puts(dest);
输出结果为 123
看到了吗，strcpy函数中的参数是字符串数组的名字，而数组名本质上是指针，那么，src+3 就可以实现将 src中从第4个字符开始复制n个字符给 dest 了
char dest[4] = {""};
char src[] = {"123456789"};
strncpy(dest, src+3, 3);
puts(dest);
输出结果为 456

http://blog.csdn.net/u011317840/article/details/47808235
// crt_sprintf.c
// compile with: /W3
// This program uses sprintf to format various
//data and place them in the string named buffer.
// 程序使用sprintf 将各种数据格式化后置于字符数组buffer中
#include <stdio.h>
int main( void )
{
   char  buffer[200], s[] = "computer", c = 'l';
   int   i = 35, j;
   float fp = 1.7320534f;
   // 格式化并打印各种数据到buffer
   j  = sprintf( buffer,    "String:    %s\n", s ); // C4996
   j += sprintf( buffer + j, "   Character: %c\n", c ); // C4996
   j += sprintf( buffer + j, "   Integer:   %d\n", i ); // C4996
   j += sprintf( buffer + j, "   Real:      %f\n", fp );// C4996
   printf( "%s",buffer);
}

#include<stdio.h>
#include<windows.h>
void strTonum( );
void Tran(double gps);
double * longitude_num;
double * latitude_num;
int main()
{
    while(1)
    {
        strTonum(str_tmp);  
        Tran(*longitude_num);
        Tran(*latitude_num);    
    }
    return 0;
}
void strTonum(char *str)
{
    //116.575594,40.052042
        //116°34'32.1384"
    char str_tmp[22];
    printf("GPS:\n\n");
    scanf("%s",&str_tmp);
    //经度
    char longitude_str[12] = {0};
    //纬度
    char latitude_str[11] = {0};
    snprintf(longitude_str,11,str);     
    strncpy(latitude_str,str+11,9);
    //字符串转数字    
    double temp_f1 = 0, temp_f2 = 0;
    temp_f1 = atof(longitude_str);
    longitude_num = &temp_f1;
    temp_f2 = atof(latitude_str);
    latitude_num = &temp_f2;
}
void Tran(double gps)
{
    int du =  (int)(gps);
    int fen = (int)((gps - du)*60);
    float miao = ((gps - du)*60 - fen)*60;
    char gsp_str[30] = {0};
    int j = 0;
    j = sprintf(gsp_str,"%d,",du);
    j+= sprintf(gsp_str+j,"%d,",fen);
    j+=  sprintf(gsp_str+j,"%f",miao);
    printf("\n");
    printf("%s\n\n",gsp_str);
}