sscanf和sscanf_s 函数解析
sscanf 和 sscanf_s 测试代码
#include <string>
#include <stdio.h>
#include <iostream>
int main(int argc, char** argv){
//sscanf
char str[512] = {0};
//取指定长度的字符串。如在下例中，取最大长度为4字节的字符串。
sscanf("123456 ", "%4s", str);
printf("str=%s\n", str);
//取到指定字符为止的字符串。如在下例中，取遇到空格为止字符串。
sscanf("123456 abcdedf", "%[^ ]", str);
printf("str=%s\n", str);
//取仅包含指定字符集的字符串。如在下例中，取仅包含1到9和小写字母的字符串。
sscanf("123456abcdedfBCDEF", "%[1-9a-z]", str);
printf("str=%s\n", str);
//取到指定字符集为止的字符串。如在下例中，取遇到大写字母为止的字符串。
sscanf("123456abcdedfBCDEF", "%[^A-Z]", str);
printf("str=%s\n", str);
char cc;
tm tm_temp = { 0 };
std::string stime("2009-01-02_11:12:13");
//必须严格按照分隔符形式匹配填写，若遇到不匹配项则终止解析
int num = sscanf(stime.c_str(), "%4d-%2d-%2d_%2d:%2d:%2d",
&tm_temp.tm_year,
&tm_temp.tm_mon,
&tm_temp.tm_mday,
&tm_temp.tm_hour,
&tm_temp.tm_min,
&tm_temp.tm_sec
);
std::cout << num << " "<< tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//可以不按照分割符号形式填写，字符数必须一致，例如可以正确解析“2009/01/02_11:12:13”
stime = "2009/01/02_11:12:13";
num = sscanf(stime.c_str(), "%4d%c%2d%c%2d%c%2d%c%2d%c%2d",
&tm_temp.tm_year, &cc,
&tm_temp.tm_mon, &cc,
&tm_temp.tm_mday, &cc,
&tm_temp.tm_hour, &cc,
&tm_temp.tm_min, &cc,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//可以不按照分割符号形式填写，字符数必须一致，同上， %1s可以等同于 %c
num = sscanf(stime.c_str(), "%4d%1s%2d%1s%2d%1s%2d%1s%2d%1s%2d",
&tm_temp.tm_year, &cc,
&tm_temp.tm_mon, &cc,
&tm_temp.tm_mday, &cc,
&tm_temp.tm_hour, &cc,
&tm_temp.tm_min, &cc,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//可以不按照分割符形式和数量填写，类型必须一致，例如可以正确解析“2009/01/02___11:12:13”
//这里使用了sscanf的正则表达式，与通用的正则表示类似但不完全相同，%*c表示忽略连续多个字符
stime = "2009/01/02___11:12:13";
sscanf(stime.c_str(), "%4d%*c%2d%*c%2d%*c%2d%*c%2d%*c%2d",
&tm_temp.tm_year,
&tm_temp.tm_mon,
&tm_temp.tm_mday,
&tm_temp.tm_hour,
&tm_temp.tm_min,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//sscanf_s
stime = "2009-01-02_11:12:13";
//与sscanf第一种方法相同，可以使用"%4d-%2d-%2d_%2d:%2d:%2d"格式匹配解析
num = sscanf_s(stime.c_str(), "%4d-%2d-%2d_%2d:%2d:%2d",
&tm_temp.tm_year,
&tm_temp.tm_mon,
&tm_temp.tm_mday,
&tm_temp.tm_hour,
&tm_temp.tm_min,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//使用%c格式对数据解析时，必须对相应的缓冲区增加长度参数，否则将会出错
num = sscanf_s(stime.c_str(), "%4d%c%2d%c%2d%c%2d%c%2d%c%2d",
&tm_temp.tm_year, &cc, 1,
&tm_temp.tm_mon, &cc, 1,
&tm_temp.tm_mday, &cc, 1,
&tm_temp.tm_hour, &cc, 1,
&tm_temp.tm_min, &cc, 1,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//使用%s格式对数据解析时，缓冲长度必须大于字符串长度，否则不予解析
num = sscanf_s(stime.c_str(), "%4d%1s%2d%1s%2d%1s%2d%1s%2d%1s%2d",
&tm_temp.tm_year, &cc, 2,
&tm_temp.tm_mon, &cc, 2,
&tm_temp.tm_mday, &cc, 2,
&tm_temp.tm_hour, &cc, 2,
&tm_temp.tm_min, &cc, 2,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
//与sscanf一样，sscanf_s同样支持正则表达式
stime = "2009/01/02___11:12:13";
sscanf_s(stime.c_str(), "%4d%*c%2d%*c%2d%*c%2d%*c%2d%*c%2d",
&tm_temp.tm_year,
&tm_temp.tm_mon,
&tm_temp.tm_mday,
&tm_temp.tm_hour,
&tm_temp.tm_min,
&tm_temp.tm_sec
);
std::cout << num << " " << tm_temp.tm_year << " " << tm_temp.tm_mon << " " << tm_temp.tm_mday << " "
<< tm_temp.tm_hour << " " << tm_temp.tm_min << " " << tm_temp.tm_sec << std::endl;
getchar();
return 0;
}
输出信息如下
str=1234
str=123456
str=123456abcdedf
str=123456abcdedf
6 2009 1 2 11 12 13
11 2009 1 2 11 12 13
11 2009 1 2 11 12 13
11 2009 1 2 11 12 13
6 2009 1 2 11 12 13
11 2009 1 2 11 12 13
11 2009 1 2 11 12 13
11 2009 1 2 11 12 13
