sscanf_s函数用法

sscanf的安全版本sscanf_s的函数定义：

int sscanf_s( const char *buffer, const char *format [, argument ] ... );

在msdn中有如下mark，一定要仔细看哟，特别注意红色的部分，否则会出错的，我就在这里折腾了大半天才明白的

The sscanf_s function reads data from buffer into the location given by each argument. The arguments after the format string specify pointers to variables with a type that corresponds to a type specifier in format. Unlike the less secure version sscanf_s, a buffer size parametersizeOfBuffer is required when using the type field characters c, C, s, S and [. This parameter must be supplied as an additional parameter after each buffer which requires it.

也可以看下面这个例子的，注意红色的部分

// crt_sscanf_s.c
// This program uses sscanf_s to read data items
// from a string named tokenstring, then displays them.

#include

int main( void )
{
   char  tokenstring[] = "15 12 14...";
   char  s[81];
   char  c;
   int   i;
   float fp;

   // Input various data from tokenstring:
   // max 80 character string plus NULL terminator
   sscanf_s( tokenstring, "%s", s, sizeof(s) );
   sscanf_s( tokenstring, "%c", &c, sizeof(char) );
   sscanf_s( tokenstring, "%d", &i );
   sscanf_s( tokenstring, "%f", &fp );

   // Output the data read
   printf_s( "String    = %s\n", s );
   printf_s( "Character = %c\n", c );
   printf_s( "Integer:  = %d\n", i );
   printf_s( "Real:     = %f\n", fp );
}

Output

String = 15 Character = 1 Integer: = 15 Real: = 15.000000

fscanf_s,fwscanf_s用法和sscanf_s差不多，只是把字符串换成了打开的流。