fscanf sfscanf sReads formatte(2)

The main difference between the more secure functions (that have the _s suffix) and the other versions is that the more secure functions require the size in characters of each c, C, s, S, and [ type field to be passed as an argument immediately following the variable. For more information, see scanf_s, _scanf_s_l, wscanf_s, _wscanf_s_l and scanf Width Specification.

The versions of these functions that have the _l suffix are identical except that they use the locale parameter thats passed in instead of the current thread locale.

Generic-Text Routine Mappings

TCHAR.H routine

_UNICODE & _MBCS not defined

_MBCS defined

_UNICODE defined

Function

Required header

For additional compatibility information, see Compatibility.

// crt_fscanf_s.c
// This program writes formatted
// data to a file. It then uses fscanf to
// read the various data back from the file.

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

FILE *stream;

int main( void )
{
   long l;
   float fp;
   char s[81];
   char c;

   errno_t err = fopen_s( &stream, "fscanf.out", "w+" );
   if( err )
      printf_s( "The file fscanf.out was not opened\n" );
   else
   {
      fprintf_s( stream, "%s %ld %f%c", "a-string", 
               65000, 3.14159, x );
      // Set pointer to beginning of file:
      fseek( stream, 0L, SEEK_SET );

      // Read data back from file:
      fscanf_s( stream, "%s", s, _countof(s) );
      fscanf_s( stream, "%ld", &l );

      fscanf_s( stream, "%f", &fp );
      fscanf_s( stream, "%c", &c, 1 );

      // Output data read:
      printf( "%s\n", s );
      printf( "%ld\n", l );
      printf( "%f\n", fp );
      printf( "%c\n", c );

      fclose( stream );
   }
}

a-string
65000
3.141590
x

System::IO::StreamReader::ReadLine. See also Parse methods, such as System::Double::Parse.

Stream I/O

_cscanf_s, _cscanf_s_l, _cwscanf_s, _cwscanf_s_l

fprintf_s, _fprintf_s_l, fwprintf_s, _fwprintf_s_l

scanf_s, _scanf_s_l, wscanf_s, _wscanf_s_l

根本感觉不到sscanf 与 sscanf_s 的区别。 sscanf_s( tokenstring, "%s", s, _countof(s) )。下面总结了sscanf的以及sscanf_s的常用方法，也体现了“_s”版本函数与原函数的特别之处：。

fscanf, _fscanf_l, fwscanf, _fwscanf_l

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