fprintf_s、_fprintf_s_l、fwprintf_s、_fwprintf_s_lfprintf_s, _fprintf_s_l, fwprintf_s, _fwprintf_s_l

将格式化数据输出到流。Print formatted data to a stream. CRT 中的安全功能中所述,这些版本的 fprintf、_fprintf_l、fwprintf、_fwprintf_l 具有安全增强功能。These are versions of fprintf, _fprintf_l, fwprintf, _fwprintf_l with security enhancements as described in Security Features in the CRT.


int fprintf_s(
   FILE *stream,
   const char *format [,
   argument_list ]
int _fprintf_s_l(
   FILE *stream,
   const char *format,
   locale_t locale [,
   argument_list ]
int fwprintf_s(
   FILE *stream,
   const wchar_t *format [,
   argument_list ]
int _fwprintf_s_l(
   FILE *stream,
   const wchar_t *format,
   locale_t locale [,
   argument_list ]


指向文件结构的指针。Pointer to FILE structure.

窗体控件字符串。Format-control string.

格式字符串的可选自变量。Optional arguments to the format string.

要使用的区域设置。The locale to use.

返回值Return Value

fprintf_s返回写入的字节数。fprintf_s returns the number of bytes written. fwprintf_s返回写入的宽字符数。fwprintf_s returns the number of wide characters written. 其中每个函数在出现输出错误时返回一个负值。Each of these functions returns a negative value instead when an output error occurs.


fprintf_s格式和输出一系列字符和值输出到fprintf_s formats and prints a series of characters and values to the output stream. 在每个自变量argument_list (如果有) 进行转换和输出中的相应格式规范根据格式Each argument in argument_list (if any) is converted and output according to the corresponding format specification in format. 格式自变量使用格式规范语法 printf 和 wprintf 函数The format argument uses the format specification syntax for printf and wprintf functions.

fwprintf_s是宽字符版本的fprintf_s; 在fwprintf_s格式是宽字符字符串。fwprintf_s is a wide-character version of fprintf_s; in fwprintf_s, format is a wide-character string. 如果在 ANSI 模式下打开流,则这些函数行为相同。These functions behave identically if the stream is opened in ANSI mode. fprintf_s当前不支持输出到 UNICODE 流。fprintf_s doesn't currently support output into a UNICODE stream.

使用这些函数的版本 _l后缀是相同,只不过它们使用传递而不是当前区域设置的区域设置参数。The versions of these functions with the _l suffix are identical except that they use the locale parameter passed in instead of the current locale.


确保 format 不是用户定义的字符串。Ensure that format is not a user-defined string.

如不安全版本 (请参阅fprintf、 _fprintf_l、 fwprintf、 _fwprintf_l),这些函数验证其参数和中所述将调用无效参数处理程序,参数验证,如果任一格式是 null 指针。Like the non-secure versions (see fprintf, _fprintf_l, fwprintf, _fwprintf_l), these functions validate their parameters and invoke the invalid parameter handler, as described in Parameter Validation, if either stream or format is a null pointer. 格式字符串本身也需进行验证。The format string itself is also validated. 如果有任何未知或格式错误的格式化说明符,则这些函数将生成无效参数异常。If there are any unknown or badly formed formatting specifiers, these functions generate the invalid parameter exception. 在所有情况下,如果允许执行继续,则函数返回-1 并设置errnoEINVALIn all cases, If execution is allowed to continue, the functions return -1 and set errno to EINVAL. 有关这些代码以及其他错误代码的详细信息,请参阅 _doserrno、errno、_sys_errlist 和 _sys_nerrSee _doserrno, errno, _sys_errlist, and _sys_nerr for more information on these, and other, error codes.

一般文本例程映射Generic-Text Routine Mappings

TCHAR.H 例程TCHAR.H routine 未定义 _UNICODE 和 _MBCS_UNICODE & _MBCS not defined 已定义 _MBCS_MBCS defined 已定义 _UNICODE_UNICODE defined
_ftprintf_s_ftprintf_s fprintf_sfprintf_s fprintf_sfprintf_s fwprintf_sfwprintf_s
_ftprintf_s_l_ftprintf_s_l _fprintf_s_l_fprintf_s_l _fprintf_s_l_fprintf_s_l _fwprintf_s_l_fwprintf_s_l

有关更多信息,请参见 格式规范For more information, see Format Specifications.


函数Function 必需的标头Required header
fprintf_s_fprintf_s_lfprintf_s, _fprintf_s_l <stdio.h><stdio.h>
fwprintf_s_fwprintf_s_lfwprintf_s, _fwprintf_s_l <stdio.h> 或 <wchar.h><stdio.h> or <wchar.h>

有关其他兼容性信息,请参阅 兼容性For additional compatibility information, see Compatibility.


// crt_fprintf_s.c
// This program uses fprintf_s to format various
// data and print it to the file named FPRINTF_S.OUT. It
// then displays FPRINTF_S.OUT on the screen using the system
// function to invoke the operating-system TYPE command.

#include <stdio.h>
#include <process.h>

FILE *stream;

int main( void )
   int    i = 10;
   double fp = 1.5;
   char   s[] = "this is a string";
   char   c = '\n';

   fopen_s( &stream, "fprintf_s.out", "w" );
   fprintf_s( stream, "%s%c", s, c );
   fprintf_s( stream, "%d\n", i );
   fprintf_s( stream, "%f\n", fp );
   fclose( stream );
   system( "type fprintf_s.out" );
this is a string

请参阅See also

流 I/OStream I/O
_cprintf、_cprintf_l、_cwprintf、_cwprintf_l_cprintf, _cprintf_l, _cwprintf, _cwprintf_l
fscanf、_fscanf_l、fwscanf、_fwscanf_lfscanf, _fscanf_l, fwscanf, _fwscanf_l
sprintf、_sprintf_l、swprintf、_swprintf_l、__swprintf_lsprintf, _sprintf_l, swprintf, _swprintf_l, __swprintf_l