sscanf、_sscanf_l、swscanf、_swscanf_lsscanf, _sscanf_l, swscanf, _swscanf_l

从字符串中读取格式化数据。Read formatted data from a string. 这些函数的更安全版本已发布;请参阅 sscanf_s、_sscanf_s_l、swscanf_s、_swscanf_s_lMore secure versions of these functions are available; see sscanf_s, _sscanf_s_l, swscanf_s, _swscanf_s_l.

语法Syntax

int sscanf(  
   const char *buffer,  
   const char *format [,  
   argument ] ...   
);  
int _sscanf_l(  
   const char *buffer,  
   const char *format,  
   locale_t locale [,  
   argument ] ...   
);  
int swscanf(  
   const wchar_t *buffer,  
   const wchar_t *format [,  
   argument ] ...   
);  
int _swscanf_l(  
   const wchar_t *buffer,  
   const wchar_t *format,  
   locale_t locale [,  
   argument ] ...   
);  

参数Parameters

buffer
存储的数据Stored data

format
窗体控件字符串。Format-control string. 有关详细信息,请参阅格式规范For more information, see Format Specifications.

argument
可选自变量Optional arguments

locale
要使用的区域设置The locale to use

返回值Return Value

每个函数都将返回成功转换并分配的字段数;返回值不包括已读取但未分配的字段。Each of these functions returns the number of fields successfully converted and assigned; the return value does not include fields that were read but not assigned. 返回值为 0 表示没有分配任何字段。A return value of 0 indicates that no fields were assigned. 如果在首次转换前到达字符串的结尾,则返回值为 EOF 以指示错误。The return value is EOF for an error or if the end of the string is reached before the first conversion.

如果 bufferformatNULL 指针,则调用无效的参数处理程序,如参数验证中所述。If buffer or format is a NULL pointer, the invalid parameter handler is invoked, as described in Parameter Validation. 如果允许执行继续,则这些函数返回 -1 并将 errno 设置为 EINVALIf execution is allowed to continue, these functions return -1 and set errno to EINVAL.

有关这些代码及其他错误代码的信息,请参阅 _doserrno、errno、_sys_errlist 和 _sys_nerrFor information on these and other error codes, see _doserrno, errno, _sys_errlist, and _sys_nerr.

备注Remarks

sscanf 函数将数据从 buffer 读入每个 argument 给定的位置。The sscanf function reads data from buffer into the location given by each argument. 每个 argument 必须为指向类型与 format 中的类型说明符对应的变量的指针。Every argument must be a pointer to a variable with a type that corresponds to a type specifier in format. format 参数控制输入字段的解释,并且格式和函数与 scanf 函数的 format 参数相同。The format argument controls the interpretation of the input fields and has the same form and function as the format argument for the scanf function. 如果复制出现在重叠的字符串之间,则该行为不确定。If copying takes place between strings that overlap, the behavior is undefined.

重要

使用 sscanf 读取字符串时,请始终指定 %s 格式的宽度(例如 "%32s" 而不是 "%s");否则,输入格式不正确很容易导致缓冲区溢出。When reading a string with sscanf, always specify a width for the %s format (for example, "%32s" instead of "%s"); otherwise, improperly formatted input can easily cause a buffer overrun.

swscanfsscanf 的宽字符版本;swscanf 的参数是宽字符串。swscanf is a wide-character version of sscanf; the arguments to swscanf are wide-character strings. sscanf 不处理多字节十六进制字符。sscanf does not handle multibyte hexadecimal characters. swscanf 不处理 Unicode 全角十六进制或“兼容区”字符。swscanf does not handle Unicode full-width hexadecimal or "compatibility zone" characters. 除此以外,swscanfsscanf 的行为完全相同。Otherwise, swscanf and sscanf behave identically.

这些带有 _l 后缀的函数的版本相同,只不过它们使用传递的区域设置参数而不是当前线程区域设置。The versions of these functions with the _l suffix are identical except that they use the locale parameter passed in instead of the current thread locale.

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
_stscanf sscanf sscanf swscanf
_stscanf_l _sscanf_l _sscanf_l _swscanf_l

惠?Requirements

例程所返回的值Routine 必需的标头Required header
sscanf, _sscanf_lsscanf, _sscanf_l <stdio.h><stdio.h>
swscanf, _swscanf_lswscanf, _swscanf_l <stdio.h> 或 <wchar.h><stdio.h> or <wchar.h>

有关其他兼容性信息,请参见“简介”中的 兼容性For additional compatibility information, see Compatibility in the Introduction.

示例Example

// crt_sscanf.c  
// compile with: /W3  
// This program uses sscanf to read data items  
// from a string named tokenstring, then displays them.  

#include <stdio.h>  

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:  
   sscanf( tokenstring, "%80s", s ); // C4996  
   sscanf( tokenstring, "%c", &c );  // C4996  
   sscanf( tokenstring, "%d", &i );  // C4996  
   sscanf( tokenstring, "%f", &fp ); // C4996  
   // Note: sscanf is deprecated; consider using sscanf_s instead  

   // Output the data read  
   printf( "String    = %s\n", s );  
   printf( "Character = %c\n", c );  
   printf( "Integer:  = %d\n", i );  
   printf( "Real:     = %f\n", fp );  
}  
String    = 15  
Character = 1  
Integer:  = 15  
Real:     = 15.000000  

请参阅See Also

流 I/O Stream I/O
fscanf、_fscanf_l、fwscanf、_fwscanf_l fscanf, _fscanf_l, fwscanf, _fwscanf_l
scanf、_scanf_l、wscanf、_wscanf_l scanf, _scanf_l, wscanf, _wscanf_l
sprintf、_sprintf_l、swprintf、_swprintf_l、__swprintf_l sprintf, _sprintf_l, swprintf, _swprintf_l, __swprintf_l
snprintf、_snprintf、_snprintf_l、_snwprintf、_snwprintf_lsnprintf, _snprintf, _snprintf_l, _snwprintf, _snwprintf_l