vsscanf、vswscanfvsscanf, vswscanf

从字符串中读取格式化数据。Reads formatted data from a string. 提供这些函数的更多安全版本;请参阅 vsscanf_s、vswscanf_sMore secure versions of these functions are available; see vsscanf_s, vswscanf_s.

语法Syntax

int vsscanf(
   const char *buffer,
   const char *format,
   va_list arglist
);
int vswscanf(
   const wchar_t *buffer,
   const wchar_t *format,
   va_list arglist
);

参数Parameters

bufferbuffer
存储的数据Stored data

formatformat
窗体控件字符串。Format-control string. 有关详细信息,请参阅格式规范字段:scanf 和 wscanf 函数For more information, see Format Specification Fields: scanf and wscanf Functions.

arglistarglist
变量参数列表。Variable argument list.

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 that are 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. 返回值是EOF错误或如果在第一个转换之前到达字符串的末尾。The return value is EOF for an error or if the end of the string is reached before the first conversion.

如果缓冲区格式NULL调用指针,无效参数处理程序,如中所述参数验证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,这些函数将返回-1 并设置errnoEINVALIf execution is allowed to continue, these functions return -1 and set errno to EINVAL.

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

备注Remarks

Vsscanf函数读取来自数据缓冲区到每个参数中给定的位置arglist参数列表。The vsscanf function reads data from buffer into the locations that are given by each argument in the arglist argument list. 列表中的每个参数必须是指向具有中的类型说明符相对应的类型的变量格式Every argument in the list must be a pointer to a variable that has a type that corresponds to a type specifier in format. 格式参数控制字段输入的解释,并且具有相同格式和函数作为格式参数scanf函数。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

当你使用vsscanf若要读取一个字符串,始终指定的宽度 %s格式 (例如, "%32 秒" 而不是 "%s");否则,输入格式不正确可能导致缓冲区溢出。When you use vsscanf to read a string, always specify a width for the %s format (for example, "%32s" instead of "%s"); otherwise, incorrectly formatted input can cause a buffer overrun.

vswscanf是宽字符版本vsscanf; 的自变量vswscanf都是宽字符字符串。vswscanf is a wide-character version of vsscanf; the arguments to vswscanf are wide-character strings. vsscanf不处理多字节十六进制字符。vsscanf does not handle multibyte hexadecimal characters. vswscanf不处理 Unicode 全角十六进制或"兼容区"字符。vswscanf does not handle Unicode full-width hexadecimal or "compatibility zone" characters. 否则为vswscanfvsscanf行为方式相同。Otherwise, vswscanf and vsscanf behave identically.

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
_vstscanf_vstscanf vsscanfvsscanf vsscanfvsscanf vswscanfvswscanf

要求Requirements

例程所返回的值Routine 必需的标头Required header
vsscanfvsscanf <stdio.h><stdio.h>
vswscanfvswscanf <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.

示例Example

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

#include <stdio.h>
#include <stdarg.h>

int call_vsscanf(char *tokenstring, char *format, ...)
{
    int result;
    va_list arglist;
    va_start(arglist, format);
    result = vsscanf(tokenstring, format, arglist);
    va_end(arglist);
    return result;
}

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:
    call_vsscanf(tokenstring, "%80s", s);
    call_vsscanf(tokenstring, "%c", &c);
    call_vsscanf(tokenstring, "%d", &i);
    call_vsscanf(tokenstring, "%f", &fp);

    // 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/OStream I/O
scanf、_scanf_l、wscanf、_wscanf_lscanf, _scanf_l, wscanf, _wscanf_l
sscanf、_sscanf_l、swscanf、_swscanf_lsscanf, _sscanf_l, swscanf, _swscanf_l
sprintf、_sprintf_l、swprintf、_swprintf_l、__swprintf_lsprintf, _sprintf_l, swprintf, _swprintf_l, __swprintf_l
vsscanf_s、vswscanf_svsscanf_s, vswscanf_s