C Library Functions -mblen()

C Standard Library - <stdlib.h>

Description

C Library Functionsint mblen(const char *str, size_t n)Return parameterstrThe length of the multibyte character pointed to.

Declaration

Below is the declaration of the mblen() function.

int mblen(const char *str, size_t n)

Parameter

  • str-- Pointer to the first byte of a multibyte character.
  • n-- Maximum number of bytes to check for the character length.

Return Value

If a non-null wide character is recognized, the mblen() function returns the number of bytes parsed from the multibyte sequence starting at str. If a null wide character is recognized, it returns 0. If an invalid multibyte sequence is recognized, or a complete multibyte character cannot be parsed, it returns -1.

Example

The following example demonstrates the usage of the mblen() function.

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

int main()
{
   int len;
   char *pmbnull  = NULL;
   char *pmb = (char *)malloc( MB_CUR_MAX );
   wchar_t *pwc = L"Hi";
   wchar_t *pwcs = (wchar_t *)malloc( sizeof( wchar_t ));

   printf("转换为多字节字符串\n");
   len = wcstombs( pmb, pwc, MB_CUR_MAX);
   printf("被转换的字符 %d\n", len);
   printf("第一个多字节字符的十六进制值:%#.4x\n", pmb);
   
   len = mblen( pmb, MB_CUR_MAX );
   printf( "多字节字符 %x 的字节长度:%u\n", pmb, len );
   
   pmb = NULL;
   
   len = mblen( pmb, MB_CUR_MAX );
   printf( "多字节字符 %x 的字节长度:%u\n", pmb, len );
   
   return(0);
}

Let us compile and run the above program, which will produce the following result:

转换为多字节字符串
被转换的字符 1
第一个多字节字符的十六进制值:0x168c6010
多字节字符 168c6010 的字节长度:1
多字节字符 0 的字节长度:0

C Standard Library - <stdlib.h>

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