NAME

       mblen - determine number of bytes in next multibyte character

SYNOPSIS

       #include <stdlib.h>

       int mblen(const char *s, size_t n);

DESCRIPTION

       If s is not a NULL pointer, the mblen() function inspects at most n bytes of the multibyte
       string starting at s and extracts the next complete multibyte character.  It uses a static
       anonymous  shift  state known only to the mblen() function.  If the multibyte character is
       not the null wide character, it returns the number of bytes that were consumed from s.  If
       the multibyte character is the null wide character, it returns 0.

       If  the  n  bytes  starting  at  s  do not contain a complete multibyte character, mblen()
       returns -1.  This can happen even if n is greater than or  equal  to  MB_CUR_MAX,  if  the
       multibyte string contains redundant shift sequences.

       If  the  multibyte  string starting at s contains an invalid multibyte sequence before the
       next complete character, mblen() also returns -1.

       If s is a NULL pointer, the mblen() function resets the shift state, known  to  only  this
       function,  to  the initial state, and returns nonzero if the encoding has nontrivial shift
       state, or zero if the encoding is stateless.

RETURN VALUE

       The mblen() function returns the number  of  bytes  parsed  from  the  multibyte  sequence
       starting  at s, if a non-null wide character was recognized.  It returns 0, if a null wide
       character was recognized.  It returns -1, if an invalid multibyte sequence was encountered
       or if it couldn't parse a complete multibyte character.

ATTRIBUTES

   Multithreading (see pthreads(7))
       The mblen() function is not thread-safe.

CONFORMING TO

       C99.

NOTES

       The behavior of mblen() depends on the LC_CTYPE category of the current locale.

       The function mbrlen(3) provides a better interface to the same functionality.

SEE ALSO

       mbrlen(3)

COLOPHON

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