strlen, wcslen, _mbslen, _mbstrlen
Get the length of a string.
size_tstrlen(constchar*string);
size_twcslen(constwchar_t*string);
size_t_mbslen(constunsignedchar*string);
size_t_mbstrlen(constchar*string);
Routine | Required Header | Compatibility |
strlen | <string.h> | ANSI, Win 95, Win NT |
wcslen | <string.h> or <wchar.h> | ANSI, Win 95, Win NT |
_mbslen | <mbstring.h> | Win 95, Win NT |
_mbstrlen | <stdlib.h> | Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
LIBC.LIB | Single thread static library, retail version |
LIBCMT.LIB | Multithread static library, retail version |
MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
Each of these functions returns the number of characters in string, excluding the terminal NULL. No return value is reserved to indicate an error.
Parameter
string
Null-terminated string
Remarks
Each of these functions returns the number of characters in string, not including the terminating null character. wcslen is a wide-character version of strlen; the argument of wcslen is a wide-character string. wcslen and strlen behave identically otherwise.
Generic-Text Routine Mappings
TCHAR.H Routine | _UNICODE & _MBCS Not Defined | _MBCS Defined | _UNICODE Defined |
_tcslen | strlen | strlen | wcslen |
_tcsclen | strlen | _mbslen | wcslen |
_mbslen and _mbstrlen return the number of multibyte characters in a multibyte-character string. _mbslen recognizes multibyte-character sequences according to the multibyte code page currently in use; it does not test for multibyte-character validity. _mbstrlen tests for multibyte-character validity and recognizes multibyte-character sequences according to the LC_CTYPE category setting of the current locale. For more information about the LC_CTYPE category, see setlocale.
Example
/* STRLEN.C */
#include <string.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>
void main( void )
{
char buffer[61] = "How long am I?";
int len;
len = strlen( buffer );
printf( "'%s' is %d characters long\n", buffer, len );
}
Output
'How long am I?' is 14 characters long
String Manipulation Routines | Locale Routines
See Also setlocale, strcat, strcmp, strcoll Functions, strcpy, strrchr, _strset, strspn