Format
#include <wchar.h>
size_t mbrlen (const char *s, size_t n, mbstate_t *ps);Language Level: ANSI
Threadsafe: Yes, if ps is not NULL.
Locale Sensitive: The behavior of this function might be affected by the LC_CTYPE category of the current locale. This function might also be affected by the LC_UNI_CTYPE category of the current locale if LOCALETYPE(*LOCALEUCS2) or LOCALETYPE(*LOCALEUTF) is specified on the compilation command. This function is not available when LOCALETYPE(*CLD) is specified on the compilation command. For more information, see Understanding CCSIDs and Locales.
Description
This function is the restartable version of mblen().
The mbrlen() function determines the length of a multibyte character.
n is the number of bytes (at most) of the multibyte string to examine.
This function differs from its corresponding internal-state multibyte character function in that it has an extra parameter, ps of type pointer to mbstate_t that points to an object that can completely describe the current conversion state of the associated multibyte character sequence. If ps is a NULL pointer, mbrlen() behaves like mblen().
mbrlen() is a restartable version of mblen(). In other words, shift-state information is passed as one of the arguments (ps represents the initial shift) and is updated on exit. With mbrlen(), you can switch from one multibyte string to another, provided that you have kept the shift-state information.
Return Value
If s is a null pointer and if the active locale allows mixed-byte strings, the mbrlen() function returns nonzero. If s is a null pointer and if the active locale does not allow mixed-byte strings, zero will be returned.
If s is not a null pointer, the mbrlen() function returns one of the following:
Example that uses mbrlen()
/* This program is compiled with LOCALETYPE(*LOCALE) and */
/* SYSIFCOPT(*IFSIO) */
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
#include <wchar.h>
#include <errno.h>
#define LOCNAME "qsys.lib/JA_JP.locale"
#define LOCNAME_EN "qsys.lib/EN_US.locale"
int main(void)
{
int length, sl = 0;
char string[10];
mbstate_t ps = 0;
memset(string, '\0', 10);
string[0] = 0xC1;
string[1] = 0x0E;
string[2] = 0x41;
string[3] = 0x71;
string[4] = 0x41;
string[5] = 0x72;
string[6] = 0x0F;
string[7] = 0xC2;
/* In this first example we will find the length of */
/* of a multibyte character when the CCSID of locale */
/* associated with LC_CTYPE is 37. */
/* For single byte cases the state will always */
/* remain in the initial state 0 */
if (setlocale(LC_ALL, LOCNAME_EN) == NULL)
printf("setlocale failed.\n");
length = mbrlen(string, MB_CUR_MAX, &ps);
/* In this case length is 1, which is always the case for */
/* single byte CCSID */
printf("length = %d, state = %d\n\n", length, ps);
printf("MB_CUR_MAX: %d\n\n", MB_CUR_MAX);
/* Now let's try a multibyte example. We first must set the */
/* locale to a multibyte locale. We choose a locale with */
/* CCSID 5026 */
if (setlocale(LC_ALL, LOCNAME) == NULL)
printf("setlocale failed.\n");
length = mbrlen(string, MB_CUR_MAX, &ps);
/* The first is single byte so length is 1 and */
/* the state is still the initial state 0 */
printf("length = %d, state = %d\n\n", length, ps);
printf("MB_CUR_MAX: %d\n\n", MB_CUR_MAX);
sl += length;
length = mbrlen(&string[sl], MB_CUR_MAX, &ps);
/* The next character is a mixed byte. Length is 3 to */
/* account for the shiftout 0x0e. State is */
/* changed to double byte state. */
printf("length = %d, state = %d\n\n", length, ps);
sl += length;
length = mbrlen(&string[sl], MB_CUR_MAX, &ps);
/* The next character is also a double byte character. */
/* The state is changed to initial state since this was */
/* the last double byte character. Length is 3 to */
/* account for the ending 0x0f shiftin. */
printf("length = %d, state = %d\n\n", length, ps);
sl += length;
length = mbrlen(&string[sl], MB_CUR_MAX, &ps);
/* The next character is single byte so length is 1 and */
/* state remains in initial state. */
printf("length = %d, state = %d\n\n", length, ps);
}
/* The output should look like this:
length = 1, state = 0
MB_CUR_MAX: 1
length = 1, state = 0
MB_CUR_MAX: 4
length = 3, state = 2
length = 3, state = 0
length = 1, state = 0
*/
* * * End of File * * * Related Information