utf8nx2loc

Converts a string from UTF-8 to the local code page, providing the caller with full control of the mapping and handling of unmappable characters.

Library:LibC
Service:Characters and Strings

Syntax

  #include <unilib.h> 
   
  int utf8nx2loc (
     UniRuleTable_t       table,
     char                *dest,
     size_t              *destLen,
     const char          *src,
     size_t               srcLen,
     Uni2LocNoMapFunc_t   noMapFunc,
     void                *noMapFuncParm,
     int                  noMapFlag);

Parameters

table

(IN) Specifies the table to use for the conversion. To use the host's default code page, specify UNI_LOCAL_DEFAULT. Otherwise, specify the value returned from the UniGetTable function.

dest

(OUT) Points to the converted string.

destLen

(IN/OUT) Points to the maximum number of bytes that the destination string can hold when the function is called. When the function returns, it contains the number of bytes in the converted string.

src

(IN) Points to the source string in UTF-8 format.

srcLen

(IN) Specifies the number of UTF-8 characters in the source string.

noMapFunc

(IN) Points to the function to call when unmappable characters are found.

noMapFuncParm

(IN) Specifies an optional value for the noMapFunc function, which you can use in your noMapFunc function to distinguish between uses of the function. Whatever value you pass here, that value is passed to the no-map function when the utf8nx2loc function encounters a character that is not in its tables.

noMapFlag

(IN) Specifies whether to replace an unmappable character or simply return an error. It uses one of the following flags, but only the UNI_MAP_BY_FUNC flag enables calling the noMapFunc function.

Flag

Value

Description

UNI_MAP_NO_CHAR

0

Returns the UNI_ERR_UNMAPPABLE_CHAR error code as soon as a character is found to be unmappable. The result is null-terminated at the offending position in the string.

UNI_MAP_BY_FUNC

1

Passes a pointer to the current locations in the source and destination strings to the noMapFunc function if the noMapFunc parameter is not nil.

UNI_MAP_SELF

2

Uses the source character. In many cases this does not result in anything useful.

Return Values

If successful, returns 0. Otherwise, returns a negative error code:

Decimal

Name

Description

-496

UNI_ERR_BAD_HANDLE

The table parameter specifies a nonexistent rule table.

-532

UNI_ERR_UNMAPPABLE_CHAR

A character in the source is unmappable.

Remarks

The function you provide for the noMapFunc parameter must conform to the following syntax:

  typedef int (*Utf82LocNoMapFunc_t)
     ( char         **dest,
       size_t         remaining,
       const char   **src,
       void          *userParm );
dest

(IN/OUT) Points to a pointer to the current position in the destination string. If the translation by the function results in a character output to this string, this pointer must be updated to point one character beyond it.

remaining

(IN/OUT) Specifies the number of characters in the source string that remain to be translated.

src

(IN/OUT) Points to a pointer to the current position in the source string.

  • If your noMapFunc consumes the character at this position, do not increment the pointer beyond the present position for utf8nx2loc does this.

  • If your noMapFunc consumes n characters, increment the value by n-1.

userParm

(IN) Specifies an optional parameter for the noMapFunc function. This is the value passed to utf8nx2loc in the noMapFuncParm parameter.

After your function is called, you can use it to convert the unmappable character and allow utf8nx2loc to continue converting the string, or you can use your function to convert the remaining characters.

See Also