iconv_open

Allocates a conversion descriptor for a specified codeset conversion.

Format

#include  <iconv.h>

iconv_t iconv_open  (const char *tocode, const char
                    *fromcode);

Arguments

tocode

The name of the codeset to which characters are converted.

fromcode

The name of the source codeset. See Chapter 10 for information on obtaining a list of currently available codesets or for details on adding new codesets.

Return Values

x

A conversion descriptor. Indicates the call was successful. This descriptor is used in subsequent calls to iconv

(iconv_t) -1

Indicates an error occurred. The function sets errno to one of the following: EMFILE - The process does not have enough I/O channels to open a file. ENOMEM - Insufficient space is available. EINVAL - The conversion specified by fromcode and tocode is not supported. EVMSERR - Nontranslatable VMS error occur. vaxc$errno contains the VMS error code. A value of SS$_BADCHKSUM in vaxc$errno indicates that a conversion table file was found, but its contents is corrupted. A value of SS$_IDMISMATCH in vaxc$errno indicates that the conversion table file version does not match the version of the C Run-Time Library.

Example

#include <stdio.h>
#include <iconv.h>
#include <errno.h>

int main ()
{
    /*                                                                   */
    /* Declare variables to be used                                      */
    /*                                                                   */
    char fromcodeset[30];
    char tocodeset[30];
    int  iconv_opened;
    iconv_t iconv_struct;                   /* Iconv descriptor      */

    /*                                                                   */
    /* Initialize variables                                              */
    /*                                                                   */
    sprintf(fromcodeset,"DECHANYU");
    sprintf(tocodeset,"EUCTW");
    iconv_opened = FALSE;

    /*                                                                   */
    /* Attempt to create a conversion descriptor for the codesets        */
    /* specified. If the return value from iconv_open is -1 then         */
    /* an error has occurred. Check value of errno.                      */
    /*                                                                   */
    if ((iconv_struct = iconv_open (tocodeset, fromcodeset)) == (iconv_t)-1)
    {
        /*                                                               */
        /* Check the value of errno                                      */
        /*                                                               */
        switch (errno)
        {
        case EMFILE:
        case ENFILE:
          printf("Too many iconv conversion files open\n");
          break;

        case ENOMEM:
          printf("Not enough memory\n");
          break;

        case EINVAL:
          printf("Unsupported conversion\n");
          break;

        default:
          printf("Unexpected error from iconv_open\n");
          break;
        }
    }
    else
        /*                                                               */
 /* Successfully allocated a conversion descriptor   */
 /*         */
 iconv_opened = TRUE;

    /*                                                                   */
    /*  Was a conversion descriptor allocated                            */
    /*                                                                   */
    if (iconv_opened)
    {
        /*                                                               */
        /* Attempt to deallocate the conversion descriptor. If           */
        /* iconv_close returns -1 then an error has occurred.            */
        /*                                                               */
        if (iconv_close (iconv_struct) == -1)
        {
            /*                                                           */
            /* An error occurred. Check the value of errno               */
            /*                                                           */
            switch (errno)
            {
            case EBADF:
                printf("Conversion descriptor is invalid\n");
                break;
            default:
                printf("Unexpected error from iconv_close\n");
                break;
            }
        }
    }
    return(1);
}