Thread: Data structure for storing multiple language versions of my software

Hello, I have created a simple program for a microcontroller. I have created a menu displayed on an LCD.
Now I want to add the possibility of choosing a language version, so that a group of strings that are used for language A are exchanged with group of strings from language B.


How to do that?


Thank you in advance for any suggestions!

Originally Posted by laserlight

I am not sure if it is applicable to you, but one of the tools used for this purpose is gettext.

Thank you for your help, but it is not applicable for my idea. I am running the app on a microcontroller.

------
I have an idea - is array of string arrays applicable and would solve the problem?

I would personally use something like the following:

Code:

#define LANGS 2

static const char *const message[][LANGS] = {

#define MSG_HELLO 0
    /* 0 */ { "Hello", "Terve" },

#define MSG_READY 1
    /* 1 */ { "Ready", "Valmis" },

#define MSG_ERROR 2
    /* 2 */ { "Error", "Virhe" },

};

Note, however, that these strings are stored in ROM (FLASH or EEPROM), not in RAM. Some microcontrollers differentiate the two.

Originally Posted by Nominal Animal

I would personally use something like the following:

Code:

#define LANGS 2
/*didnt want to copy your whole code*/

Note, however, that these strings are stored in ROM (FLASH or EEPROM), not in RAM. Some microcontrollers differentiate the two.

Thank you for the suggestion. However, it does not seem to work on my PC.
My code:

Code:

#include <stdio.h>
#include <stdlib.h>


int main()
{
    #define LANGUAGES 2


static const char *const message[][LANGUAGES] = {


#define MSG_INTRO 0
     /*0*/  { "Hello", "Witamy" },


#define MSG_MENU1 1
     /*1*/  { "Option1", "Opcja1" },


#define MSG_MENU2 2
     /*2*/  { "Option2", "Opcja2" },


};
    printf("The text is %s", message[MSG_INTRO][LANGUAGES]);
    return 0;
}

When run - printf shows "The text is Option1".
And when I put MSG_MENU1 into printf then I get "The text is Option2".
And what is even more funny with MSG_MENU2 I get some random rubbish printed out.
Why is that happening? I am so confused.

Originally Posted by Pole

Thank you for the suggestion. However, it does not seem to work on my PC.

No, because your code is wrong. The message array should be global, and here,

Originally Posted by Pole

Code:

    printf("The text is %s", message[MSG_INTRO][LANGUAGES]);

your latter index (LANGUAGES) is out of bounds. Remember, in C indexes start at 0, and reach up to and including SIZE-1.

Here is a fixed example:

Code:

#include <stdlib.h>
#include <stdio.h>

#define LANG_EN     0
#define LANG_PL     1
#define LANG_COUNT  2

static const char *const message[][LANG_COUNT] = {

#define MSG_INTRO 0
    /* 0 */ { "Hello", "Witamy" },
 
 
#define MSG_MENU1 1
    /* 1 */ { "Option1", "Opcja1" },
 

#define MSG_MENU2 2
    /* 2 */ { "Option2", "Opcja2" },

#define MSG_COUNT 3
};

int main(void)
{
    printf("message[MSG_INTRO][LANG_EN] = \"%s\"\n", message[MSG_INTRO][LANG_EN]);
    printf("message[MSG_MENU2][LANG_PL] = \"%s\"\n", message[MSG_MENU2][LANG_PL]);
    return EXIT_SUCCESS;
}

To iterate over all possible messages in each language, use e.g.

Code:

int main(void)
{
    int msg, lang;

    for (msg = 0; msg < MSG_COUNT; msg++)
        for (lang = 0; lang < LANG_COUNT; lang++)
            printf("message[%d][%d] = \"%s\"\n", msg, lang, message[msg][lang]);

    return EXIT_SUCCESS;
}

instead.