How to select a string from an arry of strings

I have defined the following:

Code:

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static volatile char const *name_list[8][8] = {"Line 0  ", "Line 1  ", "Line 2  ", "Line 3  ", "Line 4  ", "Line 5  ", "Line 6  ", "Line 7", "Line 8  "};

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My question is: how do I select a string from this array and in what kind of variable can I store the selected string?

Quote:

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Originally Posted by MNM(tm)

I have defined the following:

Code:

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static volatile char const *name_list[8][8] = {"Line 0  ", "Line 1  ", "Line 2  ", "Line 3  ", "Line 4  ", "Line 5  ", "Line 6  ", "Line 7", "Line 8  "};

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My question is: how do I select a string from this array and in what kind of variable can I store the selected string?

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Use an index, or a pointer, to select your string. You only need *name_list[8]], (or name_list[8][8]), but not both, for your array.

what would this do?

Code:

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printf("%s \n", name_list[2]);

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strings are most commonly stored in char arrays in C. What is the problem with using one, here?

Quote:

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Originally Posted by Adak

You only need *name_list[8], (or name_list[8][8]).

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In both cases I get a compiler error: "Too many initializer values", so that's why I have to use "char const *name_list[8][8] ..."

But when I also define another variable:

Code:

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static volatile char *selected_name;

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and I try to assign a selected string form the array to it, by using:

Code:

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selected_name = name_list[8];

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the compiler complains with an error: "expression must be a modifiable lvalue"



ps.: "char const name_list[][8] ..." seems to be accepted by the compiler as well.

You can not use the assignment operator with C-strings, you need to use strcpy().

Jim

Humbug. :(

strcpy() needs string.h to be included, and that's not available in my compiler. (I'm using TI's Code Composer Studio to write programs for MSP430 processors).

I guess I'm going to need to use pointers then?

Or a loop to copy character by character until the end of string character. Are you sure that this compiler does not include string.h?

Jim

Yup, I'm sure.

Well of course, 0 to 8 strings, is NINE strings, so there's the cause of your "too many initializers" error.

Writing you own strcpy() is easy:

Code:

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for(i=0;origin_array[i];i++) {
  destination_array[i]=origin_array[i];
}
destination_array[i]='\0';

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Maybe you just need to add a const like this:

Code:

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static volatile const char *selected_name;

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Why are you using volatile ?

You could generate it programatically, and then reverse it to get the strings back out again:

Code:

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    register u8 i;
    char **strs;
    strs = kmalloc(8,GFP_KERNEL);
   
    for (i = 0; i < 8; i++) {
        strs[i] = kmalloc(8,GFP_KERNEL);
        strs[i][0] = 'L';
        strs[i][1] = 'i';
        strs[i][2] = 'n';
        strs[i][3] = 'e';
        strs[i][4] = ' ';
        strs[i][5] = i + '0';
    }

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Quote:

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Originally Posted by oogabooga

Maybe you just need to add a const like this:

Code:

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static volatile const char *selected_name;

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Why are you using volatile ?

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To make sure the compiler creates the const in RAM instead of Flash Memory.

Quote:

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Originally Posted by MNM(tm)

To make sure the compiler creates the const in RAM instead of Flash Memory.

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IIRC, volatile does NOT mean it does what you want.

It means the value can change without code changing it; it tells the compiler NOT to optimize the variable out.

Tim S.

Okay, then I was making a terribly wrong assumption. :eek:
Thanks for making this clear to me. :)

Just curious, why wouldn't your compiler include string.h? It's apart of the standard C library, and all of those headers should be installed by default.