recoding strings

[nime]

Hello,
I have data written on DOS on my specific codepage (852).
If I want to read this data in windows I must recode strings to replace non english characters and I do this successfully with VB program.

Now I want to replace those characters, readed from file, with C and I can't do this with following code.
Probably because I am total C newbie.

	int i;
	char* ps = mystring;
	for (i = 0; i <= sizeof(mystring); i++)
             {
	 switch(*ps){
               case 230: *ps=208;
               break;
               case 209: *ps=230;
               break;
               .
               .
               .      
               }
             }

I get error: case label value exceeds maximum value for type
After some digging I found that char values can be to 127 what causes those error.
Shown part of program change characters well when they are under ASCII 127.
What should I do to be able to change ASCII characters in range 0-255?

Of course, I would like to recode again before writing data back to disk so my DOS program would be able to read it. But this is the same problem as described above.

For more information here is my "lookup" table in form:
char_from, char_to, ASCII_from, ASCII_to

ć Đ 230 208
Ń ć 209 230
Đ Ć 208 198
† Ž 134 142
¬ č 172 232
Ź ž 143 158
¦ š 166 154
ź Š 159 138
§ Č 167 200
ç đ 231 240

Thanks in advance, nime.

[cas]

It sounds like you're asking your compiler to error out there with -Werror, because the code is not invalid. However, it is a useful warning. The problem is that char on your system is signed. Thus anything 128-255 will (reasonably assuming an 8-bit char) be represented as a negative value. The simplest fix would be to cast the controlling expression of your switch to an unsigned char.

[nime]

Hm, cas,
that sounds more complicated than in VB.
I understand what you tell but after few tryes I cant get it to work.
Can you please show me where and how to cast with a little example code?

[cas]

switch((unsigned char)*ps)

[nime]

Thanks cas, you are guru!

In meantime, when I dont know C enough, I found one more "interesting" solution "by hand"

        case 127-209: *ps=127-208;
         break;
        case 127-208: *ps=127-240;
         break;
         .
         .
         .

But I can't try if this works at the moment.
Anyway, one solution will surely be good I belive.

Thanks again, nime.

[CommonTater]

Thanks cas, you are guru!

In meantime, when I dont know C enough, I found one more "interesting" solution "by hand"

        case 127-209: *ps=127-208;
         break;
        case 127-208: *ps=127-240;
         break;
         .
         .
         .

But I can't try if this works at the moment.
Anyway, one solution will surely be good I belive.

Thanks again, nime.

switch doesn't work with hypenated values, ranges or sets. It needs and explicit constant.

[Bayint Naung]

replace non-ascii char with what?
you can just use isascii() from ctype.h.

isascii()
checks whether c is a 7-bit unsigned char value that fits into
the ASCII character set.

Try to read man pages yourself.

Edit: arhh. Ok, I didn't see your table.
You can use table.

unsigned char trans_tab[ ] = { 
   ......
  [230-127] = 208, ..       
};
unsigned char ch = (unsigned char) *p;
if( !ascii( ch ) ) 
   ch = trans_tab[ ch - 127];

Since ascii chars are not going to change,rite?
Then you just need 255-127 elements in your table.

[nime]

Thank you guys.
Cas's solution works just excellent. Properly and very fast.
I can read my data now in notepad just well

switch((unsigned char)*ps)

But when we're here one more simple question about C.

I would like to refresh my progressbar after every 1000 readed records.
In VB I do like this:

 If (count/1000)=Fix(count/1000)
    ' count is divided by 1000 without reminder 
    ' time to refresh!
    end if

How to do this with C?

[nime]

I found!
I someone would need it here is sample:

// 'o' is int declared before

if ((float)o/1000 == o/1000)
     printf("%d \n", o/1000);

[tabstop]

switch doesn't work with hypenated values, ranges or sets. It needs and explicit constant.

I'm pretty sure (given the "overlap") that OP is not intending "ranges" so much as "subtraction".

[CommonTater]

I'm pretty sure (given the "overlap") that OP is not intending "ranges" so much as "subtraction".

He should still be getting at least a warning that "case requires constant"... which is what I got when I tried it in PellesC.

[Bayint Naung]

I compiled with gcc -Wall and get no warnings.
I think const op const should give const

[tabstop]

He should still be getting at least a warning that "case requires constant"... which is what I got when I tried it in PellesC.

That's an error in PellesC. switch is obliged to accept constant expressions, at least in C99 (I don't have the C89 standard).

[CommonTater]

That's an error in PellesC. switch is obliged to accept constant expressions, at least in C99 (I don't have the C89 standard).

If I do it with the actual numbers... like it was posted... no error.... try it with variables (which is where I thought it was heading) and it complains.

Pelles C is C-99.

[Bayint Naung]

case 10 + 3 :
should be OK.
while case n: //where n is variable
the compiler will give error.