3 replies to this topic

[zz5-ux]

greetings, the following code demonstrates increasing a character by +1 over and over. If you replace 300 below with 900 you can see the keymap loop. Non-printable characters display in the range 31-191 and 287-299.

#include <stdio.h>

main() {

        char let = 'a';


        int x;

        for (x=0;x<300;x++) {

                printf("%d let %c\n",x,let);

                let++;

        }

}

My question is.. Are these really non-printable characters and of no use to copy/paste ability in the terminal? also.. Which numbered item is the real newline char, is that the newline shown 21 spaces before the '!' character?

Basically I am changing the characters in a string one by one using manipulation of numbers, but the end result should fall as a readable character. So a readable loop range may need to be specified when adding numbers instead of simply..

to_main[i]=to_mod[i]+32;

[Flying Dutchman]

Printable characters start at 32, I think, that's ASCII code for space. The ones you should remember/know are '0' = 48, 'A' = 65 and 'a' = 97. You can print ASCII code yourself aswell.

for (int i = 0; i < 256; ++i)

    printf("char: %c, code %3d\n", i, i);

[zz5-ux]

thanks, that is a better way to display it. I ended up using.. tab[9], newline[10], readable[32->126]

[dargueta]

zz5-ux said:

My question is.. Are these really non-printable characters and of no use to copy/paste ability in the terminal? also.. Which numbered item is the real newline char, is that the newline shown 21 spaces before the '!' character?

That depends on your system. On *NIX systems, 0x0a is the newline character, Windows uses 0x0d 0x0a, and Mac OS (at least the older versions) use 0x0d. You can't really assume anything about what the character set your terminal uses, so you should use the functions/macros defined in ctype.h to figure out which ones are printable. There's a function in there called isprint() that you'll find useful.