Thread: Check if non ASCII character is inputted

  1. #1
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    Jun 2020
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    Check if non ASCII character is inputted

    hello, I'm trying to put in my code to check if non ASCII character is a valid input if not get an error message.

    Code:
    #include <stdio.h>
    #include<string.h>
    #include<stdlib.h>
    #include<ctype.h>
    #include<math.h>
    
    
    int key= 65;
    
    
    unsigned int easyendecrypt(char c);
    
    
    int main(void) {
        int c;
        while ((c = getc(stdin)) !=EOF) {
            putc(easyendecrypt(c), stdout);
        }
        key = 'A';
        printf("\n");
        return 0;
    }
    
    
    unsigned int easyendecrypt(char c) {
        unsigned int k;
    
    #ifdef DECRYPT
        fprintf(stderr, "decrypting with %c\n",key);
        k = c - key;
        key = k;
        return k;
    #else
        fprintf(stderr,"encrypting with %c\n",key);
        k = c + key;
        key = c;
        return k;
    #endif
    }
    

  2. #2
    and the hat of int overfl Salem's Avatar
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    Lookup isprint() in ctype.h
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

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