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cvariablesascii

how do i get a variables ASCII value and use it in a sum

for(i=0;i < strlen();i++;)
{
postnum = argv[i] - k
}

i'm trying to write a Caesars encryption program for a course i'm taking, and pretty much i want to have the ASCII value of the i'th character in the string to have a key(k) added to the ASCII value to encrypt the string. i know to get a chars ASCII number you do 'a' or what ever letter you need but how do i get it from a char variable?

Solution

  • Just treat each character as an int and add k to the char:

     int i, k = 1;
 char *str = "abc";
 char *ctext = malloc(sizeof(char) * (strlen(str) + 1));
 for (i = 0; i < strlen(str); i++) {
      ctext[i] = str[i] + k;
 }
 ctext[i] = '\0';

 printf("%s\n", ctext);

    will output:

    bcd