Thread: Program will not exit on EOF

Hi my program is functioning properly and doing all it is supposed to do, but i just cant get the bloody thing to exist with the while loop

can anyone tell me why this is happening? or how to fix it?

Code:

#include <stdio.h>

int rotate_right(int);
int rotate_left(int);
int encode(int, int);

int main(void){

  int shift, ch;

  printf("Enter a number for amount of rotation: ");
  scanf("%d",&shift);

  printf("Enter text to scramble: ");


  while((ch = getchar())!=EOF){

    ch = encode(ch,shift);
    putchar(ch);

  }


        return 0;

}

int encode(int ch, int shift){

  while(shift!=0){

    if(shift>0){

      ch = rotate_right(ch);

      shift--;

    }
    else if(shift<0){

      ch = rotate_left(ch);
      shift++;
    }
  }

  return ch;
}

int rotate_right(int ch){

  if((ch >= 'A'&& ch < 'Z')||(ch >= 'a'&& ch < 'z'))
    ch++;
  else if(ch == 'Z')
    ch = 'A';
  else if(ch == 'z')
    ch = 'a';

  return ch;
}

int rotate_left(int ch){

  if((ch > 'A'&& ch <= 'Z')||(ch > 'a'&& ch <= 'z'))
    ch--;
  else if(ch == 'A')
    ch = 'Z';
  else if(ch == 'a')
    ch = 'z';

  return ch;
}

What OS and how are you entering EOF?

i do this on Netbeans and Cygwin, but what i am confused about further(based on the question you just asked) what is EOF? i thought it was end of file? so after i enter the text for the program to scramble, shouldnt the loop automatically exist when it reaches the enter key from stream?

what is EOF? i thought it was end of file?

That's right EOF is end of file.

so after i enter the text for the program to scramble, shouldnt the loop automatically exist when it reaches the enter key from stream?

The enter key doesn't generate EOF it generates the end of line character. EOF is generated by a control key combination either CTRL Z for Windows or CTRL D for Linux.

Jim

ahh thank you for that clarification

so if i wanted to exit on end of line, how would i go about implementing this?

Jim wants to say that CTRL Z is equivalent to EOF.So on you code check if EOF,then input CTRL Z and see what happens

so if i wanted to exit on end of line, how would i go about implementing this?

Then you would need to check your character to see if it contains this character (0x0a).

Jim

Originally Posted by jimblumberg

Then you would need to check your character to see if it contains this character (0x0a).

Jim

Or use '\n' to make the intention clear and to make the program portable.