So, it's not comparing anything in my code, it's assigning the values of space, tab and newline to the variable x, which is always successful, and, therefore, always true. So every if loop executes on every character.
/*******************************/
Update.
I re-wrote the code, and made another rookie mistake that plagued me for two hours.
This code is the solution:
Code:
/*
* blank.c
*
* Exercise 1-8, write a program that counts blanks, tabs and newlines.
*/
#include <stdio.h>
main(){
int x,s,t,n;
s = 0; // counter for spaces
t = 0; // counter for tabs
n = 0; // counter for newlines
while ((x = getchar()) != EOF){
if (x == ' ') // x is a blank space
s++;
if (x == '\t') // x is a tab
t++;
if (x == '\n') // x is a newline
n++;
} // End while
printf("\nThere were ");
printf("%d", s);
printf(" spaces.\n");
printf("There were ");
printf("%d", t);
printf(" tabs.\n");
printf("There were ");
printf("%d", n);
printf(" newlines.\n\n");
} // End main
However, in the comparisons, I initially used double quotes, and the program insisted that there were zero spaces, zero tabs, and zero newlines-- exactly what I'd initialized the variables to. They weren't incrementing.
I finally found the answer in K&R-- they had mentioned it, and I read right over it. It has to be single quotes, double quotes is a text string.
I won't say that an exercise looks easy again. I'm off to look at 1-9.
---------- Post updated 01-16-10 at 01:37 ---------- Previous update was 01-15-10 at 01:43 ----------
Okay, I'm back.
Now I'm completely baffled.
Exercise 1-9, with this code:
Code:
/*
* copy.c
*
* Exercise 1-9. Write a program to copy it's input to it's output,
* replacing each string of one or more blanks by a single blank.
*/
#include <stdio.h>
main() {
int c; //the current character
while ((c = getchar()) != EOF) {
if (c == ' ') { // If there's a blank space
while ((c = getchar() == ' ')) { /* Get another character, check to
see if it's a blank space. We don't
care how many blank spaces there are, so
if it's a blank space, do nothing. If it's
not a blank space, break out of the while
loop. */
; /* The do nothing command. When it breaks out of this loop,
c will be holding the first character after the string
of blank spaces.*/
} // end while
printf(" "); //But there was at least one blank space, so we need
// to print one blank space.
} // end if
printf(c); // print the character
} // end while
} // end main
When I run this code with a text file, using cat /Text.txt|./a.out
the only thing that happens is that another curser appears and says:
Bus error.
My other programs still run, this is the only one that creates a bus error.
---------- Post updated at 05:02 ---------- Previous update was at 01:37 ----------
Okay, I replaced the final printf with a putchar, and the bus error went away.
The program now runs, but it doesn't do anything like it should.
Code:
/*
* copy.c
*
* Exercise 1-9. Write a program to copy it's input to it's output,
* replacing each string of one or more blanks by a single blank.
*/
#include <stdio.h>
main() {
int c; //the current character
while ((c = getchar()) != EOF) {
if (c == ' ') { // If there's a blank space
while ((c = getchar() == ' ')) {
/* Get another character, check to see if it's a blank space. I don't
care how many blank spaces there are, so if it's a blank space, do nothing.
If it's not a blank space, break out of the while loop. */
; /* The do nothing command. When it breaks out of this loop,
c will be holding the first character after the string
of blank spaces.*/
} // end while
printf(" "); //But there was at least one blank space, so we need
// to print one blank space.
} // end if
putchar(c); // print the character
} // end while
} // end main
Now it deletes "random" characters, (I'm sure there's a pattern, or at least a reason, but I don't see it.) and leaves long lines of blank spaces. The mystery continues.
Last edited by Jammer Six; 01-15-2010 at 09:04 AM..
Reason: update
Hi,
I am a beginner at shell scripting, though I have several years of Oracle programming experience. Can anyone recommend a site where I can find some exercises on shell programming. Is there anywhere I can telnet as I dont have UNIX OS on my PC?
Thanks
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I have just 3 things that I really need to know the solution, please allow me to show it.
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01-16-2010
I'm off to look at 1-9.