Bizzare compiler behaviour

[portaldude]

Goodday everyone.

I recently took up learn the C programming language, using the excellent book "The C programming language". I am only a few pages in and have encountered following example


#include <stdio.h>

main()
{
int c;

while ((c = getchar()) != EOF)
putchar(c);
}

Courious as I am, I wanted to play around with the program a bit and such, I copied it, saved it in a .c file format and compiled, using the GCC compiler that came with my Ubuntu distrubution, using the command


gcc myfile.c


There after, I ran the program and to my big surprise, it started to behave bizzarly.

If I wrote something in the terminal window like "I am testing this program", the program would output "PPPPPPPPPPPPPPPPPPPPPPPPPP"(that exact output), or a long lines of blanks.

I tried the GCC compiler in Windows, and there it would output my input flawless.

Does anyone know what is going on? Is there a bug in the compiler?

[Bachstelze]

The program behaves as expected here. Which commands exactly did you use to compile and run it?

[portaldude]

I simply used the command gcc myfile.c to compile it. Then ./a.out to run it. No axtra options, just thoose.

[Bachstelze]

Well, it does work fine here... Do you have all the necessary stuff installed?


sudo apt-get install build-essential

[nvteighen]

#include <stdio.h>

main()
{
int c;

while ((c = getchar()) != EOF)
putchar(c);
}



That code is outdated... well, "The C Programming Language" is an outdated book, as the C language has changed a bit since that book was published.

Try using:


#include <stdio.h>

int main(void)
{
int c = 0;

while ((c = getchar()) != EOF)
putchar(c);

return 0;
}


This code works for me...

Just a note: always compile using the -Wall option. It will show all warnings so you'll have it easier to detect any issue you may get.