Thread: K&R example does not compile under Ubuntu 10.10 using CC. Example from Sect 1.9

From page 29 K&R 2nd 1988, So here it goes (With some mods from me):

insert

Code:

#include <stdio.h>

main() {

    int len;
    int max =0;
    char line[500];
    char longest[500];

    while( (len = getline(line, 500)) > 0) {
        if( len > max ){
            max = len;
            copy(longest, line);
        }
    }
    if (max > 0)
        printf("%s", longest);
//  return 0;
}

int getline(char that_line[], int lim){
    int c, i;

    for (i=0; i < lim-1 && (c=getchar()) != EOF && c!='\n'; ++i)
        that_line[i] = c;

    if (c == '\n') {
        that_line[i] = c;
        ++i;
    }
    that_line[i] = '\0';

    return i;
}

void copy(char dest[], char from[]) {
    int i = 0;

    while( (dest[i] = from[i]) != '\0')
        ++i;
}

$cc example.c

Here the the error msgs:
19.c: In function ‘main’:
19.c:10: warning: passing argument 1 of ‘getline’ from incompatible pointer type
/usr/include/stdio.h:671: note: expected ‘char ** __restrict__’ but argument is of type ‘char *’
19.c:10: warning: passing argument 2 of ‘getline’ makes pointer from integer without a cast
/usr/include/stdio.h:671: note: expected ‘size_t * __restrict__’ but argument is of type ‘int’
19.c:10: error: too few arguments to function ‘getline’
19.c: At top level:
19.c:21: error: conflicting types for ‘getline’
/usr/include/stdio.h:671: note: previous declaration of ‘getline’ was here
19.c:36: warning: conflicting types for ‘copy’
19.c:13: note: previous implicit declaration of ‘copy’ was here

So whats wrong with the code..
Has the standard changed much since to C99 or something that the compiler uses..

Yeah the code was modded bit by me...
but I doubt if I wrote it carbon copy- or use Visual Studio the result will differ ?

Like many ppl today, I guess I m from Java..

Can someone explain why it failed & what has changed maybe since..
What's a good reference book for learning the language.
Assume I know quite some about Java can program well already..

It's just my prob with C with playing pointers etc too

Thanks a lot.

Yes your method worked. Thanks.

I use the 1988 2nd ed book.

=================
But, in order for only $ gcc example.c to work..
How should I change to the code then ?

And maybe what current C book / online reference is best to use with gcc standard ?

Thanks again.

Oops..
19.c is the file name

/home/me/cwork >gcc 19.c
19.c:3: error: conflicting types for ‘getline’
/usr/include/stdio.h:671: note: previous declaration of ‘getline’ was here
19.c:24: error: conflicting types for ‘getline’
/usr/include/stdio.h:671: note: previous declaration of ‘getline’ was here

I just changed the method name into get_a_line( ... )
it fixed it... using just $ gcc 19.c

So ok. getline was a method already defined in stdio.h

But, thanks!!!! hehe

Yes. I realized that soon after replying.
So sorry and thanks.

But how to correctly terminate the program so it prints out the result ?

/home/me/cwork >./a.out
test
sliz
aaaaaaaaaaaaa

0
^C