Errors compiling example from ANSI C book, Linked Lists chapter

Question

I am doing some examples out of an older C book [A First Book of ANSI C] and am getting an error while trying to compile this example code:

#include <stdio.h>

struct tele_typ {
  char name[30];
  char phone_no[15];
  struct tele_typ *nextaddr;
};

main() {
  struct tele_typ t1 = {"Acme, Sam", "(201) 555-6678"};
  struct tele_typ t2 = {"Dolan, Edith", "(213) 682-3104"};
  struct tele_typ t3 = {"Lanfrank, John", "(415) 718-4581"};
  tele_typ *first;    /* create a pointer to a structure */

  first = &t1;          /* store t1's address in first */
  t1.nextaddr = &t2;    /* store t2's address in t1.nextaddr */
  t2.nextaddr = &t3;    /* store t3's address in t2.nextaddr */
  t3.nextaddr = NULL;   /* store the NULL address in t3.nextaddr */

  printf("\n%s %s %s",first->name,t1.nextaddr->name,t2.nextaddr->name);
}

..and the output from gcc newstruct.c -o newstruct:

newstruct.c: In function 'main':
newstruct.c:13:3: error: unknown type name 'tele_typ'
newstruct.c:15:9: warning: assignment from incompatible pointer type [enabled by default]
newstruct.c:20:28: error: request for member 'name' in something not a structure or union

It's chapter 10.4 on Linked Lists. Is there an error in the book? or has something changed in the standards/gcc version 4.6.2 20120120 (prerelease)? Thank you!

Answer 1

I couldn't reproduce the first warning; are you sure the code you've pasted here is the code that gives you the warning?

The error unknown type name 'tele_typ' is easy to fix: you've declared a type struct tele_typ, but don't have the struct in front of the line:

  tele_typ *first;    /* create a pointer to a structure */

If you change this to:

  struct tele_typ *first;    /* create a pointer to a structure */

It'll compile without error. (And also without warnings in my gcc-4.5.real (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2.)

If you wanted to compile the function body exactly as-is, then you'd also want to add:

typedef struct tele_typ tele_typ;

immediately after the struct tele_typ definition:

struct tele_typ {
  char name[30];
  char phone_no[15];
  struct tele_typ *nextaddr;
};

typedef struct tele_typ tele_typ;

But I'm a little worried about a C book that doesn't give the main() function a return type or typed parameters. int main(int argc, char* argv[]) or int main(int argc, char** argv) is usual, and any book that deviates from these two options strikes me as a little strange. The C Programming Language is a fine book; it is hard to improve upon it for its clarity and correctness. Consider switching to the original.