Head First C book example

[keisu]

I don't get something from the book to run

#include <stdio.h>
#include <string.h>


char tracks[][80] = {
        "I left my heart in Harvard Med School",
        "Newark, Newark - a wonderful town",
        "Dancing with a Dork",
        "From here to maternity",
        "The girl from Iwo Jima",
};


void find_track(char search_for[])
{
    int i;
    for (i = 0; i < 5; i++) {
        if (strstr(tracks[i], search_for))
            printf("Track %i: '%s'\n", i, tracks[i]);
    }


}


int main(void)
{
    char search_for[80];
    printf("Search for: ");
    fgets(search_for, 80, stdin);
    find_track(search_for);


    return 0;
}

if anyone could help I'd be grateful
thanks
Mike

edit: What I meant was: it runs, but it doesn't produce the correct results. It shows nothing, where I expect to get something for writing a substring, for example "town"

[Adak]

What errors or warnings are you receiving?

The first thing I see is that search_for is being sent to find_track, but when it arrives, find_track will be receiving a pointer to search_for: char *search_for.

[keisu]

What errors or warnings are you receiving?

The first thing I see is that search_for is being sent to find_track, but when it arrives, find_track will be receiving a pointer to search_for: char *search_for.

Sorry, should have phrased myself a little differently. I don't get any errors/warnings(from my IDE at least). It just doesn't produce the correct result, when I run the program and type "town", I'm supposed to get
"Newark, Newark - a wonderful town"
But I dont get anything.

[Adak]

Well disregard my comment above. I tend to just do these things, automatically.

OK. Add this to main(), right after the fgets(), to remove the newline that is the monkey wrench in the code.

  int len;
  len = strlen(search_for);
   if(search_for[len-1]=='\n')
      search_for[len-1]='\0';

And all is well.

[oogabooga]

fgets leaves the newline character at the end of the string. A common idiom to remove it is:

char *p;
// ...
fgets(buffer, sizeof buffer, stdin);
if ((p = strchr(buffer, '\n')) != NULL)
    *p = 0;

[keisu]

fgets leaves the newline character at the end of the string. A common idiom to remove it is:

char *p;
// ...
fgets(buffer, sizeof buffer, stdin);
if ((p = strchr(buffer, '\n')) != NULL)
    *p = 0;

Thanks it works. But just to see if I understand that code snippet correctly. strchr returns a pointer to the character's location, if found, otherwise it returns null.
And *p = 0 removes it?

It would seem the author got the example wrong anyway. Guess thats to be expected if one purchases the early release of a book.

[oogabooga]

But just to see if I understand that code snippet correctly. strchr returns a pointer to the character's location, if found, otherwise it returns null. And *p = 0 removes it?

Yes. If you entered hello, then the array right after fgets would contain h e l l o \n \0 x x x x .... (where x represents arbitrary byte values). fgets retains the newline (if there is space for it) and ensures that the string is zero-terminated. If p = strchr(buffer, '\n') returns non-null then p points to the newline character and *p = 0 sets that array element to 0, giving h e l l o \0 \0 x x x x ....