Words with line numbers

Hello, I would like to know how can I print a line from a string, starting from a specific word. I have the following tasks:
Write a program that prints all lines from input that contain a given word.
Only the part of the line starting with the word must be printed.
Prefix it with the line number.
a) Consider only standalone words.
b) Count also occurrences as substrings in other words.
Handle arbitrarily long words.
a) :

Code:

---

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#define MAX 100
int main()
{
    char s[MAX];
    char mask[MAX];
    char delim[] = "\n.!?, ";
    char wordString[] = "ana";
    unsigned lineCounter = 0;
    unsigned ok;
    while(fgets(s, sizeof s, stdin))
    {
        //printf("%s", s);
        lineCounter++;
        strcpy(mask, s);
        char* word = strtok(mask, delim);
        while(word != NULL)
        {
            if(strcmp(word, wordString) == 0)
            {
                ok = 1; // if a word on the line coincides with the given word, stop comparing words => ok=1
                break;
            }
            else
            {
                ok = 0; // if ok=0 => there is no word coinciding with the given word on the line
            }
            word = strtok(NULL, delim);
        }
        //printf("%d", ok);
        if(ok == 1)
        {


            printf("%d  %s\n",lineCounter, s);
        }
        else
            printf("The line doesn't contain the given word.\n");
    }
    //printf("There are %d lines in the input.", lineCounter);
    return 0;
}

---

Input:
andrew goes shopping.
john saw ana in the park
she goes shooping
ana is singing
Output :
The line doesn't contain the given word.
2 john saw ana in the park // this should be just "ana in the park"
The line doesn't contain the given word.
4 ana is singing

I've solved b) in a similar fashion, only using strstr instead of strcmp, they're both working fine, I just want to know how can I print the line starting from the word I want.(I thought maybe I should use a for loop inside the second while and keep track of the position of the first letter of the word, but I think I'm missing an idea).

As soon as you've got some code working, refactor it to make functions out of it.

Code:

---

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#define MAX 100

int contains_word(const char *buff, const char *find)
{
  char mask[MAX];
  char delim[] = "\n.!?, ";
  strcpy(mask, buff);
  char* word = strtok(mask, delim);
  int ok = 0;
  while(word != NULL)
  {
    if(strcmp(word, find) == 0)
    {
        ok = 1; // if a word on the line coincides with the given word, stop comparing words => ok=1
        break;
    }
    word = strtok(NULL, delim);
  }
  return ok;
}

int main()
{
  char s[MAX];
  char wordString[] = "ana";
  unsigned lineCounter = 0;
  unsigned ok;
  while(fgets(s, sizeof s, stdin))
  {
    lineCounter++;
    if( contains_word(s, wordString) )
    {
      printf("%d  %s\n",lineCounter, s);
    }
    else
    {
      printf("The line doesn't contain the given word.\n");
    }
  }
}

---

Each function has a single well-defined purpose.

> I just want to know how can I print the line starting from the word I want.
> ... but I think I'm missing an idea).
At the point where you do ok = 1, you can do this.

Code:

---

position = word - mask;

---

Later on, you can do this.

Code:

---

printf("%d %s", lineCounter, &s[position] );

---

Quote:

---

Originally Posted by Salem

As soon as you've got some code working, refactor it to make functions out of it.

Code:

---

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#define MAX 100

int contains_word(const char *buff, const char *find)
{
  char mask[MAX];
  char delim[] = "\n.!?, ";
  strcpy(mask, buff);
  char* word = strtok(mask, delim);
  int ok = 0;
  while(word != NULL)
  {
    if(strcmp(word, find) == 0)
    {
        ok = 1; // if a word on the line coincides with the given word, stop comparing words => ok=1
        break;
    }
    word = strtok(NULL, delim);
  }
  return ok;
}

int main()
{
  char s[MAX];
  char wordString[] = "ana";
  unsigned lineCounter = 0;
  unsigned ok;
  while(fgets(s, sizeof s, stdin))
  {
    lineCounter++;
    if( contains_word(s, wordString) )
    {
      printf("%d  %s\n",lineCounter, s);
    }
    else
    {
      printf("The line doesn't contain the given word.\n");
    }
  }
}

---

Each function has a single well-defined purpose.

> I just want to know how can I print the line starting from the word I want.
> ... but I think I'm missing an idea).
At the point where you do ok = 1, you can do this.

Code:

---

position = word - mask;

---

Later on, you can do this.

Code:

---

printf("%d %s", lineCounter, &s[position] );

---

---

Thanks a lot! It's working now but could you please explain something: if we subtract 2 strings, we basically get the difference in memory from the first string to the second, right? If so, why is position = word - mask and not mask - word, since mask is basically the "source"? I know it's fine like this because I tried the second one and it just printed garbage, but why?

Imagine that the address of mask was 1000. Then the address of word would start from 1000 onwards. So, if the address of word is 1004, word - mask = 4, whereas mask - word = -4, which wouldn't make sense as a position.

Quote:

---

Originally Posted by laserlight

Imagine that the address of mask was 1000. Then the address of word would start from 1000 onwards. So, if the address of word is 1004, word - mask = 4, whereas mask - word = -4, which wouldn't make sense as a position.

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Oh okay, got it now. Thanks!