Notes

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


#define BUFFER_SIZE 1000


/* Function declarations */
int indexOf(FILE *fptr, const char *word, int *line, int *col);


int main()
{
FILE *fptr;
char path[100];

char word[50];

int line, col;


/* Input file path */
printf("Enter file path: ");
scanf("%s", path);

/* Input word to search in file */
printf("Enter word to search in file: ");
scanf("%s", word);


/* Try to open file */
fptr = fopen(path, "r");

/* Exit if file not opened successfully */
if (fptr == NULL)
{
printf("Unable to open file.n");
printf("Please check you have read/write previleges.n");

exit(EXIT_FAILURE);
}


// Find index of word in fptr
indexOf(fptr, word, &line, &col);

if (line != -1)
printf("'%s' found at line: %d, col: %dn", word, line + 1, col + 1);
else
printf("'%s' does not exists.", word);


// Close file
fclose(fptr);

return 0;
}


/**
* Finds, first index of a word in given file. First index is represented
* using line and column.
*/
int indexOf(FILE *fptr, const char *word, int *line, int *col)
{
char str[BUFFER_SIZE];
char *pos;

*line = -1;
*col = -1;

while ((fgets(str, BUFFER_SIZE, fptr)) != NULL)
{
*line += 1;

// Find first occurrence of word in str
pos = strstr(str, word);

if (pos != NULL)
{
// First index of word in str is
// Memory address of pos - memory
// address of str.
*col = (pos - str);
break;
}
}


// If word is not found then set line to -1
if (*col == -1)
*line = -1;

return *col;
}