find a word in a file in c code example

Example 1: search a word in a string in c

/**
 * C program to find last occurrence of a word in given string
 */

#include <stdio.h>
#include <string.h>
#define MAX_SIZE 100 // Maximum string size

int main()
{
    char str[MAX_SIZE];
    char word[MAX_SIZE];
    int i, j, found;

    /* Input string and word from user */
    printf("Enter any string: ");
    gets(str);
    fflush(stdin);
    printf("Enter any word to search: ");
    gets(word);

    /*
     * Run a loop from starting index of string to
     * length of string - word length
     */
    for(i=0; i<strlen(str) - strlen(word); i++)
    {
        // Match word at current position
        found = 1;
        for(j=0; j<strlen(word); j++)
        {
            // If word is not matched
            if(str[i + j] != word[j])
            {
                found = 0;
                break;
            }
        }

        // If word have been found then print found message
        if(found == 1)
        {
            printf("'%s' found at index: %d \n", word, i);
        }
    }

    return 0;
}

Example 2: how to search in a file in c

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

int main(int argc, char const *argv[])
{
int num =0;
char word[2000];
char *string[50];

FILE *in_file = fopen("student.txt", "r");
//FILE *out_file = fopen("output.txt", "w");

if (in_file == NULL)
{
    printf("Error file missing\n");
    exit(-1);
}

while(student[0]!= '0')
{
    printf("please enter a word(enter 0 to end)\n");
    scanf("%s", student);


    while(!feof(in_file))
    {
        fscanf(in_file,"%s", string);
        if(!strcmp(string, student))==0//if match found
        num++;
    }
    printf("we found the word %s in the file %d times\n",word,num );
    num = 0;
}

return 0;
 }