C check string's from a text file - c

Question

I am new at c and I am writing a code that get a string from the user and compare it to a strings from the text file and my code is only working when I compare between two characters and when I compare between two strings it's not working If someone know how can I fix the problem it's will be verey helpful. the compare line is in the searchFile function. the text file is a csv file so insted compare the char to string I need to compare between what befor the , to the string_to_search. example for csv file at the end of the code
Example: string to search = 'c' work, string to search 'name' doesn't work
#include <stdio.h>
#define STR_LEN 100
int searchFile(char* string_to_search, char* path);
int main(int argc, char* argv[])
{
FILE* text_file = 0;
int found = 0, choice = 0;
char string_to_search[STR_LEN] = {0};
if (!(fopen(argv[1], "r") == NULL)) //check if file exists
{
do
{
printf("Please enter your choice:\n");
printf("1 - Search a term in the document.\n");
printf("2 - change a value in a specific place.\n");
printf("3 - copy a value from one place to another\n");
printf("4 - Exit\n");
scanf("%d", &choice);
getchar();
switch (choice)
{
case 1:
fgets(string_to_search, STR_LEN, stdin);
string_to_search[strcspn(string_to_search, "\n")] = 0;
found = searchFile(string_to_search, argv[1]); //found = where the string line
if (found != 0)
printf("Value was found in row %d\n", found);
else
printf("Value Wasn't Found\n");
}
}while(choice != 4);
}
else
{
printf("file does not exists\n");
}
getchar();
return 0;
}
int searchFile(char* string_to_search, char* path)
{
FILE* file = fopen(path, "r");
char ch = ' ';
int i = 0, len = 0, count = 1;
fseek(file, 0, SEEK_END);
len = ftell(file);
fseek(file, 0, SEEK_SET);
len = len - 2;
char* string = (char*)malloc(sizeof(char) * len);
do //copying the chars to a string
{
ch = fgetc(file);
string[i] = ch;
i++;
} while (ch != EOF);
fclose(file);
for (i = 0; i < len; i++)
{
if (string[i] == *string_to_search) //the compare
{
free(string);
return count;
}
if (string[i] == '\n')
{
count++;
}
}
free(string);
return 0;
}
Example for a CSV file:
roee,itay,3,4
5,6,7,8
a,b,c,d
e,f,g,h

Answer 1

You have to change the following line:
if (string[i] == *string_to_search) //the compare
into
if (string[i] == string_to_search[i]) //the compare
The problem is that *string_to_search always refers to the first character of string_to_search. With the [i] you will get the nth character of the string as you have done it for the variable string. So as you noticed it works for a comparsion of two characters but not for two strings, because on a string you will always compare with the first character of string_to_search. For example if you want to compare "aaa" it will also work.
But as noted in the comment section you may also want to use strcmp() instead of the loop. There you will also have to pass string_to_search and not *string_to_search, because you want to pass the pointer to the string and not a single character.