Reading & Displaying each line from File

#include <stdio.h>
int main(void){
FILE *fpt; // file pointer
char c,d;
char str[50];
fpt=fopen("test.csv","r"); // file already exit for reading
if(fpt==NULL)
    printf("Can't open file ");
else {
while(fgets(str,50,fpt)){
puts(str);
}
 
}
fclose(fpt);
return 0;
}

id,name,class,mark,gender

1,John Deo,Four,75,female

2,Max Ruin,Three,85,male

3,Arnold,Three,55,male
------
------
------

Getting the first line of data

if(fgets(str,50,fpt)){
puts(str);
}

id,name,class,mark,gender

Example: Reading Until End of File

#include <stdio.h>

int main() {
    FILE *file;
    char line[100];
    file = fopen("data.txt", "r");

    if (file == NULL) {
        printf("Error opening file.\n");
        return 1;
    }

    while (!feof(file)) {
        if (fgets(line, sizeof(line), file) != NULL) {
            printf("%s", line);
        }
    }

    fclose(file);
    return 0;
}

Example 1: Reading a File Line by Line

This example demonstrates how to read a text file line by line using fgets().

#include <stdio.h>

int main() {
    FILE *file;
    char line[256];
    
    file = fopen("example.txt", "r");
    if (file == NULL) {
        printf("Error opening file.\n");
        return 1;
    }

    while (fgets(line, sizeof(line), file)) {
        printf("%s", line);
    }
    
    fclose(file);
    return 0;
}

This is the content of example.txt file.
Each line will be printed until the end of the file.

Example 2: Handling File Errors

This example shows how to handle errors when trying to open a file.

#include <stdio.h>

int main() {
    FILE *file;
    
    file = fopen("nonexistent.txt", "r");
    if (file == NULL) {
        perror("Error opening file");
        return 1;
    }
    
    fclose(file);
    return 0;
}

Error opening file: No such file or directory

Example 3: Reading File Data into Variables

This example reads numerical data from a file into variables using fscanf().

#include <stdio.h>

int main() {
    FILE *file;
    int num;
    float price;
    
    file = fopen("data.txt", "r");
    if (file == NULL) {
        printf("Error opening file.\n");
        return 1;
    }

    while (fscanf(file, "%d %f", &num, &price) == 2) {
        printf("Product ID: %d, Price: %.2f\n", num, price);
    }
    
    fclose(file);
    return 0;
}

Product ID: 101, Price: 25.99
Product ID: 102, Price: 15.75