File Size using C program in Linux and Windows

Get file size using stat() function

/*C program to find the size of a file in Linux.*/

#include <stdio.h>
#include <sys/stat.h>

/*function to get size of the file.*/
long int findSize(const char* file_name)
{
    struct stat st; /*declare stat variable*/

    /*get the size using stat()*/

    if (stat(file_name, &st) == 0)
        return (st.st_size);
    else
        return -1;
}

int main()
{
    char i;
    FILE* fp; /*to create file*/
    long int size = 0;

    /*Open file in write mode*/
    fp = fopen("temp.txt", "w");

    /*writing A to Z characters into file*/
    for (i = 'A'; i <= 'Z'; i++)
        fputc(i, fp);

    /*close the file*/
    fclose(fp);

    /*call function to get size*/
    size = findSize("temp.txt");

    if (size != -1)
        printf("File size is: %ld\n", size);
    else
        printf("There is some ERROR.\n");

    return 0;
}

Output:

File size is: 26

Get file size using fseek() and ftell() function

/*C program to find the size of a file in Linux and Windwos.*/

#include <stdio.h>

int main()
{
    FILE* fp; /*to create file*/
    long int size = 0;

    /*Open file in Read Mode*/
    fp = fopen("temp.txt", "r");

    /*Move file point at the end of file.*/
    fseek(fp, 0, SEEK_END);

    /*Get the current position of the file pointer.*/
    size = ftell(fp);

    if (size != -1)
        printf("File size is: %ld\n", size);
    else
        printf("There is some ERROR.\n");

    return 0;
}

Output:

File size is: 26