Tried the code from the other posts, they dont work

Using standard/IO Library, write lab.c program that returns how many character in a file using fseek() and ftell():

>>gcc lab4.c o lab4

>>./lab4 a.txt

This C program will return how many characters in a.txt. So if a.txt contains:

abcdefghijklmnopqrstuvwxyz

it will return:

Number of characters is 26