C language filelength() function: counts the number of bytes of the file opened by the open() function

Function name : filelength

Header file : <io.h>

Function prototype : int filelength(int handle);

Function : Count the number of bytes of the file opened by the open() function

Parameters : int handle is the file handle to be counted

Return value : Returns the length of the open file

Program example : Use the open function to open a file and count the number of bytes in the file

 #include<stdio.h>#include<io.h>#include<fcntl.h>intmain(void){intfd=open(D:\a.txt,_O_RDWR+O_CREAT);if(fd==-1 ){print f(cannotreatethefilen);return1;}intlen=filelength(fd);printf(thefilelengthis%dn,len);close(fd);printf(OK);return0;}

Running results

 thefilelengthis46