Write a C program that reverses the bytes of a given arbitra

Write a C program that reverses the bytes of a given arbitrary length file and outputs them to another specified file, which should be overwritten if it already exists. So, invoking your program as follows ./reverse infile outfile will result in the first byte of outfile being the last byte of infile, and so on until the last byte of outfile is the first byte of infile. The given filenames are just an example, make your own infile. You must use fseek()/fread()/fwrite().

Solution

ans:

#include<stdio.h>
#include<stdlib.h>
int main()
{
FILE *s;//input file(Source file)
FILE *d; //output file(Destination file i.e in reverse order)
char ch;//to read charcter by character
int i; //loop counter
long int n;//represents number of characters in source file
s=fopen(\"file1.c\",\"r\"); //opens source file in read mode
d=fopen(\"file2.c\",\"w\");//opens destination file in write mode
if(s==NULL || d==NULL)
{
printf(\"file is not opened\");
exit(0);
}

fseek(s,-1L,2);
n=ftell(s); //gives the position of file pointer
n++;
fseek(s,-1L,2);//keeps cursor at last character of the file
while(n){ //loop to read characters for source file
ch=fgetc(s);//used to read one character from source file
fputc(ch,d); //to insert into destination file
if(ch==\'\ \') //if charater is \'\ \'i.e next line
fseek(s,-3L,1);
else
fseek(s,-2L,1);
n--;
}
fclose(s);
fclose(d);
return 0;
}

Output:

file1.c

welcome to siit
venky
ajay

file2.c

yaja
yknev
tiis ot emoclewÿa