Q1:

On executing the below program what will be the contents of 'target.txt' file if the source file contains a line 'To err is human'?

#include<stdio.h>

int main()
{
    int i, fss;
    char ch, source[20] = 'source.txt', target[20]='target.txt', t;
    FILE *fs, *ft;
    fs = fopen(source, 'r');
    ft = fopen(target, 'w');
    while(1)
    {
        ch=getc(fs);
        if(ch==EOF)
            break;
        else
        {
            fseek(fs, 4L, SEEK_CUR);
            fputc(ch, ft);
        }
    }
    return 0;
}

The file source.txt is opened in read mode and target.txt is opened in write mode. The file source.txt contains 'To err is human'. Inside the while loop, ch=getc(fs); The first character('T') of the source.txt is stored in variable ch and it's checked for EOF. if(ch==EOF) If EOF(End of file) is true, the loop breaks and program execution stops. If not EOF encountered, fseek(fs, 4L, SEEK_CUR); the file pointer advances 4 character from the current position. Hence the file pointer is in 5th character of file source.txt. fputc(ch, ft); It writes the character 'T' stored in variable ch to target.txt. The while loop runs three times and it write the character 1st and 5th and 11th characters ('Trh') in the target.txt file.