## Homework

 1. Write a C program ‹sync.c› and a shell script ‹sync.sh›.
 2. The C program should ‹fork()› & the child should then ‹exec()›
    the script.
 3. The parent process:
    
    a. waits until ‹file1.txt› appears
    b. when it does, it copies its content into ‹file2.txt›
    c. waits for the script to finish and prints its exit code
    d. use POSIX ‹read()› and ‹write()› above
    
 4. The shell script:
    
    a. prints its own pid (found in ‹$$›) into ‹file1.txt›
    b. waits until ‹file2.txt› appears
    c. waits a second to make sure the content is written
    d. reads ‹file2.txt› and checks that its content matches
    e. if it matches, ends with exit code 0, otherwise 1
    f. the shell built-in ‹exit 0› and ‹exit 1› can be used for (e)

That is all! Or is it.
