I just thought about backing up my home directory to a zip file so I used
zip backup-13-jul-09 .
Then I read about the argument
so I found a file called readme.txt in my home directory opened it and added "Hello World" to the bottom line then performed the
zip -u backup-13-jul-09 .
command but it didn't update the readme.txt file to include "Hello World" on the last line.
Its probably something simple but can someone help me out please?