UNIX for Dummies Questions & Answers

Hello all,

I'm sorry if this is answered elsewhere, I've used the search function and can't find the specifics of what I'm after.

I am brand new to playing with linux, and ideally I want to get better to help the company that I now work for.

What I want to do:
Create a script that I can run daily to check for differences from today to yesterday on my linux server.

My Idea
Use a DF command and record the information from it in a file named size_DDMMYY
Search for every file/folder name on the linux server and write them to a file named linux_DDMMYY
Compare yesterdays size_DDMMYY to todays size_DDMMYY and write the size difference to a file named sizeDiff_DDMMYY
Compare yesterdays linux_DDMMYY to todays linux_DDMMYY and write the difference (new files added, old files deleted) to a file named linuxDiff_DDMMYY

My problem:
At the moment I haven't written any code down, I'm just writing/testing ideas on how to go about this. I've been playing with the diff command but have hit a brick wall. It appears that the diff command compares:
line1 in file1 to line1 in file2 and
line2 in file1 to line2 in file2 etc.

If my linux_DDMMYY output file has new files added to it or old files removed, the diff command would be ineffective (due to line checking not string checking)

What I want it to do(i think) is grab the string from line1 in file1 and search file2 for the same string and then move to the next line in file1 etc.

At the moment I've concluded that using a diff command isn't going to help, i've gone through the other commands that can be used with diff but have yielded no ideal results.

Any help or insight would be greatly appreciated.

Thanks in advance,
Mick

For you idea - it's better to use find:
To find all files modified between 24 and 48 hours ago in DIRECTORY and its suddirectories:

Code:

find DIRECTORY -ctime 1 -type f

To find all the files that were modified yesterday from the current working directory and all of its subdirectories:

Code:

find . -daystart -ctime 0 -type f

For your problem - it's possible to use associative arrays from any scripting language - look for "Finding Elements in One Array but Not Another" on PLEAC in chapter 4 "Arrays".

I don't appear to get an output when I run this?

Just wondering if I'm able to get a datestamp and filesize in the output?
Either way this is very useful, adding > filename to the end allowed me to save it in a file.

Thanks very much : )


P.S. i tried adding -al and -l on the end of find . -daystart -ctime 0 -type f but got an error saying "invalid predicate"

You can pipe so:

Code:

find ... | xargs ls -l

Thanks heaps, I'm not real familiar with this sorta thing as you may have noticed but I learnt a new terminology, pipe. ^.^

Not to push your good will, but now that I have files being updated with the relevant information, is there any language you'd suggest to create an array to compare two lists?
Ideally I just want to compare the difference between the size of the same file from one day to the next. As a newbie programmer, arrays have always been less than friendly towards me.