Shell Programming and Scripting

Hi ,

Can some one help me how to pass ls command output to diff command

ex : - ls *.xml will return files which have time stamps

Code:

         abc-<time-stamp>.xml
        xyz-<time-stamp>.xml

           diff   abc-<time-stamp>.xml  xyz-<time-stamp>.xml >> newfile.txt

we need to check this some 30 directories , so we need cd to directory and do ls and then pass file names from ls to diff

---------- Post updated at 07:04 AM ---------- Previous update was at 06:30 AM ----------

Can some one respond quickly

Using terms like "urgent" or "quickly" and/or bumping up posts is not THAT well received in these fora as people are volunteers spending their free time trying to help people solve their problems.

You can help speed up things from your side by giving an excellent specification or description of the problem, respectively, including details of your system and using code tags as required by forum rules.

Assuming you are using a modern bourne type shell, you can use "command substitution" to supply a command's output to e.g. diff. To give a more taylored answer, more info is needed, like
- how many files are in each of those directories?
- check every files against each of the other files?
- all results to the same newfile?
- any dirs in that path to be excluded?

Do you want files that have same name - time-stamp is the same value on both files?
Otherwise you need to be more exact in your requirement - by that I mean: please explain what you are doing -NOT how you think it should be done

If you do differences on every file from each of 30 directories, you will have a mountain of output to deal with. After a long wait. That would be true even if you had only 3 files in each directory.

@ Rudic

- how many files are in each of those directories?
we will have many other files , we need to diff with the first file that was created in each directory of that day and with latest last file at the time of doing diff
- check every files against each of the other files?
No , need to diff from first file that was created in each directory of that day and with latest last file at the time of doing diff
- all results to the same newfile?
yes all results will be same file

we can put come thing echo "========= dir1 ============" in between
- any dirs in that path to be excluded?
no all dirs need to be checked




@ Jim

we need to diff with the first file that was created in each directory of that day and with latest last file at the time of doing diff and output should go single file

So - where lies your problem? Using ls (together with other commands) to gain the two desired filenames, or presenting them to diff?
And, what you specify in post#4 will need a script, more or less, which goes beyond what you said in post#1 and the title. Why don't you start over and give us a detailed spec accompanied with meaningful input and desired output samples? We still don't know your OS nor shell version...

yeah we need script
im looking how we can present the desired files to diff , i hope specification clear

its Redhat 6 OS being used

Is this a homework assignment? Homework assignments must be filed in the Homework & Coursework Questions forum and must include a fully filled out homework template from the Rules for Homework & Coursework Questions forum.

What shell are you using?

Why are you restricting our options by just using ls to get a list of file when find would simplify this task?