UNIX for Dummies Questions & Answers

Hi,
I need a help with zip and tar. I have no done any scripts before with zip command.

What I need to achieve is list files in a directory with a specific name (ID_DATE format- given examples) and then zip (or gunzip which I need to use, I am not sure) with timestamp on the file name and then take all these files and tar them to one single file and move to another directory.

examples below:

cd landing
cd archival

cd archival

I wrote the below script, but it zips all the files into one single file instead of zipping them individually.. can some one help me?

thanks!

.zip is a container, not just a form of compression, which is why you end up with lots of files in one folder.

Try gzip, which is pure compression. gzip 1 2 3 will compress the files 1, 2, and 3 into 1.gz, 1.gz, and 3.gz for example.

thanks for the response Corona688.

Do you mean .gz itself is a package which compresses multiple files to individual .gz files?

I am not sure what happens in my script, I changed to gzip as you mentioned and would like to .gz files individually and then tar them to a single file.

Below is my script which gzips multiple files to one file instead of individual .gz files.
can someone please help?

No. A .gz file is a data stream with no particular content. It might be used to hold a single compressed file, like I demonstrated. It might be used to hold a tarball. Lots of different UNIX compressors work like this -- they compress a data stream and don't care one bit about the finer details of the contents. This is very different from a .zip file which knows what the 3000 files in it are.

Often it's paired with tar though, which is a bit like a .zip without compression. The nice thing about tar though, is that it's streamable -- you don't need the entire file to start extracting it, etc. Any particular reason? Usually what happens is the exact opposite -- create a tarball(bundle of files slapped together with tar), and compress that. That's what a .tar.gz is.

Code:

tar -zcf filename.tar.gz folder/

Without knowing anything about what data your script is reading from it's awful hard to see what's going wrong with it why.

thanks for your inputs corona688. My script is getting some input parameters which helps it to find the file names and then lists all the files with specific names and gunzip and tars them to an archive folder. Timestamp is added as part of the tar-red file name to have an option to store multiple files on a day.

I have modified the script to do tar instead of gzip.. please find the modified script attached, I see that a .tar.gz file is created. But in order to verify that it has tar-red properly, I would like to unzip (or do what ever is required) to see the files back in its original state. Can you please help me with how to get the original files seperately?

Also, I am getting the error message below when I run the script.. can you please advice?

SCRIPT:
Error message:

Thanks!

Without seeing what your input files look like, I still have no idea what your script is doing. Post a sample, mangled if you must, but a sample of your input data so I can see what your program is supposed to be doing! What's your system? Some versions of tar have a verify option.

The error message is not an error, by the way, just a warning. It means what it says -- in storing the files, it converts '/path/to/file' into 'path/to/file' so it's not an absolute path any more.

What's more worrying is that you're running it more than once, which makes no sense at all, since tar can hold multiple files.

Please post a sample of your input data!

Hi Corona,

Please find the input files. What I am trying to achieve is zip all of these files and then tar them to a single file with the timestamp appended to the tar file name.

thanks!