Shell Programming and Scripting

I'm running in CentOS Linux, but this is a core unix question:
> ls */a/b/*.*
list hundreds of files with several extensions and I'd like not to lists those with extension ".o", say. So, after checking the man page for ls, I tried
> ls -I "*.o" */a/b/*.*
and
> ls --ignore="*.o" */a/b/*.*
but both still got me the *.o files.
Why weren't they ignored as expected? Shouldn't 'ls -I="*.o"' make ls skip all files that end in '.o' ?
I even tried
> ls --ignore="*/a/b/*.o" */a/b/*.*
but same results: the .o files were listed -uff!

Another way is to use grep with the -v option to suppress those files:

Code:

ls <whatever> | grep -v '.o$'

Thanks, this works. I'm still interested in knowing why the ignore option of ls doesn't work as indicated in the man page.

That's a good question.

Code:

ls --ignore=PATTERN

where PATTERN is a REGEX in quotes should work...

but I can't get it to work on Linux regardless of the REGEX I use

I have never used the --ignore option, as I always use |grep -v, but it is interesting why it does not work.

According to the info pages pattern is not a regex but what is called a "shell pattern" with which I guess they mean globbing. I noticed it does not seem to work when the file list contains a wild card.

So this works:

Code:

ls -l -I '*.o'

But this does not:

Code:

ls -ld -I '*.o' *

So see if this works:

Code:

ls -R --ignore='*.o'

According to many man pages "shell pattern" == REGEX which seems like some of the confusion... because I agree regular expressions do not work.

simply using

Code:

ls -I "*.o"

doesn't help when what you want to list is distributed over many directories, as in the original question

Code:

ls */a/b/*.*

The man ls page in my system shows that for -I PATTERN PATTERN is a Shell PATTERN. But since ls -I *.o works on the current directory, it must be the right pattern. Confusing little issue, indeed.