UNIX for Beginners Questions & Answers

I think some clarification about "hidden files" is in order, because it seems this in first place has lead to the confusion:

"Hidden files" is a concept going back to the MS-DOS ("FAT") file system. There was an attribute in the directory entry marking a file "hiidden" (or not hidden) and all programs processing or creating file lists didn't show files with this attribute set as long as not explicitly told to do so.

There is no such concept at all in place in UNIX filesystems! In fact "ls" by convention does not display file(name)s starting with a "." unless told otherwise by the use of the "-a" switch. Still, this is only "ls" and it makes the files/directories any special at all. The whole mechanism is just to allow for the rc-files, config directories and other things one is "normally" not interested in to be filtered from display when doing an "ls". But that is no attribute inherent to the file, it is just a mechanism inside "ls".

I hope this helps.

bakunin

Thank you, bakunin, for that tidbit. Wasn't sure how to refer to the dot-prefixed file and dir naming convention/scheme apart from how it is dubbed by others out here in the wild; hence the chosen title for my post.

@Aia:
Thanks for letting me know which entity(?) is being passed along to Perl in this particular situation. I'd suspected as much, but was unable to banish the offending code appendage during my learning exercises the other day.

On other points, I have a question for you: Is it better to have more or less information in any particular coding scenario? Sending commands to the system via Perl is an accepted and widespread practice; and one which could be of overall benefit to others at some junctures.

Case in point: a friend of mine is an Electrophysicist of near-retirement age who dabbles in Perl; and only recently discovered the use of backticks in passing along system commands. After our conversation, he was grateful for the information; and began his own digging in that direction. In the context of this microcosm, perfecting one's crossover capabilities in this area of Perl codewriting is, I believe, a worthy undertaking for folks from all walks who may visit here...

That being said, the personal comments in your last post came across, quite frankly, as insular and strident; particularly in light of the forum in which the OP was posted. Some who visit these pages may have to deal with that type of interaction on a regular basis in real life and in potentially serious matters; and come to unix.com to relax, learn, and pursue better things.

At any rate, all the best to you; and many thanks for the valuable contributions which you present in these forums.

Good day, all!

Hi, LinQ

Please, do not misunderstand my point. Using the back ticks and any other facilities that Perl has to make a system call is perfectly acceptable when the need arise (apart from getting abused most of the time). My comment was referring specifically to "your" specific attempt in the while loop you shown. Using ls -a ... | grep ... (eq or ge) something in a while loop is a broken code, it does not work, even if it appears to work to you and the only way to fix it is to not use it.
Sorry, if that's not agreeable to you. Next time, I will try to remember to keep my keyboard as inactive as tits on a boar.