4 Feb Peteris Krumins has a new book, Perl One-Liners Explained. His new book is in the same style as his previous books on awk and sed. the gnarly Perl one-liner for accomplishing short tasks that do not need a complete The -e switch allows me to write Perl scripts directly on the command line. Perl One-liners. Perl one-liners are small and awesome Perl programs that fit in a . I explain this example in detail in one-liner (page 41), but basically you.

Author: Talrajas Mabei
Country: Kenya
Language: English (Spanish)
Genre: Business
Published (Last): 12 March 2008
Pages: 66
PDF File Size: 11.80 Mb
ePub File Size: 13.28 Mb
ISBN: 139-4-92116-406-2
Downloads: 68231
Price: Free* [*Free Regsitration Required]
Uploader: Malar

Generate a random 8 character password In most environments onne-liners passwords have to consist of 6 characters with at least 1 capital and ending with 2 numbers e. Literally every day when I’m programming, I have to do all kinds of data processing tasks, changing files, verifying output, doing quick calculations, parsing data, etc, and knowing Perl one-liners makes it really fast to get things done.

The filename can be used when sending output to a new command that needs the original on-liners. It slurps lines paragraph wise, then appends N-1 new-line.

Enter your email address:. Regex facilities for text processing were first implemented by Ken Thompson, long before Perl. On Solaris it reboots the machine.

I tried a few things on my own, but didn’t get anywhere with this, and have a feeling that this is an important concept for me to get. The unless statement is equivalent to if notbut is different from if! I recommend the practices outlined in Perl Best Practices when developing scripts or applications with Perl. The most amazing achievement of the computer software industry is its continuing cancellation of the steady and staggering gains made by the computer hardware industry.


I am under source control so there’s no harm in just operating right on the files. I’m new to Perl and was searching for a basic tutorial. The subject “File Spacing” is less than clear, it doesn’t tell me what to expect. Also, the subject is awfully narrow. This one-liner does just that.

I have written my fourth book!

Leave a new one-linfrs. In most environments the passwords have to consist of 6 characters with at least 1 capital and ending with 2 numbers e.

Perl Regex One-Liner Cookbook

Not that there aren’t any programs that can do the same thing, they can; but they’re clumsy, unstable, require much more work on my part than a simple perl script and they explanied always incomplete they do ALMOST exactly what you need, with perl scripts you make it do EXACTLY what you need. Fun factoid most have forgotten: If you feel unproductive or uncomfortable with Perl, you should avoid it and use whatever language strikes your fancy.

By using “-e” you can handily specify the program to execute on the command line. Interesting, didn’t know of that reason for using pkill – thanks. To alter the last line of a file with an in-place edit, use the eof function as explainned test:. Follow me on Twitter for my latest adventures!

I use some tilde-delimited. Fifteenth site in online tools network: UNIX one-liner to kill a hanging Firefox process: It’s definitely possible to do that. Thank you so much.

Allor list all the files via a Unix shell command.

Perl One-Liners Explained

Fun to find out when logged in as root. You don’t even need to have done any real Perl programming to get a lot out of that book, but if you want to learn Perl it will help you as well. I am starting yet another article series here. Fixed in the article. Perl6 also does numeric division properly and, if I’m not mistaken, eliminates NPEs so what’s not to like? The “x” operator repeats the thing on the left N times.


Let’s take a look at several practical examples that you can easily do with one-liners. Anno, thank you for your review. It includes the table of contents, preface, introduction to Perl one-liners and the first page of the second chapter.

: Perl One Liners

One-,iners Krumins pkrumins Permalink. All the other newlines get ignored. Your twitter handle, if you have one. This one-liner uses “-n” flag. This one-liner deletes all repeated blank lines from the input or from the given file. As far as I understand it, regexps were originally a part of ed having been derived from QEDthe original Unix text editor.

Perl One Liners

Please download the e-book preview to read it. I haven’t checked every technical detail, I’ll trust you to get that right. And Perl was, I think, the first first-class scripting language that integrated regexes so closely to control structures and other language features in a way that feels truly natural.

Perl uses the -0 one-linees to allow changing the input record separator. Is there a one-liner for that too? One liners may be used as quick example code, or could be found in someone?