September 2012
Beginner
744 pages
15h 48m
English
Content preview from Beginning PerlBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Chapter 9
Files and Directories
WHAT YOU WILL LEARN IN THIS CHAPTER:
- Understanding files handling
- Working with directories
- Understanding Unicode and Unicode rules
- Useful file manipulation modules
Up to this point, except for a brief discussion of @ARGV in Chapter 3, the data in your program has been embedded in the program, which isn’t useful. In the real world, we’re constantly reading data from files, Web services, databases, and a variety of other sources. This chapter introduces you to the basics of reading and writing to files and directories.
WROX.COM CODE DOWNLOAD FOR THIS CHAPTER
The wrox.com code downloads for this chapter are found at www.wrox.com/remtitle.cgi?isbn=1118013847 on the Download Code tab. The code for this chapter is divided into the following major examples:
- .targets.txt.swp
- .tree.pl.swo
- .tree.pl.swp
- example_9_1_spies.pl
- example_9_2_tree.pl
- listing_9_1_targets.pl
- listing_9_2_reading_from_data.pl
- spies1.txt
- spies2.txt
- spies3.txt
- spies4.txt
- targets.txt
BASIC FILE HANDLING
As you probably know by now, most common operating systems have their data internally organized around files and directories. Even if the data is stored in a database, it’s probably represented as files somewhere. Perl makes it easy to read and write files, and you can see the most common ways to do that.
Opening and Reading a File
For this section, type the following into a file named targets.txt in a directory named chapter_9.
James|007|Spy Number 6|6|Ex-spy Agent 99|99|Spy with unknown ...Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.