Perl Boot Camp, Part 7: perldoc (Unix Power Tools, 3rd Edition)
41.10. Perl Boot Camp, Part 7: perldoc
We all need a little help sometimes, and it's at
those times that perldoc comes in handy. Normally,
core Perl and module documentation is accessible through your
system's manpage system, but you
can also use the perldoc program, which has a few
convenient features that you should be aware of. Like
man, perldoc takes the name of
a module or core Perl document as an argument.
Your system's perl comes bundled
with hundreds of pages of very readable documentation. The top of the
document tree can be accessed with either perldoc
perl or man perl. This page is little
more than a table of contents[126] for the rest of the perl
documentation. There are over 40 documents listed there, but there
are a couple that will be immediately useful to novice Perl
programmers, as Table 41-10 shows.
[126]There's actually a more complete table of
contents available: man perltoc.
Table 41-10. Frequently used Perl manpages
Name
Description
perlsyn
The complete guide to Perl syntax
perldata
Perl's data types explained
perlop
Perl's operators and their precedence
perlfunc
The complete guide to all of Perl's built-in
functions
perlre
The complete guide to Perl's regular expressions
In many cases (such as the ones above), perldoc
doesn't do anything man
can't. However with perldoc, you
can easily look up built-in Perl functions with the
-f flag (-t formats any POD
elements for a text console). For instance, to see the entry on
print, try this:
$ perldoc -tf print
You'll get back something like the following (which
has been abbreviated):
print FILEHANDLE LIST
print LIST
print Prints a string or a list of strings. Returns
true if successful. FILEHANDLE may be a scalar
variable name, in which case the variable contains
the name of or a reference to the filehandle, thus
introducing one level of indirection.
...
Perl has quite a large FAQ. You can read each of the nine sections
(perlfaq1 through perlfaq9)
to find the answer to your question or you can use the
-q flag to keyword search all of the FAQ.
$ perldoc -q fork
Found in /usr/local/lib/perl5/5.6.1/pod/perlfaq8.pod
How do I fork a daemon process?
If by daemon process you mean one that's detached (disas-
sociated from its tty), then the following process is
reported to work on most Unixish systems. Non-Unix users
should check their Your_OS::Process module for other solu-
tions.
...
Do take advantage of the copious documentation already on your
system: you will be reward many times over.
-- JJ
41.9. Perl Boot Camp, Part 6: Modules41.11. CPAN
Copyright © 2003 O'Reilly & Associates. All rights reserved.
Wyszukiwarka
Podobne podstrony:
ch41CH41 (2)ch41ch41ch41ch41ch41ch41 (3)ch41ch41ch41ch41ch41CH41ch41ch41ch41ch41więcej podobnych podstron