"ri”って何だ？
rubyの「ri」は、perlにおけるperldocのような存在(らしい…)。
CentOS5にデフォルトではinstallされていなかったのでinstallしてみた。
# yum install ri Loading "installonlyn" plugin Loading "fastestmirror" plugin Setting up Install Process Setting up repositories base 100% |=========================| 1.1 kB 00:00 updates 100% |=========================| 951 B 00:00 addons 100% |=========================| 951 B 00:00 extras 100% |=========================| 1.1 kB 00:00 Loading mirror speeds from cached hostfile Reading repository metadata in from local files Parsing package install arguments Resolving Dependencies --> Populating transaction set with selected packages. Please wait. ---> Downloading header for ruby-ri to pack into transaction set. ruby-ri-1.8.5-5.el5.i386. 100% |=========================| 1.0 MB 00:04 ---> Package ruby-ri.i386 0:1.8.5-5.el5 set to be updated --> Running transaction check --> Processing Dependency: ruby-rdoc = 1.8.5-5.el5 for package: ruby-ri --> Restarting Dependency Resolution with new changes. --> Populating transaction set with selected packages. Please wait. ---> Downloading header for ruby-rdoc to pack into transaction set. ruby-rdoc-1.8.5-5.el5.i38 100% |=========================| 25 kB 00:00 ---> Package ruby-rdoc.i386 0:1.8.5-5.el5 set to be updated --> Running transaction check Dependencies Resolved ============================================================================= Package Arch Version Repository Size ============================================================================= Installing: ruby-ri i386 1.8.5-5.el5 base 1.7 M Installing for dependencies: ruby-rdoc i386 1.8.5-5.el5 base 135 k Transaction Summary ============================================================================= Install 2 Package(s) Update 0 Package(s) Remove 0 Package(s) Total download size: 1.8 M Is this ok [y/N]: y Downloading Packages: (1/2): ruby-ri-1.8.5-5.el 100% |=========================| 1.7 MB 00:06 (2/2): ruby-rdoc-1.8.5-5. 100% |=========================| 135 kB 00:00 Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing: ruby-rdoc ######################### [1/2] Installing: ruby-ri ######################### [2/2] Installed: ruby-ri.i386 0:1.8.5-5.el5 Dependency Installed: ruby-rdoc.i386 0:1.8.5-5.el5 Complete! #
使用例(１)
- 失敗
# ri print
More than one method matched your request. You can refine
your search by asking for information on one of:
CGI::print, CGI#print, Zlib::GzipWriter#printf,
Zlib::GzipWriter#print, Kernel#sprintf, Kernel#printf,
Kernel#print, MatchData#pretty_print, Hash#pretty_print_cycle,
Hash#pretty_print, File::Stat#pretty_print,
Racc::Parser#racc_print_stacks, Racc::Parser#racc_print_states,
RI::TextFormatter#bold_print, RI::TextFormatter#raw_print_line,
RI::HtmlFormatter#bold_print, RI::OverstrikeFormatter#bold_print,
RI::AttributeFormatter#bold_print, RI::AnsiFormatter#bold_print,
DEBUGGER__::Context#debug_print_help, Range#pretty_print,
Struct#pretty_print_cycle, Struct#pretty_print,
Array#pretty_print_cycle, Array#pretty_print,
PP::ObjectMixin#pretty_print_cycle, PP::ObjectMixin#pretty_print,
PP::ObjectMixin#pretty_print_instance_variables,
PP::ObjectMixin#pretty_print_inspect, RDoc::Stats#print, IO#printf,
IO#print, Net::WriteAdapter#printf, Net::WriteAdapter#print,
Net::Telnet#print, Net::HTTP::get_print, StringIO#printf,
StringIO#print使用例(２)
- 成功
- どのパッケージ(？）に属しているか明示的に記述しないとだめらしい…。
# ri Kernel#print
----------------------------------------------------------- Kernel#print
print(obj, ...) => nil
------------------------------------------------------------------------
Prints each object in turn to +$stdout+. If the output field
separator (+$,+) is not +nil+, its contents will appear between
each field. If the output record separator (+$\+) is not +nil+, it
will be appended to the output. If no arguments are given, prints
+$_+. Objects that aren't strings will be converted by calling
their +to_s+ method.
print "cat", [1,2,3], 99, "\n"
$, = ", "
$\ = "\n"
print "cat", [1,2,3], 99
_produces:_
cat12399
cat, 1, 2, 3, 99
#
