一步一步学Ruby(二十一):文件操作2

1、打开读取文件

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file = File.open( "cnblogslink.txt" ) file.each { |line| print "#{file.lineno}. ", line } file.close

输出:

1. 社区
2. 新闻
3. 社区
4. 新闻
5. 招聘
6. 博问
7. 小组 
8. 闪存 
9. 网摘 
10. .NET频道

file.lineno显示的是行号

2、ARGV and ARGF

ARGV

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ARGV << "cnblogslink.txt"   #The gets method is a Kernel method that gets lines from ARGV print while gets   p ARGV.class   =begin 输出:   社区   新闻   社区   新闻   招聘   博问   小组    闪存    网摘    .NET频道   Array =end

ARGF

我们在test.rb里写如下代码：

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while line = ARGF.gets  print line end

在命令行里执行得到如下结果

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c:\studyruby>test.rb cnblogslink.txt cnblogslink2.txt 社区 新闻 社区 新闻 招聘 博问 小组 闪存 网摘 .NET频道 社区 新闻 社区 新闻 招聘 博问 小组 闪存 网摘 .NET频道

3、文件信息查询

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#文件是否存在 p File::exists?( "cnblogslink.txt" ) # => true   #是否是文件 p File.file?( "cnblogslink.txt" ) # => true   #是否是目录 p File::directory?( "c:/ruby" ) # => true p File::directory?( "cnblogslink.txt" ) # => false   #文件权限 p File.readable?( "cnblogslink.txt" ) # => true p File.writable?( "cnblogslink.txt" ) # => true p File.executable?( "cnblogslink.txt" ) # => false   #是否是零长度 p File.zero?( "cnblogslink.txt" ) # => false   #文件大小 bytes p File.size?( "cnblogslink.txt" ) # => 74 p File.size( "cnblogslink.txt" ) # => 74   #文件或文件夹 p File::ftype( "cnblogslink.txt" ) # => "file"   #文件创建、修改、最后一次存取时间 p File::ctime( "cnblogslink.txt" ) # => Sat Sep 19 08:05:07 +0800 2009 p File::mtime( "cnblogslink.txt" ) # => Sat Sep 19 08:06:34 +0800 2009 p File::atime( "cnblogslink.txt" ) # => Sat Sep 19 08:05:07 +0800 2009

4、查找文件

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puts "查找目录下所有文件及文件夹" Dir["c:/ruby/*"].each {|x|       puts x }    puts "条件查询" Dir.foreach('c:/ruby') {     |x| puts x if x != "." && x != ".." }    puts "查找某一类型文件" Dir["*.rb"].each {|x|   puts x  }    puts "Open 查询" Dir.open('c:/ruby') { |d| d.grep /l/ }.each{|x| puts x}   puts "---------------------------"      Dir.open('c:/ruby') { |d| d.each { |x| puts x } }     puts "正则表达式查询" Dir["c:/ruby/ruby/[rs]*"].each{|x| puts x}   puts "------------------------" Dir["c:/ruby/[^s]*"].each{|x| puts x}   puts "------------------------"    Dir["c:/ruby/{ruby,li}*"].each{|x| puts x}   puts "------------------------"    Dir["c:/ruby/?b*"].each{|x| puts x}            puts "查找目录及子目录的文件" require 'find'     Find.find('./') { |path| puts path }

以上内容得到以下输出：

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>ruby test.rb 查找目录下所有文件及文件夹 c:/ruby/bin c:/ruby/ChangeLog.txt c:/ruby/doc c:/ruby/lib c:/ruby/LICENSE.txt c:/ruby/man c:/ruby/MANIFEST c:/ruby/misc c:/ruby/README.1st c:/ruby/ReleaseNotes.txt c:/ruby/ruby.ico c:/ruby/rubyopt.del c:/ruby/rubyw.ico c:/ruby/samples c:/ruby/scite c:/ruby/share c:/ruby/src c:/ruby/uninstall.exe 条件查询 bin ChangeLog.txt doc lib LICENSE.txt man MANIFEST misc README.1st ReleaseNotes.txt ruby.ico rubyopt.del rubyw.ico samples scite share src uninstall.exe 查找某一类型文件 test.rb test2.rb Open 查询 lib ReleaseNotes.txt rubyopt.del samples uninstall.exe --------------------------- . .. bin ChangeLog.txt doc lib LICENSE.txt man MANIFEST misc README.1st ReleaseNotes.txt ruby.ico rubyopt.del rubyw.ico samples scite share src uninstall.exe 正则表达式查询 ------------------------ c:/ruby/bin c:/ruby/ChangeLog.txt c:/ruby/doc c:/ruby/lib c:/ruby/LICENSE.txt c:/ruby/man c:/ruby/MANIFEST c:/ruby/misc c:/ruby/README.1st c:/ruby/ReleaseNotes.txt c:/ruby/ruby.ico c:/ruby/rubyopt.del c:/ruby/rubyw.ico c:/ruby/uninstall.exe ------------------------ c:/ruby/ruby.ico c:/ruby/rubyopt.del c:/ruby/rubyw.ico c:/ruby/lib c:/ruby/LICENSE.txt ------------------------ 查找目录记子目录的文件 ./ ./test2.rb ./test2 ./test2/test2.rb ./test2/test.rb ./test1 ./test.rb ./output ./films.txt ./cnblogslink2.txt ./cnblogslink.txt ./beans.txt >Exit code: 0