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Ruby常用文件操作方法

  • 时间:2021-07-28 21:14 编辑: 来源: 阅读:
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摘要:Ruby常用文件操作方法
[b]一、新建文件[/b]
[u]复制代码[/u] 代码如下:
    f=File.new(File.join("C:","Test.txt"), "w+")     f.puts("I am Jack")     f.puts("Hello World")
文件模式 "r" :Read-only. Starts at beginning of file (default mode). "r+" :Read-write. Starts at beginning of file. "w" :Write-only. Truncates existing file to zero length or creates a new file for writing. "w+" :Read-write. Truncates existing file to zero length or creates a new file for reading and writing. "a" :Write-only. Starts at end of file if file exists; otherwise, creates a new file for writing. "a+" :Read-write. Starts at end of file if file exists; otherwise, creates a new file for reading and writing. "b" :(DOS/Windows only.) Binary file mode. May appear with any of the key letters listed above [b]二、读取文件[/b]
[u]复制代码[/u] 代码如下:
    file=File.open(File.join("C:","Test.txt"),"r")     file.each { |line| print "#{file.lineno}.", line }     file.close
[b]三、新建、删除、重命名文件[/b]
[u]复制代码[/u] 代码如下:
    File.new( "books.txt", "w" )     File.rename( "books.txt", "chaps.txt" )     File.delete( "chaps.txt" )
[b]四、目录操作[/b] [b]1     创建目录[/b]
[u]复制代码[/u] 代码如下:
    Dir.mkdir("c:/testdir")      #删除目录      Dir.rmdir("c:/testdir")      #查询目录里的文件      p Dir.entries(File.join("C:","Ruby")).join(' ')      #遍历目录      Dir.entries(File.join("C:","Ruby")).each {           |e| puts e     }
[b]1、ARGV and ARGF [/b]
[u]复制代码[/u] 代码如下:
ARGV     ARGV << "cnblogslink.txt"     #The gets method is a Kernel method that gets lines from ARGV     print while gets     p ARGV.class ARGF     while line = ARGF.gets      print line     end
[b]2、文件信息查询[/b]
[u]复制代码[/u] 代码如下:
    #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
[b]3、查找文件[/b]
[u]复制代码[/u] 代码如下:
    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 "---------------------------"          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 }
[b]3、查询目录及子目录文件[/b]
[u]复制代码[/u] 代码如下:
    require "find" Find.find("/etc/passwd", "/var/spool/lp1", ".") do |f|   Find.prune if f == "."   puts f end
原型:ref.find( [ aName ]* ) {| aFileName | block } prune:Skips the current file or directory, restarting the loop with the next entry. If the current file is a directory, that directory will not be recursively entered. Meaningful only within the block associated with Find::find. [b]4、文件比较 复制等[/b]
[u]复制代码[/u] 代码如下:
    require 'ftools'     File.copy 'testfile', 'testfile1'  » true     File.compare 'testfile', 'testfile1'  » true
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