Ruby常用文件操作方法

一、新建文件

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

二、读取文件

file=File.open(File.join("C:","Test.txt"),"r")

    file.each { |line| print "#{file.lineno}.", line }

    file.close

三、新建、删除、重命名文件

File.new( "books.txt", "w" )

    File.rename( "books.txt", "chaps.txt" )

    File.delete( "chaps.txt" )

四、目录操作
1 创建目录

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

    }

1、ARGV and ARGF

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

2、文件信息查询

#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

3、查找文件

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 }

3、查询目录及子目录文件

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.

4、文件比较 复制等

require 'ftools' 

    File.copy 'testfile', 'testfile1'  » true 

    File.compare 'testfile', 'testfile1'  » true

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