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Ruby常用文件操作方法

2019-03-02 13:13:10浏览:944 来源:山村网   
核心摘要:  这篇文章主要介绍了Ruby常用文件操作方法,本文讲解了新建文件、读取文件、删除、重命名文件、目录操作等常用文件操作方法,需

  这篇文章主要介绍了Ruby常用文件操作方法,本文讲解了新建文件、读取文件、删除、重命名文件、目录操作等常用文件操作方法,需要的朋友可以参考下

  一、新建文件

   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

  二、读取文件

  代码如下:

  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

   代码如下:

  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

  复制代码 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

  }

  1、ARGV and ARGF

  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

  2、文件信息查询

  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

  3、查找文件

   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 }

  3、查询目录及子目录文件

  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.

  4、文件比较 复制等

  代码如下:

  require 'ftools'

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

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

(责任编辑:豆豆)
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