如何使用Ruby中的“split”方法

Python012

如何使用Ruby中的“split”方法,第1张

这个是将一串字符串转化成数组的方法

(1) 在默认无参传入的时候 ,是以空格为间隔 ,获得数组

 pry(main)> " now's the time".split

 => ["now's", "the", "time"]

(2) 如果接受一个字符参数 ,那么会按照这个字符参数进行分割变成数组

pry(main)> "mellow yellow".split("ello")

 => ["m", "w y", "w"]

(3)如果接受的是两个参数 ,后面的参数是用来确定分割数组里面元素的个数,如果在按规则分割的时候 剩下多余的就变成一个元素

pry(main)> "mellow,yellow".split(//,4)

 => ["m", "e", "l", "low,yellow"]

(4)当然split 参数 也接受正则表达式,如下

pry(main)> "hi mom".split(%r{\s*})

 => ["h", "i", "m", "o", "m"]

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 existsotherwise, creates a new file for writing.

"a+" :Read-write. Starts at end of file if file existsotherwise, 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")

04     #删除目录

05     Dir.rmdir("c:/testdir")

07     #查询目录里的文件

08     p Dir.entries(File.join("C:","Ruby")).join(' ')

10     #遍历目录

11     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

system(“.ruby”)或者load 'another.rb'

具体代码如下:

# 返回ls的输出

s=`ls`

cmd= "ls"

s= `#{cmd}`

# 返回true or false

s= system('ls')

cmd= 'ls'

s= system(cmd)

#返回输出

s= %x[uptime]

#用top进程替换当前ruby进程

exec "top"

cmd = 'top'

exec cmd