Using the power of Ruby for more effective system management (1)

In addition to being used as a powerful Web application development platform, Ruby is rarely mentioned in combination with the Rails framework, which is a powerful scripting language, just like Python or Perl. It has very powerful functions. Because it can use a lot of built-in and external libraries, it can be used to solve many script writing requirements in the system management work environment. Furthermore, Ruby programming is also very interesting!

Introduction

Ruby is an extremely rich, free, simple, scalable, portable, and object-oriented scripting language. Recently, it is widely used in the Web field. To a certain extent, this is attributed to the very powerful Web application development framework Rails, Which is exactly written in Ruby. Rails, also known as Ruby on RailsROR), as its name implies, provides a very powerful platform for rapid and effective Web application development. It is highly scalable. Many websites on the Web are built using Ruby on Rails.

In addition to using Rails as a Web application development platform, Ruby is rarely mentioned, that is, as a powerful scripting language, like Python or Perl. It has very powerful functions, because it can use a lot of built-in and external libraries, so it can use its power to solve many script programming requirements in the general system management work environment.

System Management requires a large number of scripts to make things simpler and more effective. Writing scripts can better meet user management, process management, file management, software package management, and other basic automation requirements than monotonous manual work. Ruby is very useful in this scenario. It has a set of good libraries to meet this requirement.

For this article, I assume that the reader has Ruby application knowledge. The basic examples provided here use pure Ruby, so any UNIX-like classes supported by Ruby can be used? System and Windows? . For more advanced Cfruby examples, a UNIX system is required. All the examples below are already in a Linux? Ruby v1.8.4 is used on the machine for testing. They should also be used in the latest Ruby version.

Ruby in practice

In the first example, search for files that match the specified mode in the specified path and provide detailed information about these files in a user-friendly manner. To achieve this goal, you don't have to rely on any command line utility, but you only need to use Ruby's built-in APIs. Therefore, this example can be run on any platform running Ruby.

In addition, this example shows how powerful Ruby is to simplify script writing. Rather than simply simulating the * nix "find" command, it is built on the command, so it has a strong customization capability when using Ruby.

Listing 1. Search for files that match the specified mode in a given path and display their details

Require 'Find' Puts "" Puts "----------------------- File Search -----------------------------------" Puts "" Print "Enter the search path :" Searchpath = gets Searchpath = searchpath. chomp Puts "" Print "Enter the search pattern :" Pattern = gets Pattern = pattern. chomp Puts "----------------------------------------------------------------------" Puts "Searching in" + searchpath + "for files matching pattern" + pattern Puts "----------------------------------------------------------------------" Puts "" Find. find (searchpath) do | path | If FileTest. directory? (Path) If File. basename (path) [0] = ?. Find. prune # Don't look any further into this directory. Else Next End Else If File. fnmatch (pattern, File. basename (path )) Puts "Filename:" + File. basename (path) S = sprintf ("% o", File. stat (path). mode) Print "Permissions :" Puts s Print "Owning uid :" Puts File. stat (path). uid Print "Owning gid :" Puts File. stat (path). uid Print "Size (bytes ):" Puts File. stat (path). size Puts "---------------------------------------------------" End End End

In this example:

Lines 5th-11-request the user to provide the search path and search mode.
Row 3-use the "Find" method in the "find" class in Ruby to traverse the specified search path.
Row 3-check whether the detected file is a directory. If the directory is not ".", recursively traverse the directory.
Row 3-use the "fnmatch" method in the "File" class to check whether the detected File conforms to the specified mode.
Lines 25th-34-if the file meets the pattern, the detailed information of the file is printed.

The following is an example output of this script.

Listing 2. example output of the first example

[Root @ logan] # ruby findexample. rb ----------------------- File Search ----------------------------------- Enter the search path:/test Enter the search pattern: *. rb ---------------------------------------------------------------------- Searching in/test for files matching pattern *. rb ---------------------------------------------------------------------- Filename: s. rb Permissions 100644 Owning uid: 1 Owning gid: 1 Size (bytes): 57 --------------------------------------------------- Filename: test. rb Permissions 100644 Owning uid: 0 Owning gid: 0 Size (bytes): 996 --------------------------------------------------- Filename: s1.rb Permissions 100644 Owning uid: 1 Owning gid: 1 Size (bytes): 39 ---------------------------------------------------

During system management, the most common requirement is to effectively use zip files to manage backups, or transfer a group of files from one computer to another. Ruby has many advantages in this regard. The second example is built on the basis of the first example, but contains a scenario where you need to package the searched files into a zip file.

The built-in zlib module can be used to process gzip files, which is good enough in most cases. However, here I will use another good Ruby library, "rubyzip", to create and process zip archives. Please refer to the reference section and find the download link. Note that this example uses pure Ruby, which does not depend on any command line utility currently provided on the computer.