Shell

Shell implements an idiomatic Ruby interface for common UNIX shell commands.

It provides users the ability to execute commands with filters and pipes, like sh/csh by using native facilities of Ruby.

Examples

Temp file creation

In this example we will create three tmpFile's in three different folders under the /tmp directory.

sh = Shell .cd ("/tmp") # Change to the /tmp directory
sh.mkdir "shell-test-1" unless sh.exists?("shell-test-1")
# make the 'shell-test-1' directory if it doesn't already exist
sh.cd ("shell-test-1") # Change to the /tmp/shell-test-1 directory
for dir in ["dir1", "dir3", "dir5"]
 if !sh.exists?(dir)
 sh.mkdir dir # make dir if it doesn't already exist
 sh.cd (dir) do
 # change to the `dir` directory
 f = sh.open("tmpFile", "w") # open a new file in write mode
 f.print "TEST\n" # write to the file
 f.close # close the file handler
 end
 print sh.pwd # output the process working directory
 end
end

Temp file creation with self

This example is identical to the first, except we’re using CommandProcessor#transact.

CommandProcessor#transact executes the given block against self, in this case sh; our Shell object. Within the block we can substitute sh.cd to cd, because the scope within the block uses sh already.

sh = Shell .cd ("/tmp")
sh.transact do
 mkdir "shell-test-1" unless exists?("shell-test-1")
 cd ("shell-test-1")
 for dir in ["dir1", "dir3", "dir5"]
 if !exists?(dir)
 mkdir dir
 cd (dir) do
 f = open("tmpFile", "w")
 f.print "TEST\n"
 f.close
 end
 print pwd
 end
 end
end

Pipe /etc/printcap into a file

In this example we will read the operating system file /etc/printcap, generated by cupsd, and then output it to a new file relative to the pwd of sh.

sh = Shell .new 
sh.cat("/etc/printcap") | sh.tee("tee1") > "tee2"
(sh.cat < "/etc/printcap") | sh.tee("tee11") > "tee12"
sh.cat("/etc/printcap") | sh.tee("tee1") >> "tee2"
(sh.cat < "/etc/printcap") | sh.tee("tee11") >> "tee12"

frozen_string_literal: false

shell/filter.rb -
 $Release Version: 0.7 $
 $Revision$
 by Keiju ISHITSUKA(keiju@ruby-lang.org)

–

frozen_string_literal: false

version.rb - shell version definition file
 $Release Version: 0.7$
 $Revision$
 by Keiju ISHITSUKA(keiju@ruby-lang.org)

–

Related methods