class 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 doesnt' 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 Shell::CommandProcessor#transact.
Shell::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"
Attributes
Returns the current working directory.
Returns the current working directory.
Returns the current working directory.
Returns the current working directory.
Returns the command search path in an array
Returns the umask
Public Class Methods
Convenience method for Shell::CommandProcessor.alias_command
# File lib/shell.rb, line 369 def Shell.alias_command(ali, command, *opts, &block) CommandProcessor.alias_command(ali, command, *opts, &block) end
Creates a new Shell instance with the current
working directory set to path
.
# File lib/shell.rb, line 127 def cd(path) new(path) end
# File lib/shell.rb, line 116 def debug=(val) @debug = val @verbose = val if val end
Convenience method for Shell::CommandProcessor.def_system_command
# File lib/shell.rb, line 359 def Shell.def_system_command(command, path = command) CommandProcessor.def_system_command(command, path) end
# File lib/shell.rb, line 160 def default_record_separator if @default_record_separator @default_record_separator else $/ end end
# File lib/shell.rb, line 168 def default_record_separator=(rs) @default_record_separator = rs end
Returns the directories in the current shell's PATH environment variable as an array of directory names. This sets the #system_path for all instances of Shell.
Example: If in your current shell, you did:
$ echo $PATH /usr/bin:/bin:/usr/local/bin
Running this method in the above shell would then return:
["/usr/bin", "/bin", "/usr/local/bin"]
# File lib/shell.rb, line 144 def default_system_path if @default_system_path @default_system_path else ENV["PATH"].split(":") end end
Sets the #system_path that new instances of Shell should have as their initial system_path.
path
should be an array of directory name strings.
# File lib/shell.rb, line 156 def default_system_path=(path) @default_system_path = path end
Convenience method for Shell::CommandProcessor.install_system_commands
# File lib/shell.rb, line 379 def Shell.install_system_commands(pre = "sys_") CommandProcessor.install_system_commands(pre) end
Creates a Shell object which current directory is
set to the process current directory, unless otherwise specified by the
pwd
argument.
# File lib/shell.rb, line 185 def initialize(pwd = Dir.pwd, umask = nil) @cwd = File.expand_path(pwd) @dir_stack = [] @umask = umask @system_path = Shell.default_system_path @record_separator = Shell.default_record_separator @command_processor = CommandProcessor.new(self) @process_controller = ProcessController.new(self) @verbose = Shell.verbose @debug = Shell.debug end
# File lib/shell.rb, line 392 def self.notify(*opts) Shell::debug_output_synchronize do if opts[-1].kind_of?(String) yorn = verbose? else yorn = opts.pop end return unless yorn if @debug_display_thread_id if @debug_display_process_id prefix = "shell(##{Process.pid}:#{Thread.current.to_s.sub("Thread", "Th")}): " else prefix = "shell(#{Thread.current.to_s.sub("Thread", "Th")}): " end else prefix = "shell: " end _head = true STDERR.print opts.collect{|mes| mes = mes.dup yield mes if iterator? if _head _head = false # "shell" " + mes prefix + mes else " "* prefix.size + mes end }.join("\n")+"\n" end end
Convenience method for Shell::CommandProcessor.unalias_command
# File lib/shell.rb, line 374 def Shell.unalias_command(ali) CommandProcessor.unalias_command(ali) end
Convenience method for Shell::CommandProcessor.undef_system_command
# File lib/shell.rb, line 364 def Shell.undef_system_command(command) CommandProcessor.undef_system_command(command) end
Public Instance Methods
Creates a Shell object which current directory is
set to path
.
If a block is given, it restores the current directory when the block ends.
If called as iterator, it restores the current directory when the block ends.
# File lib/shell.rb, line 262 def chdir(path = nil, verbose = @verbose) check_point if iterator? notify("chdir(with block) #{path}") if verbose cwd_old = @cwd begin chdir(path, nil) yield ensure chdir(cwd_old, nil) end else notify("chdir #{path}") if verbose path = "~" unless path @cwd = expand_path(path) notify "current dir: #{@cwd}" rehash Void.new(self) end end
# File lib/shell.rb, line 217 def debug=(val) @debug = val @verbose = val if val end
# File lib/shell.rb, line 228 def expand_path(path) File.expand_path(path, @cwd) end
# File lib/shell.rb, line 384 def inspect if debug.kind_of?(Integer) && debug > 2 super else to_s end end
Returns a list of scheduled jobs.
# File lib/shell.rb, line 346 def jobs @process_controller.jobs end
Sends the given signal
to the given job
# File lib/shell.rb, line 354 def kill(sig, command) @process_controller.kill_job(sig, command) end
Pops a directory from the directory stack, and sets the current directory to it.
# File lib/shell.rb, line 330 def popdir check_point notify("popdir") if pop = @dir_stack.pop chdir pop notify "dir stack: [#{@dir_stack.join ', '}]" self else Shell.Fail DirStackEmpty end Void.new(self) end
Pushes the current directory to the directory stack, changing the current
directory to path
.
If path
is omitted, it exchanges its current directory and the
top of its directory stack.
If a block is given, it restores the current directory when the block ends.
# File lib/shell.rb, line 296 def pushdir(path = nil, verbose = @verbose) check_point if iterator? notify("pushdir(with block) #{path}") if verbose pushdir(path, nil) begin yield ensure popdir end elsif path notify("pushdir #{path}") if verbose @dir_stack.push @cwd chdir(path, nil) notify "dir stack: [#{@dir_stack.join ', '}]" self else notify("pushdir") if verbose if pop = @dir_stack.pop @dir_stack.push @cwd chdir pop notify "dir stack: [#{@dir_stack.join ', '}]" self else Shell.Fail DirStackEmpty end end Void.new(self) end
Sets the system path (the Shell instance's PATH environment variable).
path
should be an array of directory name strings.
# File lib/shell.rb, line 206 def system_path=(path) @system_path = path rehash end