What's shell.rb?

It realizes a wish to do execution of commands with filters and pipes like sh/csh by using just native facilities of ruby.

Main classes

Shell

Every shell object has its own current working directory, and executes each command as if it stands in the directory.

Shell#cwd

Shell#dir

Shell#getwd

Shell#pwd

Returns the current directory

Shell#system_path

Returns the command search path in an array

Shell#umask

Returns the umask

Filter

Any result of command exection is a Filter. Filter include Enumerable, therefore a Filter object can use all Enumerable facilities.

Main methods

Command definitions

In order to execute a command on your OS, you need to define it as a Shell method.

Alternatively, you can execute any command via Shell#system even if it is not defined.

Shell.def_system_command(command, path = command)

Defines a command. Registers <path> as a Shell method <command>.

ex) Shell.def_system_command "ls"

Defines ls.

Shell.def_system_command "sys_sort", "sort"

Defines sys_sort as sort.

Shell.undef_system_command(command)

Undefines a commmand

Shell.alias_command(ali, command, *opts) {...}

Aliases a command.

ex)

Shell.alias_command "lsC", "ls", "-CBF", "--show-control-chars"
Shell.alias_command("lsC", "ls"){|*opts| ["-CBF", "--show-control-chars", *opts]}

Shell.unalias_command(ali)

Unaliases a command.

Shell.install_system_commands(pre = "sys_")

Defines all commands in the default_system_path as Shell method, all with <pre> prefixed to their names.

Creation

Shell.new

Creates a Shell object which current directory is set to the process current directory.

Shell.cd(path)

Creates a Shell object which current directory is set to <path>.

Process management

Shell#jobs

Returns a list of scheduled jobs.

Shell#kill sig, job

Sends a signal <sig> to <job>.

Current directory operations

Shell#cd(path, &block)

Shell#chdir

Changes the current directory to <path>. If a block is given, it restores the current directory when the block ends.

Shell#pushd(path = nil, &block)

Shell#pushdir

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.

Shell#popd

Shell#popdir

Pops a directory from the directory stack, and sets the current directory to it.

File and directory operations

Shell#foreach(path = nil, &block)

Same as:

File#foreach (when path is a file)
Dir#foreach (when path is a directory)

Shell#open(path, mode)

Same as:

File#open (when path is a file)
Dir#open (when path is a directory)

Shell#unlink(path)

Same as:

Dir#open (when path is a file)
Dir#unlink (when path is a directory)

Shell#test(command, file1, file2)

Shell#[command, file1, file2]

Same as test(). ex)

sh[?e, "foo"]
sh[:e, "foo"]
sh["e", "foo"]
sh[:exists?, "foo"]
sh["exists?", "foo"]

Shell#mkdir(*path)

Same as Dir.mkdir (with multiple directories allowed)

Shell#rmdir(*path)

Same as Dir.rmdir (with multiple directories allowed)

Command execution

System#system(command, *opts)

Executes <command> with <opts>.

ex)

print sh.system("ls", "-l")
sh.system("ls", "-l") | sh.head > STDOUT

System#rehash

Does rehash.

Shell#transact &block

Executes a block as self. ex)

sh.transact{system("ls", "-l") | head > STDOUT}

Shell#out(dev = STDOUT, &block)

Does transact, with redirecting the result output to <dev>.

Internal commands

Shell#echo(*strings)

Shell#cat(*files)

Shell#glob(patten)

Shell#tee(file)

Return Filter objects, which are results of their execution.

Filter#each &block

Iterates a block for each line of it.

Filter#<(src)

Inputs from <src>, which is either a string of a file name or an IO.

Filter#>(to)

Outputs to <to>, which is either a string of a file name or an IO.

Filter#>>(to)

Appends the ouput to <to>, which is either a string of a file name or an IO.

Filter#|(filter)

Processes a pipeline.

Filter#+(filter)

(filter1 + filter2) outputs filter1, and then outputs filter2.

Filter#to_a

Filter#to_s

Built-in commands

Shell#atime(file)

Shell#basename(file, *opt)

Shell#chmod(mode, *files)

Shell#chown(owner, group, *file)

Shell#ctime(file)

Shell#delete(*file)

Shell#dirname(file)

Shell#ftype(file)

Shell#join(*file)

Shell#link(file_from, file_to)

Shell#lstat(file)

Shell#mtime(file)

Shell#readlink(file)

Shell#rename(file_from, file_to)

Shell#split(file)

Shell#stat(file)

Shell#symlink(file_from, file_to)

Shell#truncate(file, length)

Shell#utime(atime, mtime, *file)

Equivalent to the class methods of File with the same names.

Shell#blockdev?(file)

Shell#chardev?(file)

Shell#directory?(file)

Shell#executable?(file)

Shell#executable_real?(file)

Shell#exist?(file)/Shell#exists?(file)

Shell#file?(file)

Shell#grpowned?(file)

Shell#owned?(file)

Shell#pipe?(file)

Shell#readable?(file)

Shell#readable_real?(file)

Shell#setgid?(file)

Shell#setuid?(file)

Shell#size(file)/Shell#size?(file)

Shell#socket?(file)

Shell#sticky?(file)

Shell#symlink?(file)

Shell#writable?(file)

Shell#writable_real?(file)

Shell#zero?(file)

Equivalent to the class methods of FileTest with the same names.

Shell#syscopy(filename_from, filename_to)

Shell#copy(filename_from, filename_to)

Shell#move(filename_from, filename_to)

Shell#compare(filename_from, filename_to)

Shell#safe_unlink(*filenames)

Shell#makedirs(*filenames)

Shell#install(filename_from, filename_to, mode)

Equivalent to the class methods of FileTools with the same names.

And also, there are some aliases for convenience:

Shell#cmp <- Shell#compare

Shell#mv <- Shell#move

Shell#cp <- Shell#copy

Shell#rm_f <- Shell#safe_unlink

Shell#mkpath <- Shell#makedirs

Samples

ex1

sh = Shell.cd("/tmp")
sh.mkdir "shell-test-1" unless sh.exists?("shell-test-1")
sh.cd("shell-test-1")
for dir in ["dir1", "dir3", "dir5"]
  if !sh.exists?(dir)
    sh.mkdir dir
    sh.cd(dir) do

f = sh.open("tmpFile", "w")
f.print "TEST\n"
f.close

end
print sh.pwd

end

end

ex2

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

ex3

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"

ex4

print sh.cat("/etc/passwd").head.collect{|l| l =~ /keiju/}