module Shellwords - Documentation for Ruby 3.5 (original) (raw)

Manipulates strings like the UNIX Bourne shell ↑

This module manipulates strings according to the word parsing rules of the UNIX Bourne shell.

The shellwords() function was originally a port of shellwords.pl, but modified to conform to the Shell & Utilities volume of the IEEE Std 1003.1-2008, 2016 Edition

Usage ↑

You can use Shellwords to parse a string into a Bourne shell friendly Array.

require 'shellwords'

argv = Shellwords.split('three blind "mice"') argv

Once you’ve required Shellwords, you can use the split alias String#shellsplit.

argv = "see how they run".shellsplit argv

They treat quotes as special characters, so an unmatched quote will cause an ArgumentError.

argv = "they all ran after the farmer's wife".shellsplit

Shellwords also provides methods that do the opposite. Shellwords.escape, or its alias, String#shellescape, escapes shell metacharacters in a string for use in a command line.

filename = "special's.txt"

system("cat -- #{filename.shellescape}")

Note the ‘–’. Without it, cat(1) will treat the following argument as a command line option if it starts with ‘-’. It is guaranteed that Shellwords.escape converts a string to a form that a Bourne shell will parse back to the original string, but it is the programmer’s responsibility to make sure that passing an arbitrary argument to a command does no harm.

Shellwords also comes with a core extension for Array, Array#shelljoin.

dir = "Funny GIFs" argv = %W[ls -lta -- #{dir}] system(argv.shelljoin + " | less")

You can use this method to build a complete command line out of an array of arguments.

Contact ↑

Constants

VERSION

The version number string.

Public Class Methods

Source

def shellescape(str) str = str.to_s

return "''".dup if str.empty?

raise ArgumentError, "NUL character" if str.index("\0")

str = str.dup

str.gsub!(/[^A-Za-z0-9_-.,:+/@\n]/, "\\\&")

str.gsub!(/\n/, "'\n'")

return str end

Escapes a string so that it can be safely used in a Bourne shell command line. str can be a non-string object that responds to to_s.

str must not contain NUL characters because of nature of exec system call.

Note that a resulted string should be used unquoted and is not intended for use in double quotes nor in single quotes.

argv = Shellwords.escape("It's better to give than to receive") argv

String#shellescape is a shorthand for this function.

argv = "It's better to give than to receive".shellescape argv

pattern = "^[ \t]*def " open("| grep -Ern -e #{pattern.shellescape} lib") { |grep| grep.each_line { |line| file, lineno, matched_line = line.split(':', 3)

} }

It is the caller’s responsibility to encode the string in the right encoding for the shell environment where this string is used.

Multibyte characters are treated as multibyte characters, not as bytes.

Returns an empty quoted String if str has a length of zero.

Source

def shelljoin(array) array.map { |arg| shellescape(arg) }.join(' ') end

Builds a command line string from an argument list, array.

All elements are joined into a single string with fields separated by a space, where each element is escaped for the Bourne shell and stringified using to_s. See also Shellwords.shellescape.

ary = ["There's", "a", "time", "and", "place", "for", "everything"] argv = Shellwords.join(ary) argv

Array#shelljoin is a shortcut for this function.

ary = ["Don't", "rock", "the", "boat"] argv = ary.shelljoin argv

You can also mix non-string objects in the elements as allowed in Array#join.

output = #{['ps', '-p', <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow></mrow><annotation encoding="application/x-tex"></annotation></semantics></math></span><span class="katex-html" aria-hidden="true"></span></span>].shelljoin}

Also aliased as: join

Source

def shellsplit(line) words = [] field = String.new line.scan(/\G\s*(?>([^\0\s\'"]+)|'([^\0'])'|"((?:[^\0"\]|\[^\0]))"|(\[^\0]?)|(\S))(\s|\z)?/m) do |word, sq, dq, esc, garbage, sep| if garbage b = $.begin(0) line = $[0] line = "..." + line if b > 0 raise ArgumentError, "#{garbage == "\0" ? 'Nul character' : 'Unmatched quote'} at #{b}: #{line}" end

field << (word || sq || (dq && dq.gsub(/\\([$`"\\\n])/, '\\1')) || esc.gsub(/\\(.)/, '\\1'))
if sep
  words << field
  field = String.new
end

end words end

Splits a string into an array of tokens in the same way the UNIX Bourne shell does.

argv = Shellwords.split('here are "two words"') argv

line must not contain NUL characters because of nature of exec system call.

Note, however, that this is not a command line parser. Shell metacharacters except for the single and double quotes and backslash are not treated as such.

argv = Shellwords.split('ruby my_prog.rb | less') argv

String#shellsplit is a shortcut for this function.

argv = 'here are "two words"'.shellsplit argv

Private Instance Methods

Source

def shellescape(str) str = str.to_s

return "''".dup if str.empty?

raise ArgumentError, "NUL character" if str.index("\0")

str = str.dup

str.gsub!(/[^A-Za-z0-9_-.,:+/@\n]/, "\\\&")

str.gsub!(/\n/, "'\n'")

return str end

Escapes a string so that it can be safely used in a Bourne shell command line. str can be a non-string object that responds to to_s.

str must not contain NUL characters because of nature of exec system call.

Note that a resulted string should be used unquoted and is not intended for use in double quotes nor in single quotes.

argv = Shellwords.escape("It's better to give than to receive") argv

String#shellescape is a shorthand for this function.

argv = "It's better to give than to receive".shellescape argv

pattern = "^[ \t]*def " open("| grep -Ern -e #{pattern.shellescape} lib") { |grep| grep.each_line { |line| file, lineno, matched_line = line.split(':', 3)

} }

It is the caller’s responsibility to encode the string in the right encoding for the shell environment where this string is used.

Multibyte characters are treated as multibyte characters, not as bytes.

Returns an empty quoted String if str has a length of zero.

Source

def shelljoin(array) array.map { |arg| shellescape(arg) }.join(' ') end

Builds a command line string from an argument list, array.

All elements are joined into a single string with fields separated by a space, where each element is escaped for the Bourne shell and stringified using to_s. See also Shellwords.shellescape.

ary = ["There's", "a", "time", "and", "place", "for", "everything"] argv = Shellwords.join(ary) argv

Array#shelljoin is a shortcut for this function.

ary = ["Don't", "rock", "the", "boat"] argv = ary.shelljoin argv

You can also mix non-string objects in the elements as allowed in Array#join.

output = #{['ps', '-p', <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow></mrow><annotation encoding="application/x-tex"></annotation></semantics></math></span><span class="katex-html" aria-hidden="true"></span></span>].shelljoin}

Also aliased as: join

Source

def shellsplit(line) words = [] field = String.new line.scan(/\G\s*(?>([^\0\s\'"]+)|'([^\0'])'|"((?:[^\0"\]|\[^\0]))"|(\[^\0]?)|(\S))(\s|\z)?/m) do |word, sq, dq, esc, garbage, sep| if garbage b = $.begin(0) line = $[0] line = "..." + line if b > 0 raise ArgumentError, "#{garbage == "\0" ? 'Nul character' : 'Unmatched quote'} at #{b}: #{line}" end

field << (word || sq || (dq && dq.gsub(/\\([$`"\\\n])/, '\\1')) || esc.gsub(/\\(.)/, '\\1'))
if sep
  words << field
  field = String.new
end

end words end

Splits a string into an array of tokens in the same way the UNIX Bourne shell does.

argv = Shellwords.split('here are "two words"') argv

line must not contain NUL characters because of nature of exec system call.

Note, however, that this is not a command line parser. Shell metacharacters except for the single and double quotes and backslash are not treated as such.

argv = Shellwords.split('ruby my_prog.rb | less') argv

String#shellsplit is a shortcut for this function.

argv = 'here are "two words"'.shellsplit argv