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Commit 2cbcd20

Browse files
updates for version 1.5
1 parent e5db9b3 commit 2cbcd20

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+786
-147
lines changed

‎README.md

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@@ -27,7 +27,7 @@ For a preview of the book, see [sample chapters](https://github.com/learnbyexamp
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The book can also be [viewed as a single markdown file in this repo](./ruby_oneliners.md). See my blogpost on [generating pdf/epub from markdown using pandoc](https://learnbyexample.github.io/customizing-pandoc/) if you are interested in the ebook creation process.
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For online `html` version of the book, visit https://learnbyexample.github.io/learn_ruby_oneliners/
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For web version of the book, visit https://learnbyexample.github.io/learn_ruby_oneliners/
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<br>
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@@ -63,8 +63,12 @@ Twitter: https://twitter.com/learn_byexample
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* [stackoverflow](https://stackoverflow.com/) — for getting answers to pertinent questions on Ruby, one-liners, etc
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* [tex.stackexchange](https://tex.stackexchange.com/) — for help on `pandoc` and `tex` related questions
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* [LibreOffice Draw](https://www.libreoffice.org/discover/draw/) — cover image
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* [pngquant](https://pngquant.org/) and [svgcleaner](https://github.com/RazrFalcon/svgcleaner) for optimizing images
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* [Warning](https://commons.wikimedia.org/wiki/File:Warning_icon.svg) and [Info](https://commons.wikimedia.org/wiki/File:Info_icon_002.svg) icons by [Amada44](https://commons.wikimedia.org/wiki/User:Amada44) under public domain
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* [softwareengineering.stackexchange](https://softwareengineering.stackexchange.com/questions/39/whats-your-favourite-quote-about-programming) and [skolakoda](https://skolakoda.org/programming-quotes) for programming quotes
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* [mdBook](https://github.com/rust-lang/mdBook) — for web version of the book
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* [mdBook-pagetoc](https://github.com/JorelAli/mdBook-pagetoc) — for adding table of contents for each chapter
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* [minify-html](https://github.com/wilsonzlin/minify-html) — for minifying html files
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A heartfelt thanks to all my readers. Your valuable support has significantly eased my financial concerns and allows me to continue writing books.
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‎code_snippets/Field_separators.sh

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@@ -137,6 +137,8 @@ echo "$s" | ruby -ane 'puts $F.sort * ":"'
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echo "$s" | ruby -ane 'puts $F.sort_by(&:size) * ":"'
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echo '23 756 -983 5' | ruby -lane 'puts $F.sort_by(&:to_i) * ":"'
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echo 'foobar' | ruby -lne 'puts $_.chars.sort.reverse * ""'
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s='try a bad to good i teal by nice how'

‎code_snippets/Line_processing.sh

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@@ -28,9 +28,13 @@ ruby -ne 'print if $_.match?(/on\b/)' programming_quotes.txt
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echo 'Uryyb Jbeyq' | ruby -pe '$_.tr!("a-zA-Z", "n-za-mN-ZA-M")'
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printf 'foo:123:baz' | ruby -ne 'puts $_.tr("^0-9", "-")'
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echo 'foo:123:baz' | ruby -pe '$_.tr!("^0-9\n", "-")'
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printf 'foo:123:baz' | ruby -ne 'puts $_.tr("^0-9", "")'
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echo 'foo:123:baz' | ruby -pe '$_.tr!("^0-9\n", "")'
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s='orange apple appleseed cab'
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echo "$s" | ruby -pe 'gsub(/\b(?!apple\b)\w++/) {$&.tr("a-z", "1-9")}'
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## Conditional substitution
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@@ -63,13 +67,19 @@ printf 'sea\neat\ndrop\n' | ruby -ne 'print; exit(2) if /at/'
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echo $?
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## Line numbers
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ruby -pe 'exit if /cake/' table.txt
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ruby -pe 'exit if /cake/; END{puts "bye"}' table.txt
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ruby -pe 'BEGIN{puts "hi"; exit; puts "hello"}; END{puts "bye"}' table.txt
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## Line number based processing
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ruby -ne 'print if $. == 3' programming_quotes.txt
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ruby -ne 'print if $. == 2 || $. == 5' programming_quotes.txt
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printf 'gates\nnot\nused\n' | ruby -pe 'gsub(/t/, "*") if $. == 2'
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printf 'gates\nnot\nused\n' | ruby -pe '$_.tr!("a-z", "*") if $. == 2'
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seq 14 25 | ruby -ne 'print if $. >= 10'
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@@ -79,10 +89,6 @@ ruby -ne 'puts "#{$.}:#{$_}" if $<.eof' programming_quotes.txt
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ruby -ne 'print if $<.eof' programming_quotes.txt table.txt
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seq 14 25 | ruby -ne 'print if 3..5'
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seq 14 25 | ruby -ne 'print if (3...5).include?($.)'
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seq 3542 4623452 | ruby -ne '(print; exit) if $. == 2452'
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seq 3542 4623452 | ruby -ne 'print if $. == 250; (print; exit) if $. == 2452'
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time seq 3542 4623452 | ruby -ne 'print if $. == 2452' > f2
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## Fixed string matching
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## Flip-Flop operator
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seq 14 25 | ruby -ne 'print if 3..5'
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seq 14 25 | ruby -ne 'print if (3...5).include?($.)'
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ruby -ne 'print if /are/../by/' programming_quotes.txt
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ruby -ne 'print if 5../use/' programming_quotes.txt
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ruby -ne 'print if !(/ll/..$<.eof)' programming_quotes.txt table.txt
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ruby -ne 'print if 9../worth/' programming_quotes.txt
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ruby -ne 'print if /affect/../XYZ/' programming_quotes.txt
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## Working with fixed strings
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echo 'int a[5]' | ruby -ne 'print if /a[5]/'
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echo 'int a[5]' | ruby -ne 'print if $_.include?("a[5]")'
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echo 'int a[5]' | ruby -pe 'sub(/a[5]/, "b")'
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echo 'int a[5]' | ruby -pe 'sub("a[5]", "b")'
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ruby -e 'a=5; puts "value of a:\t#{a}"'
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echo 'int #{a}' | ruby -ne 'print if $_.include?(%q/#{a}/)'
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echo 'int #{a}' | ruby -pe 'sub(%q/#{a}/, "b")'
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echo 'int #{a}' | s='#{a}' ruby -ne 'print if $_.include?(ENV["s"])'
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echo 'int #{a\\}' | s='#{a\\}' ruby -pe 'sub(ENV["s"], "b")'
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cat eqns.txt
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s='a+b' ruby -ne 'print if $_.start_with?(ENV["s"])' eqns.txt
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s='a+b' ruby -ne 'print if $_.index(ENV["s"], 1)' eqns.txt
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printf 'a.b\na+b\n' | ruby -lne 'print if /^a.b$/'
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printf 'a.b\na+b\n' | ruby -lne 'print if $_ == %q/a.b/'
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printf '1 a.b\n2 a+b\n' | ruby -lane 'print if $F[1] != %q/a.b/'
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echo 'x+y' | ruby -pe 'sub(%q/x+y/, "x\y\0円z")'
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echo 'x+y' | r='x\y\0円z' ruby -pe 'sub(%q/x+y/, ENV["r"])'
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echo 'x+y' | r='x\y\0円z' ruby -pe 'sub(%q/x+y/, ENV["r"].gsub(/\\/, "\\0円"))'
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ruby -e 'puts %q/x\y\0円z/'
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echo 'x+y' | ruby -pe 'sub(%q/x+y/, %q/x\y\0円z/.gsub(/\\/, "\\0円"))'
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## In-place file editing
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cat colors.txt

‎code_snippets/Multiple_file_input.sh

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ruby -e 'puts ARGV' f[1-3].txt greeting.txt
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ruby -lne 'print ARGV' f[12].txt table.txt
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ruby -ne 'puts "#{ARGV.size}: " + ARGV * ","' f[12].txt table.txt
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ruby -ne 'puts "--- #{ARGF.filename} ---" if $. == 1;
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print;
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ARGF.close if ARGF.eof' greeting.txt table.txt
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ruby -ne 'print if ARGF.eof' greeting.txt table.txt
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ruby -ne '(print; ARGF.close) if $.==2' greeting.txt table.txt
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ruby -pe 'ARGF.close if $.>=1' greeting.txt table.txt
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ruby -e 'puts gets' greeting.txt
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ruby -e 'puts gets, "---", ARGF.read' greeting.txt
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ruby -e 'puts readlines' greeting.txt
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ruby -e 'puts ARGF.readchar' greeting.txt
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## STDIN
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echo 'apple' | ruby -e 'puts readline' greeting.txt
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printf 'apple\nmango\n' | ruby -e 'puts readline'
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printf 'apple\nmango\n' | ruby -e 'puts readline' greeting.txt
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echo 'apple' | ruby -e 'puts STDIN.readline' greeting.txt
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printf 'apple\nmango\n' | ruby -e 'puts STDIN.readline' greeting.txt
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## Skipping remaining contents per file
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ruby -ne '(puts ARGF.filename; ARGF.close) if /I/' f[1-3].txt greeting.txt
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ruby -ne '$m1=true if /o/; $m2=true if /at/;
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ruby -ne '$m1=true if /e\b/; $m2=true if /[bm]at/i;
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(puts ARGF.filename; $m1=$m2=false; ARGF.close; next) if $m1 && $m2;
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$m1=$m2=false if ARGF.eof' f[1-3].txt greeting.txt
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‎code_snippets/Oneliner_introduction.sh

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rgx="$r" ruby -ne 'print if /#{ENV["rgx"]}/' word_anchors.txt
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r='\Bpar\B'
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ruby -sne 'print if /#{$rgx}/' -- -rgx="$r" word_anchors.txt
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## Executing external commands
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ruby -e 'system("echo Hello World")'

‎code_snippets/Processing_multiple_records.sh

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ruby -e 'ip=readlines; n=2; ip.each_with_index { |s, i|
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c=i-n; c=0 if c<0;
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(puts ip[c..i]; puts "---") if s.match?(/toy|flower/) }' context.txt
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(print $s; puts ip[c..i]; $s="---\n") if s.match?(/toy|flower/) }
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' context.txt
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ruby -e 'ip=readlines; n=2; ip.each_with_index { |s, i| c=i-n;
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puts ip[c] if c>=0 && s.match?(/language/) }' context.txt
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ruby -ne 'print $p2 if $.>2 && /toy|flower/; $p2=$p1; $p1=$_' context.txt
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tac context.txt | ruby -ne 'print if $n.to_i>0 && ($n-=1)==0;
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$n=2 if /language/' | tac
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## Records bounded by distinct markers
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cat uniform.txt
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seq 30 | ruby -ne 'BEGIN{n=2; c=0}; ($f=true; c+=1) if /4/;
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print if $f && c!=n; $f=false if /6/'
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seq 30 | ruby -ne '($f=true; buf=$_; $m=false; next) if /4/;
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seq 30 | ruby -ne '($f=true; buf=$_; next) if /4/;
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buf << $_ if $f;
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($f=false; print buf if $m) if /6/;
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$m=true if /\A15\Z/'
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($f=false; print buf if buf.match?(/^15$/)) if /6/;'
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## Broken blocks
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‎code_snippets/Record_separators.sh

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echo "$s" | ruby -0072 -lne 'print if /a/'
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s=' a\t\tb:1000\n\n\n\n123 7777:x y \n \n z '
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s=' a\t\tb\n\t\n:1000\n\n\n\n123 7777:x y \n \n z '
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printf '%b' "$s" | ruby -0072 -lane 'puts $F * ","'
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printf '%b' "$s" | ruby -00 -ne 'print if $. <= 2'
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s='\n\n\na\nb\n\n12\n34\n\nhi\nhello\n\n\n\n'
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s='\n\n\na\n\n12\n34\n\nhi\nhello\n\n\n\n'
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printf '%b' "$s" | ruby -00 -lne 'puts "#{$_}\n---\n" if $. <= 2'
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printf '%b' "$s" | ruby -00 -lne 'puts "#{$_}\n---" if $. <= 2'
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printf '%b' "$s" | ruby -00 -lne 'puts "#{$_}\n---\n" if $<.eof'
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printf '%b' "$s" | ruby -00 -lne 'puts "#{$_}\n---" if $<.eof'
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printf '%b' "$s" | ruby -00 -ne 'END{puts $.}'
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‎code_snippets/Two_file_processing.sh

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## gets
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ruby -pe 'BEGIN{m=3; n=2; n.times {$s = STDIN.gets}}
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ruby -pe 'BEGIN{m=3; n=2; n.times {$s = STDIN.gets}};
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$_ = $s if $. == m' <greeting.txt table.txt
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ruby -ne 'a=$_; n = STDIN.gets.split[-1].to_f;
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print a if n > 0' <table.txt greeting.txt
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## Multiline fixed string substitution
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head -n2 table.txt > search.txt
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cat repl.txt
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ruby -0777 -ne 'ARGV.size==2 ? s=$_ : ARGV.size==1 ? r=$_ :
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print(gsub(s, r.gsub(/\\/, "\\0円")))
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' search.txt repl.txt table.txt
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## Add file content conditionally
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ruby -pe 'BEGIN{r = STDIN.read}; $_ = r if /[ot]/' <dept.txt greeting.txt
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ruby -pe 'BEGIN{r = STDIN.read}; print r if /nice/' <dept.txt greeting.txt
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ruby -pe 'BEGIN{r = STDIN.read}; $_ << r if /nice/' <dept.txt greeting.txt
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‎example_files/repl.txt

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21ドル$&30円x\\yz
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wise ice go goa

‎example_files/search.txt

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brown bread mat hair 42
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blue cake mug shirt -7

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