updates for version 2.0

Author: learnbyexample

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2020 Sundeep Agarwal
+Copyright (c) 2023 Sundeep Agarwal
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,40 +1,36 @@
-# GNU AWK
+# CLI text processing with GNU awk
 
-Example based guide to mastering GNU awk.
+Example based guide to mastering GNU awk. Visit https://youtu.be/KIa_EaYwGDI for a short video about the book.
 
-<p align="center">
-    <img src="./images/gawk.png" width="320px" height="400px" />
-</p>
+<p align="center"><img src="./images/gawk_ls.png" alt="CLI text processing with GNU awk ebook cover image" /></p>
 
-The book also includes exercises to test your understanding, which is presented together as a single file in this repo - [Exercises.md](./exercises/Exercises.md)
+The book also includes exercises to test your understanding, which are presented together as a single file in this repo — [Exercises.md](./exercises/Exercises.md).
 
 For solutions to the exercises, see [Exercise_solutions.md](./exercises/Exercise_solutions.md).
 
+You can also use [this interactive TUI app](https://github.com/learnbyexample/TUI-apps/blob/main/AwkExercises) to practice some of the exercises from the book.
+
 See [Version_changes.md](./Version_changes.md) to keep track of changes made to the book.
 
 <br>
 
 # E-book
 
-You can purchase the pdf/epub versions of the book using these links:
-
-* https://learnbyexample.gumroad.com/l/gnu_awk
-* https://leanpub.com/gnu_awk
-
-You can also get the book as part of these bundles:
-
-* **Magical one-liners** bundle from https://learnbyexample.gumroad.com/l/oneliners or https://leanpub.com/b/oneliners
-* **Awesome Regex** bundle from https://learnbyexample.gumroad.com/l/regex or https://leanpub.com/b/regex
-* **All books bundle** bundle from https://learnbyexample.gumroad.com/l/all-books
-    * Includes all my programming books
-
-See https://learnbyexample.github.io/books/ for list of other books
+* You can purchase the pdf/epub versions of the book using these links:
+    * https://learnbyexample.gumroad.com/l/gnu_awk
+    * https://leanpub.com/gnu_awk
+* You can also get the book as part of these bundles:
+    * **All books bundle** bundle from https://learnbyexample.gumroad.com/l/all-books
+        * Includes all my programming books
+    * **Magical one-liners** bundle from https://learnbyexample.gumroad.com/l/oneliners or https://leanpub.com/b/oneliners
+    * **Awesome Regex** bundle from https://learnbyexample.gumroad.com/l/regex or https://leanpub.com/b/regex
+* See https://learnbyexample.github.io/books/ for a list of other books
 
-For a preview of the book, see [sample chapters](https://github.com/learnbyexample/learn_gnuawk/blob/master/sample_chapters/gnu_awk_sample.pdf)
+For a preview of the book, see [sample chapters](./sample_chapters/gnu_awk_sample.pdf).
 
-The book can also be [viewed as a single markdown file in this repo](./gnu_awk.md). See my blogpost on [generating pdf from markdown using pandoc](https://learnbyexample.github.io/tutorial/ebook-generation/customizing-pandoc/) if you are interested in the ebook creation process.
+The book can also be [viewed as a single markdown file in this repo](./gnu_awk.md). See my blogpost on [generating pdfs from markdown using pandoc](https://learnbyexample.github.io/customizing-pandoc/) if you are interested in the ebook creation process.
 
-For web version of the book, visit https://learnbyexample.github.io/learn_gnuawk/
+For the web version of the book, visit https://learnbyexample.github.io/learn_gnuawk/
 
 <br>
 
@@ -52,15 +48,17 @@ For web version of the book, visit https://learnbyexample.github.io/learn_gnuawk
 
 <br>
 
-# Feedback
+# Feedback and Contributing
 
-[Open an issue](https://github.com/learnbyexample/learn_gnuawk/issues) if you spot any typo/errors.
+⚠️ ⚠️ Please DO NOT submit pull requests. Main reason being any modification requires changes in multiple places.
 
-:warning: :warning: Please DO NOT submit pull requests. Main reason being any modification requires changes in multiple places.
+I would highly appreciate it if you'd let me know how you felt about this book. It could be anything from a simple thank you, pointing out a typo, mistakes in code snippets, which aspects of the book worked for you (or didn't!) and so on. Reader feedback is essential and especially so for self-published authors.
 
-I'd also highly appreciate your feedback about the book.
+You can reach me via:
 
-Twitter: https://twitter.com/learn_byexample
+* Issue Manager: [https://github.com/learnbyexample/learn_gnuawk/issues](https://github.com/learnbyexample/learn_gnuawk/issues)
+* E-mail: `echo 'bGVhcm5ieWV4YW1wbGUubmV0QGdtYWlsLmNvbQo=' | base64 --decode`
+* Twitter: [https://twitter.com/learn_byexample](https://twitter.com/learn_byexample)
 
 <br>
 
@@ -89,13 +87,14 @@ Twitter: https://twitter.com/learn_byexample
 # Acknowledgements
 
 * [GNU awk documentation](https://www.gnu.org/software/gawk/manual/) — manual and examples
-* [stackoverflow](https://stackoverflow.com/) and [unix.stackexchange](https://unix.stackexchange.com/) — for getting answers to pertinent questions on `bash`, `awk` and other commands
+* [stackoverflow](https://stackoverflow.com/) and [unix.stackexchange](https://unix.stackexchange.com/) — for getting answers to pertinent questions on `awk` and related commands
 * [tex.stackexchange](https://tex.stackexchange.com/) — for help on [pandoc](https://github.com/jgm/pandoc/) and `tex` related questions
-* [LibreOffice Draw](https://www.libreoffice.org/discover/draw/) — cover image
-* [pngquant](https://pngquant.org/) and [svgcleaner](https://github.com/RazrFalcon/svgcleaner) for optimizing images
-* [softwareengineering.stackexchange](https://softwareengineering.stackexchange.com/questions/39/whats-your-favourite-quote-about-programming) and [skolakoda](https://skolakoda.org/programming-quotes) for programming quotes
+* [/r/commandline/](https://old.reddit.com/r/commandline), [/r/linux4noobs/](https://old.reddit.com/r/linux4noobs/), [/r/linuxquestions/](https://old.reddit.com/r/linuxquestions/) and [/r/linux/](https://old.reddit.com/r/linux/) — helpful forums
+* [canva](https://www.canva.com/) — cover image
+* [oxipng](https://github.com/shssoichiro/oxipng), [pngquant](https://pngquant.org/) and [svgcleaner](https://github.com/RazrFalcon/svgcleaner) — optimizing images
 * [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
 * [arifmahmudrana](https://github.com/arifmahmudrana) for spotting an ambiguous explanation
+* [Pound-Hash](https://github.com/Pound-Hash) for critical feedback
 * [mdBook](https://github.com/rust-lang/mdBook) — for web version of the book
     * [mdBook-pagetoc](https://github.com/JorelAli/mdBook-pagetoc) — for adding table of contents for each chapter
     * [minify-html](https://github.com/wilsonzlin/minify-html) — for minifying html files
@@ -106,7 +105,7 @@ Special thanks to all my friends and online acquaintances for their help, suppor
 
 # License
 
-The book is licensed under a [Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License](https://creativecommons.org/licenses/by-nc-sa/4.0/)
+The book is licensed under a [Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License](https://creativecommons.org/licenses/by-nc-sa/4.0/).
 
-The code snippets are licensed under MIT, see [LICENSE](./LICENSE) file
+The code snippets are licensed under MIT, see [LICENSE](./LICENSE) file.
 

Version_changes.md

@@ -1,5 +1,19 @@
 <br>
 
+### 2.0
+
+* Command version updated to **GNU awk 5.2.2**
+* Many more exercises added, and you can practice some of them using this [interactive TUI app](https://github.com/learnbyexample/TUI-apps/blob/main/AwkExercises)
+* Long sections split into smaller ones
+* In general, many of the examples, exercises, solutions, descriptions and external links were updated/corrected
+* Updated Acknowledgements section
+* Code snippets related to info/warning sections will now appear as a single block
+* Book title changed to **CLI text processing with GNU awk**
+* New cover image
+* Images centered for EPUB format
+
+<br>
+
 ### 1.4
 
 * Added example for `NF` value when input line doesn't contain the input field separator or if it is empty.

code_snippets/Builtin_functions.sh

@@ -74,17 +74,17 @@ echo 'abcdefghij' | awk -v FS= '{print $3, $5}'
 
 ## match
 
-s='051 035 154 12 26 98234'
+s='051 035 154 12 26 98234 3'
 
 echo "$s" | awk 'match($0, /[0-9]{4,}/){print substr($0, RSTART, RLENGTH)}'
 
 echo "$s" | awk 'match($0, /0*[1-9][0-9]{2,}/, m){print m[0]}'
 
-echo 'foo=42, baz=314' | awk 'match($0, /baz=([0-9]+)/, m){print m[0]}'
+echo 'apple=42, fig=314' | awk 'match($0, /fig=([0-9]+)/, m){print m[0]}'
 
-echo 'foo=42, baz=314' | awk 'match($0, /baz=([0-9]+)/, m){print m[1]}'
+echo 'apple=42, fig=314' | awk 'match($0, /fig=([0-9]+)/, m){print m[1]}'
 
-s='42 foo-5, baz3; x-83, y-20: f12'
+s='42 apple-5, fig3; x-83, y-20: f12'
 
 echo "$s" | awk '{ while( match($0, /([0-9]+),/, m) ){print m[1];
                  $0=substr($0, RSTART+RLENGTH)} }'

code_snippets/Control_Structures.sh

@@ -28,15 +28,15 @@ echo 'titillate' | awk '{do{print} while(gsub(/til/, ""))}'
 
 ## next
 
-awk '/\<par/{print "%% " $0; next} {print /s/ ? "X" : "Y"}' word_anchors.txt
+awk '/\<par/{print "%% " $0; next} {print /s/ ? "X" : "Y"}' anchors.txt
 
 ## exit
 
 seq 3542 4623452 | awk 'NR==2452{print; exit}'
 
 echo $?
 
-awk '/^br/{print "Invalid input"; exit 1}' table.txt
+awk '/^br/{print "invalid data"; exit 1}' table.txt
 
 echo $?
 

code_snippets/Field_separators.sh

@@ -66,7 +66,7 @@ echo '   a   b   c   ' | awk -F' ' '{print NF}'
 
 echo '   a   b   c   ' | awk -F'[ ]' '{print NF}'
 
-echo 'RECONSTRUCTED' | awk -F'[aeiou]+' -v IGNORECASE=1 '{print $1}'
+echo 'RECONSTRUCTED' | awk -F'[aeiou]+' -v IGNORECASE=1 '{print $NF}'
 
 echo 'RECONSTRUCTED' | awk -F'e' -v IGNORECASE=1 '{print $1}'
 
@@ -92,6 +92,12 @@ echo 'Sample123string42with777numbers' | awk -F'[0-9]+' -v OFS=, '1'
 
 echo 'Sample123string42with777numbers' | awk -F'[0-9]+' -v OFS=, '{$1=$1} 1'
 
+echo -v{,O}FS=:
+
+echo 'goal:amazing:whistle:kwality' | awk -v{,O}FS=: '{$2 = 42} 1'
+
+echo 'goal:amazing:whistle:kwality' | awk '{$2 = 42} 1' {,O}FS=:
+
 ## Manipulating NF
 
 echo 'goal:amazing:whistle:kwality' | awk -F: -v OFS=, '{NF=2} 1'
@@ -108,7 +114,13 @@ s='Sample123string42with777numbers'
 
 echo "$s" | awk -v FPAT='[0-9]+' '{print $2}'
 
-echo "$s" | awk -v FPAT='[a-zA-Z]+' -v OFS=, '{$1=$1} 1'
+s='coat Bin food tar12 best Apple fig_42'
+
+echo "$s" | awk -v FPAT='\\<[a-z0-9]+\\>' -v OFS=, '{$1=$1} 1'
+
+s='items: "apple" and "mango"'
+
+echo "$s" | awk -v FPAT='"[^"]+"' '{print $1}'
 
 s='eagle,"fox,42",bee,frog'
 

code_snippets/Gotchas_and_Tips.sh

@@ -6,7 +6,7 @@ awk -v word="cake" '$2==word' table.txt
 
 awk -v field=2 '{print $field}' table.txt
 
-## Dos style line endings
+## DOS style line endings
 
 printf 'mat dog\n123 789\n' | awk '{print $2, $1}'
 
@@ -36,7 +36,7 @@ echo 'hi log_42 12b' | awk '{gsub(/\</, ":")} 1'
 
 echo 'hi log_42 12b' | awk '{gsub(/\>/, ":")} 1'
 
-## Relying on default initial value
+## Relying on the default initial value
 
 awk '{sum += $NF} END{print sum}' table.txt
 
@@ -46,7 +46,7 @@ awk '{sum += $NF} ENDFILE{print FILENAME ":" sum}' table.txt marks.txt
 
 awk '{sum += $NF} ENDFILE{print FILENAME ":" sum; sum=0}' table.txt marks.txt
 
-## Code in replacement section
+## Code in the replacement section
 
 awk '{sub(/^(br|ye)/, ++c ") &")} 1' table.txt
 
@@ -64,6 +64,8 @@ awk '{sum += $1} END{print sum}' /dev/null
 
 awk '{sum += $1} END{print +sum}' /dev/null
 
+## Locale based numbers
+
 echo '3.14' | awk '{$0++} 1'
 
 echo '3,14' | awk '{$0++} 1'
@@ -90,21 +92,21 @@ awk 'NF>2{print $(NF-2)}' varying.txt
 
 ## Faster execution
 
-time awk '/^([a-d][r-z]){3}$/' /usr/share/dict/words > f1
+time awk '/^([a-d][r-z]){3}$/' words.txt > f1
 
-time LC_ALL=C awk '/^([a-d][r-z]){3}$/' /usr/share/dict/words > f2
+time LC_ALL=C awk '/^([a-d][r-z]){3}$/' words.txt > f2
 
-time mawk '/^[a-d][r-z][a-d][r-z][a-d][r-z]$/' /usr/share/dict/words > f3
+time mawk '/^[a-d][r-z][a-d][r-z][a-d][r-z]$/' words.txt > f3
 
 diff -s f1 f2
 
 diff -s f2 f3
 
 rm f[123]
 
-time awk -F'a' 'NF==4{cnt++} END{print +cnt}' /usr/share/dict/words
+time awk -F'a' 'NF==4{cnt++} END{print +cnt}' words.txt
 
-time LC_ALL=C awk -F'a' 'NF==4{cnt++} END{print +cnt}' /usr/share/dict/words
+time LC_ALL=C awk -F'a' 'NF==4{cnt++} END{print +cnt}' words.txt
 
-time mawk -F'a' 'NF==4{cnt++} END{print +cnt}' /usr/share/dict/words
+time mawk -F'a' 'NF==4{cnt++} END{print +cnt}' words.txt
 

code_snippets/Installation_and_Documentation.sh

@@ -1,19 +1,17 @@
 ## Installation
 
-wget https://ftp.gnu.org/gnu/gawk/gawk-5.1.0.tar.xz
+wget https://ftp.gnu.org/gnu/gawk/gawk-5.2.2.tar.xz
 
-tar -Jxf gawk-5.1.0.tar.xz
+tar -Jxf gawk-5.2.2.tar.xz
 
-cd gawk-5.1.0/
+cd gawk-5.2.2/
 
 ./configure
 
 make
 
 sudo make install
 
-type -a awk
-
 awk --version | head -n1
 
 ## Documentation

code_snippets/Processing_multiple_records.sh

@@ -1,10 +1,10 @@
 ## Processing consecutive records
 
-awk 'p ~ /as/ && /not/{print p ORS $0} {p=$0}' programming_quotes.txt
+awk 'p ~ /he/ && /you/{print p ORS $0} {p=$0}' para.txt
 
-awk 'p ~ /as/ && /not/{print p} {p=$0}' programming_quotes.txt
+awk 'p ~ /he/ && /you/{print p} {p=$0}' para.txt
 
-awk 'p ~ /as/ && /not/; {p=$0}' programming_quotes.txt
+awk 'p ~ /he/ && /you/; {p=$0}' para.txt
 
 ## Context matching
 

code_snippets/Record_separators.sh

@@ -1,8 +1,8 @@
 ## Input record separator
 
-printf 'this,is\na,sample' | awk -v RS=, '{print NR ")", $0}'
+printf 'this,is\na,sample,text' | awk -v RS=, '{print NR ")", $0}'
 
-s='   a\t\tb:1000\n\n\n\n123 7777:x  y \n \n z  '
+s='   a\t\tb:1000\n\n\t \n\n123 7777:x  y \n \n z  :apple banana cherry'
 
 printf '%b' "$s" | awk -v RS=: -v OFS=, '{$1=$1} 1'
 
@@ -18,7 +18,7 @@ awk -v IGNORECASE=1 -v RS='[e]' 'NR==1' report.log
 
 ## Output record separator
 
-printf 'foo\0bar\0' | awk -v RS='\0' -v ORS='.\n' '1'
+printf 'apple\0banana\0cherry\0' | awk -v RS='\0' -v ORS='.\n' '1'
 
 cat msg.txt
 
@@ -44,11 +44,11 @@ echo 'Sample123string42with777numbers' | awk -v RS='[0-9]+' '{print NR, RT}'
 
 ## Paragraph mode
 
-cat programming_quotes.txt
+cat para.txt
 
-awk -v RS= -v ORS='\n\n' '/you/' programming_quotes.txt
+awk -v RS= -v ORS='\n\n' '/do/' para.txt
 
-awk -v RS= '/you/{print s $0; s="\n"}' programming_quotes.txt
+awk -v RS= '/do/{print s $0; s="\n"}' para.txt
 
 s='\n\n\na\nb\n\n12\n34\n\nhi\nhello\n'
 
@@ -66,7 +66,7 @@ s='a:b\nc:d\n\n1\n2\n3'
 
 printf '%b' "$s" | awk -F: -v RS= -v ORS='\n---\n' '{$1=$1} 1'
 
-printf '%b' "$s" | awk -F':+' -v RS= -v ORS='\n---\n' '{$1=$1} 1'
+printf '%b' "$s" | awk -F'[:]' -v RS= -v ORS='\n---\n' '{$1=$1} 1'
 
 printf '%b' "$s" | awk -F: -v RS='\n\n+' -v ORS='\n---\n' '{$1=$1} 1'