From 8f6ded78070bc3b2eeef5af4b3124afe112178cb Mon Sep 17 00:00:00 2001
From: sejo <tejocote+codeberg@posteo.net>
Date: Tue, 30 Nov 2021 21:16:39 -0600
Subject: [PATCH] awk notes

---
 src/advent_of_code_2021.gmo |  7 +++++
 src/apuntes.gmo             |  1 +
 src/awk.gmo                 | 62 +++++++++++++++++++++++++++++++++++++
 src/now.gmo                 |  2 ++
 src/wiki.gmo                |  2 +-
 5 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 src/advent_of_code_2021.gmo
 create mode 100644 src/awk.gmo

diff --git a/src/advent_of_code_2021.gmo b/src/advent_of_code_2021.gmo
new file mode 100644
index 0000000..368ef7e
--- /dev/null
+++ b/src/advent_of_code_2021.gmo
@@ -0,0 +1,7 @@
+# advent of code 2021: awk
+
+my first time participating in advent of code!
+
+=> https://adventofcode.com/2021/
+
+decided to use {awk} as a programming language in order to keep practicing and learning it :)
diff --git a/src/apuntes.gmo b/src/apuntes.gmo
index 655746d..fb68a43 100644
--- a/src/apuntes.gmo
+++ b/src/apuntes.gmo
@@ -14,6 +14,7 @@ recordatorios de procesos
 => ./imagemagick.gmi {imagemagick}
 => ./ed.gmi {ed}
 => ./postfix.gmi {postfix}
+=> ./awk.gmi {awk}
 
 ## misc
 
diff --git a/src/awk.gmo b/src/awk.gmo
new file mode 100644
index 0000000..66e2d06
--- /dev/null
+++ b/src/awk.gmo
@@ -0,0 +1,62 @@
+# awk
+
+an awk-ward (or not really) language.
+
+some notes in process.
+
+# some built-in variables
+
+* FS: input field separator (by default, space)
+* RS: record field separator (by default, newline)
+* NF: number of fields in current record
+* NR: number of current record
+* FNR: number of current record relative to current file
+* OFS: output field separator (by default, space)
+* ORS: output record separator (by default, newline)
+* RLENGTH: length of the string matched by match( )
+
+$0 represents the entire input record, and $n the nth field in the current record
+
+=> https://www.tutorialspoint.com/awk/awk_built_in_variables.htm awk tutorial: built-in variables
+
+# some built-in functions
+
+
+=> https://www.tutorialspoint.com/awk/awk_built_in_functions.htm awk tutorial: built-in functions
+=> https://www.tutorialspoint.com/awk/awk_miscellaneous_functions.htm miscellaneous functions
+=> https://www.tutorialspoint.com/awk/awk_string_functions.htm string functions
+
+## strings
+
+the index of the first character is 1!
+
+* index( string, sub) : index of sub as a substring of string
+* length( string )
+* match( string, regex ) : index of the longest match of regex in string
+* split( string, arr, regex ) : split string into array using regex as separato
+* printf( format, expr-list)
+* strtonum(string): useful to convert from hexadecimal (0x prefix) or octal (0 prefix)
+* gsub( regex, sub, string): global substitution of regex with sub in string. if string is ommited, $0 is used
+* sub(regex, sub, string): substitute regex with sub in string, once. if string is omitted, $0 is used
+* substr(string, start, len): returns the substring from start index, with length len. if len is ommitted, it goes until the end of the string
+* tolower( str )
+* toupper( str )
+
+## misc
+
+* getline: read the next line
+* next: stops the current processing and start over with next line
+* system: execute the specified command and returns its exit status
+* delete: delete an element from an array, or an array
+
+# other notes
+
+## loop through the elements of an array
+
+```
+arr["a"] = 1
+arr["b"] = 2
+
+for(key in arr)
+  print key ": " arr[key]
+```
diff --git a/src/now.gmo b/src/now.gmo
index ea1cadf..0716580 100644
--- a/src/now.gmo
+++ b/src/now.gmo
@@ -6,6 +6,8 @@ developing the {qiudanz technique} in the context of a micro-residency in the sl
 
 see the {qiudanz devlog} for updates!
 
+participating in {advent of code 2021}
+
 finished teaching an {intro to uxn programming} online workshop via babycastles academy!
 
 practicing/learning skateboarding.
diff --git a/src/wiki.gmo b/src/wiki.gmo
index c73e1d6..3216603 100644
--- a/src/wiki.gmo
+++ b/src/wiki.gmo
@@ -25,6 +25,6 @@ it is heavily inspired by xxiivv and several sites in that webring
 
 the source files are written in a gemtext-like format, ready to be used in the {gemini} protocol, and to be easily convertible to html.
 
-the site is built to its corresponding formats with a custom engine composed of a shell script, awk scripts, and a python script.
+the site is built to its corresponding formats with a custom engine composed of a shell script, {awk} scripts, and a python script.
 
 => https://tildegit.org/sejo/compudanzas compudanzas site generator and source files