make silently be default

Each category - sound/, networking/, et c. - now has its own little
database in .dbs/.  So the database only recompiles based on categories,
rather than a complete recompile every time a single file changes.

Makefile

@@ -0,0 +1,71 @@
+MAKEFLAGS += -j
+MAKEFLAGS += -s
+EDITOR ?= vi
+FZF != command -v sk || command -v fzy || command -v fzf || \
+	{ echo install a fuzzy finder && exit 1 ;}
+
+help: ## Print the help message
+	@awk 'BEGIN {FS = ":.*?## "} /^[0-9a-zA-Z._-]+:.*?## / {printf "\033[36m%s\033[0m : %s\n", $$1, $$2}' $(MAKEFILE_LIST) | \
+		sort | \
+		column -s ':' -t
+
+articles != find * -type f -name "*.md"
+
+categories != ls -d */
+
+databases = $(patsubst %/, .dbs/%.rec, $(categories))
+
+default += $(databases)
+
+$(databases): .dbs/%.rec: %/ | .dbs/
+	$(info making $(@F))
+	mkdir -p $(@D)
+	for entry in $(shell find $< -type f -name "*.md") ; do \
+		sed -n '2,/^---$$/ {/^---$$/d; p}' "$$entry" |\
+		sed -e 's/\[ //'  -e 's/ \]//' |\
+		tr -d '"' ;\
+		printf "wordcount: %s\n" "$$(wc -w < $$entry)" ;\
+		printf "file: %s\n\n" "$$entry" ;\
+	done >> $@
+	for entry in $(shell find $< -type f -name "*.md"); do \
+		recset $@ -e "file = '$${entry}'" -f wordcount --set-add="$$(wc -w < $${entry})" ;\
+	done
+
+db.rec: $(databases)
+	printf '%s\n' '%rec: guide' > $@
+	printf '%s\n' '%type: wordcount int' >> $@
+	printf '%s\n\n' '%sort: title' >> $@
+	cat $^ >> $@
+	recsel $@ -e "requires != ''" -CR title,requires |\
+	while read title requires; do \
+		IFS=', ' && for provider in $$requires; do \
+			recset $@ -e "title = '$${provider}'" -f provides -a "$${title}" ;\
+		done ;\
+	done
+	$(info Created main database: $@)
+	recfix --sort $@
+
+default += db.rec
+
+.git/info/exclude: $(default)
+	echo $^ | tr ' ' '\n' > $@
+
+default += .git/info/exclude
+
+.PHONY: database
+database: $(default) ## Make a recfiles database
+
+.PHONY: article
+article: ## Write an article
+	@path=$$(find $(categories) -type d | sort | uniq | $(FZF)) ;\
+	read -p "Title: " title ;\
+	filename="$$(echo "$$title" | tr '[:upper:]' '[:lower:]' | tr ' ' '_')" ;\
+	printf '%s\n' '---' >> $$path/$$filename.md ;\
+	printf 'title: "%s"\n' "$$title" >> $$path/$$filename.md ;\
+	printf 'tags: [ "%s" ]\n' "$$path" | sed 's#\/#", "#g' >> $$path/$$filename.md ;\
+	printf '%s\n\n' '---' >> $$path/$$filename.md ;\
+	$(EDITOR) +5 "$$path/$$filename.md"
+
+.PHONY: clean
+clean: ## Remove all generated files
+	$(RM) $(default)

README.md

@@ -1,77 +1,79 @@
 ---
-title: "Knowledge Base"
+title: "Linux Knowledge Base"
 ---
 
-# Linux Knowledgebase
+The Linux Knowledge-Base provides quick-start guides for working with terminal programs.
 
-This is a list of quickstart guides for Linux programs, designed to get the user up and running as fast as possible.
+# Setup
+
+Install `make`, `recutils`, and any fuzzy-finder (i.e. `sk`, `fzy`, or `fzf`).
+
+## Usage
+
+
+```sh
+make
+make database
+
+recsel db.rec -q database
+recsel db.rec -q gpg
+recsel db.rec -e "title = 'ssh'"
+recsel db.rec -e "title ~ 'ssh'"
+recsel db.rec -e "title ~ 'bash'" -R title,wordcount
+```
 
 # Style
 
-## Praxis Only
+## No History, No Context
 
-We leave theory alone as much as possible.
-The documentation should be of the form 'if you want *X*, type *Y*'.
+- Nobody cares about how the project started.
+- Nobody wants to read what `ffmpeg` is, because anyone who wants to use it already knows what it is.
 
-We don't need to explain what a program does - anyone looking up 'how to X', already knows what they want to do.
-We don't even need to explain which program to use - if someone wants to combine an mp4 and webm video into a single video file, they only care about that result, not about learning `ffmpeg`.
+## Be Opinionated
 
-Any interest in these tools only comes after we can use them.
+- Guides should not ask the reader to select options half-way through.
+- Options for different filesystems, databases, et c., should be written as separate guides.
 
-## Chronological
+## Repetition Beats Reference
 
-Entries should read like scripts - everything in the right order, with small notes on what this does.
+If a database requires three commands to set up, it's better to repeat those three commands for every program that requires a database than to just link to another file which discusses databases.
 
-The chronology should never branch.
-If `gitea` can use three different types of database, the documentation should simply pick one and continue instructions from there.
-Repetition works better than a reference - if a database requires three commands to set up, it's better to repeat those three commands for every program that requires a database than to just link to another file which discusses databases.
+## Show Arguments as Variables
 
----
+Look at this line:
 
-### Closing
-
-Introductory documents should show anything required to cleanly uninstall a program, without leaving bulky configuration files behind.
-
-## Three Input Types
-
-There are three types of examples:
-
-Fixed input:
-
-```bash
-ls
+```sh
+grep ls --color=always  $HISTFILE | less -R
 ```
 
-Anything with arbitrary input should be shown as a variable.
+What else can go in place of `always`?
+Can you say `--color=red`?
+Can you put anything?
+The answer is not obvious.
 
-```bash
-ls $FILE
+What about this line:
+
+```sh
+git branch new
+git checkout new
 ```
 
-Non-commands (e.g. output) should be shown as quoted text:
+Do you always use `new`?
+Can you use another word here?
+The answer is not obvious.
 
-> LK           img
-> Mail         kn
-> Projects     music
-
----
-
-# Example
-
-```
-How to see which websites you're actively accessing:
-
-` ` `bash
-ss -tr dst :$PORT
-` ` `   
-
-> State  Recv-Q  Send-Q   Local Address:Port     Peer Address:Port   Process  
-> ESTAB  0       0         192.168.0.14:42476  149.154.167.91:https           
-> ESTAB  0       0         192.168.0.14:43644   104.17.90.199:https           
+It's better to make all arbitrary values variables.
 
+```sh
+git branch $branch_name
+git checkout $branch_name
+PAGER='less -R'
+grep ls --color=always $HISTFILE | $PAGER
 ```
 
-# What's wrong with everything else?
+Now we can see what can be changed.
+
+# What's Wrong with Everything Else?
 
 ## Man pages
 
@@ -79,12 +81,14 @@ ss -tr dst :$PORT
 - Often presumes you know everything except that one program.
 - Often written in the 80's, and it shows.
 - Zero respect for your time.
+- Often references `info` pages (yuck).
 
-## curl cheat.sh/
+## `curl cheat.sh`
 
 - Doesn't have the programs I like.
 - Too short to get you started on many programs.
 - Poor understanding of priority (`git stash` is covered before `git commit`).
+- Repetitive
 
 # Current State
 

basics/Joyous_ASCII.md

@@ -6,7 +6,20 @@ tags: [ "fun" ]
 - `asciiquarium`
 - `cbonsai -lim "$(fortune)"`
 
-```bash
+```sh
 cow=$(cowsay -l | sort -R | head  -1)
 fortune -s | figlet | cowsay -nf $cow | lolcat
 ```
+
+Watch the [Collatz Conjecture](https://en.wikipedia.org/wiki/Collatz_conjecture) collapse:
+
+```sh
+x="$(du -sc ~/.cache | tr -d '[:alpha:]' | tail -1)"
+until [ "$x" -eq "1" ]; do
+    test "$(( x % 2 ))" -eq 0 && x=$(( x / 2 )) || \
+        x=$(( x * 3 + 1 ))
+    clear -x
+    figlet "$x" | lolcat
+    sleep 1
+done
+```

basics/at.md

@@ -1,6 +1,6 @@
 ---
 title: "at"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics", "time" ]
 ---
 Install with:
 

basics/basics.md

@@ -1,6 +1,6 @@
 ---
 title: "Basics"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 
 You need about a dozen commands to move around Linux.
@@ -342,11 +342,12 @@ apt install $PROGRAM
 
 Remove `lolcat`, because it's useless:
 
-```bash
+```sh
 sudo apt remove lolcat
 ```
 
-... and that's pretty much it.  You can move, create, destroy, install things, and look things up.
+...and that's pretty much it.
+You can move, create, destroy, install things, and look things up.
 
 # Review
 

basics/clock.md

@@ -1,6 +1,6 @@
 ---
 title: "clock"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics", "time" ]
 ---
 
 Show system time:

basics/column.md

@@ -0,0 +1,36 @@
+---
+title: "column"
+tags: [ "basics", "format", "json" ]
+---
+
+Put output into column.
+
+```bash
+du -h /etc/* | column
+```
+
+Reformat file with an explicit separator (`-s`):
+
+```bash
+column -ts: /etc/passwd
+```
+
+Give columns names (`-N`), so you can hide some (`-H`):
+
+```bash
+column -ts: -N User,PW,UID,GID,Description,Home,shell -H PW,GID /etc/passwd
+```
+
+Reorder with `-O` (unspecified items remain):
+
+
+```bash
+column -ts: -N User,PW,UID,GID,Description,Home,shell -H PW,GID -O User,Description,shell /etc/passwd 
+```
+
+Output to json format with `-J`:
+
+```bash
+column -J -ts: -H PW,GID,shell -N User,PW,UID,GID,Description,Home,shell /etc/passwd
+```
+

basics/conditionals.md

@@ -1,6 +1,6 @@
 ---
 title: "conditionals"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 # If statements
 

basics/cron.md

@@ -1,6 +1,6 @@
 ---
 title: "cron"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics", "time" ]
 ---
 # Cronie
 

basics/games.md

@@ -1,6 +1,6 @@
 ---
 title: "bash games"
-tags: [ "Documentation", "Games" ]
+tags: [ "Games" ]
 ---
 
 Games are a great way to learn bash.

basics/kernel.md

@@ -1,6 +1,6 @@
 ---
 title: "kernel"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 ## Living Space
 

basics/kill.md

@@ -1,6 +1,6 @@
 ---
 title: "kill"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 
 If you want to kill a program in a graphical environment, open a terminal and type:

basics/locale.md

@@ -1,6 +1,6 @@
 ---
 title: "locale"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics", "time" ]
 ---
 
 Your locale tells the computer your location, preferred time-and-date format, standard language, papersize, et c.

basics/locating.md

@@ -1,62 +1,33 @@
 ---
 title: "locating"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 # Type
 
 `type` shows what kind of thing you're running, be it an alias, function, or binary program.
 
-```bash
-type cmus
+```sh
+type cd
+type ls
+type -P ls
+type -a cat
 ```
 
 # Whereis the Program
 
-Ask where the `angband` program is, along with all its configuration files:
+Where is `grep` and all its configuration files?
 
-`whereis angband`
-
-Also `which` shows where a binary file (the program) is, 
-
-```bash
-which cmus
+```sh
+whereis grep
 ```
 
-# Search Instantly with `plocate`
+Which one of these is the binary file which you actually use?
 
-You can search every file on the computer instantly by installing `plocate`.
-
-Once installed, run `sudo updatedb` to create the database of (nearly) every file on the computer.
-
-Check how big the database is:
-
-```bash
-du -h /var/lib/plocate/plocate.db
+```sh
+which grep
 ```
 
-Once you have the database, you can find nearly any file instantly.
+# More
 
-- Search for gifs: `locate .gif`
-- Search for gifs in the `/usr/` directory: `locate /usr/ .gif`
-- Search for jpg images with 'dog' or 'Dog' in the name: `locate -i dog jpg`
-- Search for videos: `plocate --regex '.mp4$|.mkv$|.wmv$|.webm$|.mov$|.avi$'`
-
-For best results, run `updatedb` regularly, perhaps in [crontab](../system/cron.md).
-
-## Search More Places
-
-`plocate` will not search `/tmp/`, because nobody cares about those files, and won't search inside `/mnt/`, because that's where USB sticks get mounted, so the files keep changing as USB sticks come and go.
-
-Change where `plocate` searches by editing the configuration file at `/etc/updatedb.conf`.
-
-By default, the `/mnt` directory is 'pruned' from the database.
-So if you want to search `/mnt` for videos, remove the word `/mnt` from the configuration file.
-
-
-```bash
-cat /etc/updatedb.conf
-sudo sed 's#/mnt/##' /etc/updatedb.conf
-sudo updatedb
-plocate --regex '.mp4$|.mkv$|.wmv$|.webm$|.mov$|.avi$'
-```
+- [Search instantly with `plocate`](data/search_system.md)
 

basics/processes.md

@@ -1,6 +1,6 @@
 ---
 title: "processes"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 # Proccesses
 

basics/time.md

@@ -1,6 +1,6 @@
 ---
 title: "time"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics", "time" ]
 ---
 # systemd
 

basics/users.md

@@ -1,6 +1,6 @@
 ---
 title: "users"
-tags: [ "Documentation", "Basics" ]
+tags: [ "Basics" ]
 ---
 # Basic Information
 

chat/profanity-otr.md

@@ -1,57 +0,0 @@
----
-title: "profanity"
-tags: [ "Documentation", "Chat", "OTR" ]
----
-# otr
-
-'Off The Record' encryption seems mostly dead to me.
-But this is what I did, back in the day...
-
-Install libotr-dev or libotr5-dev or whatever..
-
-```
-sudo apt -y install lib5otr-dev
-```
-
-Make your otr keys.
-
-```
-/otr gen
-```
-
-Then you can start an otr converstation.
-
-```
-/otr start bob@jobbies.org
-```
-
-Or if you already have a conversation windows open, switch to our using:
-
-```
-/otr
-```
-
-Finally, verify!
-
-```
-/otr question "Who are you?" bob
-```
-
-Bob is verified upon the answer, 'bob'.
-
-### OTR Finger Prints
-
-Get yours with 
-
-```
-/otr myfp
-```
-
-```
-/otr theirfp
-```
-
-```
-/otr myfp
-```
-

chat/profanity.md

@@ -1,6 +1,6 @@
 ---
 title: "profanity"
-tags: [ "Documentation", "Chat", "omemo" ]
+tags: [ "Chat", "omemo" ]
 ---
 # Setup (Commands)
 

chat/wgetpaste.md

@@ -1,29 +1,29 @@
 ---
 title: "wgetpaste"
-tags: [ "Documentation", "Chat" ]
+tags: [ "Chat" ]
 ---
 
 See available pastebins:
 
-```bash
+```sh
 wgetpaste -S
 ```
 
 Upload script.sh to bpaste:
 
-```bash
+```sh
 wgetpaste -s bpaste script.sh
 ```
 
 Input clipboard to dpaste with the heading "Title"
 
-```bash
+```sh
 wgetpaste -s dpaste -d Title -x
 ```
 
 Paste in the file then load the result to the right-hand clipboard:
 
-```bash
+```sh
 wgetpaste -s dpaste -X
 ```
 

data/backups/archives.md

@@ -1,6 +1,6 @@
 ---
 title: "Archives"
-tags: [ "Documentation", "tar", "backups" ]
+tags: [ "tar", "backups", ".tgz", "tar.gz" ]
 ---
 # `tar`
 

data/backups/unison.md

@@ -1,6 +1,6 @@
 ---
 title: "unison"
-tags: [ "Documentation", "Backups" ]
+tags: [ "Backups", "synch" ]
 ---
 
 Install unison on both machines, and make sure both have the same version of unison, with the same version of the ocaml compiler (the smallest difference will cause problems).

data/base_16.md

@@ -1,6 +1,6 @@
 ---
 title: "Base 16"
-tags: [ "Documentation", "Data" ]
+tags: [ "Data" ]
 ---
 
 ```bash

data/exiftool.md

@@ -1,6 +1,6 @@
 ---
 title: "exiftool"
-tags: [ "Documentation", "Metadata" ]
+tags: [ "Metadata" ]
 ---
 
 Find metadata.

data/git/basics.md

@@ -1,6 +1,6 @@
 ---
 title: "git"
-tags: [ "Documentation", "data" ]
+tags: [ "data" ]
 ---
 # Starting
 

data/git/git-lfs.md

@@ -1,6 +1,6 @@
 ---
 title: "git-lfs"
-tags: [ "Documentation", "data" ]
+tags: [ "data" ]
 ---
 
 Install, and add with

data/git/hooks.md

@@ -1,6 +1,6 @@
 ---
 title: "git hooks"
-tags: [ "Documentation", "data", "git" ]
+tags: [ "data", "git" ]
 ---
 
 Check out the sample hooks:

data/git/subtree.md

@@ -1,6 +1,6 @@
 ---
 title: "git"
-tags: [ "Documentation", "data", "git", "subtree" ]
+tags: [ "data", "git", "subtree" ]
 ---
 
 ## Pulling a Subtree from an existing git

data/gpg.md

@@ -1,6 +1,6 @@
 ---
 title: "gpg"
-tags: [ "Documentation", "data", "GPG" ]
+tags: [ "data", "GPG" ]
 ---
 
 - [Setup](gpg/basics.md)

data/gpg/basics.md

@@ -1,6 +1,6 @@
 ---
 title: "GPG Basics"
-tags: [ "Documentation", "data", "GPG" ]
+tags: [ "data", "GPG" ]
 ---
 # Making keys
 

data/gpg/extras.md

@@ -1,6 +1,7 @@
 ---
 title: "gpg"
-tags: [ "Documentation", "vim", "data", "GPG" ]
+tags: [ "vim", "data", "GPG" ]
+requires: [ "GPG Basics", "vim basics" ]
 ---
 
 The `vim-gnupg` plugin lets vim edit gpg-encrypted files as if they were unencrypted.

data/groff.md

@@ -1,6 +1,6 @@
 ---
 title: "groff"
-tags: [ "Documentation", "Data" ]
+tags: [ "Data" ]
 ---
 # Basic Documents
 

data/khard.md

@@ -1,6 +1,6 @@
 ---
 title: "khard"
-tags: [ "Documentation", "Data" ]
+tags: [ "Data" ]
 ---
 Get the basic config:
 

data/newsboat.md

@@ -1,6 +1,6 @@
 ---
 title: "newsboat"
-tags: [ "Documentation", "RSS" ]
+tags: [ "RSS" ]
 ---
 Create the configuration directory before you start, and add at least 1 URL.
 

data/pass.md

@@ -1,6 +1,6 @@
 ---
 title: "pass"
-tags: [ "Documentation", "data" ]
+tags: [ "data" ]
 ---
 [Video instructions](https://www.hooktube.com/watch?v=hlRQTj1D9LA)
 

data/pdf-to-txt.md

@@ -1,6 +1,6 @@
 ---
 title: "pdf to txt"
-tags: [ "Documentation", "data", "pdf", "ocr" ]
+tags: [ "data", "pdf", "ocr" ]
 ---
 How to translate pdf book images to text (results are very poor, and will need lots of corrections).
 

data/pdf_erasure.md

@@ -1,8 +1,11 @@
 ---
 title: "PDF Metadata Erasure"
-tags: [ "Documentation", "Metadata", "Ghost Script" ]
+tags: [ "Metadata", "Ghost Script", "gs", ".pdf" ]
 ---
 
+You cannot erase pdf metadata with `exiftool` (it only *appends* your changes).
+To delete pdf metadata, you'll need `gs`.
+
 Make a text file called 'pdfmark.txt'.
 
 

data/recfiles.md

@@ -0,0 +1,51 @@
+---
+title: "Recfiles"
+tags: [ "data", "database" ]
+---
+
+Create:
+
+```sh
+database=games.rec
+touch $database
+for g in Vojvodina Saboter Carcassonne Chess; do
+    recins -r "Name: $g" -r "Played: yes" $database
+done
+```
+
+Read:
+
+```sh
+recsel $database
+query=Carc
+recsel --quick=$query $database
+
+game=Vojvodina
+recsel --expression="Name = '${game}'" $database
+```
+
+Update:
+
+```sh
+recset --expression="Name = '${game}'" -f Played --set="no" $database
+new_field=Played
+value=no
+recset -f "$new_field" --delete $database
+recset -f "$new_field" --set-add="$value" $database
+recsel $database
+```
+
+Delete:
+
+```sh
+recdel --expression="Name = '${game}'" $database
+recset -f "$new_field" --delete $database
+```
+
+- [Extended example](recfiles/extended.md)
+- [Playing with board games data](recfiles/Board_Games.md)
+
+# Resources
+
+- [Recfiles for gemini capsules](gemini://tilde.town/~dozens/gemlog/21.gmi)
+

data/recfiles/Board_Games.md

@@ -0,0 +1,62 @@
+---
+title: "Board Games with Recfiles"
+tags: [ "data", "recfiles", "games" ]
+requires: "Recfiles"
+---
+
+You can play with a board games database from boardgamegeek.com.
+
+## Download the Database
+
+```sh
+mkdir board_games
+cd board_games
+curl -Lo bg.zip 'https://www.kaggle.com/api/v1/datasets/download/threnjen/board-games-database-from-boardgamegeek'
+unzip bg.zip
+```
+
+The header line shows fields with a bunch of colons, which will confused `recutils`, so we'll have to get rid of them.
+
+```sh
+sed -i '1s/://g' *.csv 
+```
+
+Convert the games to `.rec` format.
+
+```sh
+csv2rec games.csv > games.rec
+```
+
+## Queries
+
+If you try to look at older games, you'll find lots of results.
+
+```sh
+recsel games.rec -e "YearPublished < 1800" -c
+recsel games.rec -e "YearPublished < 1800" -Cp Name
+```
+But most are wrong.
+The problem is games with a `YearPublished` date of `0`, probably because the year published is unknown.
+
+```sh
+recsel games.rec -e "Name = 'The Goblin King is Angry'" -p YearPublished
+```
+
+Fix the query by removing games published in '0 AD'.
+
+```sh
+recsel games.rec -e "YearPublished < 1800 && YearPublished != 0" -R YearPublished,Name
+```
+
+Or fix the database setting `YearPublished` to 'unknown':
+
+```sh
+recsel games.rec -e "YearPublished = 0" -Cp Name
+recset games.rec -e "YearPublished = 0" -f "YearPublished" -S 'unknown'
+```
+
+Strategic games which work best with 3 players, sorted by Average Rating:
+
+```sh
+recsel games.rec -e "BestPlayers = 3 && CatStrategy = 1" -CR Name --sort=AvgRating
+```

data/recfiles/extended.md

@@ -0,0 +1,118 @@
+---
+title: "Recfiles Extended Example"
+tags: [ "data", "database", "recfiles" ]
+---
+
+## Create
+
+Make a database for your boardgames, specifying only one field and value:
+
+```bash
+database=games.rec
+n=Name
+g=Vojvodina
+touch $database
+recins -f $n --value $g $database
+recsel $database
+```
+
+Insert a few more, with the estimated playtime:
+
+```bash
+recins -f Name -v Saboter -f Playtime -v 30 $database
+recins -f Name -v Chess -f Playtime -v 30 $database
+```
+
+View all games, or select one by number:
+
+```bash
+recsel $database
+recsel -n 0 $database
+```
+
+Each game should note whether or not you have played it yet, so you can add that field and set the default to `yes`.
+
+```bash
+f=played
+v=yes
+recset -f $f -a $v $database
+```
+
+...but the field is wrong, it should have a capital letter:
+
+```bash
+new_field=Played
+recset -f $f --rename $new_field
+```
+
+## Read
+
+Check how many records the database has:
+
+```bash
+recinf $database
+```
+
+Look at just the games you've never played:
+
+```bash
+recsel --expression="Played = 'no'" $database
+```
+
+Print how many, then just print the names:
+
+```bash
+recsel -e "Played = 'no'" --count $database
+recsel -e "Played = 'no'" --print=Name $database
+```
+
+## Update
+
+To change a game's `Played` field from `no` to `yes`, use `recset` to specify the number, and change that field.
+
+```bash
+num=0
+f=Played
+value=yes
+recsel --number=$num $database
+recset --number=$num -f $f --set=$value $database
+```
+
+Find all games with a playtime of `30`, and set the field `Max_Players` to `4`.
+
+```bash
+recset -e "Playtime = 40" -f Max_Players --set 50 games.rec
+```
+
+This doesn't work, because that field does not exist.
+You can `--set-add` the field, to add it wherever it does not exist.
+
+```bash
+recset -e "Playtime = 40" -f Max_Players --set-add 50 games.rec
+```
+
+## Delete
+
+Remove `Played` record from first game:
+
+```bash
+num=0
+recset --number=$num -f Played --delete $database
+```
+
+You can comment the line instead of deleting it:
+
+```bash
+num=1
+recset --number=$num -f Played --delete $database
+recsel $database
+cat $database
+```
+
+Delete an entire record:
+
+```bash
+num=2
+recdel --number=$num $database
+```
+

data/sc-im.md

@@ -1,6 +1,6 @@
 ---
 title: "sc-im"
-tags: [ "Documentation", "TUI", "data" ]
+tags: [ "TUI", "data", "spreadsheet", ".csv" ]
 ---
 
 - [Sample file](sc-im/sample.sc)

data/search_system.md

@@ -0,0 +1,49 @@
+---
+title: "Search System"
+tags: [ "data", "search", "locate", "plocate" ]
+requires: "cron"
+---
+
+You can search every file on the computer instantly by installing `plocate`.
+
+Once installed, run `sudo updatedb` to create the database of (nearly) every file on the computer.
+
+Check how big the database is:
+
+```sh
+du -h /var/lib/plocate/plocate.db
+```
+
+Once you have the database, you can find nearly any file instantly.
+
+- Search for gifs: `locate .gif`
+- Search for gifs in the `/usr/` directory: `locate /usr/ .gif`
+- Search for jpg images with 'dog' or 'Dog' in the name: `locate -i dog jpg`
+- Search for videos: `plocate --regex '.mp4$|.mkv$|.wmv$|.webm$|.mov$|.avi$'`
+
+For best results, run `updatedb` regularly, perhaps in [crontab](../system/cron.md).
+
+## Search More Places
+
+`plocate` will not search `/tmp/`, because nobody cares about those files, and won't search inside `/mnt/`, because that's where USB sticks get mounted, so the files keep changing as USB sticks come and go.
+
+Change where `plocate` searches by editing the configuration file at `/etc/updatedb.conf`.
+
+By default, the `/mnt` directory is 'pruned' from the database.
+So if you want to search `/mnt` for videos, remove the word `/mnt` from the configuration file.
+
+
+```bash
+su root
+cat /etc/updatedb.conf
+sed -i 's#/mnt/##' /etc/updatedb.conf
+updatedb
+exit
+```
+
+Now you can search in `/mnt` for films:
+
+```sh
+plocate --regex '.mp4$|.mkv$|.wmv$|.webm$|.mov$|.avi$'
+```
+

data/soft_https.md

@@ -1,6 +1,6 @@
 ---
 title: "Soft Serve through https"
-tags: [ "data", "git" ]
+tags: [ "data", "git server", "lfs" ]
 ---
 
 ## `http` Setup

data/sqlite.md

@@ -1,6 +1,6 @@
 ---
 title: "sqlite"
-tags: [ "Documentation", "data" ]
+tags: [ "data" ]
 ---
 
 Work with a database:

data/taskwarrior/task.md

@@ -1,6 +1,6 @@
 ---
 title: "task"
-tags: [ "Documentation", "Organization" ]
+tags: [ "Organization" ]
 ---
 
 Set up the configuration file:

data/taskwarrior/timew.md

@@ -1,6 +1,6 @@
 ---
-title: "timew"
-tags: [ "Documentation", "Data" ]
+title: "timewarrior"
+tags: [ "Data", "tracking", "time", "timew" ]
 ---
 # Summaries
 

data/w3m.md

@@ -1,6 +1,6 @@
 ---
 title: "w3m"
-tags: [ "Documentation", "browsers" ]
+tags: [ "browsers" ]
 ---
 Open a search tab:
 

distros/android/ssh_to_phone.md

@@ -8,7 +8,7 @@ tags: [ "networking", "ssh", "android" ]
 3. Open fdroid, and run:
 
 
-```bash
+```sh
 pkg upgrade
 pkg install busybox termux-services openssh openssh-sftp-server
 source $PREFIX/etc/profile.d/start-services.sh

distros/arch/Maintenance.md

@@ -0,0 +1,53 @@
+---
+title: "Maintenance"
+tags: [ "arch" ]
+---
+
+# Package Cache
+
+Clean the cache of old packages in `/var/cachepacman/pkg/`:
+
+```bash
+ls /var/cache/pacman/pkg/ | wc -l
+sudo pacman -Sc
+ls /var/cache/pacman/pkg/ | wc -l
+```
+And the same for `yay` (with `-Yc` to remove old dependencies):
+
+```bash
+ls ~/.cache/yay/ | wc -l
+yay -Sc
+yay -Yc
+ls ~/.cache/yay/ | wc -l
+```
+
+# New Configs
+
+If you chance a configuration file, such as `/etc/environment`, and `pacman` wants to update the file, it will place `/etc/environment.pacnew`.
+
+Check the new files, then look at the difference between the `pacman` version, and your version.
+
+```bash
+sudo find /etc/ /var/ /usr/ -name "*.pacnew" 
+diff /etc/pacman.d/mirrorlist*
+```
+
+Either,
+
+- Update the files manually,
+
+```bash
+sudo -e /etc/pacman.d/mirrorlist
+sudo rm /etc/pacman.d/mirrorlist.pacnew
+```
+
+Or,
+
+- use a tool like `pacdiff` to view the changes next to each other, and select them with `vim`.
+
+
+```bash
+sudo pacman -S pacman-contrib
+sudo pacdiff
+```
+

distros/arch/arch_pi_install.md

@@ -1,6 +1,6 @@
 ---
 title: "Arch on a Raspberry Pi 4"
-tags: [ "Documentation", "distros", "raspberry pi", "rpi" ]
+tags: [ "distros", "raspberry pi", "rpi" ]
 ---
 
 The [Official Instructions](https://archlinuxarm.org/platforms/armv8/broadcom/raspberry-pi-4) for a Raspberry pi 4 do not allow for working sound from the headphone jack, unless you use the aarch64 Installation.

distros/arch/autologin.md

@@ -1,6 +1,6 @@
 ---
 title: "autologin"
-tags: [ "Documentation", "Distros", "Arch" ]
+tags: [ "Distros", "Arch" ]
 ---
 
 # Automatic Login

distros/arch/basic-install.md

@@ -1,6 +1,7 @@
 ---
 title: "basic-install"
-tags: [ "Documentation", "arch" ]
+tags: [ "arch" ]
+requires: [ "partitions", "time" ]
 ---
 Keyboard layout changed.
 

distros/arch/fonts.md

@@ -1,24 +1,25 @@
 ---
 title: "fonts"
-tags: [ "Documentation", "distros" ]
+tags: [ "distros" ]
 ---
 # Basics
 
 Update font-cache:
 
-```bash
+```sh
+su root
 fc-cache
 ```
 
 List fonts:
 
-```bash
+```sh
 fc-list
 ```
 
 Grab the part of the font name you need for Xresources:
 
-```bash
+```sh
 fc-list | cut -d: -f2
 ```
 

distros/arch/gpu.md

@@ -1,6 +1,6 @@
 ---
 title: "fonts"
-tags: [ "Documentation", "distros" ]
+tags: [ "distros" ]
 ---
 # Step 1: Multilib
 

distros/arch/pacman.md

@@ -1,6 +1,6 @@
 ---
 title: "pacman"
-tags: [ "Documentation", "distros" ]
+tags: [ "distros" ]
 ---
 
 Packages are kept in /var/cache/pacman/pkg.

distros/debian/apt.md

@@ -1,6 +1,6 @@
 ---
 title: "apt"
-tags: [ "Documentation", "distros" ]
+tags: [ "distros" ]
 ---
 ## apt
 
@@ -8,27 +8,27 @@ tags: [ "Documentation", "distros" ]
 
 Messed up a package's configuration files?
 
-```bash
+```sh
 sudo apt-get purge [thing]
 ```
 
-```bash
+```sh
 sudo apt autoremove 
 ```
 
 Check if you still have related things:
 
-```bash
+```sh
 apt search [thing]
 ```
 
-```bash
+```sh
 sudo apt-get install [ thing ]
 ```
 
 Still have problems?
 
-```bash
+```sh
 sudo dpgk --force-confmiss -i /var/cache/apt/archives/[thing]
 ```
 

distros/void/aeroplanes.md

@@ -1,18 +1,24 @@
 ---
 title: "Aeroplane Mode in Void"
-tags: [ "Documentation", "Void" ]
+tags: [ "Void" ]
 ---
 Put your device in 'aeroplane' mode (e.g. where no trace of signal leaves it) by turning off Wi-Fi and blue-tooth.
 
-> sudo sv stop wpa_supplicant bluetoothd
+```sh
+su root
+sv stop wpa_supplicant bluetoothd
+```
 
 Find your device's name with `ip a`.
 If unsure, try this:
 
-> name=$(ip a | grep -Eo 'wlp\w{3}')
-
-> echo $name
+```sh
+name=$(ip a | grep -Eo 'wlp\w{3}')
+echo $name
+```
 
 Then set that device down:
 
-> sudo ip link set $name down
+```sh
+ip link set $name down
+```

distros/void/autologin.md

@@ -1,6 +1,6 @@
 ---
 title: "Void Autologin"
-tags: [ "Documentation", "Void" ]
+tags: [ "Void" ]
 ---
 
 Make the autologin service:

distros/void/extrace.md

@@ -1,22 +1,22 @@
 ---
 title: "extrace"
-tags: [ "Documentation", "Void" ]
+tags: [ "Void" ]
 ---
 Monitor all processes:
 
-```bash
+```sh
 extrace
 ```
 
 Monitor one process:
 
-```bash
+```sh
 extrace ls
 ```
 
 Monitor a script:
 
-```bash
+```sh
 ./script.sh | extrace
 ```
 

distros/void/jenkins.md

@@ -9,16 +9,17 @@ Jenkins is janky.
 ## Start
 Start the service file.
 
-```bash
-sudo ln -s /etc/sv/jenkins /var/service
-sudo sv start jenkins
+```sh
+su root
+ln -s /etc/sv/jenkins /var/service
+sv start jenkins
 ```
 
 Then visit the web interface with `$BROWSER localhost:8080`.
 
 If it's not working, try running the command from the run file the first time:
 
-```bash
+```sh
 chpst -u jenkins java -jar /opt/jenkins/jenkins.war
 ```
 

distros/void/locale.md

@@ -6,13 +6,13 @@ tags: [ "void", "locale" ]
 Check the current locales:
 
 
-```bash
+```sh
 locale -a
 ```
 
 Add the languages you want by editing `/etc/default/libc-locales`, and uncommenting your choice:
 
-```bash
+```sh
 #en_DK.UTF-8 UTF-8  
 #en_DK ISO-8859-1  
 en_GB.UTF-8 UTF-8  
@@ -25,13 +25,14 @@ Now you can generate what you need for those languages.
 However, instead of generating what you need, you're going to generate everything which needs updating:
 
 
-```bash
-sudo xbps-reconfigure glibc-locales
+```sh
+su root
+xbps-reconfigure glibc-locales
 ```
 
 Finally, select your chosen locale by placing it in `/etc/locale.conf`.
 
-```bash
+```sh
 echo "LC_ALL=en_GB.UTF-8
 LANG=en_GB.UTF-8
 LANGUAGE=en_GB.UTF-8" > /etc/locale.conf
@@ -48,7 +49,7 @@ en_GB ISO-8859-1
 Check your new locales are available:
 
 
-```bash
+```sh
 locale -a
 ```
 

distros/void/sv.md

@@ -1,6 +1,6 @@
 ---
 title: "sv"
-tags: [ "Documentation", "Void" ]
+tags: [ "Void" ]
 ---
 # List Services
 

distros/void/void_basics.md

@@ -1,6 +1,6 @@
 ---
 title: "Void Linux Basics"
-tags: [ "Documentation", "Void" ]
+tags: [ "Void" ]
 ---
 # Updates
 

distros/void/xbps.md

@@ -1,6 +1,6 @@
 ---
 title: "xbps"
-tags: [ "Documentation", "Void" ]
+tags: [ "Void" ]
 ---
 ## Search
 

hardware/brightness.md

@@ -1,6 +1,6 @@
 ---
 title: "brightness"
-tags: [ "Documentation", "hardware" ]
+tags: [ "hardware", "laptop" ]
 ---
 # Brightness
 

hardware/keyboard.md

@@ -0,0 +1,65 @@
+---
+title: "keyboard"
+tags: [ "keyboard", "vim" ]
+---
+
+# System-Wide Capslock and Escape Swap
+
+This works everywhere, including in a bare-ass tty.
+
+Select a keymap, and create a new custom map.
+
+```bash
+su root
+
+basemap=/usr/share/kbd/keymaps/i386/qwerty/pl1.map.gz
+newmap=/usr/share/kbd/keymaps/custom.map.gz
+
+gunzip -c $basemap | \
+    sed 's/Caps_Lock/\n/g;s/Escape/Caps_Lock/g;s/\n/Escape/g' | \
+    gzip > $newmap
+```
+
+Tell the system to use this keymap at startup by naming it in the `rc.conf` file:
+
+```bash
+echo "KEYMAP=$newmap" >> /etc/rc.conf
+
+cat /etc/rc.conf
+reboot
+```
+
+# Set Layout with X Display
+
+Set layout to British English.
+
+```bash
+setxkbmap -layout gb
+```
+
+Or Polish with:
+
+```bash
+setxkbmap -layout pl
+```
+
+| Language | short |
+|:--------|:------|
+| Polish  | pl |
+| Serbian | rs |
+
+Set 'alt + shift', as the command which cycles through the British English, Polish and Serbian keyboard layout.
+
+```bash
+setxkbmap -layout gb,pl,rs -option grp:alt_shift_toggle
+```
+
+## Alt_GR
+
+Remap, e.g., the right Windows key, to Alt_Gr.
+
+```
+    key <RWIN> {[  ISO_Level3_Shift    ]};
+```
+
+

hardware/keyboard/keyboard.md

@@ -1,68 +0,0 @@
----
-title: "keyboard"
-tags: [ "Documentation", "keyboard" ]
----
-# Set Layout with X Display
-
-Set layout to British English.
-
-```bash
-setxkbmap -layout gb
-```
-
-Or Polish with:
-
-```bash
-setxkbmap -layout pl
-```
-
-| Language | short |
-|:--------|:------|
-| Polish  | pl |
-| Serbian | rs |
-
-Set 'alt + shift', as the command which cycles through the British English, Polish and Serbian keyboard layout.
-
-```bash
-setxkbmap -layout gb,pl,rs -option grp:alt_shift_toggle
-```
-
-## Alt_GR
-
-Remap, e.g., the right Windows key, to Alt_Gr.
-
-```
-    key <RWIN> {[  ISO_Level3_Shift    ]};
-```
-
-# Set TTY Keymap
-
-Copy your keymap, e.g. if it's polish-1, then:
-
-```bash
-cp /usr/share/kbd/keymaps/i386/qwerty/pl1.map.gz /usr/share/kbd/keymaps/*custom*.map.gz
-```
-
-Then change that map:
-
-```bash
-sudo vim /usr/share/kbd/keymaps/custom.map.gz
-```
-
----
-
-You can switch Escape and Caps Lock with a single line:
-
-```bash
-sudo sh -c "gunzip -c /usr/share/kbd/keymaps/i386/qwerty/pl1.map.gz   | sed 's/ Escape/ PLACEHOLDER/ ; s/Caps_Lock/Escape/g ; s/PLACEHOLDER/Caps_Lock/' | gzip > /usr/share/kbd/keymaps/custom.map.gz"
-```
-
----
-
-Change the default keyboard mapping to the custom map:
-
-```bash
-echo 'KEYMAP="/usr/share/kbd/keymaps/*custom*.map.gz"'  | sudo tee /etc/vconsole.conf
-```
-
-Reboot to have changes take effect.

hardware/keyboard/unicode-characters

@@ -1,37 +0,0 @@
-        ☢                   ☣            s       ☠                    ⚠
- radioactive sign     biohazard sign    skull and crossbones    warning sign
-        ☤                   ⚕                    ⚚                    †
-     caduceus      staff of aesculapius   staff of hermes          dagger
-        ☯                   ⚖                    ☮                    ⚘
-     yin yang             scales               peace               flower
-        ⚔                   ☭                    ⚒                    ⚓
-  crossed swords    hammer and sickle     hammer and pick          anchor
-        ⚛                   ⚜                    ⚡                   ⚶
-   atom symbol         fleur-de-lis          lightning              vesta
-        ☥                   ✠                    ✙                    ✞
-       ankh               cross                cross                cross
-        ✟                   ✧                    ⋆                    ★
-      cross              diamond                star                star
-        ☆                   ✪                    ✫                    ✬
-       star                star                 star                star
-        ✭                   ✮                    ✯                    ✰
-       star                star                 star                star
-≪
-        ☸                   ✵                    ❂                    ☘
- wheel of dharma           star                 sun               shamrock
-        ♡                   ♥                    ❤                    ⚘
-      heart               heart              big heart             flower
-        ❀                   ❃                    ❁                    ✼
-      flower              flower               flower              flower
-        ☀                   ✌                    ♫                    ♪
-       sun                V sign        music note / melody  music note / melody
-        ☃                   ❄                    ❅                    ❆
-     snowman            snowflake            snowflake            snowflake
-        ☕                  ☂                    ❦                    ✈
-      cofee              umbrella       floral heart / leaf       airplane
-        ♕                   ♛                    ♖                    ♜
-white king / crown  black king / crown   white rook / tower  black rook / tower
-        ☁                   ☾
-      cloud        waning crescent moon
-
-

hardware/monitor.md

@@ -1,12 +1,16 @@
 ---
 title: "monitor"
-tags: [ "Documentation", "hardware" ]
+tags: [ "hardware" ]
 ---
 See screen size
 
-> xrandr -q
+```sh
+xrandr -q
+```
 
 Automatically configure:
 
-> xrandr --auto
+```sh
+xrandr --auto
+```
 

hardware/printers.md

@@ -1,6 +1,6 @@
 ---
 title: "printers"
-tags: [ "Documentation", "hardware" ]
+tags: [ "hardware" ]
 ---
 # Cups: The Common Unix Printing System
 

networking/fail2ban.md

@@ -1,6 +1,7 @@
 ---
 title: "fail2ban"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
+requires: [ "ssh" ]
 ---
 # SSH Daemon Jail
 

networking/graph-easy.md

@@ -1,6 +1,6 @@
 ---
 title: "Easy Network Graph"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 Set up a file like this, called `troubleshooting.txt`.
 

networking/iptables.md

@@ -1,6 +1,6 @@
 ---
 title: "iptables"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 # Intro
 

networking/nmap.md

@@ -1,6 +1,6 @@
 ---
 title: "nmap"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 
 Example:

networking/pi-hole-server.md

@@ -1,6 +1,6 @@
 ---
 title: "pi-hole-server"
-tags: [ "Documentation", "Distros" ]
+tags: [ "Distros" ]
 ---
 # Installation
 

networking/rclone.md

@@ -1,6 +1,6 @@
 ---
 title: "rclone"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 The manpage's 'Synopsis' provides a fast reference.
 ```

networking/scraping/youtube-dl.md

@@ -1,6 +1,6 @@
 ---
 title: "Download videos"
-tags: [ "Documentation", "Scraping" ]
+tags: [ "Scraping" ]
 ---
 Install `yt-dlp`.
 

networking/servers/agate.md

@@ -1,6 +1,6 @@
 ---
 title: "Agate on Arch Linux"
-tags: [ "Documentation", "Networking", "Arch", "Gemini" ]
+tags: [ "Networking", "Arch", "Gemini" ]
 ---
 
 Docs are [here](https://github.com/mbrubeck/agate).

networking/ssh/sshfs.md

@@ -1,6 +1,7 @@
 ---
 title: "sshfs"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
+requires: [ "ssh" ]
 ---
 # Mount 
 

networking/ssh/tricks.md

@@ -1,6 +1,7 @@
 ---
-title: "ssh tricks"
-tags: [ "Documentation", "Networking", "ssh", "tricks" ]
+title: "ssh-tricks"
+tags: [ "Networking", "ssh", "tricks" ]
+requires: [ "ssh" ]
 ---
 
 Mount a remote filesystem locally with fuse-sshfs:

networking/tor.md

@@ -1,6 +1,6 @@
 ---
 title: "tor"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 
 # Get a hostname

networking/transmission.md

@@ -1,6 +1,6 @@
 ---
 title: "transmission"
-tags: [ "Documentation", "Networking", "Torrenting" ]
+tags: [ "Networking", "Torrenting" ]
 ---
 # Torrench
 

networking/troubleshooting.md

@@ -1,6 +1,6 @@
 ---
 title: "troubleshooting"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 
 # Do you have an IP?

networking/website/nginx.md

@@ -1,6 +1,6 @@
 ---
 title: "nginx"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 Install nginx:
 

networking/wifi.md

@@ -1,6 +1,6 @@
 ---
 title: "wifi"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 # Netstat Stuff
 

networking/wireguard.md

@@ -1,6 +1,6 @@
 ---
 title: "wireguard"
-tags: [ "Documentation", "Networking", "VPN" ]
+tags: [ "Networking", "VPN" ]
 ---
 <!--
 from 

networking/wireless.md

@@ -1,6 +1,6 @@
 ---
 title: "wireless"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 
 # Check wifi's working

networking/wpa_supplicant.md

@@ -1,6 +1,6 @@
 ---
 title: "wpa_supplicant"
-tags: [ "Documentation", "Networking" ]
+tags: [ "Networking" ]
 ---
 
 wpa_supplicant configurations are stored in /etc/wpa_supplicant/wpa_supplicant-wlan0 (or equivalent).

new.sh

@@ -1,27 +0,0 @@
-#!/bin/sh
-
-echo Select a category
-
-category="$(find . -type d -printf '%P\n' | fzy)"
-
-[ ! -d "$category" ] && mkdir "$category"
-
-echo Select a name
-
-read name
-
-filePath="$category/$(echo $name | sed 's/ /_/g').md"
-
-tagsList="$(echo \"$category | sed 's#\/#", "#g')\""
-
-[ -e "$filePath" ] && $EDITOR "$filePath" && exit 0
-
-echo "---
-title: \"$name\"
-tags: [ $tagsList ]
----
-
-" > "$filePath"
-
-$EDITOR "$filePath"
-

sound/basics.md

@@ -1,6 +1,6 @@
 ---
 title: "Basic Sound"
-tags: [ "Documentation", "Sound" ]
+tags: [ "Sound" ]
 ---
 # Pulse
 

sound/festival.md

@@ -1,16 +1,16 @@
 ---
 title: "festival"
-tags: [ "Documentation", "Sound" ]
+tags: [ "Sound" ]
 ---
 # Basics
 
 Add your user to the audio group, and install `festival-english`.
 
-```bash
+```sh
 echo "(Parameter.set 'Audio_Method 'Audio_Command)" >> /usr/share/festival/voices.scm
 ```
 
-```bash
+```sh
 echo "(Parameter.set 'Audio_Command "aplay -q -c 1 -t raw -f s16 -r $SR $FILE")" /usr/share/festival/voices.scm
 ```
 

sound/mpd.md

@@ -1,6 +1,6 @@
 ---
 title: "mpd"
-tags: [ "Documentation", "Sound" ]
+tags: [ "Sound" ]
 ---
 # Setup
 

sound/ncmpcpp.md

@@ -1,6 +1,6 @@
 ---
 title: "ncmpcpp"
-tags: [ "Documentation", "Sound" ]
+tags: [ "Sound" ]
 ---
 
 # Music Player Daemon

system/Makefiles.md

@@ -0,0 +1,185 @@
+---
+title: "Makefiles"
+tags: [ "system", "make" ]
+---
+
+The `make` system wants to know:
+
+1. What file you want to make,
+1. Which other files it depends on, and
+1. How to build the file.
+
+Start with a basic test-area.
+
+```sh
+mkdir make_test ; cd $_
+printf "%s:\n" README.md > Makefile
+printf "\t%s\n" 'echo "Basic makefile example." > $@' >> Makefile
+make
+```
+
+**NB:** Always tell `make` how to build files with a `\t` (tab) character.
+Using four spaces will not work!
+
+## Dependency Files
+
+Now we've made a `README.md` file, we can show how a makefile looks in the README:
+
+```make
+README.md: Makefile
+	echo "Basic makefile example." > $@
+	echo "" >> $@
+	echo '```' >> $@
+	cat $< >> $@
+	echo '```' >> $@
+```
+
+Note the order:
+
+1. The first thing is the file you want, then a colon (`:`).
+1. After the colon, any file it depends on.
+1. Finally, the shell commands to execute.
+
+# Strange Sigils
+
+Notice that the file above can print into the README by using `echo "" >> $@`.
+The `$@` stands for 'the file which we want', and `$<` stands for 'the first dependency file'.
+The `make` program starts by replacing those variables, and the result it:
+
+```make
+README.md: Makefile
+	echo "Basic makefile example." > README.md
+	echo "" >> README.md
+	echo '```' >> README.md
+	cat Makefile >> README.md
+	echo '```' >> README.md
+
+
+```
+
+|  Sigil  | Meaning                                |
+|:-------:|:--------------------------------------:|
+| `$@`    | The file we want                       |
+| `$<`    | First dependency file                  |
+| `$^`    | All dependency files                   |
+| `$(@F)` | Filename of the file we want           |
+| `$(@D)` | Directory path of the file we want     |
+| `$(<F)` | Filename of the first dependency       |
+| `$(@D)` | Directory path of the first dependency |
+
+## Basic Variables
+
+You can assign a variable normally, but must refer to it in brackets.
+
+
+```make
+storage_directory = backups
+
+README.md: Makefile
+	echo "Basic makefile example." > $@
+	echo "" >> $@
+	echo '```' >> $@
+	cat $< >> $@
+	echo '```' >> $@
+
+$(storage_directory)/README.md: README.md
+    mkdir $(@D)
+    cp $< $@
+
+```
+
+Now you can tell `make` to create the backup:
+
+```sh
+make backups/README.md
+```
+
+## Command Variables
+
+The backup `README.md` could be named after the current minute of the day, using `date +%M`.
+This allows up-to-the-minute backups:
+
+```make
+current_minute != date +%M
+
+storage_directory = backups
+
+README.md: Makefile
+	echo "Basic makefile example." > $@
+	echo "" >> $@
+	echo '```' >> $@
+	cat $< >> $@
+	echo '```' >> $@
+
+$(storage_directory)/backup_$(current_minute).md: README.md
+	mkdir $(@D)
+	cp $< $@
+
+```
+
+...but the repeated use of `mkdir` is causing an error, because that directory already exists.
+
+We can solve this by using `mkdir -p`.
+
+## Phony Targets
+
+But we don't want to look up the current minute of the day to make backups.
+Better to just say `make backup`.
+However, this will confuse `make`, because `make` thinks everything is a file, so it would try to make a file called `backup`.
+
+The solution is to tell `make` that `backup` is a phony target.
+
+```make
+  [ ... ]
+
+.PHONY: backup
+backup: $(storage_directory)/backup_$(current_minute).md
+$(storage_directory)/backup_$(current_minute).md: README.md
+	mkdir -p $(@D)
+	cp $< $@
+
+```
+
+Now run `make backup` to create an up-to-date backup.
+
+# Order
+
+Makefile thinks like this:
+
+1. Fill in all the variables in the file, from top to bottom.
+1. If variables are missing, go through the file again.
+1. Figure out the order the files should be built in.
+
+In this case, the makefile can see that `backup` depends on the current backup file (with the minute in the filename), which depends on the `README.md` file, which depends on the Makefile itself.
+
+```graph
+
+┌──────────────────────┐
+│       Makefile       │
+└──────────────────────┘
+  │
+  │
+  ▼
+┌──────────────────────┐
+│      README.md       │
+└──────────────────────┘
+  │
+  │
+  ▼
+┌──────────────────────┐
+│ backups/backup_06.md │
+└──────────────────────┘
+  │
+  │
+  ▼
+┌──────────────────────┐
+│        backup        │
+└──────────────────────┘
+```
+
+# The Rest
+
+- [File patterns](Makefiles/patterns.md)
+- [Makefile graphs](Makefiles/graph-easy.md)
+- [In-build help](Makefiles/help.md)
+- [Makefile graphs](Makefiles/graph-easy.md)

system/Makefiles/graph-easy.md

@@ -0,0 +1,15 @@
+---
+title: "Makefile Graphs"
+tags: [ "system", "make", "graph" ]
+---
+
+If you have `graph-easy` (often in the package `perl-graph-easy` or similar), you can make a graph from the makefile with `make2graph` (the package is often called `makefile2graph`).
+
+Start with the command to 'make all targets' (`-B`), and 'do a dummy run' (`-n`) with debug into (`-d`):
+
+```bash
+make -Bnd
+make -Bnd | make2graph
+make -Bnd | make2graph | graph-easy --boxart
+```
+

system/Makefiles/help.md

@@ -0,0 +1,18 @@
+---
+title: "Makefiles"
+tags: [ "system", "make", "help" ]
+---
+
+Make your first target 'help' to give an overview of the main targets.
+Running `make help` will search for text which starts with `## ` and show what that target does.
+
+```make
+help: ## Print the help message
+	@awk 'BEGIN {FS = ":.*?## "} /^[0-9a-zA-Z._-]+:.*?## / {printf "\033[36m%s\033[0m : %s\n", $$1, $$2}' $(MAKEFILE_LIST) | \
+		sort | \
+		column -s ':' -t
+
+clean: ## Remove generated files
+	$(RM) $(defaults)
+```
+

system/Makefiles/patterns.md

@@ -0,0 +1,56 @@
+
+---
+title: "Makefile Patterns"
+tags: [ "system", "make" ]
+---
+
+Using the [basic example](../Makefile.md), you can make a complete backup of all backup files.
+This file will depend upon everything inside the `$(storage_directory)`.
+Unlike `bash`, you can't just say `storage_directory/*`: the pattern must be stated as a 'wildcard'.
+
+```make
+$(storage_directory)/backup.tgz: $(wildcard $(storage_directory)/*.md)
+	tar czf $@ $^
+```
+
+The `make` rules start by processing variables:
+
+```make
+backups/backup.tgz: $(wildcard backups/*.md)
+	tar czf backups/backup.tgz $^
+```
+
+Then the `wildcard` variable equals whichever backup files are in the `backups/` directory:
+
+```make
+backups/backup.tgz: backups/backup_29.md backups/backup_30.md
+    tar czf backups/backup.tgz backups/backup_29.md backups/backup_30.md
+```
+
+The phony `backup` target should now point to this tar backup.
+
+
+```make
+current_minute != date +%M
+
+storage_directory = backups
+
+.PHONY: backup
+backup: $(storage_directory)/backup.tgz
+$(storage_directory)/backup.tgz: $(wildcard $(storage_directory)/*.md)
+	tar czf $@ $^
+
+README.md: Makefile
+	echo "Basic makefile example." > $@
+	echo "" >> $@
+	echo '```' >> $@
+	cat $< >> $@
+	echo '```' >> $@
+
+$(storage_directory)/backup_$(current_minute).md: README.md
+	mkdir -p $(@D)
+	cp $< $@
+
+```
+
+

system/android.md

@@ -1,6 +1,6 @@
 ---
 title: "android"
-tags: [ "Documentation", "System" ]
+tags: [ "System", "phone" ]
 ---
 # mtpfs
 

system/awk.md

@@ -1,6 +1,6 @@
 ---
 title: "awk"
-tags: [ "Documentation", "System" ]
+tags: [ "System", ".csv" ]
 ---
 # Basics
 

system/bash_tricks.md

@@ -1,6 +1,6 @@
 ---
 title: "bash tips"
-tags: [ "Documentation", "Shell", "POSIX" ]
+tags: [ "Shell", "POSIX" ]
 ---
 ## Track Live Changes
 
@@ -30,7 +30,7 @@ There are a bunch of files:
 
 Goal: swap the word "Column" for "Alice" in all files.
 
-```
+```sh
 IFS=$'\n'
 for f in $(find . -name "Col*"); do
 mv "$f" $(echo "$f" | sed s/Column/Alice/)