Add more gawk flashcards.

notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json

@@ -60,14 +60,17 @@
     "Linux/Signals.md": "f58f1a36a9fe53928fdc3dc02fc4c3e3",
     "linux/index.md": "6e50c924ee9e09294fd3b907fbdeaf0f",
     "linux/signals.md": "e9ab74723981ebc232189c84d3b0da74",
-    "templates/daily.md": "0f22c7ef0b0f35efada88d61c95e9815",
+    "templates/daily.md": "7866014e730e85683155207a02e367d8",
     "daily/2024-01-31.md": "72e343cef8d56e169cac7b360a88fcf0",
     "posix/index.md": "f7b1ae55f8f5e8f50f89738b1aca9111",
-    "posix/signals.md": "26161c6a79a0c413032c6c17e460412c",
+    "posix/signals.md": "2120ddd933fc0d57abb93c33f639afd8",
-    "gawk.md": "9bf70ef138a9a281b86400aee393cae7",
+    "gawk.md": "c0cf6decdf02f5513e386525b02bdf58",
     "bash/index.md": "3b5296277f095acdf16655adcdf524af",
-    "bash/shebang.md": "bc30f75bcddff59d6f907fae89c17283",
+    "bash/shebang.md": "ad178efeb4a05190b80b5df108c175c7",
-    "bash/robustness.md": "e474fd33469fc393bfde45cd7b9411ba"
+    "bash/robustness.md": "de97cd77aae047b5eea27440b43c9c42",
+    "journal/2024-02-01.md": "f4cc061bfc8e41ce15ae9a354c65ffe9",
+    "journal/2024-01-31.md": "7c7fbfccabc316f9e676826bf8dfe970",
+    "bash/quoting.md": "8086c0a576f30d77248faac16a4be79e"
   },
   "fields_dict": {
     "Basic": [

notes/bash/quoting.md

@@ -0,0 +1,47 @@
+---
+title: Quoting
+TARGET DECK: Obsidian::STEM
+FILE TAGS: bash
+tags:
+  - bash
+---
+
+%%ANKI
+Basic
+How do you escape a `'` within a single-quote string?
+Back: This is impossible.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706816752230-->
+END%%
+
+%%ANKI
+Basic
+What does the null string refer to?
+Back: The empty string, i.e. `""`.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706816752237-->
+END%%
+
+%%ANKI
+Basic
+When does Bash remove null strings from a command?
+Back: When they occur as part of a non-null command-line argument.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706816752241-->
+END%%
+
+%%ANKI
+Basic
+What is wrong with the following command?
+```bash
+$ # -F specifies the field separator
+$ awk -F"" 'program' files
+```
+Back: Bash removes the null string before executing the command.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706816764555-->
+END%%
+
+## References
+
+* Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)

notes/bash/robustness.md

@@ -7,7 +7,9 @@ tags:
   - shell
 ---
 
-An interesting point Robbins[^robbins] discusses in his introduction to [[gawk]] is this idea of command robustness. He states that:
+## Overview
+
+An interesting point Robbins discusses in his introduction to [[gawk]] is this idea of command robustness. He states that:
 
 > A self-contained shell script is more reliable because there are no other files to misplace.
 
@@ -27,7 +29,7 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1706726911475-->
 END%%
 
-The point he is arguing is that the first command below is considered more robust than the second since the command is more loosely coupled to its environment:
+He argues that the first command below is more robust than the second since the command is more loosely coupled to its environment:
 
 ```bash
 $ awk 'program' input-file1 input-file2 ...
@@ -55,4 +57,6 @@ It's interesting to think what else can be used as a measure of a command's robu
 * Whether a program acts atomically
 	* Is it possible intermediate files are left that affect subsequent runs?
 
-[^robbins]: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+## References
+
+* Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)

notes/bash/shebang.md

@@ -6,6 +6,8 @@ tags:
   - bash
 ---
 
+## Overview
+
 The shebang (also writting shabang or sha-bang) is a magic character at the start of a script indicating what command should be run when invoking the script directly. It always begins with ASCII characters `#!`.[^mendel]
 
 %%ANKI
@@ -44,12 +46,13 @@ Some systems limit the length of interpreters to just 32 characters. A simple wo
 
 %%ANKI
 Basic
-What workaround is used when shabang interpreter names are too long?
+What workaround is used when shebang interpreter names are too long?
 Back: Introduce a symbolic link.
 Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
 <!--ID: 1706726911470-->
 END%%
 
-[^mendel]: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.
+## References
 
-[^robbins]: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+* Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.
+* Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)

notes/gawk.md

@@ -8,7 +8,7 @@ tags:
   - gawk
 ---
 
-## Introduction
+## Overview
 
 %%ANKI
 Basic
@@ -25,7 +25,7 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1706726911439-->
 END%%
 
-> Dark corners are basically fractal - no matter how much you illuminate, there's always a smaller but darker one.
+> Dark corners are basically fractal - no matter how much you illuminate, there's always a smaller but darker one. #quote
 
 The above quote is attributed to Brian Kernighan (one of the authors of the [[C]] K&R book).
 
@@ -83,4 +83,111 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1706726911454-->
 END%%
 
-[^robbins]: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+%%ANKI
+Basic
+Write the `awk` command that searches file `mail-list` for string `li`.
+Back:
+```bash
+$ awk '/li/ { print }' mail-list
+```
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706819150999-->
+END%%
+
+%%ANKI
+Basic
+How is an `awk` rule without a pattern interpreted?
+Back: As applying the specified action for every input line.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706822165633-->
+END%%
+
+%%ANKI
+Basic
+How is an `awk` rule without an action interpreted?
+Back: As printing every line matching the specified pattern.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706822165637-->
+END%%
+
+%%ANKI
+Basic
+Describe what the following command does in in a single sentence:
+```bash
+$ awk 'length($0) > 80' data
+```
+Back: Prints every line of `data` that is longer than `80` characters.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706822165641-->
+END%%
+
+**Targets** are specified as `$n` where `n` is a placeholder for the `n`th whitespace-separated **field**s of the input line. For example, `$1` refers to the first field of the input line. `$0` is a special target referring to the entire list of arguments, i.e. the entire line.
+
+%%ANKI
+Basic
+What is `$0` a placeholder for?
+Back: The entire input line.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706823790230-->
+END%%
+
+%%ANKI
+Basic
+What is `$1` a placeholder for?
+Back: The first field of the input line.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706823790233-->
+END%%
+
+%%ANKI
+Basic
+What is the `BEGIN` pattern?
+Back: Code associated with it executes before any input is read.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706823790236-->
+END%%
+
+%%ANKI
+Basic
+What is the `END` pattern?
+Back: Code associated with it executes after all input has been read.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706823790239-->
+END%%
+
+%%ANKI
+Basic
+Describe what the following command does in in a single sentence:
+```bash
+$ awk 'NF > 0' data
+```
+Back: Prints every line of `data` with at least one field.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706823927382-->
+END%%
+
+%%ANKI
+Basic
+Describe what the following command does in in a single sentence:
+```bash
+$ awk 'END { print NR }' data
+```
+Back: Prints the number of lines in `data`.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706824091124-->
+END%%
+
+%%ANKI
+Basic
+Describe what the following command does in in a single sentence:
+```bash
+$ awk 'NR % 2 == 0' data
+```
+Back: Prints every even-numbered line in `data`.
+Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)
+<!--ID: 1706824091128-->
+END%%
+
+## References
+
+* Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf)

notes/posix/signals.md

@@ -7,7 +7,9 @@ tags:
   - signal
 ---
 
-This is an overview of specific POSIX signals.[^dowling]
+## Overview
+
+This is an overview of specific POSIX signals.
 
 Code  | Name
 ----- | --------------
@@ -112,4 +114,33 @@ Reference: `man 1 ps`
 <!--ID: 1706670390919-->
 END%%
 
-[^dowling]: Dowling, “A List of Signals and What They Mean.”
+### SIGINT (2)
+
+Indicates the process was interrupted by the user. Happens when pressing `Ctrl-C` from the controlling terminal.
+
+%%ANKI
+Cloze
+Signal {`SIGINT`} corresponds to number {2}.
+Reference: Dowling, “A List of Signals and What They Mean.”
+<!--ID: 1706815743860-->
+END%%
+
+%%ANKI
+Basic
+What control sequence usually triggers a `SIGINT`?
+Back: `Ctrl-C`
+Reference: Dowling, “A List of Signals and What They Mean.”
+<!--ID: 1706815743867-->
+END%%
+
+%%ANKI
+Basic
+What is the `INT` in `SIGINT` short for?
+Back: **Int**errupt
+Reference: Dowling, “A List of Signals and What They Mean.”
+<!--ID: 1706815743870-->
+END%%
+
+## References
+
+* Dowling, “A List of Signals and What They Mean.”