Begin 2024-02-13 entry.

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

@@ -88,8 +88,8 @@
     "bash/shebang.md": "9006547710f9a079a3666169fbeda7aa",
     "c/escape-sequences.md": "0d6219ebb51f6f21e026de67603e25b8",
     "c/index.md": "a021c92f19831bdd2bca4cbf813882fe",
-    "gawk/index.md": "0a305a0477085fd2f4145536735ca94a",
+    "gawk/index.md": "dd851e023e11c556c0272a0dcb6dd55d",
-    "gawk/variables.md": "7408f450957ab007fbdbd687121da0d3",
+    "gawk/variables.md": "a9cd0344390974b3bfdf794d75d434e5",
     "index.md": "e48e895feeed7046425bb2ee15419770",
     "journal/2024-01-31.md": "7c7fbfccabc316f9e676826bf8dfe970",
     "journal/2024-02-01.md": "3aa232387d2dc662384976fd116888eb",
@@ -152,7 +152,9 @@
     "c/strings.md": "38f9cf9e2325565589f62e191221a83a",
     "logic/truth-tables.md": "7892ceaa416c9a65acc79ca1e6ff778f",
     "logic/short-circuit.md": "26d300f407f14883022d0ef8dc4f7300",
-    "logic/boolean-algebra.md": "c5d699d407e03d280aa1f201bc3e8b02"
+    "logic/boolean-algebra.md": "c5d699d407e03d280aa1f201bc3e8b02",
+    "_journal/2024-02-13.md": "75ba5d7d77862c50a172a59415ec6a84",
+    "_journal/2024-02/2024-02-12.md": "618c0035a69b48227119379236a02f44"
   },
   "fields_dict": {
     "Basic": [

notes/_journal/2024-02-13.md

@@ -0,0 +1,13 @@
+---
+title: "2024-02-13"
+---
+
+- [x] Anki Flashcards
+- [x] KoL
+- [ ] Sheet Music (10 min.)
+- [ ] OGS (1 Life & Death Problem)
+- [ ] Korean (Read 1 Story)
+- [ ] Interview Prep (1 Practice Problem)
+- [ ] Log Work Hours (Max 3 hours)
+
+* Read more on record and field separators in `gawk`.

notes/gawk/index.md

@@ -27,13 +27,6 @@ END%%
 
 The above quote is attributed to Brian Kernighan (one of the authors of the [[C]] K&R book).
 
-%%ANKI
-Cloze
-Dark corners are basically {1:fractal} - {1:no matter how much you illuminate, there's always a smaller but darker one.} - Brian Kernighan
-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: 1706726911442-->
-END%%
-
 ## Setup
 
 Robbins suggests executing command `set +H` on [[bash]] startup to disable [[C]] shell-style command history.
@@ -129,14 +122,6 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1707310981378-->
 END%%
 
-%%ANKI
-Basic
-What is the default record separator?
-Back: The newline character.
-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: 1707310981380-->
-END%%
-
 %%ANKI
 Basic
 In `awk`, what does a "field" refer to?

notes/gawk/variables.md

@@ -73,25 +73,9 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1707405259925-->
 END%%
 
-* `RS` (**R**ecord **S**eparator)
-	* The separator used to distinguish records from one another.
 * `RT` (**R**ecord **T**ext)
 	* The matching separator used to distinguish the currently read record.
 
-%%ANKI
-Cloze
-The {`RS`} variable is used to change the {record separator}.
-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: 1707310981382-->
-END%%
-
-%%ANKI
-Cloze
-If `RS` is a string with {more than one character}, it is treated as a {regexp}.
-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: 1707310981384-->
-END%%
-
 %%ANKI
 Cloze
 The {`RT`} variable matches the {input characters that matched `RS`}.
@@ -107,6 +91,39 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1707310981388-->
 END%%
 
+* `RS` (**R**ecord **S**eparator)
+	* The separator used to distinguish records from one another.
+	* Defaults to `"\n"`.
+
+`RS == ??`             | Description
+---------------------- | -------------------------------------
+`"\n"`                 | Records are separated by the newline character. This is the default.
+*any single character* | Records are separated by each occurrence of the character. Multiple successive occurrences delimit empty records.
+`""`                   | Records are separated by runs of blank lines. Leading/trailing newlines in a file are ignored. If `FS` is a single character, then `"\n"` also serves as a field separator.
+*regexp*               | Records are separated by occurrences of characters that match *regexp*. Leading/trailing matches delimit empty records.
+
+%%ANKI
+Cloze
+The {`RS`} variable is used to change the {record separator}.
+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: 1707310981382-->
+END%%
+
+%%ANKI
+Basic
+What is the default value of `RS`?
+Back: `"\n"`
+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: 1707310981380-->
+END%%
+
+%%ANKI
+Cloze
+If `RS` is a string with {more than one character}, it is treated as a {regexp}.
+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: 1707310981384-->
+END%%
+
 %%ANKI
 Basic
 What value of `RS` may `gawk` not process correctly?
@@ -131,11 +148,31 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1707310981394-->
 END%%
 
+%%ANKI
+Basic
+How is `RS = ""` interpreted?
+Back: `""` indicates runs of newlines should be treated as the record separator.
+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: 1707829409163-->
+END%%
+
+%%ANKI
+Basic
+What distinguishes `RS` value `""` and `\n\n+`?
+Back: When set to the former, `awk` strips leading/trailing newlines from the file.
+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: 1707829409170-->
+END%%
+
+%%ANKI
+Cloze
+If `RS = ""` and `FS` is set to {a single character}, the {newline character} *always* acts as a field separator.
+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: 1707829509362-->
+END%%
+
 * `NF` (**N**umber of **F**ields)
 	* The 1-indexed number of fields found in the current record.
-* `FS` (**F**ield **S**eparator)
-	* The separator used to distinguish fields from one another.
-	* Defaults to `" "` which is a special character for **runs** of spaces, tabs, and newlines.
 
 %%ANKI
 Basic
@@ -168,6 +205,33 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1707405259930-->
 END%%
 
+%%ANKI
+Basic
+What does incrementing `NF` do?
+Back: Creates the field and rebuilds the record.
+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: 1707829863717-->
+END%%
+
+%%ANKI
+Basic
+What does decrementing `NF` do?
+Back: Throws away fields and rebuilds the record.
+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: 1707829863726-->
+END%%
+
+* `FS` (**F**ield **S**eparator)
+	* The separator used to distinguish fields from one another.
+
+`FS == ??`                   | Description
+---------------------------- | -------------------------------------
+`" "`                        | Fields are separated by runs of whitespace. Leading/trailing whitespace is ignored. This is the default.
+*any other single character* | Fields are separated by each occurrence of the character. Multiple successive occurrences delimit empty fields, as do leading/trailing occurrences.
+`"\n"`                       | Specific instance of the above row. It is used to treat the record as a single field (assuming newlines separate records).
+*regexp*                     | Fields are separated by occurrences of characters that match *regexp*. Leading/trailing matches delimit empty fields.
+`""`                         | Each individual character in the record becomes a separate field.
+
 %%ANKI
 Cloze
 The {`FS`} variable is used to change the {field separator}.
@@ -208,7 +272,7 @@ END%%
 %%ANKI
 Basic
 What distinguishes `FS` value `" "` and `[ \t\n]+`?
-Back: When set to the former, `awk` strips leading and trailing whitespace from each record.
+Back: When set to the former, `awk` strips leading/trailing whitespace from each record.
 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: 1707618833558-->
 END%%
@@ -222,7 +286,7 @@ END%%
 
 %%ANKI
 Cloze
-Setting `FS` to {`"\n"`} treats the {record as the single field}.
+If `RS` has its default value, setting `FS` to {`"\n"`} treats the {record as the single 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: 1707756447067-->
 END%%
@@ -230,7 +294,7 @@ END%%
 %%ANKI
 Basic
 What value of `FS` ensures `$1 = $0`?
-Back: `"\n"`
+Back: `RS`
 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: 1707756447069-->
 END%%
@@ -243,6 +307,16 @@ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 202
 <!--ID: 1707756447071-->
 END%%
 
+* `OFS` (**O**utput **F**ield **S**eparator)
+	* Specifies the field separator used on printing.
+
+%%ANKI
+Cloze
+The {`OFS`} variable is used to change the {output field separator}.
+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: 1707829783790-->
+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)