feat(user/mw_create_month_journal.sh):Add mediawiki script

- Note: Useful for creating monthly journals

diff --git a/user/mw_create_month_journal.sh b/user/mw_create_month_journal.sh
new file mode 100755 (executable)
index 0000000..9ed0206
--- /dev/null
+++ b/user/mw_create_month_journal.sh
@@ -0,0 +1,106 @@
+#!/usr/bin/env bash
+# Desc: Prints mediawiki code for a journal month in the bk4 wiki.
+# Usage: /bin/bash mw_create_month_journal.sh [int year] [int month]
+# Input: arg1: year
+#        arg2: month
+# Example: /bin/bash mw_create_month_journal.sh 2023 03 > output.txt
+# Version: 0.0.1
+
+yyyy="$1";
+mm="$2";
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+
+# Check input
+## Check arg count
+if [[ $# -ne 2 ]]; then die "FATAL:Invalid arg count:$#"; fi;
+## Strip leading zeros (because August/octal)
+yyyy="$((10#${yyyy}))";
+mm="$((10#${mm}))";
+## Check year
+re="[0-9]+";
+if [[ ! $yyyy =~ $re ]]; then die "FATAL:Invalid year string:$yyyy"; fi;
+if [[ ! $yyyy -ge 1582 ]]; then die "FATAL:Invalid year string:$yyyy"; fi;
+## Check month
+if [[ $mm -lt 1 ]] || [[ $mm -gt 12 ]]; then die "FATAL:Invalid month:$mm"; fi;
+
+
+# Calc working vars
+## Years
+if [[ $mm -gt 1 ]]; then
+    yyyy_prev="$yyyy";
+else    
+    yyyy_prev="$((yyyy - 1))";
+fi;
+if [[ $mm -lt 12 ]]; then
+    yyyy_next="$yyyy";
+else
+    yyyy_next="$((yyyy + 1))";
+fi;
+## Months
+mm_prev="$((mm - 1))";
+mm_next="$((mm + 1))";
+if [[ $mm_prev -lt 1 ]]; then mm_prev="$((mm_prev + 12))"; fi;
+if [[ $mm_next -gt 12 ]]; then mm_next="$((mm_next - 12))"; fi;
+## Leap Years
+if [[ ! $((yyyy % 4)) -eq 0 ]]; then
+    ### Year is not evenly divisible by 4.
+    leapyear="no";
+elif [[ ! $((yyyy % 100)) -eq 0 ]]; then
+    ### Year is not evenly divisible by 100.
+    leapyear="yes";
+elif [[ ! $((yyyy % 400)) -eq 0 ]]; then
+    ### year is not evenly divisible by 400.
+    leapyear="no";
+else
+    ### year is divisible by 4, 100, and 400
+    leapyear="yes";
+fi;
+
+# Form and print header
+printf "Journal for [[%d]]-%02d. " "$yyyy" "$mm";
+printf "Preceded by [[%d-%02d]]. " "$yyyy_prev" "$mm_prev";
+printf "Followed by [[%d-%02d]]. " "$yyyy_next" "$mm_next";
+printf "\n\n";
+
+printf "==Events==\n";
+printf "\n";
+
+printf "==Tasks==\n";
+printf "\n";
+
+# Form and print body
+for (( dd=1; dd <= 31; dd++ )); do
+    if [[ $mm -eq 2 ]] && [[ $dd -eq 29 ]] && \
+           [[ $leapyear == "no" ]]; then break; fi;
+    if [[ $mm -eq 2 ]] && [[ $dd -ge 30 ]]; then break; fi;
+    if [[ $mm -eq 4 ]] && [[ $dd -ge 31 ]]; then break; fi;
+    if [[ $mm -eq 6 ]] && [[ $dd -ge 31 ]]; then break; fi;
+    if [[ $mm -eq 9 ]] && [[ $dd -ge 31 ]]; then break; fi;
+    if [[ $mm -eq 11 ]] && [[ $dd -ge 31 ]]; then break; fi;
+    printf "==%4d-%02d-%02d==\n" "$yyyy" "$mm" "$dd";
+    fs_iso8601_alt="+%G-W%V-%u, %Y-%j, %a"; # alternate ISO-8601 dates
+    date_alt="$(date --date="$yyyy-$mm-$dd" "$fs_iso8601_alt")";
+    printf "%s\n" "$date_alt";
+    printf "\n";
+done;
+printf "\n";
+
+# Form and print footer
+s1="==References==";
+s2="<references>";
+s3="</references>";
+printf "%s\n%s\n%s\n" "$s1" "$s2" "$s3";
+printf "\n";
+
+printf "==See Also==\n";
+printf "\n";
+
+printf "==Ext. Links==\n";
+printf "\n";
+
+s1="[[Category:Journals by month]]";
+printf "%s\n" "$s1";
+printf "\n";