From 418b5dad205c70ff232d084d170853f1db3081ce Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Thu, 2 Jun 2022 10:57:12 +0100
Subject: initial random journal page

---
 README.md            | 26 ++++++++++++++++++++++++++
 randomjournalpage.sh | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)
 create mode 100644 README.md
 create mode 100755 randomjournalpage.sh

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..65be27d
--- /dev/null
+++ b/README.md
@@ -0,0 +1,26 @@
+# Read a random journal
+
+This is a quick and dirty script which I use personally to grab a random PDF file (a scanned version of one of my bullet journals)and to extract a random set of pages from it in order to reflect/read what was happening in the past. This also includes various notes of books I have read and random ideas I wrote down and my want to reconsider.
+
+## Requirements
+
+For Fedora Linux:
+
+```
+# for (obviously) qpdf
+sudo dnf install qpdf
+# for pdfinfo
+sudo dnf install poppler-utils
+```
+
+## Usage
+
+Simply configure the journal path and the PDF vewer in the script and run: `./randomjournalpage.sh`
+
+## Testing
+
+There is no real testing done. It's a pretty simple script. However, the script passes the following ShellCheck command:
+
+```
+shellcheck randomjournalpage.sh --exclude SC2155
+```
diff --git a/randomjournalpage.sh b/randomjournalpage.sh
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index 0000000..d8d3e32
--- /dev/null
+++ b/randomjournalpage.sh
@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+
+declare -r JOURNAL_DIR="$HOME/Nextcloud/Documents/Notebooks"
+declare -i NUM_PAGES_TO_EXTRACT=42 # This is the answear!
+declare -r PDF_VIEWER_COMMAND=/usr/bin/evince
+declare -r OUT_PDF=$HOME/.random_journal.pdf
+
+get_random_journal () {
+    find "$1" -name \*.pdf | sort -R | head -n 1
+}
+
+extract () {
+    local -r in_pdf="$1"; shift
+    local -i from="$1"; shift
+    local -i to="$1"; shift
+    local -r out_pdf="$1"; shift
+
+    echo "Extracting pages ${from}-${to} from $in_pdf"
+    qpdf --empty --pages "$in_pdf" "${from}-${to}" -- "$out_pdf"
+    chmod 600 "$out_pdf"
+}
+
+main () {
+    local -r random_journal=$(get_random_journal "$JOURNAL_DIR")
+    local -i num_pages=$(pdfinfo "$random_journal" | awk '/Pages/ { print $2 }')
+
+    local -i extract_from=$(( 1 + (RANDOM % num_pages) - NUM_PAGES_TO_EXTRACT ))
+    if [ $extract_from -lt 1 ]; then
+        extract_from=1
+    fi
+
+    local -i extract_to=$(( extract_from + NUM_PAGES_TO_EXTRACT -1 ))
+    if [ $extract_to -gt "$num_pages" ]; then
+        extract_to=$num_pages
+    fi
+
+    extract "$random_journal" "$extract_from" "$extract_to" "$OUT_PDF"
+    $PDF_VIEWER_COMMAND "$OUT_PDF"
+}
+
+main
+
-- 
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