commit bd457316be5686aace4f6ae9680d2115242b9118
Author: Love Billenius <lovebillenius@disroot.org>
Date:   Tue Aug 6 19:11:10 2024 +0200

    grid and margin

diff --git a/pdf-jammer.sh b/pdf-jammer.sh
new file mode 100755
index 0000000..d1189eb
--- /dev/null
+++ b/pdf-jammer.sh
@@ -0,0 +1,66 @@
+#!/bin/bash
+#           _  __       _                                         _     
+# _ __   __| |/ _|     (_) __ _ _ __ ___  _ __ ___   ___ _ __ ___| |__  
+#| '_ \ / _` | |_ _____| |/ _` | '_ ` _ \| '_ ` _ \ / _ \ '__/ __| '_ \ 
+#| |_) | (_| |  _|_____| | (_| | | | | | | | | | | |  __/ | _\__ \ | | |
+#| .__/ \__,_|_|      _/ |\__,_|_| |_| |_|_| |_| |_|\___|_|(_)___/_| |_|
+#|_|                 |__/                                               
+#
+
+# Ensure necessary binaries
+for cmd in pdfjam pdfcrop pdfinfo pdfcropmargins; do
+  if ! command -v "$cmd" &>/dev/null; then
+    echo "Please install $cmd to use this script."
+    exit 1
+  fi
+done
+
+# Args
+if [ "$#" -lt 3 ] || [ "$#" -gt 4 ]; then
+  echo "Usage: $0 input.pdf rows columns [margin]"
+  exit 1
+fi
+
+input_pdf="$1"
+rows="$2"
+columns="$3"
+margin="${4:-0}" # Set margin if provided, else default to 0
+
+intermediate_pdf=$(mktemp --suffix=.pdf)
+cropped_output_pdf=$(mktemp --suffix=.pdf)
+
+# Cleanup temporary files on exit
+trap 'rm -f "$intermediate_pdf" "$cropped_output_pdf"' EXIT
+
+# Generate the grid PDF
+pdfjam \
+	--nup "$columns"x"$rows" \
+	--a4paper \
+	--outfile "$intermediate_pdf" \
+	$(for i in $(seq 1 $((rows * columns))); do echo "$input_pdf"; done)
+if [ $? -ne 0 ]; then
+  echo "Error: pdfjam failed to generate the grid PDF."
+  exit 1
+fi
+
+# Apply margin if provided
+if [[ "$margin" != 0 ]]; then
+  pdfcropmargins \
+	  -o "$cropped_output_pdf" \
+	  -s \
+	  -p 100 \
+	  -a4 \
+	  -$margin -$margin -$margin -$margin \
+	  "$intermediate_pdf"
+  if [ $? -ne 0 ]; then
+    echo "Error: pdfcropmargins failed to apply the margins."
+    exit 1
+  fi
+else
+  mv "$intermediate_pdf" "$cropped_output_pdf"
+fi
+
+final_pdf="jammed.pdf"
+mv "$cropped_output_pdf" "$final_pdf"
+
+echo "Final centered PDF created as $final_pdf"