Initial version of qpdf-decode.sh

qpdf-decode.sh

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+#!/bin/bash
+
+# qpdf-decode: a script for calling qpdf with a password to decrypt a pdf.
+# If the operation succeeds, the output will be a default new file adding a
+# suffix "_decrypted" to the source file name. Be careful: if the output file
+# already existes, it will be overwriten without warning!
+#
+# Parameters:
+# 1. PASSWORD
+# 2. file to be decrypted
+# 3. (optional) file to save (default: the same name concatenating _decrypted)
+#
+# Copyright © 2023 Dalton Scavassa <https://daltux.net/>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+
+if [ -z "$1" ] ||  [[ "$@" == *"--help"* ]]; then
+	echo Usage:
+	echo "$0 <password> <file to decode> <optional: file to save (default *_decrypted)>"
+	exit
+fi
+
+pass=$1
+infile=$2
+
+if [ -z "$pass" ] ; then
+	echo ERROR: missing a password for decrypting the pdf file.
+	exit 1
+fi
+
+if [ -z "$infile" ] ; then
+	echo ERROR: missing the pdf file to be processed.
+	exit 2
+fi
+
+outfile=${infile}_decrypted
+outfile=${3:-$outfile}
+
+if which qpdf >> /dev/null ; then
+	qpdf --verbose --password="$pass" --decrypt "$infile" "$outfile"
+else
+	echo qpdf not found!
+	exit 3
+fi
+