Search for a string from all pdf in current directory, and return file name

seachpdf.sh

#!/bin/sh
# Copyright (c) 2016 Ulysse Buonomo <buonomo.ulysse@gmail.com> (MIT license)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# Usage:
#    search <pattern>

[ $# -lt 1 ] && echo "$0: missing argument" && exit 1

if ! [ -d txt ]; then
  mkdir txt
  for i in *.pdf;do
    pdftotext $i txt/`basename $i pdf`txt
  done
fi

for i in txt/*.txt;do
  grep "$@" < $i > /dev/null && echo `basename $i txt`pdf
done