bash-script error

Question

bash-5.0-6 trying to run the following script results in syntax-error:

wget -nv -O index.html "https://de.wikibooks.org/w/index.php?title=Spezial%3APrefixindex&namespace=0&from=$buch"

the resulting error-message:

2020-08-24 20:38:51 URL:https://de.wikibooks.org/w/index.php?title=Spezial:Pr%C3%A4fixindex&namespace=0&from=Mathematik%3A_Lineare_Algebra [96400] -> "index.html" [1]
get_wikibooks.sh: 18: Syntax error: Unterminated quoted string

it seems, that the sign "%" causes the error. But how can I write the script, so that it is useable ?

thanks in advance bye hans

P.S. My complete code is:

set -x
#!/bin/bash
buch=$(zenity --entry --title "Download eines Wikibooks" --text "Bitte geben Sie den Buchtitel an:")
buch=$(echo $buch | sed "s/ /_/g")
mkdir -p ~/wikibooks/$buch
cd ~/wikibooks/$buch
wget -nv -O index.html 'https://de.wikibooks.org/w/index.php?title=Spezial%3APrefixindex&namespace=0&from=$buch'
if [ $? -ne 0 ] ; then
        zenity --error --title "Download eines Wikibooks - Fehler" \
          --text "Ein Fehler ist aufgetreten\! \nÜberprüfen sie die Internet-Verbindung und den Buchtitel."
fi
wget -nv -c $(cat index.html | tr '"' '\n’ | egrep "^/wiki$buch" | sort -u | sed "s#^#https://de.wikibooks.org#")
if [ $? -ne 0 ] ; then
        zenity --error --title "Download eines Wikibooks - Fehler" \
          --text "Ein Fehler ist aufgetreten\! \nÜberprüfen sie die Internet-Verbindung und den Buchtitel."
fi
for i in $(ls); do sed "s#href=\"/wiki/$buch#href=\"./$buch#g" $i > $i.temp; mv $i.temp $i; done
zenity --info --title "Download eines Wikibooks" --text "Herunterladen des Buches erfolgreich\!"

Answer 1

The code has quoting errors. Consider this line:

wget -nv -c $(cat index.html | tr '"' '\n’ | egrep "^/wiki$buch" | sort -u | sed "s#^#https://de.wikibooks.org#")

The tr command is tr '"' '\n’. The final quote in that command is a unicode (not ASCII) backquote. This is not valid as a shell-single-quote.

Replace tr '"' '\n’ with tr '"' '\n'.

After you have done that, cut and paste your code into shellcheck.net and correct any remaining errors (important) or warnings (might be important) that it identifies.

Answer 2

Issuing the same command on it's own works fine. However since you have $ within the URL, it might be counted a as variable since you re using " try:

wget -nv -O index.html 'https://de.wikibooks.org/w/index.php?title=Spezial%3APrefixindex&namespace=0&from=$buch'

note the ' single quotes.. unless $buch is a variable within your bash script.