Escaped asterisk (*) in list of characters outputs file in folder - bash

Question

At the very beginning of my Bash script I'm passing a set of characters like this:
#!/bin/bash
set0="0 1 2 3 4 5 6 7 8 9"
set1="° § + \" ç % & / ( ) = ? ' ^ ! £ $ - _ ; , : . *"
The script combines every single character with the others in order to get all possible combination with length of n.
As you can see in set1 above I have to escape the quote " character for example. My problem now is, that I have to escape the asterisk * as well. But I couldn't figure out how.
This didn't work so far:
#!/bin/bash
set1="° § + \" ç % & / ( ) = ? ' ^ ! £ $ - _ ; , : . \*"
It echoes \*. If I don't escape the asterisk * with a backslash \ the script echoes all the files in current directory all time.
Do you know how I can escape the asterisk * successfully?
This is the whole script:
8 chars0="a b c d e f g h i j k l m n o p q r s t u v w x y z"
9 chars1="A B C D E F G H I J K L M N O P Q R S T U V W X Y Z"
10 chars2="0 1 2 3 4 5 6 7 8 9"
11 chars3="° § + \" ç % & / ( ) = ? ' ^ ! £ $ - _ ; , : . *"
12
13 function increment {
14 INPUT=$1
15 [[ ${#INPUT} -ge $minlen ]] && echo $1
16 if [[ ${#INPUT} -lt $maxlen ]]; then
17 for c in $chars; do
18 increment $1$c
19 done
20 fi
21 }
22
23 function showUsage {
24 echo "$0 MAXLEN [MINLEN] [a [A [n [p]]]]"
25 echo
26 echo " MAXLEN integer Maximum lenght, or specific lengt if MINLEN is omitted"
27 echo " MINLEN integer Minimum lenght, equals MAXLEN if omitted"
28 echo ""
29 echo " characters:"
30 echo " a lower case a-z"
31 echo " A Uppercase A-Z"
32 echo " n numeric 0-9"
33 echo " p punctuation . ?"
34 }
35
36
37
38
39 ## argument handler
40 [[ "$1" = "" ]] && showUsage && exit
41 maxlen=$1
42 [[ $2 -eq 0 ]] && minlen=$maxlen || minlen=$2
43
44
45 for arg in "$#"; do
46 case $arg in
47 a) chars="$chars $chars0" ;;
48 A) chars="$chars $chars1" ;;
49 n) chars="$chars $chars2" ;;
50 p) chars="$chars $chars3" ;;
51 esac;
52 done
53
54 #fallback
55 [[ "$chars" = "" ]] && chars="$chars0"
56
57
58
59 ## kickof
60
61 for i in $chars; do
62 increment $i
63 done

Answer 1

Thank you for all your suggestions. The one that helped me fixing this was
set -f
It's a quick fix of course. But it works well for me.

Answer 2

The best way to do this is maybe to use:
set -o noglob
set="* + ?"
for i in $set; do echo $i; done
*
+
?
The problem when you use the variable. noglob will prevent all of the file glob characters from expanding.

Answer 3

You can't safely loop on a list of words in a string like this, without having nasty globbing effects. In your case, it boils down to this:
a=*
for i in $a; do
echo "$a"
done
You'll see that the files in your current directory are printed, because the (unquoted! horror!) $a in the for statement expands to * which will glob to the list of files in current dir.
You must fix this by using another design. You're lucky, Bash supports arrays very well, so redesign your code to use arrays. For example:
chars=( ° § + \" ç % \& / '(' ')' = \? \' ^ ! £ $ - _ \; , : . \* )
(this defines the array chars) and to loop through that:
for i in "${chars[#]}"; do
echo "$i"
done
(observe the quotes).
Below is a rewriting of your code to show you how to use arrays (and I've fixed/improved some other minor stuff too):
#!/bin/bash
chars_alpha=( {a..z} )
chars_ALPHA=( {A..Z} )
chars_digit=( {0..9} )
chars_punct=( '°' '§' '+' '"' 'ç' '%' '&' '/' '(' ')' '=' '?' "'" '^' '!' '£' '$' '-' '_' ';' ',' ':' '.' '*' )
increment() {
local input=$1
(( ${#input} >= minlen )) && printf '%s\n' "$input"
if (( ${#input} < maxlen )); then
for c in "${chars[#]}"; do
increment "$input$c"
done
fi
}
showUsage() {
cat <<EOF
$0 MAXLEN [MINLEN] [a] [A] [n] [p]
MAXLEN integer Maximum lenght, or specific lengt if MINLEN is omitted
MINLEN integer Minimum lenght, equals MAXLEN if omitted
characters:
a lower case a-z
A Uppercase A-Z
n numeric 0-9
p punctuation . ? etc.
EOF
}
## argument handler
(($#)) || { showUsage; exit 1; }
[[ $1 = +([[:digit:]]) ]] || { showUsage; exit 1; }
((maxlen=10#$1))
shift
# Check that maxlen is >0 or exit gracefully
((maxlen>0)) || exit 0
if [[ $1 = +([[:digit:]]) ]]; then
((minlen=10#$1))
shift
else
((minlen=maxlen))
fi
# Check that minlen<=maxlen otherwise swap them
if ((minlen>maxlen)); then
((temp=minlen,minlen=maxlen,maxlen=temp))
fi
chars=()
while (($#)); do
case $1 in
(a) chars+=( "${chars_alpha[#]}" ); chars_alpha=() ;;
(A) chars+=( "${chars_ALPHA[#]}" ); chars_ALPHA=() ;;
(n) chars+=( "${chars_digit[#]}" ); chars_digit=() ;;
(p) chars+=( "${chars_punct[#]}" ); chars_punct=() ;;
(*) printf >&2 'Ignored arguments %s\n' "$1" ;;
esac
shift
done
#fallback
(( ${#chars[#]} )) || chars=( "${chars_alpha[#]}" )
#kick off!
increment
One of the fixes includes using printf instead of echo. With echo, your code is broken, since the strings:
-e
-n
-E
would never be printed! see help echo to understand why. Try it yourself too:
echo -e
echo -n
echo -E
don't output anything!

Answer 4

Use single quotes to wrap your string instead of double quotes. You won't have to have to escape any characters beside the single quote.