Is there an easy way to set nullglob for one glob

Question

In bash, if you do this:

mkdir /tmp/empty
array=(/tmp/empty/*)

you find that array now has one element, \"/tmp/empty/*\"

Answer 1

This is the simplest solution I've found:

For example, to expand the literal **/*.mp3 into a glob for only a particular variable, you can use

VAR=**/*.mp3(N)

Source: https://unix.stackexchange.com/a/204944/56160

Answer 2

With mapfile in Bash 4, you can load an array from a subshell with something like: mapfile array < <(shopt -s nullglob; for f in ./*; do echo "$f"; done). Full example:

$ shopt nullglob
nullglob        off
$ find
.
./bar baz
./qux quux
$ mapfile array < <(shopt -s nullglob; for f in ./*; do echo "$f"; done)
$ shopt nullglob
nullglob        off
$ echo ${#array[@]}
2
$ echo ${array[0]}
bar baz
$ echo ${array[1]}
qux quux
$ rm *
$ mapfile array < <(shopt -s nullglob; for f in ./*; do echo "$f"; done)
$ echo ${#array[@]}
0

• Be sure to glob with ./* instead of a bare * when using echo to print the file name
• Doesn't work with newline characters in the filename :( as pointed out by derobert

---

If you need to handle newlines in the filename, you will have to do the much more verbose:

array=()
while read -r -d $'\0'; do
    array+=("$REPLY")
done < <(shopt -s nullglob; for f in ./*; do printf "$f\0"; done)

But by this point, it may be simpler to follow the advice of one of the other answers.

Answer 3

Unset it when done:

shopt -u nullglob

And properly (i.e. storing the previous state):

shopt -u | grep -q nullglob && changed=true && shopt -s nullglob
... do whatever you want ...
[ $changed ] && shopt -u nullglob; unset changed

Answer 4

This may be close to what you want; as is, it requires executing a command to expand the glob.

$ ls
file1 file2
$ array=( $(shopt -s nullglob; ls foo*) )
$ ls foo*
ls: foo*: No such file or directory
$ echo ${array[*]}
file1 file2

Instead of setting array in the subshell, we create a subshell using $() whose output is captured by array.

Answer 5

This is just a tiny bit better than your original suggestion:

local nullglob=$(shopt -p nullglob) ; shopt -s nullglob

... do whatever you want ...

$nullglob ; unset nullglob