animal_name=""
if [[ -z "${!animal_name// }" ]]; then
animal_name="doggo"
fi
echo sudo chmod ...... ${!animal_name}
Is there any way to reference a variable in bash?
4 Answers
Ditch the "{}"
animal_name=""
if [[ -z "$animal_name" ]]; then
animal_name="doggo"
fi
sudo chmod {flag} $animal_name
3 Comments
lost9123193
sorry made an edit. I have more thing happening in the echo. Can i still use this?
kiwibg
Sure thing. :) I'll edit the answer to show your use case
kiwibg
One question though - why use the echo? Are you trying to execute chmod or print out the whole "chmod {flag} $animal_name"?
I think your error is in line 3 (or 2, depending on how you look at it.)
animal_name=""
if [[ -z "${!animal_name// }" ]]; then # Error: event not found: animal_name//
animal_name="doggo"
fi
echo sudo chmod ...... $animal_name
The fix that I found was to remove the 2 slashes in "${!animal_name// }" and that worked for me.
2 Comments
Base64__
Edited to include the
chmod ....... Could you provide some more background? like do you have a file/executable named doggo? what's the purpose of sudo chmod ...... {!animal_name}?lost9123193
oh i think im getting this mixed up with javascript... do you know what {!animal_name} means when I include {! }?
If you are just trying to make sure the variable has some value, you can use defaults.
echo sudo chmod ...... ${animal_name:-doggo}
This will use doggo is animal_name is empty, but will leave it empty.
$: animal_name=
$: echo sudo chmod ...... ${animal_name:-doggo}
sudo chmod ...... doggo
$: echo "[$animal_name]" # still empty
[]
$: animal_name=bob
$: echo sudo chmod ...... ${animal_name:-doggo} # doesn't change is already set
sudo chmod ...... bob
If you want animal_name to ALWAYS default to doggo thereafter, use = instead of - and it will assign it as well if it's empty.
echo sudo chmod ...... ${animal_name:=doggo}
so:
$: animal_name=
$: echo sudo chmod ...... ${animal_name:=doggo}
sudo chmod ...... doggo
$: echo "[$animal_name]" # this time it was set
[doggo]
$: animal_name=bob
$: echo sudo chmod ...... ${animal_name:=doggo} # doesn't change if already set
sudo chmod ...... bob
1 Comment
Paul Hodges
Heck, this is the answer Cyrus gave in the comments yesterday, lol...
Probably you mean indirection? This may help.
animal_name=""
doggo="I am doggo!"
if [[ -z "${animal_name}" ]]; then
animal_name="doggo"
fi
echo sudo chmod ...... ${!animal_name}
The ${!animal_name} reference the value of doggo, so the output is:
sudo chmod ...... I am doggo!
echo "${animal_name:=doggo}"