Why is variable in bash script executing as a command when I run it?

witchkinkofangmar · 07-21-2020, 04:16 PM

My variable:

Code:

ipaCheck=$(ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended | echo $?)

Executes as a command everytime I run the script. I want it to store the command, not run it.

michaelk · 07-21-2020, 04:34 PM

https://www.gnu.org/software/bash/ma...stitution.html

Because that is how command substitution works.

If you want to store the command as a string then

Code:

ipaCheck="ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended | echo $?"

However, without knowing what you are actually trying to accomplish I am not sure if that is what you actually need to do.

witchkinkofangmar · 07-21-2020, 04:46 PM

I just want to get the output of that command, which should be 0 or 3 if it fails and run the command without echo $? if it's not 0 or 3. So something like:

if [[ "$ipaCheck" == 0 || "$ipaCheck" == 3 ]]; then
exit 0
elif [[ "$ipaCheck" != 0 ]]; then
$ipaInstall
else
echo "Something is wrong. Please contact support."
fi

ondoho · 07-21-2020, 05:00 PM

You want a function:

Code:

ipaCheck() {
ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended | echo $?
}

Then you can use

Code:

if [[ "$(ipaCheck)" == 0 || "$(ipaCheck)" == 3 ]]; etc.

This is just to show you how it's done, not tested, probably requires some adjustment I haven't thought of now.

witchkinkofangmar · 07-21-2020, 05:41 PM

Awesome, thanks. I'll try it out.

berndbausch · 07-21-2020, 06:17 PM

Minor nit: This command

Code:

ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended | echo $?

pipes the output of ipa-client-install into the echo. This doesn't make much sense. I would replace the pipe sign with a semicolon.

Also, you say two contradicting things:

Quote:

I want it to store the command, not run it.

and

Quote:

I just want to get the output of that command

If you want the output of that command, unfortunately you need to run it.

michaelk · 07-21-2020, 09:58 PM

Your confusing output of a command with its exit status.
Every linux command executed by the shell script or user returns an exit status i.e a number (0-255) which is stored in the variable $?
You do not need command substitution but to get the exit status the command needs to be executed.

Code:

ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended
ipacheck=$?

Code:

ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended
ipacheck=$?
if [ $ipacheck -eq 0 || $ipacheck -eq 3 ]
then
   echo "All good"
else
  echo "Something is wrong"
fi

witchkinkofangmar · 07-22-2020, 01:58 PM

I decided to just check if the file that gets created exists or not. This works when I curl the script and run it but it still executes the command if I curl another script that curls this script:

works: bash -c "$(curl -fsSL 10.1.10.31:80/ipaEnroll.sh)"
doesnt work: bash -c "$(curl -fsSL 10.1.10.31:80/bootstrap.sh)"

Code:

#!/Bin/bash
#bootstrap.sh
bash -c "$(curl -fsSL 10.1.10.31:80/ipaEnroll.sh)"
bash -c "$(curl -fsSL 10.1.10.31:80/reg.sh)"

Code:

ipaUser=$(echo user | base64 --decode)
ipaPass=$(echo pass | base64 --decode)
ipaDir="/etc/ipa/default.conf"

ipaInstall() {
    ipa-client-install --mkhomedir -p $ipaUser --password $ipaPass --unattended
}

if [[ -f "$ipaDir" ]]; then
    echo "Identity management is already configured."
elif [[ ! -f "$ipaDir" ]]; then
    ipaInstall
else
    echo "contact support."
fi

berndbausch · 07-22-2020, 06:46 PM

What do you mean by "works" and "doesn't work"?

Quote:

Originally Posted by witchkinkofangmar

Code:

#!/Bin/bash
#bootstrap.sh
bash -c "$(curl -fsSL 10.1.10.31:80/ipaEnroll.sh)"
bash -c "$(curl -fsSL 10.1.10.31:80/reg.sh)"

Well, since /Bin/bash is unlikely to exist on your computer, I can see why this doesn't work.

EDIT:
The if-then-else in your second script can be simplified like this:

Code:

if [[ -f $ipaDir ]]
then echo already installed
else ipaInstall
fi

witchkinkofangmar · 07-23-2020, 02:48 PM

By doesn't work, I mean that it still is executing the command from the else condition if I curl the script that curls the ipaEnroll script. If I just curl the ipaEnroll, it works fine. It's like it's completely ignoring the condition.

michaelk · 07-23-2020, 03:57 PM

You will need to explain your process.

I do not understand why you are using curl.

Normally a web server can not execute bash scripts directly from its document root and is considered a big security hole. So how is your system configured?

I have not examined the entire process yet but it is probably some environment thing.

igadoter · 07-27-2020, 09:57 PM

Quote:

Originally Posted by witchkinkofangmar

if [[ "$ipaCheck" == 0 || "$ipaCheck" == 3 ]]; then
exit 0

you can use case

Code:

case "ipaCheck" in 0 | 3 ) exit 0 ;; esac

but this won't work

Code:

elif [[ "$ipaCheck" != 0 ]]; then
    $ipaInstall
else
    echo "Something is wrong. Please contact support."

After the first test the failure of the second would mean only that value of ipaCheck is non-numerical - in case of bash exits complaining about mismatching types and none of $ipaInstall or echo .. will be ever executed.