Strings comparing issue on bash script

Question

this script is working properly

stat1=$(systemctl list-units --type=service | grep gravity | grep gcr | awk {'print $1'} | xargs systemctl status | grep Active | awk {'print $2'})
echo "$stat1"
if [ $stat1 == 'active' ]
then
  echo " >> Gravity service is running ..."
else
  echo " >> Gravity service not running ..."
fi

this one isn't

stat2=$(gravity status | grep status | awk {'print $3'})
echo "$stat2"
if [ $stat2 == 'active' ]
then
  echo " >> Gravity service is running ..."
else
  echo " >> Gravity service not running ..."
fi

the only difference between them is the input for stat variable on this script is white, and the other one is green. i also tried using if [[ ]] , and changed '' to "" for the stat var , none of this worked Please help me understand how to make it work.

tried this :

the result remains the same.

Answer 1

I strongly suggest you rather use the is-active query from systemctl

systemctl is-active gravity

which returns the current service status, or:

sytemctl --quiet is-active gravity

which just exits with 0 if active and non-zero otherwise, which means you could use

if sytemctl --quiet is-active gravity; then
  echo " >> Gravity service is running ..."
else
  echo " >> Gravity service not running ..."
fi

From the manual:

is-active PATTERN…

Check whether any of the specified units are active (i.e. running). Returns an exit code 0 if at least one is active, or non-zero otherwise. Unless --quiet is specified, this will also print the current unit state to standard output.

---

Now for the issue itself:

Green color is passed as part of the string and thus the match fails. Compare it to this:

if [ "$(echo 1 | grep --color=yes 1)" = 1 ]
then echo equal
else echo different
fi
#different
if [ "$(echo 1 | grep --color=no 1)" = 1 ]
then echo equal
else echo different
fi
#equal

See how it is different in the first case and identical in the second one because [ stra == strb ] tests for exactly matching strings.

You could make a regex match to avoid this problem via

if [[ $(echo 1 | grep --color=yes 1) =~ 1 ]]
then echo equal
else echo different
fi
#equal

but be aware that the regex MIGHT match the color coding (not in the case of words like "active", though). Note how this needs the extended test [[ ]] from bash.

Some programs are smart enough to not forward the color to a pipe, e.g. grep, but one may force it:

echo 1 | grep 1 | cat -A
1$
echo 1 | grep 1 --color=yes | cat -A
^[[01;31m^[[K1^[[m^[[K$

So this is how the colorizing of 1 in bold red looks like. More on bash colors here.