Bash if -gt also triggered when values equal? - bash

Question

I want my script to check if it's already running in another instance:
$ cat test.sh
#!/bin/bash
ps -ef | grep -v grep | grep -i "test.sh" | grep bash
ps -ef | grep -v grep | grep -i "test.sh" | grep -c bash
if [ `ps -ef | grep -v grep | grep -i "test.sh" | grep -c bash` -gt 1 ]; then echo "There's another instance running."
else echo "Only this instance is running."
fi
However the output is
$ ./test.sh
noes 9503 7494 0 09:32 pts/1 00:00:00 /bin/bash ./test.sh
1
There's another instance running.
Clearly, 1 is not greater than 1, so why is the if condition triggered?
Thanks

Answer 1

From test man page:
INTEGER1 -gt INTEGER2
INTEGER1 is greater than INTEGER2
So the answer is no, -gt is not triggered when values are equal. In fact, as you can see if you modify the script in this way:
$ cat test.sh
#!/bin/bash
ps -ef | grep -v grep | grep -i "test.sh" | grep bash
ps -ef | grep -v grep | grep -i "test.sh" | grep -c bash
STRINGS=`ps -ef | grep -v grep | grep -i "test.sh"`
echo "$STRINGS"
COUNT=`ps -ef | grep -v grep | grep -i "test.sh" | grep -c bash`
echo $COUNT
if [ `ps -ef | grep -v grep | grep -i "test.sh" | grep -c bash` -gt 1 ]; then echo "There's another instance running."
else echo "Only this instance is running."
fi
You get this:
$ ./test.sh
lucio 5097 4736 0 10:10 pts/2 00:00:00 /bin/bash ./test.sh
1
lucio 5097 4736 0 10:10 pts/2 00:00:00 /bin/bash ./test.sh
lucio 5106 5097 0 10:10 pts/2 00:00:00 /bin/bash ./test.sh
2
There's another instance running.
If you modify the script in this way, it will work:
#!/bin/bash
ps -ef | grep -v grep | grep -i "test.sh" | grep bash
pgrep -c test.sh
if [ $(pgrep -c test.sh) -gt 1 ]; then
echo "There's another instance running."
else
echo "Only this instance is running."
fi
This is the output:
$ ./test.sh
lucio 5197 4736 0 10:17 pts/2 00:00:00 /bin/bash ./test.sh
1
Only this instance is running.
Note the use $() instead of backticks. Check this answer for this change.