How to determine if a specific module is loaded in linux kernel

The modinfo module method does not work well for me. I prefer this method that is similar to the alternative method proposed:

#!/bin/sh

MODULE="$1"

if lsmod | grep "$MODULE" &> /dev/null ; then
  echo "$MODULE is loaded!"
  exit 0
else
  echo "$MODULE is not loaded!"
  exit 1
fi

not sure if modinfo modname and checking $? will work for you, just a suggestion.

/tmp$ sudo modinfo e1000
/tmp$ echo $?
0
/tmp$ sudo modinfo keyboard
ERROR: modinfo: could not find module keyboard
/tmp$ echo $?
1

alternatively you also grep /proc/modules