Read all lines except commented ones, lines containing 'bind|swap|shm' from/etc/fstab and print the ones in them that are not mounted? - bash

Question

Read all lines except commented ones, lines containing 'bind|swap|shm' from/etc/fstab and print the ones in them that are not mounted? I have tried the below and I was wondering if I could get a better shorter code.
mount_check()
{
fstb=$(cat /etc/fstab |egrep -vw 'bind|swap' |awk '$1 !~/#|^$/ {print $2}')
for i in ${fstb}
do
df -hPT | grep -wq ${i}
if [ $? -eq 1 ]
then
echo "The file system ${i} has an entry in /etc/fstab file but not mounted"
fi
done
}rc_mount_check=`mount_check |tee |wc -l`if [ $rc_mount_check -eq '0' ]
then
echo -e "OK: All file systems listed in /etc/fstab are mounted"
exit $OK
else
echo -e "CRITICAL: Please verify and mount the file systems\n$(mount_check)\n"
exit $CRITICAL
fi

Answer 1

Actual command which you are looking for is findmnt. Could you please try following.
awk '
!/bind|swap|shm/ && $1 !~/#|^$/{
system("if [[ -n $(findmnt -m " $2 ") ]]; \
then echo Mount " $2 " is mounted.;\
else echo Mount " $2 " is NOT mounted.;\
fi"\
)
}
' /etc/fstab
OR in form of one-liner try following(in case you need it):
awk '!/bind|swap|shm/ && $1 !~/#|^$/ {system("if [[ -n $(findmnt -m " $2 ") ]]; then echo Mount " $2 " is mounted.;else echo Mount " $2 " is NOT mounted.;fi")}' /etc/fstab

Answer 2

Assuming the currently accepted answer:
awk '
!/bind|swap|shm/ && $1 !~/#|^$/{
system("if [[ -n $(findmnt -m " $2 ") ]]; \
then echo Mount " $2 " is mounted.;\
else echo Mount " $2 " is NOT mounted.;\
fi"\
)
}
' /etc/fstab
does what you want, you should actually do something like this (untested) instead:
mounts=( $(awk '!/bind|swap|shm/ && $1 !~/#|^$/ { print $2 }' /etc/fstab) )
for mount in "${mounts[#]}"; do
if [[ -n $(findmnt -m "$mount") ]]
then echo "Mount $mount is mounted."
else echo "Mount $mount is NOT mounted."
fi
done
i.e. don't call shell to call awk to call system to call shell to call findmnt. Just have shell 1) call awk to get whatever list of mounts that first awk line spits out and then 2) call findmnt on that list. That way you're not spawning subshells upon subshells and 5 layers deep for every mount.