Getting syntax error for else in shell script

Question

Getting syntax error for below shell script. Unable to figure out where the problem lies. Please help me guys. Thanks in Advance.

Code:

#!/bin/bash

# Check if package sensors (for Ubuntu) is installed, if not install it
dpkg -l | grep -i sensors > /dev/null

if [ "$?" == "0" ]; then
  echo "Package sensors already installed on system. Analyzing temperature!"
else
  sudo apt-get install sensors && echo "Package sensors now installed"
fi

# Set threshold temperature
threshold="+80.0°C"

# Check if temp has reached threshold, trigger mail
tempnow=$(sensors | sed -n '20p' | awk '{print $NF}')

res=`echo "$tempnow $threshold" | awk '{ if($1 > $2) print "Exceeds"; else print "Normal" }'`

if [ "$res" == "Exceeds" ]
then
  echo "Temperature exceeds threshold. Triggering mail to system owners..."
  mail -s "CPU temperature too high on system" [email protected]
elif [ "$res" == "Normal" ]
  echo "Temperature under limit. Ignoring countermeasures!"
else
  echo "Unable to determine value"
fi

Output:

Package sensors already installed on system. Analyzing temperature!
/home/luckee/scripts/cputemp.sh: line 26: syntax error near unexpected token `else'
/home/luckee/scripts/cputemp.sh: line 26: `else'

Answer 1

In Line 24:

24    elif [ "$res" == "Normal" ] 
25    then           # <------ Missing in your original code
26      echo "Temperature under limit. Ignoring countermeasures!"

Use shellcheck.net, for debugging such trivial issues.

Answer 2

You need an extra then after your elif line :)

#!/bin/bash

# Check if package sensors (for Ubuntu) is installed, if not install it
dpkg -l | grep -i sensors > /dev/null

if [ "$?" == "0" ]; then
  echo "Package sensors already installed on system. Analyzing temperature!"
else
  sudo apt-get install sensors && echo "Package sensors now installed"
fi

# Set threshold temperature
threshold="+80.0°C"

# Check if temp has reached threshold, trigger mail
tempnow=$(sensors | sed -n '20p' | awk '{print $NF}')

res=`echo "$tempnow $threshold" | awk '{ if($1 > $2) print "Exceeds"; else print "Normal" }'`

if [ "$res" == "Exceeds" ]
then
  echo "Temperature exceeds threshold. Triggering mail to system owners..."
  mail -s "CPU temperature too high on system" [email protected]
elif [ "$res" == "Normal" ]
then  # <== HERE!
  echo "Temperature under limit. Ignoring countermeasures!"
else
  echo "Unable to determine value"
fi