need to change variable in this script

Question

I have script as shown below. Q can be 1, 3 or 6. So like so 1 = E, 3 = R and 6 = S. So, when I get to sending to serial port, Q should be E, R or S. I'm totally stuck. Any help?

touch $logfile

echo "file = $file"

# Split the fields into the Ademco/SIA ContactID fields
MT=`echo $EVENT | cut -b5-6`
ACCT=`echo $EVENT | cut -b1-4`
#MT=`echo $EVENT | cut -b5-6`
Q=`echo $EVENT | cut -b7`
XYZ=`echo $EVENT | cut -b8-10`
GG=`echo $EVENT | cut -b11-12`
CCC=`echo $EVENT | cut -b13-15`
S=`echo $EVENT | cut -b16`

###############################################################################
# Start Logging
################################################################################

echo "================================================================================" >> $logfile
echo "            Alarm Notification received at `date`"  >> $logfile
echo "============================================================================    ====" >> $logfile
echo Alarm String was $EVENT >> $logfile
echo Account Number $ACCT >> $logfile
echo Message Type $MT >> $logfile
echo Event Qualifier $Q >> $logfile
echo Event Code $XYZ >> $logfile
echo Group $GG >> $logfile
echo Zone $CCC >> $logfile
echo Checksum $S >> $logfile
echo "" >> $logfile
echo 5012 $MT$ACCT$Q$XYZ$GG$CCC'\024\r' >> /dev/ttyAMA0
echo 5012 $MT$ACCT$Q$XYZ$GG$CCC >> /home/monitoring/pinCaptur/signals.txt

Walter A · Accepted Answer · 2018-10-21 22:04:40Z

1

You can use tr :

Q="123456"
newQ=$(tr "136" "ERS" <<< "${Q}")
echo ${newQ}

E2R45S

answered Oct 21, 2018 at 22:04

Walter A

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Comments

Walter A · Accepted Answer · 2018-10-22 07:26:39Z

0

a switch statement is what you want here, it'll allow you to exit in case the input value is wrong.

case $Q in
  1)
    Q=E
    ;;
  3)
    Q=R
    ;;
  6)
    Q=S
    ;;
  *)
    echo "We have an issue here"
    exit 1
esac

edited Oct 22, 2018 at 7:26

Walter A

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answered Oct 21, 2018 at 22:42

Guillaume Quintard

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Comments

Socowi · Accepted Answer · 2018-10-22 08:11:08Z

0

You can map the numbers 1, 3, 6 to the letters E, R, S using if else statements or an array. Example:

map=([1]=E [3]=R [6]=S)
Q=1
echo "${map[Q]}"     # prints E
Q=3
echo "${map[Q]}"     # prints R
Q=6
echo "${map[Q]}"     # prints S

Also consider using shellcheck.net to improve your script.

edited Oct 22, 2018 at 8:11

answered Oct 21, 2018 at 21:00

Socowi

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2 Comments

Benjamin W. Over a year ago

You could use explicit indices instead of populating dummy elements: map=([1]=E [3]=R [6]=S).

Socowi Over a year ago

@BenjaminW. Thank you for the hint.

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