Bash script freezing despite outputting correctly - bash

Question

I have a text file holding numerous records formatted as follows:
Ford:Mondeo:1997:Blue:5
There are around 100 of them that I'm trying to sort via a bash script, and I'm looking to extract all cars made between 1994 and 1999. Here's what I have so far:
awk -F: '$3=="1994"' | awk -F: '$3<="1999"' $CARFILE > output/1994-1999.txt
The output file is containing all of the correct information, no duplicates etc but it freezes and doesn't echo out the confirmation afterwards. I have to ctrl + D my way out of the script.
Here's the full file for reference:
#CS101 Assignment BASH script
#--help option
#case $1 in
# --help | carslist.txt)
# cat <<-____HALP
# Script name: ${0##*/} [ --help | carslist.txt ]
# This script will organise the given text file and save various #sections to new files.
# No continuation checks are used but when each part is finished, a #confirmation message will print before the script continues.
#____HALP
# exit 0;;
#esac
CARFILE=$1
while [ ! -f "$CARFILE" ]
do
echo "We cannot detect a car file to load, please enter the new filename and press [ENTER]"
read CARFILE
done
echo "We have detected that you're using $CARFILE as your cars file, please continue."
if [ -f output ]
then
echo "Sorry, a file called 'output' exists in the working directory. The script will now exist."
elif [ -d output ]
then
echo "The directory 'output' has been detected, instead of creating a new one we'll be working in there instead."
else
mkdir output
echo "We couldn't find an existing file or directory named 'output' so we've made one for you. Aren't we generous?"
fi
grep 'Vauxhall' $CARFILE > output/Vauxhall_Cars.txt
echo "We've saved all Vauxhall information in the 'Vauxhall_Cars.txt' file. The script will now continue."
grep '2001' $CARFILE > output/Manufactured_2001.txt
echo "We've saved all cared manufactured in 2001 in the 'Manufactured_2001.txt' file. The script will now continue."
awk -F: '$1=="Volkswagen" && $4=="Blue"' $CARFILE > output/Blue_Volkswagen.txt
echo "We've saved all Blue Volkswagens cars in Blue_Volkswagen.txt. The script will now continue"
grep 'V' $CARFILE > output/Makes_V.txt
echo "All cars with the make starting with 'V' have been saved in Makes_V.txt. The script will now continue."
awk -F: '$3=="1994"' | awk -F: '$3<="1999"' $CARFILE > output/1994-1999.txt
echo "Cars made between 1994 and 1999 have been saved in 1994-1999.txt. The script will now continue."
With the run command being bash myScript.sh carslist.txt
Can anyone tell me why it's freezing after outputting correctly?
Just noticed that a record of 1993 has slipped through the cracks, is there a way of formatting the dates in the line above so it's only between 1994-1999?
Thanks in advance.

Answer 1

The expression:
awk -F: '$3=="1994"' | awk -F: '$3<="1999"' $CARFILE > output/1994-1999.txt
Means: run awk on "something" and then pipe to another awk. But you are not providing any "something", so awk is waiting for it.
This is like saying:
awk '{print}' | awk 'BEGIN {print 1}'
It indeed prints the 1 but waits for some kind of input to come.
Just join the conditions:
awk -F: '$3=="1994" && $3<="1999"' $CARFILE > output/1994-1999.txt
Regarding the rest of the script: note you are not using many double quotes. They are a good practise to prevent problems when you have names with spaces, etc. So for example you can say grep 'Vauxhall' "$CARFILE" and allow $CARFILE to contains things like "my car".
You can find out these kind of errors by pasting your script in ShellCheck.