Why am I getting this file error and a cat error even though I am passing the text file in the argument? - bash

Question

The program calls for us to read in the directory full of text files, parse data from those files into their respective attributes.
Then once the data is set, load a general template which has those attributes in the text.
I'm using a sed command to replace the specific attributes, only if the number of students is greater than 50. If so it runs the sed command and writes to a file, and into a directory.
But i am getting this error when I'm passing
test3.sh ./data assign4.template 12/16/2021 ./output
Error
cat: assign4.template: No such file or directory
test3.sh: line 62: output/MAT3103.crs: No such file or directory
The current file is MAT4353.crs
Now what I am thinking is that, for the file or directory error, it is looking in that folder and searching for a file named that
But Not entirely sure how to resolve that.
As for the cat: template error, I don't get that since I am passing the template in the terminal
As for the other paramaters being passed, the Date which is also substituted in the sed command, All output files should be written to the directory defined by the last argument. This directory may or may not already exist. Each file should be named by the course’s department code and number,and with the extension.warn
Here is the total code
#!/bin/bash
# checking if user has passed atleast four arguments are passed
if [ $# -ne 4 ]
then
echo "Atleast 4 argument should be passed"
exit 1
fi
# if output directory exits check
if [ -d output ]
then
# if output directory exists will get deleted
echo "output directory already exists. So removing its contents"
rm -f output/*
else
# output directory does not exist, so gets created here
echo "output directory does not exist. So creating a new directory"
mkdir output
fi
max_students=50
template=$2
dt=$3
cd $1
for i in *; do
echo The current file is ${i}
dept_code=$(awk 'NR==2
{print $1 ; exit}' $i)
echo $dept_code
dept_name=$(awk 'NR==2
{print $2 ; exit}' $i)
echo $dept_name
course_name=$(awk 'FNR==2' $i)
echo $course_name
course_sched=$(awk 'FNR==3' $i | awk '{print $1}')
course_sched=$(awk 'FNR==3' $i | awk '{print $1}')
echo $course_sched
course_start=$(awk 'FNR==3' $i | awk '{print $2}')
echo $course_start
course_end=$(awk 'FNR==3' $i | awk '{print $3}')
echo $course_end
credit_hours=$(awk 'FNR==4' $i)
echo $credit_hours
num_students=$(awk 'FNR==5' $i)
echo $num_students
# checking if number of students currently enrolled > max students
if (( $(echo "$num_students > $max_students" |bc -l) ))
then
# output filename creation
out_file=${i}
# using example Template and sed command to replace the variables
cat $template | sed -e "s/\[\\[\dept_code\]\]/$dept_code/" | sed -e "s/\[\\[\dept_name\]\]/$dept_name/" | sed -e "s|\[\[course_name\]\]|$course_name|" | sed -e "s|\[\[course_start\]\]|$$
fi
done

Answer 1

You define the variable as
template=$2
and since your second parameter is assign4.template, this is what the variable template is set to. Then you do a
cat $template
which is, first of all, unnecessary, since you can do an input redirection on sed instead, but most of all requires, that the file exists in your working directory. Since you have done before a
cd $1
it means that the file data/assign4.template does not exist. You have to create this file before you can use your script.

Answer 2

use single quotes in your positional arguments.
test3.sh './data' 'assign4.template' '12/16/2021' './output'
or
test3.sh data assign4.template '12/16/2021' output