#!/bin/sh -u
#  $0 [ pathname ]
# Compile a program (the optional argument) as C or C++ based on its contents.
# Prompt for a missing program name.
# Display the errors/warnings with line numbers.
# -IAN!  idallen@ncf.ca

export PATH=/bin:/usr/bin
umask 022

# 6 marks
# # Validate the number of arguments; issue a good error message.
#
if [ $# -gt 1 ]; then
	echo 1>&2 "$0: Expecting 0 or 1 argument; found $# ($*)"
	exit 1
fi

# 7 marks
# Prompt for a missing program source file.
# Put the file name into a named variable.
#
if [ $# -eq 0 ]; then
	echo 1>&2 "Enter the program source file name:"
	read myprog
else
	myprog="$1"
fi

# 2 marks
echo "You are processing file '$myprog'."

# Verify that the input is a non-empty, readable file.
#
# 5 marks
if [ ! -f "$myprog" ]; then
	echo 1>&2 "$0: '$myprog' is not a file"
	exit 1
fi
# 5 marks
if [ ! -r "$myprog" ]; then
	echo 1>&2 "$0: '$myprog' is not readable"
	exit 1
fi
# 5 marks
if [ ! -s "$myprog" ]; then
	echo 1>&2 "$0: '$myprog' is empty"
	exit 1
fi

# 9 marks
# Select the C++ compiler if a string is found indicating a C++ program.
# Save the exit status for use later.
#
if grep 'cout <<' "$myprog" >/dev/null ; then
	g++ -Wall -o newcpp "$myprog" 2>warnings.out
	cstatus=$?
fi

# 9 marks
# Select the C compiler if the following string is *not* found.
# Save the exit status for use later.
#
if ! grep '<iostream' "$myprog" >/dev/null ; then
	gcc -Wall -o newccc "$myprog" 2>warnings.out
	cstatus=$?
fi

# 3 marks
if [ $cstatus -gt 1 ]; then
	echo "Compiler exit status was $cstatus."
fi

# 7 marks
# Remove an empty error file.
# Rename and display with line numbers any errors.
#
if [ -s warnings.out ]; then
	mv warnings.out warnings.txt
	cat -n warnings.txt
	chmod 400 warnings.txt
else
	rm warnings.out
fi