#! /bin/bash

# Checks the timestamps on the .exe, .o, and .c files in this directory.
# If a .c file is newer than its .o, recompile the .c file.
# If a .o file is newer than the .exe file, relink.

# Takes one optional argument: "rebuild"
# If specified, forces a rebuild of the entire application.

# N.B.  There is a very important Unix utility that is much preferable
#       for this task than customzied bashs scripts.  I wrote this one
#       as a way of moving us towards using that utility (which is called
#       make).

APPNAME="myApp.exe"
CC="gcc"   # compile but do not link
CFLAGS="-c"
LINK="gcc"
LFLAGS="-o $APPNAME -lncurses"
SRCS="main.c a.c b.c"
OBJS="main.o a.o b.o"

if [[ $1 = rebuild ]]; then
    touch *.c
    $0
    exit $?
fi

for cFile in $SRCS; do
    oFile=${cFile%.c}.o
    oFiles="$oFiles $oFile"
    if [ $oFile -ot $cFile ]; then
        echo Compiling $cFile...
	if ! eval $CC $CFLAGS $cFile; then  # quit if any file doesn't compile
	   echo Error
	   exit 1
	fi
    fi
done

for oFile in $OBJS; do
    if [ $APPNAME -ot $oFile ]; then
       echo Linking $oFiles...
       if eval $LINK $oFiles $LFLAGS ; then
          echo Built $APPNAME
	  exit 0
       else
	  echo Build failed
          exit 1
       fi
    fi
done

echo $APPNAME is up to date