Oh dear.

narepl

#!/bin/sh
# narepl - Not A Read-Eval-Print Loop.

echo "This is not a REPL. Press ctrl-d to compile and run, ctrl-c to exit."
echo -n "> "
while true ; do
    echo "#include </dev/tty>" | gcc -x c -ldl - && ./a.out && rm ./a.out
    echo -n "> "
done

snarepl

#!/bin/bash                                                                
# snarepl - Still Not A Read-Eval-Print Loop.                              

if [ -z "$1" ]
then          
    srcfile=`mktemp -u`
    trap "rm -f $srcfile; rm -f $outfile; echo; stty echo; exit" INT
    echo "Editing a temporary file, which will be deleted upon exiting."
    read -s -p "Press enter to continue, or ctrl-c to exit. "
    echo
else
    srcfile=$1
    trap "rm -f $outfile; echo; stty echo; exit" INT
fi

if [ ! -e $srcfile ] ; then
echo '#include <stdio.h>
#include <stdlib.h>

int main(void)
{

    return 0;
}
' > $srcfile
fi

outfile=`mktemp -u`

while (true) ; do
    echo editing $srcfile
    oldtime=`stat -c %Y $srcfile`

    vim -c "set filetype=c" $srcfile +6

    newtime=`stat -c %Y $srcfile`
    if [ $newtime -gt $oldtime ]
    then
        echo compiling $srcfile
        gcc -x c -o $outfile $srcfile
    else
        echo no changes
    fi
    if [ -x $outfile ]
    then
        echo running:
        echo ========
        $outfile
        echo ========
    fi

    read -s -p "Press enter to continue, or ctrl-c to exit. "
done