#!/bin/sh

USAGE='Usage split.sh [options] filename\nOptions :\n
 -c N\tsplit filename in N files (default 2)\n
 -o O\tprefixe output files with O (default filename plus dot)\n
 -s N\tuse N-length suffixes (default 1)
'

# Need at least the filename
if [ $# -lt 1 ]; then
    echo -e $USAGE;
    exit 1
fi

# Fetch options
while getopts ":c:o:s::" optname
do
    case "$optname" in
        "c")
            COUNT=$OPTARG
            ;;
	"o")
            PREFIXE=$OPTARG
            ;;
        "s")
            SUF_LENGTH=$OPTARG
            ;;
	"?")
            echo -e "Unknown option $OPTARG\n"$USAGE
            exit 2
            ;;
        ":")
            echo -e "No argument value for option $OPTARG\n"$USAGE
            exit 1
            ;;
	*)
            echo "Unknown error while processing options"
            exit 127
            ;;
    esac
done

# Check that filename is present
if [ $OPTIND -gt $# ]; then
    echo -e "filename missing\n"$USAGE
    exit 5
fi

# and alone
if [ $# -gt $OPTIND ]; then
    echo -e "too much arguments\n"$USAGE
    exit 6
fi

FILE=${!OPTIND}

# Filename is there but does it exist?
if [ ! -r "$FILE" ]; then
    echo -e "file $FILE does not exists or is not readable"
    exit 7
fi

# Set default values for unset options
if [ "$COUNT" = "" ]; then
    COUNT=2
fi
if [ "$PREFIXE" = "" ]; then
    PREFIXE="$FILE."
fi
if [ "$SUF_LENGTH" = "" ]; then
    SUF_LENGTH=1
fi

TOTAL_LINES=`wc -l $FILE |cut -d" " -f1`
LINES=`echo $TOTAL_LINES / $COUNT + 1| bc`

split -l $LINES -d -a $SUF_LENGTH $FILE $PREFIXE