#!/bin/sh

# this renames files in a doss styleee so you can go "dosrename *.html *.htm"
# to rename all files in that directory from .html to .htm. It also works 
# the other way: "dosrename fletch.* paul.*"

t=n
case $# in
[01])   echo "Usage: dosRename file [ ... ] target" >&2
        exit 1 ;;
*) for file do
        case $file in
                *.*.*)          echo "dosRename: $file: Can't have two dots" >&2
                                exit 3 ;;
                *'*'*'*'*)      echo "dosRename: $file: Can't have more than one asterisk" >&2
                                exit 4 ;;
                *.'*')          t=main
                                nM=`echo "$file" | sed 's/\.\*//g'` ;;
                '*'.*)          t=extention
                                nE=`echo "$file" | sed 's/\*\.//g'` ;;
                *.*)            if [ $t != 'n' ]
                                then echo "dosRename: $file: Can't have files after target"
                                exit 2
                                fi ;;
                *)              echo "dosRename: $file: Must have a dot" >&2
                                exit 6 ;;
        esac
        if [ ! -f $file ] && [ $t = 'n' ]
        then    echo "dosRename: $file: Doesn't exist" >&2
                exit 5
        fi
done
        if [ $t = 'n' ]
        then    echo "dosRename: No target" >&2
                exit 7
        fi
esac
while [ $# -gt 1 ]
do      if [ $t = 'extention' ]
        then    ext=`echo "$1" | sed 's/\..*//g'
        	mv "$1" "$ext.$nE"
        fi

        if [ $t = 'main' ]
        then    mne=`echo "$1" | sed 's/.*\.//g'
        	mv "$1" "$nM.$mne"
        fi
shift
done