#!/bin/bash
#<pre><b>
# Script     : multilinks
# Version    : 1.0
# Author     : Roland Rashleigh-Berry
# Date       : 18-Jan-2005
# Purpose    : To create individual links to members of a directory
# SubScripts : none
# Notes      : Must be called in the directory you wish to create the links in
# Usage      : multilinks /xxx/dir
#              multilinks -s '*.sas' /xxx/dir  # file pattern MUST BE QUOTED
#===============================================================================
# OPTIONS:
#-opt- -------------------------------description-------------------------------
#  s   (value)  select on file pattern   (MUST be in quotes)                  
#===============================================================================
# PARAMETERS:
#-pos- -------------------------------description-------------------------------
#  1   directory to link to
#===============================================================================
# AMENDMENT HISTORY:
# init --date-- mod-id ----------------------description------------------------
# 
#===============================================================================
# This is public domain software. No guarantee as to suitability or accuracy is
# given or implied. User uses this code entirely at their own risk.
#===============================================================================

# Define give-usage-message-then-exit function
usage () {
  echo "Usage: multilinks -s <file pattern IN QUOTES> /dir/to/link/to" 1>&2
  exit 1
}


# Defaults
values=                             # Default file pattern                            


# "case" statement for action to take on selected options
while getopts "s:" param ; do
  case $param in
   "?") # bad option supplied
        usage
        ;;
   "s") # (value) select on file pattern
        values=$OPTARG
        ;;
  esac
done


# shift to bring first parameter to position 1
shift $(($OPTIND - 1))


# One directory path must be supplied
if [ $# -ne 1 ] ; then
  echo "Error: no directory path supplied" 1>&2
  usage
fi


# get a list of the directory members
ls -1 "$1" > $HOME/multilinks.tmp


################ SWITCH OFF SHELL GLOBBING ##################
set -f


# set up the pattern for the case statement
patt=*
if [ ! -z "$values" ] ; then
  patt=$values
fi

# loop through for each file and if matches pattern then set up symbolic link
for filename in $(cat $HOME/multilinks.tmp) ; do
  case "$filename" in
    $patt)
      if [ -f "$filename" ] ; then
        echo "link to $filename not created as this file already exists" 1>&2
      else
        ln -s $1/"$filename" "$filename"
      fi
    ;;
  esac
done