#! /bin/bash
# #############################################################################

       NAME_="cpfile"
    PURPOSE_="find files of size n; copy to a specified dir; rename same file names"
   SYNOPSIS_="$NAME_ [-vhl] [-i <input_dir>] -o <output_dir> -p \"<pattern>\" -s <+|-n>"
   REQUIRES_="standard GNU commands"
    VERSION_="1.1"
       DATE_="2001-10-08; last update: 2004-12-30"
     AUTHOR_="Dawid Michalczyk <dm@eonworks.com>"
        URL_="www.comp.eonworks.com"
   CATEGORY_="file"
   PLATFORM_="Linux"
      SHELL_="bash"
 DISTRIBUTE_="yes"

# #############################################################################
# This program is distributed under the terms of the GNU General Public License

usage () {

echo >&2 "$NAME_ $VERSION_ - $PURPOSE_
Usage: $SYNOPSIS_
Requires: $REQUIRES_
Options:
     -i <input_dir>, path to where to look for files. Only needed if current 
        dir is not used as input dir.
     -o <output_dir>, path to where to copy the found files. Each found file
        that has the same name as in the output dir will have an integer appended 
        incrementally to the end of the prefix starting at 1.
     -s <+|-n>, file size in bytes; +n for greater then n; -n for less then n;
        n for exactly n.
     -p \"<pattern>\", search file pattern as accepted by find's -name option; no
        case distinction is made.
     -v, verbose
     -h, usage and options (this help)
     -l, see this script"
    exit 2
}

# args check
[ $# -eq 0 ] && { echo >&2 missing argument, type $NAME_ -h for help; exit 2; }

trap "exit 2" 1 2 3 15

# var init
file_size=
input_dir=
output_dir=
file_pattern=
verbose=

while getopts vhli:o:s:p: options; do

    case $options in
        s) file_size=$OPTARG ;;
        i) input_dir=$OPTARG ;;
        o) output_dir=$OPTARG ;;
        p) file_pattern=$OPTARG ;;
        v) verbose=on ;;
        h) usage ;;
        l) more $0; exit 2 ;;
       \?) echo invalid argument, type $NAME_ -h for help; exit 2 ;;

    esac

done
shift $(( $OPTIND - 1 ))

# args check
[[ $file_pattern ]] || { echo >&2 missing file pattern argument; exit 2; }
[[ $file_size ]] || { echo >&2 missing file size argument; exit 2; }
[[ -d $output_dir ]] || { echo >&2 output dir $output_dir does not exist; exit 2; }

# local fnc
c=0
rename_file() {
# usage: fnc <file>

    # keep on checking if file exist; if so, append integer to prefix
    if [ -f ${odir}/${1} ] ;then 

        ((c++))
        new_file_name=${1%%.*}${c}.${1#*.}
        rename_file $new_file_name

    # file does not exist
    else

        echo $1
        c=0
    fi

}

find_and_cp() {

    find . -type f -iname ${file_pattern} -size ${file_size}c | while read a; do

        file_name=$(rename_file ${a##*/})
        [[ $verbose ]] && echo ${NAME_}: copying $a
        cp -- $a ${odir}/${file_name}

    done

}

# relative and full path support
odir=$(cd $output_dir; pwd;)

# main
if [ $input_dir ];then

    # relative and full path support
    idir=$(cd $input_dir; pwd;)
    [ -d $idir ] || { echo input dir $idir does not exist; exit 2; }
    cd $idir 
    find_and_cp

else

    find_and_cp

fi