LilMonstaNumber12 for GNU/Linux X11 uses X clpbd to find URLs of CPAN pkgdists and saves them in a hierarchical fs loc (creating dirs where needed).

LilMonstaNumber12

#!/bin/dash
#--+++-- cpan-grabdist.sh
# NODBG=ON # comment out after debugging
#--+++--
export HO_ME=$(echo ~)
TO_SUDO_OR_NOT=""
BEST=$(echo ~Public/Downloads) 
TARGET=${BEST:+"$BEST/CPAN-SRC"}


writeOK ()
{
    export CHK=$1
 python - <<"EOPY"
import os #       os.W_OK | os.X_OK
import grp
import subprocess
fqp = os.getenv("CHK")
whobool = os.access(fqp, os.W_OK | os.X_OK)
hasitt = grp.getgrnam("adm").gr_gid
if whobool:
    print "0",
    exit
else:
    if subprocess.Popen(["/usr/bin/sudo", "/bin/chown", "root:adm", fqp]):
       print "0",
       exit
    else: print 1,
EOPY
}

xcb_ ()
{
    for NU in 0 1 2 3 4 5 6; do
        $1 2>/dev/null \
               -p $NU |perl -an \
   -e '$l=qr/(?:<[[:alpha:]])?([hf]t{1,2}p:)/;' \
   -e 'print for map{/$l/ ? "\n\t$_" : $_} $_=~m{$l(.+)}'
    done
}

smartfetch ()
{
    REQU=$1
    SUDI=$2 ; export SUDI=${SUDI:=$TARGET}

    printf \
        'Fetching unless exists (no-clobber): %s\n' \
        "${REQU:=http://search.cpan.org/CPAN/authors/id/G/GB/GBARR/IO-1.25.tar.gz}"

  # "Permission denied": the trouble is that wget is not using the adm group to
  # save the file?
    wget --no-clobber --no-verbose \
-O $(echo -n "$REQU" |$TO_SUDO_OR_NOT perl -w \
  -MList::MoreUtils=after,lastidx,all,notall \
  -MPath::Class=dir -MFile::Path=make_path -MData::Dumper=Dumper -MFile::Spec \
 -F/ -an \
  -e  'die "No Dest" unless $ENV{"SUDI"}; my($c,$z,@o); my $g=[q(NO DATA),q()];' \
  -e  'my $ht=($ENV{"SUDI"}); my $fpopt={verbose=>0,mode=>0771,errors=>\$g};' \
  -e  'my $pard = "$ht"; my @h=q[]; push @h,split "/"=> $pard;' \
  -e  '  printf STDERR qq[%s:  putting under parent %s and %s exists already\n\n]' \
  -e  '    , $^X, join("/",@h[1..$#h]), (-d $pard ? "all" : "not all"); ' \
  -e  'my @slf=(6,7,$#F -1); my @e=@F[@slf]; my $fbn= $F[$#F];'\
  -e  'my @wuri=(@h,@F[@slf]); my $pco=dir(@wuri); my $ffile = $pco->file($F[$#F]); my @dl=$pco->dir_list;'\
  -e  'my @fret = after {$_ eq $h[$#h]} (@h,@e); # flawed' \
  -e  '  printf STDERR "%s:  will make sure that path exists: %s  +  %s\n", $^X,dir(@h),dir(@fret);' \
  -e  '  print  STDERR "Created something?: \n", do{@o=make_path($pco,$fpopt); join qq[\n],@o};' \
  -e  'if ( (!ref($g) and @$g) ' \
  -e  '  or scalar @o' \
  -e  '  or all{my $so; $c||=q[/]; do {$c=dir($c=>$_);'\
  -e  '      printf STDERR qq[%s\t%s\n]=>(($so=$c->stat) ? "*":"0")=>"$c"}; $_ eq ""||$c->stat}'\
  -e  '     @dl' \
  -e  ' )'\
  -e  '{' \
  -e  '  chmod(0775 , $ffile->dir()->stringify);' \
  -e  '  printf STDERR qq[\n%s\nSaving to %50s\n%s\n%s\n%s\n\n] =>' \
  -e  ' q[-] x 60, q[-] x 50' \
  -e  ', " ought to stat here ",' \
  -e  ' q[-] x 60,$ffile ;' \
  -e  '  print $ffile->stringify;' \
  -e  '} else {' \
  -e  '  printf STDERR "FAILED: did not make dir\n\t%s\n  --reason? %s\n",$pco->stringify,Dumper($g);' \
  -e  '  print q[/tmp/WASHOUT];' \
  -e  '}') $REQU
}

pythwunk=$(writeOK $TARGET) 
if [ "IGNORE" = "IG${NODBG:+NORE}" ] ; then printf '[%s]\n\n' "$pythwunk" ; fi

# Set a default for debugging:
TITI='http://search.cpan.org/CPAN/authors/id/G/GB/GBARR/IO-1.25.tar.gz'

suis=""
if [ x$DISPLAY != x ]
   then
  case "$(which -a ssh-askpass razor-openssh-askpass)" in
        */ssh-askpass\ * )
        export SUDO_ASKPASS=/usr/bin/ssh-askpass
        suis="-A "
  ;;
        */razor-openssh-askpass\ *)
        export SUDO_ASKPASS=/usr/bin/razor-openssh-askpass
        suis="-A "
  ;;
  esac

  # SETUP : must have `xcb' and `pgrep' installed; xcb must be started.
  if [ -n ${xcb:=`which xcb`} ] &&
          [ $(pgrep -u ${UID:-1000} -c xcb) -gt 0 ]
       then
      TITI=$(xcb_ $xcb)
      IFS=$'\t\n' printf >&2 '%-14s caught %s\n' "${0%%*/}" "$TITI"

  elif [ -n ${xsel:=`which xsel`} ]
       then
      TITI=$(xsel -b -o 2>/dev/null)
      if test 0 -eq \
  $(env T=$TITI OUTERS=$0 perl \
    -e '$_=$ENV{T}; unless (m{^[hf]t?tps?:\S+$}) { printf STDERR ' \
    -e 'qq[%-14s: bad non-URI string on X Clipboard:\n%s\n\n]=>$ENV{OUTERS}, $_; print 1 }; print 0')
            then
           for CRITTER in $TITI; do printf >&2 '%-14s: caught URI %s\n' "${0%%*/}" $CRITTER; done
       else printf >&2 '  ...Aborting with nothing to fetch.\n'; exit
      fi
  fi
fi

export TARGET

if [ -d "$TARGET" -a "$pythwunk" -eq 0 ]
     then
    printf >&2 '%-14s: GOOD. We can probably write to %s\n' "${0%%*/}" "$TARGET"
    export TO_SUDO_OR_NOT="sudo -E ${suis}-g adm -u root"

elif [ -d $(dirname $TARGET) -a $(writeOK $(dirname $TARGET)) -eq 0 ];
     then
    mkdir -m 2775 $TARGET ||
             (printf >&2 'Could not create top directory "%s"!\n' "$TARGET"; exit 1) 
    export TO_SUDO_OR_NOT="sudo -E ${suis}-g adm -u root"

elif [ -d "$TARGET" -a "$pythwunk" -ne 0 ]
     then
    TARGET=${XDG_DOWNLOAD_DIR:?"Not defined."}  # our own download area.
    export TO_SUDO_OR_NOT=""
    printf >&2 'OOPS We cannot write to %s, using instead %s\n  "%s" looks like: %s.\n\n' \
        "$BEST" "$TARGET" "$BEST" "$(stat -c \
        "owner %U group %G perms %a" "$BEST")"
fi


#***# "main()"
if [ -n "$TITI" ] && [ -n "$TARGET" ]
then
   case x$xcb in
       x???* )  for CRITTER in $TITI; do
                   ${NODBG:+echo}  smartfetch "$CRITTER" "$TARGET"
                done
           ;;
          *  )     ${NODBG:+echo}  smartfetch "$TITI" "$TARGET"
           ;;
   esac
fi


# Author: somian
# Last modified 28 SEP 2014
# vim7: ft=sh et sw=4: