Shell Programming and Scripting

cd XYZ || { echo "directory does not exist" >&2; exit 1 ;}
n=0
for i in *
do
  if [ $((n+=1)) -gt 20 ]; then
    n=1
    wait
  fi
  todir=../XYZ$n
  [ -d "$todir" ] || mkdir "$todir" 
  mv "$i" "$todir" &
done
wait

#!/bin/ksh
IAm=${0##*/}
ec=0		# Final exit code.
mvc=100		# Maximum # of files to move in one invocation of mv.  (Adjust
		# to fit your envinronment based on the actual length of your
		# filenames, the value of ARG_MAX on your system, and the amount
		# of data being passed through environment variables when you
		# invoke the mv utility.)
typeset -A d	# Use string values (not numeric values) as subscripts.  Note:
		# This only works with ksh93.  This avoids having a string like
		# 010 treated as an octal value and being converted to decimal 8.
		#
		# For filenames of the form: <alpha>*_<digit>_n2_n3.pbx
		# where n2 is 3 decimal digits (with leading zero fill) or 1 to
		# 3 decimal digits with no leading zeros, and n3 is 1 to 4
		# decimal digits.
		#
		# If n2 contains leading 0 fill, this typeset is required.  If
		# there are no leading 0s in n2, this typeset can be left out
		# and this script will work with both bash and 1993 or later
		# versinos of ksh.
cd src
for i in *_*_*_*.pbx
do	# Extract 3rd component of filename:
	n2=${i%_*}	# Remove _*.pbx from end of filename.
	n2=${n2##*_}	# Remove *_*_ from start of filename.
	d[$n2]=		# Add extracted value to list of directories to crete.
done
if [ ${!d[@]} == "*" ]
then	printf "%s: No files matching *_*_*_*.pbx found in %s\n" "$IAm" "$PWD" >&2
	exit 1
fi
for i in ${!d[@]}
do	printf "Processing files to go to directory: %s\n" $i
	# Create the directory if it doesn't already exist.
	[ ! -d ../$i ] && mkdir ../$i
	# Initialize number of files found for this directory and list of naems.
	n=0
	p=
	for j in *_*_${i}_*.pbx
	do	p="$p $j"
		if [ $((++n)) -ge $mvc ]
		then	if mv $p ../$i 
			then	printf "moved %d files to ../%s\n" $n $i
			n=0
			p=
			else	# mv already printed a diagnostic, note error
				ec=1
			fi
		fi
	done
	# If we have files that weren't already moved in the loop, move them now
	if [ $n -gt 0 ] && mv $p ../$i
	then	printf "moved %d files to ../%s\n" $n $i
	else	# mv already printed a diagnostic, note error
		ec=1
	fi
done
exit $ec