I got script that cut video into subclibs with specified full duration of preview then concat it. For some reason it put it together reversed. What's wrong with script or how to implement reverse that put it correctly.

#! /bin/bash

SUBCLIPS=4 
OUTPUTLENGTH=10

cliplength=$(echo "$OUTPUTLENGTH/$SUBCLIPS"| bc -l)

if [ -e "$1" ]; then
    videofile="$1"
else
    echo "file not found: $1"
    exit 1
fi
if [ "$2" ]; then
    OUTPUTFILE="$2"
else
    echo "No name given"
    exit 1
fi

ffmpeg_preamble="ffmpeg -hide_banner -i '$videofile' -s 320x240 -    filter_complex \""

duration=$(ffprobe -v error -show_entries format=duration -of         default=noprint_wrappers=1:nokey=1 "$videofile")

cutfilters=""
concatfilter=""

for cutno in $( seq 1 $SUBCLIPS ); do
cut=$(echo "(1 / ($SUBCLIPS+1)) * $cutno" | bc -l)
cutchar= $cutno+96
reverse=  $(printf "%sreverse")
cutletter=$(printf "\x$(printf %x $cutchar)")
cutpos=$(echo "$duration * $cut" |bc)
cutfilters=$(printf "%s[0:v]trim=start=%f:duration=%f,setpts=PTS-STARTPTS[%sv];" "$cutfilters" "$cutpos" "$cliplength" "$cutletter")
cutfilters=$(printf "%s[0:a]atrim=start=%f:duration=%f,asetpts=PTS-STARTPTS[%sa];" "$cutfilters" "$cutpos" "$cliplength" "$cutletter")
concatfilter=$(printf "%s[%sv][%sa]" "$concatfilter" "$cutletter" "$cutletter")
done

# concat the cuts together

concatfilter=$(printf "%sconcat=n=%s:v=1:a=1[outv][outa]" "$concatfilter"     "$SUBCLIPS")

ffmpeg_webmopts=" -c:v libvpx -crf 10 -b:v 1M -c:a libvorbis "
ffmpeg_postscript="\" -map [outv] -map [outa] $ffmpeg_webmopts '$OUTPUTFILE'"

# Chance to cancel before we start

printf "***(hit ctrl+c to cancel)***\n\nExecuting: %s%s%s%s\n"     "$ffmpeg_preamble" "$cutfilters" "$concatfilter" "$ffmpeg_postscript"
sleep 3
eval $(echo "$ffmpeg_preamble $cutfilters $concatfilter $ffmpeg_postscript")

I received a script that cuts video into sub-clips with a specific durationand then concats them again but for some reason the script concats the files in reverse order:

#!/bin/bash

SUBCLIPS=4 
OUTPUTLENGTH=10

cliplength=$(echo "$OUTPUTLENGTH/$SUBCLIPS"| bc -l)

if [ -e "$1" ]; then
    videofile="$1"
else
    echo "file not found: $1"
    exit 1
fi
if [ "$2" ]; then
    OUTPUTFILE="$2"
else
    echo "No name given"
    exit 1
fi

ffmpeg_preamble="ffmpeg -hide_banner -i '$videofile' -s 320x240 -filter_complex \""

duration=$(ffprobe -v error -show_entries format=duration -of         default=noprint_wrappers=1:nokey=1 "$videofile")

cutfilters=""
concatfilter=""

for cutno in $( seq 1 $SUBCLIPS ); do
  cut=$(echo "(1 / ($SUBCLIPS+1)) * $cutno" | bc -l)
  cutchar= $cutno+96
  reverse=  $(printf "%sreverse")
  cutletter=$(printf "\x$(printf %x $cutchar)")
  cutpos=$(echo "$duration * $cut" |bc)
  cutfilters=$(printf "%s[0:v]trim=start=%f:duration=%f,setpts=PTS-STARTPTS[%sv];" "$cutfilters" "$cutpos" "$cliplength" "$cutletter")
  cutfilters=$(printf "%s[0:a]atrim=start=%f:duration=%f,asetpts=PTS-STARTPTS[%sa];" "$cutfilters" "$cutpos" "$cliplength" "$cutletter")
  concatfilter=$(printf "%s[%sv][%sa]" "$concatfilter" "$cutletter" "$cutletter")
done

# concat the cuts together

concatfilter=$(printf "%sconcat=n=%s:v=1:a=1[outv][outa]" "$concatfilter"     "$SUBCLIPS")

ffmpeg_webmopts=" -c:v libvpx -crf 10 -b:v 1M -c:a libvorbis "
ffmpeg_postscript="\" -map [outv] -map [outa] $ffmpeg_webmopts '$OUTPUTFILE'"

# Chance to cancel before we start

printf "***(hit ctrl+c to cancel)***\n\nExecuting: %s%s%s%s\n"     "$ffmpeg_preamble" "$cutfilters" "$concatfilter" "$ffmpeg_postscript"
sleep 3
eval $(echo "$ffmpeg_preamble $cutfilters $concatfilter $ffmpeg_postscript")

How do I implement the above without reversal?