Shell Programming and Scripting

for word in $(<$file); do
                #echo "$word"
done
this only read every word. I tried to do:
case "$word" in
                   "zero") $word = "0"

$ read V1 V2 V3 V4 V5 V6 V7 V8 < file
$ echo $V2
two

$ read -a ARR < file2
$ echo ${ARR[1]}
two

#!/bin/sh

# #!/usr/local/bin/dash
# Tested using dash as the shell.

# Generate a file containing required words.
echo 'one two
buckle my shoe
three four
knock at the door
five six
pick up sticks
seven eight
lay them straight
nine zero
a big fat hero
multiply add
and maybe to subtract
divide too
just to satisfy you' > /tmp/txt

# Convert basic text file to single word lines.
tr ' ' '\n' < /tmp/txt > /tmp/text

# *******************************************
# **** The main pseudo-array generator. *****
INDEX=1
while read -r ARRAY
do
    eval MY_ARRAY${INDEX}='${ARRAY}'
    INDEX=$(( INDEX+1 ))
done < /tmp/text
# You now have a number of variables containing
# 1 word in each. The above is POSIX compliant.
# *******************************************

# Check the environment to see if the variables are there.
set

Last login: Fri Apr 12 18:47:43 on ttys000
AMIGA:amiga~> cd Desktop/Code/Shell
AMIGA:amiga~/Desktop/Code/Shell> ./words1.sh
ARRAY=
Apple_PubSub_Socket_Render=/private/tmp/com.apple.launchd.OnpUkj5yS0/Render
BASH=/bin/sh
BASH_ARGC=()
BASH_ARGV=()
BASH_LINENO=([0]="0")
BASH_SOURCE=([0]="./words1.sh")
BASH_VERSINFO=([0]="3" [1]="2" [2]="57" [3]="1" [4]="release" [5]="x86_64-apple-darwin18")
BASH_VERSION='3.2.57(1)-release'
DIRSTACK=()
EUID=502
GROUPS=()
HOME=/Users/amiga
HOSTNAME=Barrys-MBP
HOSTTYPE=x86_64
IFS='     
'
INDEX=40
LANG=en_GB.UTF-8
LOGNAME=amiga
MACHTYPE=x86_64-apple-darwin18
MY_ARRAY1=one
MY_ARRAY10=the
MY_ARRAY11=door
MY_ARRAY12=five
MY_ARRAY13=six
MY_ARRAY14=pick
MY_ARRAY15=up
MY_ARRAY16=sticks
MY_ARRAY17=seven
MY_ARRAY18=eight
MY_ARRAY19=lay
MY_ARRAY2=two
MY_ARRAY20=them
MY_ARRAY21=straight
MY_ARRAY22=nine
MY_ARRAY23=zero
MY_ARRAY24=a
MY_ARRAY25=big
MY_ARRAY26=fat
MY_ARRAY27=hero
MY_ARRAY28=multiply
MY_ARRAY29=add
MY_ARRAY3=buckle
MY_ARRAY30=and
MY_ARRAY31=maybe
MY_ARRAY32=to
MY_ARRAY33=subtract
MY_ARRAY34=divide
MY_ARRAY35=too
MY_ARRAY36=just
MY_ARRAY37=to
MY_ARRAY38=satisfy
MY_ARRAY39=you
MY_ARRAY4=my
MY_ARRAY5=shoe
MY_ARRAY6=three
MY_ARRAY7=four
MY_ARRAY8=knock
MY_ARRAY9=at
OPTERR=1
OPTIND=1
OSTYPE=darwin18
PATH=/Library/Frameworks/Python.framework/Versions/3.5/bin:/Users/amiga/Programs:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
PIPESTATUS=([0]="1")
POSIXLY_CORRECT=y
PPID=1363
PS4='+ '
PWD=/Users/amiga/Desktop/Code/Shell
SHELL=/bin/bash
SHELLOPTS=braceexpand:hashall:interactive-comments:posix
SHLVL=2
SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.a4cnRI4Q71/Listeners
TERM=xterm-256color
TERM_PROGRAM=Apple_Terminal
TERM_PROGRAM_VERSION=421.1
TERM_SESSION_ID=C5501462-11A6-4B33-AC5B-14C026610778
TMPDIR=/var/folders/9c/bb_c667j5nj5cbbkw__1l8n40000gp/T/
UID=502
USER=amiga
XPC_FLAGS=0x0
XPC_SERVICE_NAME=0
_=ARRAY
AMIGA:amiga~/Desktop/Code/Shell> _

set -- `cat file.txt`

#!/bin/bash
# bash-4 required
declare -A sym
sym=(
[zero]=0
[one]=1
[two]=2
[three]=3
[four]=4
[five]=5
[plus]=+
)

while read -r -a words
do
  out=""
  for word in "${words[@]}"
  do
    out+=${sym[$word]-" $word "}
  done
  echo "$out"
done