Bash Array – Resolving ‘typeset -A’ Error in Bash Script

zsh has different parameter substitution than Bash, which is documented in man zshexpn. It supports a variety of modifiers to expansion behaviour, which are put in parentheses before the variable name: ${(X)name}. The modifier to include array keys (including for associative arrays) is k: ${(k)array} expands to the list of keys in the array, except that if a key is the empty string, it is omitted. Use double quotes and the @ modifier to retain the empty key.

for x in "${(@k)array}" ; ...

will loop over the keys of the array array.

Some ideas:

1. A "parameter expansion" of a variable value (the ${...} part):

   echo "arr$COUNTER[0] = ${arr$COUNTER[0]}"
   

   will not work. You may get around by using eval (but I do not recommend it):

   eval echo "arr$COUNTER[0] = \${arr$COUNTER[0]}"
   

   That line could be written as this:

   i="arr$COUNTER[0]"; echo "$i = ${!i}"
   

   That is called indirection (the !) in Bash.

2. A similar issue happens with this line:

   declare -a "arr$COUNTER=($field)"
   

   Which should be split into two lines, and eval used:

   declare -a "arr$COUNTER"
   eval arr$COUNTER\=\( \$field \)
   

   Again, I do not recommend using eval (in this case).

3. As you are reading the whole file into the memory of the shell, we may as well use a simpler method to get all lines into an array:

   readarray -t lines <"VALUES_FILE.txt"
   

   That should be faster than calling awk for each line.

An script with all the above could be:

#!/bin/bash
valfile="VALUES_FILE.txt"

readarray -t lines <"$valfile"             ### read all lines in.

line_count="${#lines[@]}"
echo "Total number of lines $line_count"

for ((l=0;l<$line_count;l++)); do
    echo "Counter value is $l"             ### In which line are we?
    echo "Field = ${lines[l]}"             ### kepth only to help understanding.
    k="arr$l"                              ### Build the variable arr$COUNTER
    IFS=" " read -ra $k <<<"${lines[l]}"   ### Split into an array a line.
    eval max=\${#$k[@]}                    ### How many elements arr$COUNTER has?
    #echo "field $field and k=$k max=$max" ### Un-quote to "see" inside.
    for ((j=0;j<$max;j++)); do             ### for each element in the line.
        i="$k[$j]"; echo "$i = ${!i}"      ### echo it's value.
    done
done
echo "The End"
echo

However, still, AWK may be faster, if we could execute what you need in AWK.

A similar processing could be done in awk. Assuming the 6 values will be used as an IP (4 of them) and the other two are a number and an epoch time.

Just a very simple sample of an AWK script:

#!/bin/sh
valfile="VALUES_FILE.txt"
awk '
NF==6 { printf ( "IP: %s.%s.%s.%s\t",$1,$2,$3,$4)
        printf ( "number: %s\t",$5+2)
        printf ( "epoch: %s\t",$6)
        printf ( "\n" )
    }
' "$valfile"

Just make a new question with the details.