Re: [bug-gawk] Is there a way to access associative array from the environment?

[Joep van Delft]

Peng Yu schreef op 2016-03-10 05:31:
> Hi, The following command will not access "a" in $MYARRAY. Is there a
> way to do so in awk?
>
> declare -A MYARRAY
> MYARRAY=([a]=x [b]=y)
> awk -e 'BEGIN { print ENVIRON["MYARRAY"]["a"] }'

As others have noted, this is not possible from awk. One can, however,
prepare the contents of an array for awks consumption with the `awk
-e BEGIN{...} -f ...` trick. This preparation should happen from
where you call awk; usually a shell.

How this looks like exactly depends on the shell in use. In zsh, a
rough sketch of a function that spits out the contents of an array
could look like this:

% array2awk() {
    printf "BEGIN{"
    printf $1'["%s"] = "%s"; ' ${(Pkv)1}
    printf "}"
}

Please note: No sanity checking of inputs et cetera.

A test drive:

% declare -A a
% a[aaa]="a a"
% a[b]=bbbbbbbbbb

% array2awk a
BEGIN{a["aaa"] = "a a"; a["b"] = "bbbbbbbbbb"; }

% cat <<EOF >script.awk
BEGIN{ for (k in b) print k, b[k] }
EOF

% awk -e "$(array2awk b)" -f script.awk
a aaa
b b b

Cheers,

Joep