On Sun, Jan 12, 2025, at 10:19 AM, MacBeth wrote:
> On Sun, Jan 12, 2025 at 8:58 AM MacBeth <macbeth.112...@gmail.com> wrote:
>
>> And here is a version you would have to use without `sed` to get the line
>> first, before you can append the field terminator to it:
>>
>> delim=,
>> {
>> while IFS= read -r row; do
>> IFS="$delim" read -r k values < <(echo "$row$delim")
>> values="${values%$delim}"
>> printf "%-20s %s\n" "row='$row'" "k='$k' v='$values'"
>> done
>> } <<EOT
>> a,b,c,d,e
>> a,b,c,d,
>> a,b,c,d
>> a,b,c,
>> a,b,c
>> a,b,
>> a,b
>> a,
>> a
>> EOT
>>
>>
> FYI...
>
> * The non-sed version works by setting a blank IFS, preventing 'word
> splitting', which deactivates bash from possibly mangling the input, so we
> can then process it however we want to.
>
> * Be careful with $delim, it is mainly to show by example, but is not safe
> for any value... '/' in the `sed` version, for example.
The commands
echo "$row$delim"
and
values="${values%$delim}"
aren't safe either. The former is subject to the usual vagaries of
"echo", and the latter uses the expansion of $delim as a pattern.
Fixing these is not hard but is left as an exercise for the reader.
--
vq
