Re: [Help-bash] Is there a way to read empty string with `read`?

[Peng Yu]

On Mon, May 23, 2016 at 8:45 AM, Greg Wooledge <address@hidden> wrote:
> On Mon, May 23, 2016 at 07:18:16AM -0500, Peng Yu wrote:
>> Hi, The following code shows that an empty string between two TABs can
>> not be captured. Is there a way to let bash read empty strings between
>> TABs?
>
> Convert the tab characters to some other character that is not treated
> as whitespace by IFS, and which also does not appear in the input data.
>
> echo $'one\ttwo\t\tfour' > testfile
> while IFS=$'\002' read -ra array; do
>     declare -p array
> done < <(tr \\t \\002 < testfile)

I have never encountered \\002 in a tsv file. In this sense, this
probably should be a reasonable work around. There are explain about
\\002 or STX in ascii code doc. However, I am not sure whether it is
of much relevance today. Do you have any real case common examples in
which these control characters are used in a text file?

> Multiple consecutive whitespace characters are treated as a single
> delimiter by IFS.  This is by design, as it's what you want 99% of the
> time, for input files that have fields padded by whitespace.

-- 
Regards,
Peng