Mailinglist Archive: opensuse (1318 mails)

[Randall R Schulz <rschulz@xxxxxxxxx>]

On Friday 31 October 2008 20:51, David C. Rankin wrote:
> Listmates,
>
>       I'm stumped on another simple BASH problem. How do I read the last
> line of a file with a while loop without requiring a blank line at
> the end of the file? Simple example I'm stuck on:
>
> { while read alias url; do
>       echo -e "${alias}\t${url}"
> done } < ~/linux/scripts/config/repos
>
>       The repos flat text file (shown with --- above and below to show no
> blank line at the end) is:
>
> ---
> [sample data elided]
> ---
>
>       If there is no blank line at the end of the file, the while loop
> reads the "oss-src" line, but does not read the "lastline". If there
> is a blank line at the end, it reads "lastline" just fine. What is
> the trick to be able to read the last line of the repos file
> regardless of whether there is a blank at the end or not?

I can reproduce your result if the the last line (non-blank) has no 
trailing newline. Specifically, if the "lastline" line you show does 
not have a newline, then the read loop ignores it.

I guess it's a BASH oddity. Vim will warn you when you open such a file. 
I'm not sure if it will allow you to create one (I used a different 
editor to create the test data I used).


Also, in this particular case, at least, none of the curly braces 
(inside the quoted string or around the while loop) are necessary.


> --
> David C. Rankin


Randall Schulz
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