Re: [bug-gawk] in-place edit request

[Assaf Gordon]

Hi,

On 12/25/12 16:08, Aharon Robbins wrote:
> and inplace.awk becomes something like
>
>         @load "setstdout"
>         BEGINFILE {
>                 set_stdout(FILENAME "." PROCINFO["pid"])
>         }
>         ENDFILE {
>                 reset_stdout()
>                 system(sprintf("mv %s %s.bak&&  mv %s.%d %s",
>                         FILENAME, FILENAME,
>                         FILENAME, PROCINFO["pid"], FILENAME))
>         }

I like the idea of "inplace" awk (it would be very useful),
but please note that the suggested solution has some of the issues discussed 
here:
http://www.pixelbeat.org/docs/unix_file_replacement.html
(which was mentioned in the coreutil's discussion about the generic inplace 
utility)

and it would also be a bit problematic if the filename has spaces, or starts 
with a dash.
A simple quote protection would help, but not completely solve the problem, as 
"mv" could be many
things on different systems, and weird extreme cases could lead to 
unpredictable results.

sed's inplace code in "closedown()" and "ck_rename()" has some extra protection 
code that might be beneficial in order to provide a robust in-place editing.

-gordon