iconv stdio buffering

[R. Diez]

Tool "iconv" suffers from the stdio buffering problem described here:

https://stackoverflow.com/questions/14472179/how-do-i-perform-a-streaming-character-conversion

Basically, when piping to iconv in an interactive session, output stutters. Tool "stdbuf" does not help. From the page above: "But it looks like iconv is managing the buffering internally itself - it's nothing to do with the Linux pipe buffer."

Solutions are described in this page:

http://www.pixelbeat.org/programming/stdio_buffering/

iconv should have a command-line switch to help. From the page above:

"Note tail's stdout buffer would also have this problem, but tail -f calls fflush
on the stdout stream when new data is received to alleviate this
(as do tcpdump -l, grep --line-buffered and sed --unbuffered for example)."

[known workaround]
Use `recode` instead.

[Vladimir (v13d)]

This bug was reported more than 15 years ago. https://sourceware.org/bugzilla/show_bug.cgi?id=6050
But there is a patch for it since 2015 https://sourceware.org/legacy-ml/libc-alpha/2015-08/msg00297.html
Who maintains libc-bin? Could you please apply these patches?

$ iconv -V
iconv (Ubuntu GLIBC 2.31-0ubuntu9.14) 2.31
Copyright (C) 2020 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Ulrich Drepper.

$ apt-cache policy libc-bin
libc-bin:
  Installed: 2.31-0ubuntu9.14
  Candidate: 2.31-0ubuntu9.14

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Simon Chopin (schopin)]

Hi! Thanks for raising the issue.

Given the relative complexity of the patch and the low number of affected people, I don't feel we should be shipping this as a Ubuntu-specific patch. It might be a better idea for you to raise the issue on the upstream ML, possibly amending the original patch to take the various review remarks into account?