In some console applications my Linux server has started "stripping" certain repeating characters, affecting the user interface significantly.
Here are a few examples:
This htop view has inconsistently sized CPU graphs and inconsistent columns.
These iptraf-ng views show the menu box characters not being "filled out" and the columns in a live view not being even.
A few points:
- This only happens on PuTTY on Windows and the Cygwin (mintty) shell on Windows, confirmed. I haven't tested if it happens on Mac OS X Terminal. It does NOT happen at the local console.
- It does not occur if you SSH to the machine from another Linux text console.
- My high-level suspicion is that this has something to do with terminal types. However, another Linux server I have does not exhibit this behavior on PuTTY or Cygwin. Both of them report
$TERM
as being set toxterm
. - I've tried reinstalling ncurses on the server in question, which should have also refreshed the terminfo files, with no resolution.
- Both machines – both the one working fine and the one exhibiting this behavior – are using
en_US.UTF-8
as the locale (theLANG
variable). Both have hadlocale.gen
executed recently. - Apps exhibiting this behavior all seem to be curses-based apps. Pure terminal apps are fine.
If it is relevant, both systems are Arch Linux 64-bit, with all current patches applied.
Can someone help pinpoint/solve the is
Best Answer
This is triggered by a recent change in the
terminfo
database (part ofncurses
) denoting thatTERM=xterm
(and variants) support the REP (repeat previous character) escape sequence, which several terminal emulators other thanxterm
don't (yet), or just have added / soon will add support.See e.g. the Konsole or gnome-termial bugreports for further details.