Multibyte characters in the Hardstatus line

[Zvi Har'El]

Dear Screen gurus,

I am using Screen in a en_US.UTF-8 locale, inside an xterm. I am using the xterm standard escape sequence to set the window title.  I have a the following problem: There is no problem with the Ascii characters (Unicode <  0+007F), which are represented by one byte in UTF-8, but also with Latin1 characters (Unicode < U+00FF), which are arepresented but two bytes,  are displayed ok. However, other characters are displayed incorrectly: for example, the command

echo  -e '\e]0;ΑΒΓΔ\a\c'

which normally sets the title line to the four Greek character Alpha, Beta, Gamma, Delta (U+0391..U+0394) (I use xterm-223 with utf-8 title) . If I start screen in this xterm (without any hardstatus preset) I see in the title four dotted squares, 

If I run xprop on the non-screen xterm I see

WM_ICON_NAME(COMPOUND_TEXT) = "ΑΒΓΔ"
WM_NAME(COMPOUND_TEXT) = "ΑΒΓΔ"

but if I do the same inside screen I see

WM_ICON_NAME(STRING) = "\302\221\302\222\302\223\302\224"
WM_NAME(STRING) = "\302\221\302\222\302\223\302\224"

Note: GREEK CAPITAL LETTER ALPHA, U+0391 is in UTF-8 \316\221 which is modified to \302\221 , U+0091, which is a control character (PRIVATE USE ONE) and therefor not printable.

Note also the difference showing in COMPOUND_TEXT vs. STRING.

Another example:

echo -e '\e]0;אבגד\a\c'

Without screen:

I see in the title four Hebrew characters Alef, Bet, Gimmel, Dalet   (U+05D0..U+05D3)

WM_ICON_NAME(COMPOUND_TEXT) = "אבגד"
WM_NAME(COMPOUND_TEXT) = "אבגד"

Inside screen:

I see in the title the four latin1 characters Ð Ñ Ò Ó (U+00D0..U+00D3),

and xprop gives of course

WM_ICON_NAME(STRING) = "ÐÑÒÓ"
WM_NAME(STRING) = "ÐÑÒÓ"

Note: HEBREW LETTER ALEF, U+05D0 is in UTF-8  \327\220 which is modified to \303\220, U+00D0, LATIN CAPITAL LETTER ETH

I also tried unicode characters which are three UTF-8 bytes in the General Punctuation block, e.g., U+2019 RIGHT SINGLE QUOTATION MARK,  \342\200\231.

 echo -e '\e]0;’\a\c'

gave the desired xterm title with

WM_ICON_NAME(COMPOUND_TEXT) = "’"
WM_NAME(COMPOUND_TEXT) = "’"

however within screen we see a question mark in the title,

and xprop shows accordingly

WM_ICON_NAME(STRING) = "?"
WM_NAME(STRING) = "?"

I tried to research the screen sources but to now avail.

Since I see screen is actively developed, I decided to send this mail. I hope this is the correct list - perhaps when I am more proficient with screen developement I'll post to screen-developers :-)

All the best,

Zvi.

-- 
Dr. Zvi Har'El      mailto:address@hidden    Department of Mathematics
tel:+972-54-4227607 icq:179294841    Technion - Israel Institute of Technology
fax:+972-4-8293388  http://www.math.technion.ac.il/~rl/    Haifa 32000, ISRAEL
"If you can't say somethin' nice, don't say nothin' at all." -- Thumper (1942)