ZWGC(1)ZWGC(1)NAMEzwgc - Zephyr Windowgram Client program
SYNOPSISzwgc [ -reenter ] [ -nofork ] [ -ttymode ] [ -f filename ]
[ -subfile filename ] [ -loc text ] [ -default portname ]
[ -disable portname ] ... [ output driver options ] [ X
Toolkit options... ]
DESCRIPTION
Zwgc is the main zephyr(1) client. It is responsible for
receiving selected zephyr notices on behalf of the user,
formatting them, and displaying them using one or more of
the output devices.
Selection of Zephyr Notices
Zwgc subscribes to various notice classes and instances on
behalf of the user. Only notices in the subscription list
will be received. The subscription list is composed of
the default subscriptions (stored on the server), the
user's subscriptions file, and any subscriptions made
using zctl(1). The user's subscription file defaults to
$HOME/.zephyr.subs, or it can be specified with the -sub
file option. If "-" is specified as the subscription
filename, the subscriptions will be read from standard
input.
The zctl command is used to manipulate and change sub
scriptions. See the zctl(1) man page for details.
Zephyr Description Files
Zwgc formats its output messages according to the commands
in its description file. The user's description file
($HOME/.zwgc.desc by default, or whatever is specified by
-f) is read, or the system file is read if the user's does
not exist.
Every time a notice is received, zwgc runs through the
description file, and executes the appropriate commands.
Zephyr Description File Syntax
A description file is simply a list of commands. Whites
pace (spaces, tabs, and line breaks) is used to separate
tokens. The type and amount of whitespace separating
tokens is irrelevant. Comments can be delimited by # and
newline (for line-oriented comments, e.g. "# this is a
comment" on a line by itself) or by /* and */ (e.g. "/*
this is a comment */").
DESCRIPTION LANGUAGE
Expressions
Expressions are used by certain commands. They are com
posed from string literals, variable references, function
calls, and operators. Parentheses can be used anywhere in
an expression to group expressions or increase readabil
ity.
String literals are specified by putting the contents in
"double quotes".
Variables are set using the set command (see "COMMANDS",
below). They are referenced in an expression by using the
form $varname. Some variables are set by default for each
notice. All other variables retain their values between
notice interpretations, so that if you set a variable, it
retains that value until later modified.
Functions are called using a C-like syntax,
fname(expr1,expr2), where fname is the function name and
exprn are the arguments.
Binary operators use infix notation, such as "a == b".
Some commands use an expression list (exprlist), which is
simply a set of expressions separated by whitespace (e.g.
$var1 "lit1" $var2).
Default variables
The following variables are always available:
1, ...
Numeric variables are assigned values corresponding
to that field in the notice (the body of each notice
is conceptually an array of fields, each terminated
with a null character). If the number is greater
than the number of fields actually in the notice, the
value is "". For example, the standard zwrite mes
sages have two fields: $1 is the signature, and $2 is
the text of the message.
auth An indication of the authenticity of the notice.
``yes'' means the notice is authentic, ``no'' means
it is not, and ``forged'' means that the message
claimed to be authentic but the verification of the
claim failed. The ``forged'' indication usually
appears when a user has changed his Kerberos tickets
with kinit(1) but has not run ``zctl sub'' to regis
ter this change with the Zephyr servers.
class
The class of the current notice.
date The date on which the notice was sent.
default
The default output format for the current notice
error
An error message from the port read/write commands.
fromhost
The full name of the host from which the notice
appears to have been sent. This is not fully reli_
able, as the information used to determine this host
name is not guaranteed to be correct (even for
authentic messages).
fullsender
The notice sender's name, including the zephyr realm
name.
instance
The instance of the current notice.
kind The kind of notice.
message
The full text of the message, with nulls converted to
newlines.
number_of_fields
The number of fields in the message (a string repre
sentation of a decimal number).
opcode
The opcode of the current notice.
output_driver
The name of the output driver in use.
port The port from which the notice was sent.
realm
The local zephyr realm.
recipient
The recipient for the current notice. If the notice
is a multicast (sent to several people), the recipi
ent is set to ``*''.
sender
Usually a shortened version of fullsender. If the
realm of the sender is equal to the realm of the
recipient, sender omits the realm name.
time The time of day at which the notice was sent.
user The full zephyr name of the user (e.g.
marc@ATHENA.MIT.EDU).
version
The current version of zwgc.
zephyr_version
The protocol version of the notice.
All of these variables (except for error, output_driver,
and version) are re-set before each notice is processed.
Functions
Following is a list of functions available for use in the
description file.
buffer()
The contents of the current output buffer.
downcase(expr)
Returns the value of expr, converted to lower case.
get(expr)
Returns a line from the port named expr. If there is
no text waiting on the port (e.g. the program con
nected to the port has not printed any output), this
function will wait until it can read a line of text
from the port.
getenv(expr)
Returns the value of the environment variable expr,
or the empty string if it does not exist.
lany(expr1, expr2), rany(expr1, expr2)
Return a number of characters equal to the length of
expr2 from the beginning (lany) or end (rany) of
expr1 (e.g. lany("1234567890","foo") would return
"123"). If expr1 is a variable reference, the vari
able is modified to remove the characters returned.
If expr2 is longer than expr1, the value of expr1 is
returned (and expr1 is set to "", if a variable).
lbreak(expr1, expr2), rbreak(expr1, expr2)
Expr2 defines a set of characters. The function
returns the longest initial (lbreak) or final
(rbreak) string from expr1 composed of characters not
in this set (e.g. lbreak("characters", "tuv") would
return "charac"). If expr1 is a variable reference,
the variable is modified to remove the characters
returned. If no characters in expr2 are in expr1,
then expr1 is returned (and expr1 is set to "", if a
variable).
lspan(expr1, expr2), rspan(expr1, expr2)
These functions are the negation of the break func
tions; the returned string consists of characters in
the set defined by expr2
protect(expr)
Returns a string which will be evaluated identically
to expr, but will not affect any surrounding environ
ments. That is, any characters which could close
outside environments are quoted, and any environments
in expr which are not closed at the end are closed.
substitute(expr)
Evaluates variable references of the form $variable
in expr and converts $$ to $.
upcase(expr)
Returns the value of expr, converted to upper case.
verbatim(expr)
Returns a string that will be displayed exactly as
expr looks. Anything which could be mistaken for an
environment is quoted.
stylestrip(expr)
Returns expr with all environments stripped out.
zvar(expr)
Returns the value of the zephyr variable expr, or the
empty string if it does not exist. [Zephyr variables
can be set and examined with zctl(1).]
Operators
Following is a list of operators which can be used in the
description file to compose expressions:
expr1 + expr2
String concatenation of expr1 and expr2
expr1 == expr2
True if the two expressions are equal, false
otherwise.
expr1 =~ expr2
True if the regular expression pattern expr2
matches expr1.
expr1 !~ expr2
Negation of "=~".
expr1 != expr2
Negation of "=="
expr1 and expr2, expr1 & expr2
True if expr1 and expr2 are both true.
expr1 or expr2, expr1 | expr2
True if either of expr1 or expr2 are true.
! expr1, not expr1
The logical negation of expr1.
Commands
Following is a list of the commands usable in the descrip
tion language:
appendport expr1 expr2
Creates a port called expr1. All output to the port
will be appended to the file expr2. There is no
input. If the file is created, its mode is set to
read-write, owner only (no access for others).
break
Exits the innermost if, case, or while block.
case expr1 [ ((match expr [,expr ...]) | default) commands ] ... endcase
Evaluates expr1. Then, each of the match expressions is evaluated in
order. The first time an expression matches expr1, then the body of com
mands under it is executed, and the rest of the case statement is
skipped. This compare is case-insensitive. default always matches, so
it should always appear as the last set of commands. See the default
description file for an example of use.
clearbuf
Clears the output buffer (see below for details on buffering).
closeinput expr
Closes the file associated with expr.
closeoutput expr
Sends an EOF (end-of-file) to the process if expr was a port created by
execport, or closes the file if it was created by outputport or append
port.
closeport expr
Closes both input and output of expr as defined above.
fields variable1 ...
sets the list of variables to be equal to the fields in the notice. If
there are more variables than fields, the extra variables are left empty.
exec exprlist
Executes a program without any input or output. A command named by
exprlist is executed. Each expression is used as an argument to the pro
gram; the first expression names the program (it may be either an abso
lute pathname, or a program name; the user's PATH is searched to find
simple program names).
execport expr1 exprlist
Creates a port called expr1. A command named by exprlist is executed, as
described above for exec. All output to the port is sent to the standard
input of the process. Reading from the port will return the standard
output of the process.
exit Completes processing of the current notice. The remainder of the
description file is ignored after execution of this command.
if expr1 then commands1 [elseif expr2 then commands2] ... [else commandsn] endif
If expr1 evaluates to true, execute commands1, etc. [A conditional construct, similar to the
constructs in the C shell (csh).]
inputport expr1 expr2
Creates a port called expr1. All input from the port comes from the file expr2. There is no
output.
noop does nothing
outputport expr1 expr2
Creates a port called expr1. The file expr2 will be truncated, or created if it does not
exist. All output to the port will be appended to the file expr2. There is no input. If
the file is created, its mode is set to read-write, owner only (no access for others).
print expr1 ...
adds the values of the expressions to the current output buffer. The values of the expres
sions are separated by spaces in the output.
put [expr [exprlist]]
Sends data to a port. If expr is provided, then it is used as the port, otherwise the port
used is the port corresponding to the default output device. If exprlist is provided, the
expressions in the list are sent to the port, separated by spaces. If it is omitted, then
the contents of the output buffer are sent as the data.
set variable = expr
sets variable equal to expr. Variable can later be referenced by $variable.
show text endshow
Appends text to the output buffer. This command is special, because the string does not need
to be quoted. Whitespace at the beginning or end of the lines of text is ignored. The end_
show must appear as the first token on a line (it may only be preceded on that line by
whitespace). Variable substitutions and formatting commands (but not expressions or func
tions) are processed in the text. Example:
show
this is some text
from: $sender
endshow
while expr do statements endwhile
Executes statements until expr is false.
PORTS
Ports are an abstraction encompassing all I/O forms of which zwgc is capable. There are pre-
existing output ports corresponding to each of the output devices, and more ports can be created
with the port commands described above.
OUTPUT
The output is usually collected in the output buffer and saved until a put command sends the out
put to an output device (such as an X display or a terminal). The output buffer is implicitly
cleared after each notice is completely processed.
Output devices are implemented as output ports. A message is displayed in a device-dependent man
ner when a string is output to the port corresponding to the output device. Formatting commands
are embedded in the text as @ commands of the form @command(text). Command names are case-insen
sitive and consist of alphanumeric characters and underscores. Valid brackets are () [] {} and
<>. If the command name is empty (such as in ``@(foo)''), then a new environment with no changes
is created (This is useful to temporarily change some parameter of the output, such as the font).
The following output devices are supported:
stdout
Sends the string to standard output exactly as is.
stderr
Sends the string to standard error exactly as is.
plain
Sends the string with all formatting environments removed to standard output.
tty Does formatting on the message according to @ commands embedded in the text. The output,
with appropriate mode-changing sequences, is sent to the standard output. The appropriate
characteristics of the display are taken from the TERMCAP entry (see termcap(5)) for the ter
minal named by the TERM environment variable. Supported @ commands are:
@roman Roman
(plain)
let
ters
(turns
off
all
spe
cial
modes).
or
@bold
@b Bold
let
ters.
If
not
avail
able,
reverse
video,
else
under
line.
or
@italic
@i Italic
let
ters
(under
lin
ing,
if
avail
able).
@beep "bl"
term
cap
entry,
else
"^G"
(beep
the
terminal);
lim
ited
to
once
per
mes
sage.
or
@left
@l left
aligned
or
@cen
ter
@c cen
ter
aligned
or
@right
@r right
aligned
Other
@-com
mands
are
silently
ignored.
X Dis
plays
one
win
dow
per
string
out
put
to
the
port.
The
out
put
is
for
mat
ted
accord
ing
to
@
com
mands
embed
ded
in
the
string.
Sup
ported
@
com
mands
are:
@roman turns
off
@italic
and
@bold
or
@bold
@b turns
on
bold
face
or
@italic
@i turns
on
ital
ics
or
@left
@l left
aligned
or
@cen
ter
@c cen
ter
aligned
or
@right
@r right
aligned
@large large
type
size
@medium medium
type
size
@small small
type
size
@beep Ring
the
X
bell
(lim
ited
to
once
per
mes
sage)
@font sets
the
cur
rent
font
to
the
font
spec
i
fied
in
the
con
tents
of
the
envi
ron
ment
(e.g.
@font(fixed)).
This
will
remain
in
effect
for
the
rest
of
the
envi
ron
ment
(a
tem
po
rary
change
can
be
achieved
by
enclos
ing
the
font-
change
in
an
@(...)
envi
ron
ment).
If
the
named
font
is
not
avail
able,
the
font
``fixed''
is
used
instead.
@color sets
the
color
to
the
color
spec
i
fied
in
the
con
tents
of
the
envi
ron
ment.
The
color
name
should
appear
in
the
X
color
name
database.
This
color
will
remain
in
effect
for
the
rest
of
the
envi
ron
ment.
If
the
named
color
is
not
avail
able,
the
default
fore
ground
color
is
used.
Any
other
envi
ron
ment
name
not
cor
re
spond
ing
to
the
above
envi
ron
ment
names
will
set
the
cur
rent
``sub
style.''
The
attributes
of
a
given
block
of
text
are
deter
mined
by
any
active
envi
ron
ments,
eval
u
ated
in
the
con
text
of
the
cur
rent
style
and
sub
style.
The
style
is
spe
cific
to
each
win
dow.
Its
name
has
three
dot
(``.'')
sep
a
rated
fields,
which
are
by
default
the
values
of
the
class,
instance,
and
recip
i
ent
vari
ables,
with
all
dots
changed
to
under
scores
(``_'')
and
all
let
ters
con
verted
to
low
er
case.
The
style
can
be
altered
by
set
ting
the
style
vari
able.
Note
that
it
must
always
have
exactly
two
``.''
char
ac
ters
in
it.
The
sub
style
is
deter
mined
by
@
com
mands
in
the
mes
sage
text.
Zwgc
vari
ables
which
the
X
out
put
device
reads
are:
etry
default_X_geom
default
geom
e
try
for
notices,
set
from
resources
etry
X_geom over
rides
geom
e
try
in
resource
file,
if
set
ground
default_X_back
default
back
ground
color
for
notices,
set
from
resources
ground
X_back over
rides
bgcolor
in
resource
file,
if
set
style style,
as
described
above
The
expected
geom
e
try
val
ues
are
described
below.
The
fonts
and
color
for
a
piece
of
text
are
deter
mined
by
the
styles
defined
in
the
X
resources
file.
The
fol
low
ing
resources
relat
ing
to
text
style
are
used
by
zwgc:
zwgc.style.style_
names.geom
e
try
geom
e
try
for
mes
sages
of
the
spec
i
fied
style
zwgc.style.style_
names.back
ground
back
ground
color
for
mes
sages
of
the
spec
i
fied
style
zwgc.style.style_
names.sub
style.sub_
style_
name.font
fam
ily
font
fam
ily
name
for
the
spec
i
fied
style
and
sub
style
zwgc.style.style_
names.sub
style.sub_
style_
name.fore
ground
fore
ground
color
for
the
spec
i
fied
style
and
sub
style
zwgc.font
fam
ily.font_
fam_
i_
ly_
name.size.face
spec
i
fies
the
fonts
for
a
given
font
fam
ily.
size
is
one
of
small,
medium,
or
large,
and
face
is
one
of
roman,
bold,
italic,
or
bolditalic.
The
best
way
to
get
started
in
cus
tomiz
ing
X
resources
for
zwgc
is
to
exam
ine
the
default
appli
ca
tion
resources
and
other
users'
resources
to
under
stand
how
they
spec
ify
the
default
appear
ance.
X
RESOURCES
Other
X
resources
used
by
zwgc
are
listed
below.
Entries
like
zwgc*option: value
Zwgc*option: value
zwgc.option: value
*option: value
will
work.
An
entry
labeled
with
zwgc*option
in
any
of
the
sources
takes
prece
dence
over
Zwgc*option,
which
takes
prece
dence
over
*option
entries.
The
fol
low
ing
sources
are
searched
in
order:
command-line arguments (-xrm)
contents of file named by XENVIRONMENT environment variable
X server resource database (see xrdb(1))
application resources file
Log
i
cal
val
ues
can
be
(
Yes
On
True
T
)
or
(
No
Off
False
nil
).
OPTION: MEAN
ING
[default]:
cur
sor
Code num
ber
of
a
code
from
the
cur
sor
font
(should
be
an
even
inte
ger,
see
<X11/cur_
sor_
font.h>)
to
use
for
the
win
dows.
fore
ground Pri
mary
fore
ground
color
Fore
ground Sec
ondary
fore
ground
color
(if
fore
ground
not
set)
[Black
Pixel
is
the
default
if
nei
ther
is
set]
back
ground Pri
mary
back
ground
color
Back
ground Sec
ondary
back
ground
color
(if
back
ground
not
set)
[WhitePixel
is
the
default
if
nei
ther
is
set]
bor
der
Color Pri
mary
bor
der
color
Bor
der
Color Sec
ondary
bor
der
color
(if
bor
der
Color
not
set)
[Black
Pixel
is
the
default
if
nei
ther
is
set]
point
er
Color Pri
mary
mouse
pointer
color
[fore
ground
color
is
the
default
if
not
set]
rever
se
V
ideo (log
i
cal)
Tog
gles
fore
ground
and
back
ground
(and
bor
der,
if
it
matches
fore
ground
or
back
ground).
Rever
se
V
ideo Sec
ondary
tog
gle,
if
rever
se
V
ideo
is
not
set.
[off
is
the
default
if
nei
ther
is
set]
bor
der
Width Pri
mary
bor
der
width
selec
tor
Bor
der
Width Sec
ondary
bor
der
width
selec
tor
(if
bor
der
Width
is
not
set)
[1
is
the
default
value
if
nei
ther
is
set]
inter
nal
Bor
der Pri
mary
bor
der
between
edge
and
text
Inter
nal
Bor
der Sec
ondary
selec
tor
(if
inter
nal
Bor
der
not
set)
[2
is
the
default
value
if
nei
ther
is
set]
geom
e
try Pri
mary
POSI
TION
(not
size)
geom
e
try
spec
i
fier.
The
geom
e
try
should
be
of
the
form
"{+|-}x{+|-}y",
spec
i
fy
ing
an
(x,y)
coor
di
nate
for
a
cor
ner
of
the
win
dow
dis
play
ing
the
notice.
The
inter
pre
ta
tion
of
pos
i
tive
and
neg
a
tive
loca
tion
spec
i
fi
ca
tions
fol
lows
the
X
con
ven
tions.
A
spe
cial
loca
tion
of
`c'
for
either
x
or
y
indi
cates
that
the
win
dow
should
be
cen
tered
along
that
axis.
Exam
ple:
a
geom
e
try
of
"+0+c"
spec
i
fies
the
win
dow
should
be
at
the
top
of
the
screen,
centered
hor
i
zon
tally.
Geom
e
try Sec
ondary
posi
tion
specifer.
[+0+0
is
the
default
if
nei
ther
is
set.]
reset
Saver (log
i
cal)
Pri
mary
value
to
force
screen
to
unsave
when
a
mes
sage
first
appears.
Reset
Saver (log
i
cal)
Sec
ondary
value
to
force
screen
to
unsave.
[default
True]
revers
eS
tack (log
i
cal)
Pri
mary
value
to
specify
that
zwgc
should
attempt
to
stack
Win
dow
Gram
win
dows
such
that
the
old
est
mes
sages
nor
mally
show
on
top.
Some
X
win
dow
man
agers
may
silently
ignore
zwgc's
attempts
to
restack
its
win
dows.
This
option
can
cause
some
unusual
inter
ac
tions
with
other
win
dows
if
the
user
man
u
ally
restacks
either
the
other
win
dows
or
the
Win
dow
Gram
win
dows.
Revers
eS
tack Sec
ondary
value
to
enable
reverse
stack
ing.
[default
False]
title (string)
Pri
mary
win
dow
title
Title Sec
ondary
win
dow
title
[defaults
to
the
last
path
name
com
po
nent
of
the
pro
gram
name,
usu
ally
"zwgc"]
tran
sient (log
i
cal)
Pri
mary
value
which
deter
mines
if
zephyr
gram
win
dows
will
be
cre
ated
with
the
WM_TRAN
SIENT_FOR
prop
erty
set.
If
this
resource
is
true,
the
prop
erty
will
be
set,
telling
cer
tain
win
dow
man
agers
to
treat
zephyr
gram
win
dows
spe
cially.
For
instance,
twm
will
not
put
dec
o
ra
tions
on
tran
sient
win
dows,
mwm
will
not
let
you
iconify
them,
and
uwm
ignores
the
resource
entirely.
Tran
sient Secondary
tran
sient
deter
min
ing
value
[default
False]
enableDelete (log
i
cal)
If
true,
zwgc
cre
ates
a
WM_PRO
TO
COLS
prop
erty
on
all
zgrams,
with
WM_DELETE_WIN
DOW
as
con
tents.
EnableDelete Sec
ondary
value
to
enable
WM_DELETE_WIN
DOW
pro
to
col
on
zgrams
[default
False]
minTime
To
Live Pri
mary
value
which
spec
i
fies
the
min
i
mum
amount
of
time
(``min
i
mum
time
to
live'')
a
Win
dow
Gram
must
be
on-
screen
(in
mil
lisec
onds)
until
it
can
be
destroyed.
This
fea
ture
is
use
ful
to
avoid
acci
den
tally
click
ing
on
new
Win
dow
Grams
when
try
ing
to
delete
old
ones.
MinTime
To
Live Sec
ondary
value
of
``min
i
mum
time
to
live.''
icon
Name (string)
Pri
mary
icon
name
Icon
Name Sec
ondary
icon
name
[defaults
to
the
last
path
name
com
po
nent
of
the
pro
gram
name,
usu
ally
"zwgc"]
name (string)
Pri
mary
win
dow
class
name
name Sec
ondary
win
dow
class
name
[defaults
to
the
last
path
name
com
po
nent
of
the
pro
gram
name,
usu
ally
"zwgc"]
syn
chronous (log
i
cal)
Pri
mary
X
syn
chronous
mode
spec
i
fier.
On
means
to
put
the
X
library
into
syn
chronous
mode.
Syn
chronous Sec
ondary
X
syn
chronous
mode
spec
i
fier.
[default
is
`off']
The
win
dow
class
is
always
"Zwgc".
X
BUT
TONS
Click
ing
and
releas
ing
any
but
ton
with
out
the
shift
key
depressed
while
the
pointer
remains
inside
a
Win
dow
Gram
win
dow
will
cause
it
to
dis
ap
pear.
If
the
pointer
leaves
the
win
dow
while
the
but
ton
is
depressed,
the
win
dow
does
not
dis
ap
pear;
this
pro
vides
a
way
to
avoid
acci
den
tally
los
ing
mes
sages.
If
the
con
trol
but
ton
is
held
down
while
click
ing
on
a
Win
dow
Gram,
then
that
Win
dow
Gram
and
all
win
dow
grams
under
the
point
where
the
but
ton
is
released
will
be
erased.
WARN
ING:
If
you
do
this
with
too
many
Win
dow
Grams
under
the
mouse,
it
is
pos
si
ble
for
your
sub
scrip
tions
to
be
lost.
If
zctl
retrieve
returns
noth
ing,
then
issue
a
zctl
load
com
mand
to
re-
sub
scribe
to
your
default
set
of
sub
scrip
tions.
If
you
use
znol,
then
znol
-q
&
will
restore
the
sub
scrip
tions
you
need
for
znol.
Por
tions
of
the
text
of
a
mes
sage
may
be
selected
for
"past
ing"
into
other
X
appli
ca
tions
by
using
the
shift
key
in
coop
er
a
tion
with
the
pointer
but
tons.
Hold
ing
the
Shift
key
while
depress
ing
But
ton1
(usu
ally
the
left
but
ton)
will
set
a
marker
at
the
text
under
the
pointer.
Drag
ging
the
pointer
with
Shift-
But
ton1
still
depressed
extends
the
selec
tion
from
the
start
point,
until
the
but
ton
is
released.
The
end
of
the
selec
tion
may
also
be
indi
cated
by
releas
ing
But
ton1,
hold
ing
down
the
Shift
key,
and
pressing
But
ton3
(usu
ally
the
right
but
ton)
at
the
desired
end
point
of
the
selec
tion.
The
selec
tion
will
appear
with
the
text
and
back
ground
col
ors
reversed.
ADDI
TIONAL
X
FEA
TURES
If
zwgc
receives
a
WM_DELETE_WIN
DOW,
it
destroys
the
zephyr
gram
as
if
it
were
clicked
on.
If
a
zephyr
gram
is
unmapped,
it
is
removed
from
the
stack
ing
order
used
by
revers
eS
tack.
COM
MAND
LINE
zwgc
is
nor
mally
invoked
from
/usr/athena/lib/init/login,
$HOME/.xses_
sion,
or
/usr/athena/lib/init/xses_
sion
in
the
fore
ground.
When
it
has
suc
cess
fully
set
your
loca
tion
and
obtained
sub
scrip
tions,
it
will
put
itself
into
the
back
ground
(unless
the
-nofork
option
has
been
spec
i
fied).
At
this
point
it
is
safe
to
invoke
addi
tional
zephyr
com
mands,
such
as
znol(1).
(You
can
also
put
these
com
mands
in
the
init_
progs
Zephyr
vari
able;
the
value
of
this
vari
able
is
passed
as
the
argu
ment
to
the
sys_
tem(3)
library
call
dur
ing
ini
tial
iza
tion.)
zwgc
will
exit
with
an
exit
sta
tus
of
0
if
it
was
able
to
open
the
X
dis
play
suc
cess
fully
or
1
if
it
couldn't
open
the
dis
play
and
the
Zephyr
vari
able
fall_
back
was
set
to
``false''.
If
fall_
back
is
set
to
``true'',
zwgc
will
fall
back
to
``tty
mode''
(mak
ing
the
tty
driver
the
default
out
put
device)
if
it
can't
open
the
X
dis
play.
If
fall_
back
is
not
set
and
the
dis
play
can
not
be
opened,
zwgc
prints
an
explana
tory
mes
sage
and
exits
with
a
sta
tus
of
1.
If
the
-tty_
mode
option
is
spec
i
fied,
zwgc
will
ignore
any
X
dis
play
and
use
the
ter
mi
nal
as
its
pri
mary
out
put
device.
This
flag
over
rides
any
set
ting
of
the
fall
back
vari
able.
If
the
-loc
option
is
spec
i
fied,
zwgc
will
use
the
spec
i
fied
string
as
the
tty
field
for
the
loca
tion
it
sets.
This
allows
users
to
poten
tially
spec
ify
more
use
ful
aux
il
iary
infor
ma
tion
than
their
ttys
or
dis
play
names.
The
-reen_
ter
option
is
pro
vided
for
com
pat
i
bil
ity
with
the
pre
vi
ous
ver
sion
of
zwgc.
zwgc
will
exit
cleanly
(unset
loca
tion
and
can
cel
sub
scrip
tions)
on:
SIGTERM
SIGHUP
XIOError (with a message to stderr)
SIGHUP
is
what
it
expects
to
get
upon
logout.
Also,
the
sig
nals
SIG
INT,
SIGQUIT,
and
SIGT
STP
are
ignored
because
they
can
be
sent
inad
ver
tently,
and
bizarre
side-
effects
can
result.
If
you
want
them
to
be
acted
on,
then
run
zwgc-nofork
&
CON
TROL
MES
SAGES
In
order
to
allow
some
spe
cial
user
con
trols
over
the
behav
ior
of
zwgc,
cer
tain
Zephyr
con
trol
notices
can
be
sent
directly
to
zwgc
using
the
zctl(1)
pro
gram.
Cur
rently
imple
mented
con
trols
are
wg_read tell
zwgc
to
re-
read
the
cur
rent
descrip
tion
file.
wg_shut
down tell
zwgc
to
can
cel
all
sub
scrip
tions
and
stop
act
ing
on
incom
ing
notices.
zwgc
saves
the
sub
scrip
tions
that
were
in
effect
at
the
time
of
the
shut
down
so
that
it
can
restore
them
later
if
needed.
wg_startup tell
zwgc
to
restart
from
being
shut
down
and
rein
stall
the
saved
sub
scrip
tions.
Other
con
trol
messages
may
be
imple
mented
in
the
future.
EXAM
PLES
For
an
exam
ple
of
a
descrip
tion
file,
see
/usr/athena/share/zephyr/zwgc.desc.
For
an
exam
ple
of
X
resources,
see
/usr/athena/share/zephyr/zwgc_resources.
BUGS
The
X
selec
tion
code
can
high
light
the
wrong
por
tions
of
mes
sages
con
tain
ing
for
mat
ted
text
placed
with
the
@cen
ter()
or
@right()
direc
tives.
If
you
are
using
Ker
beros
sup
port
and
get
new
tick
ets
(using
``kinit''),
you
must
send
a
sub
scrip
tion
notice
to
the
server
(using
a
com
mand
such
as
``zctl
load
/dev/null'')
or
all
received
Zephyr
notices
will
appear
to
be
unau
then
tic.
(If
all
received
Zephyr
notices
appear
to
be
forged,
your
tick
ets
have
prob
a
bly
expired,
in
which
case
you
must
get
new
tick
ets
and
then
run
``zctl
load
/dev/null''.)
FILES
$HOME/.zwgc.desc
Default
loca
tion
of
user's
descrip
tion
file
/usr/athena/share/zephyr/zwgc.desc
Sys
tem-
wide
descrip
tion
file
/usr/athena/share/zephyr/zwgc_resources
Default
X
appli
ca
tion
resources.
$HOME/.zephyr.vars
File
con
tain
ing
vari
able
def
i
ni
tions
$HOME/.zephyr.subs
Sup
ple
men
tary
sub
scrip
tion
file
sources
$HOME/.Xre Stan
dard
X
resources
file
or
/tmp/wg.uid
$WGFILE File
used
to
store
Win
dow
Gram
port
num
ber
for
other
clients
SEE
ALSO
csh(1),
kinit(1),
xrdb(1),
zctl(1),
zephyr(1),
znol(1),
X(1),
getenv(3),
sys
tem(3),
term
cap(5),
zephyrd(8),
zhm(8)
Pro
ject
Athena
Tech
ni
cal
Plan
Sec
tion
E.4.1,
`Zephyr
Noti
fi
ca
tion
Ser
vice'
AUTHORS
John Carr (MIT/Project Athena) <jfc@athena.mit.edu>
Marc Horowitz (MIT/Project Athena) <marc@athena.mit.edu>
Mark Lillibridge (MIT/Project Athena) <mdl@CS.CMU.EDU>
RESTRIC
TIONS
Copy
right
(c)
1989
by
the
Mas
sachusetts
Insti
tute
of
Tech
nol
ogy.
All
Rights
Reserved.
zephyr(1)
spec
i
fies
the
terms
and
con
di
tions
for
redis
tri
bu
tion.
MIT Project Athena November 30, 1989 ZWGC(1)
