ACME(4) ACME(4)
NAME
acme - control files for text windows
SYNOPSIS
acme [ -f varfont ] [ -F fixfont ] [ file ... ]
DESCRIPTION
The text window system acme(1) serves a variety of files for
reading, writing, and controlling windows. Some of them are
virtual versions of system files for dealing with the vir-
tual console; others control operations of acme itself.
When a command is run under acme, a directory holding these
files is mounted on /mnt/acme (also bound to /chan) and also
/dev/acme; the files mentioned here appear in both these
directories.
Some of these files supply virtual versions of services
available from the underlying environment, in particular the
character terminal files cons(3). Other files are unique to
acme.
acme is a subdirectory used by win (see acme(1)) as a mount
point for the acme files associated with the window in
which win is running. It has no specific function
under acme itself.
cons is the standard and diagnostic output file for all com-
mands run under acme. (Input for commands is redirected
to /dev/null.) Text written to cons appears in a win-
dow labelled dir/+Errors, where dir is the directory in
which the command was run. The window is created if
necessary, but not until text is actually written.
consctl
Is an empty unwritable file present only for compati-
bility.
index
holds a sequence of lines of text, one per window.
Each line has 5 decimal numbers, each formatted in 11
characters plus a blank-the window ID; number of char-
acters (runes) in the tag; number of characters in the
body; a 1 if the window is a directory, 0 otherwise;
and a 1 if the window is modified, 0 otherwise-followed
by the tag up to a newline if present. Thus at charac-
ter position 5×12 starts the name of the window. If a
file has multiple zeroxed windows open, only the most
recently used will appear in the index file.
label
Page 1 Plan 9 (printed 11/23/24)
ACME(4) ACME(4)
is an empty file, writable without effect, present only
for compatibility.
new A directory analogous to the numbered directories
(q.v.). Accessing any file in new creates a new win-
dow. Thus to cause text to appear in a new window,
write it to /dev/new/body. For more control, open
/dev/new/ctl and use the interface described below.
Each acme window has associated a directory numbered by its
ID. Window IDs are chosen sequentially and may be discov-
ered by the ID command, by reading the ctl file, or indi-
rectly through the index file. The files in the numbered
directories are as follows.
addr may be written with any textual address (line number,
regular expression, etc.), in the format understood by
button 3 but without the initial colon, including com-
pound addresses, to set the address for text accessed
through the data file. When read, it returns the value
of the address that would next be read or written
through the data file, in the format #m,#n where m and
n are character (not byte) offsets. If m and n are
identical, the format is just #m. Thus a regular
expression may be evaluated by writing it to addr and
reading it back. The addr address has no effect on the
user's selection of text.
body holds contents of the window body. It may be read at
any byte offset. Text written to body is always
appended; the file offset is ignored.
ctl may be read to recover the five numbers as held in the
index file, described above, plus three more fields:
the width of the window in pixels, the name of the font
used in the window, and the width of a tab character in
pixels. Text messages may be written to ctl to affect
the window. Each message is terminated by a newline
and multiple messages may be sent in a single write.
addr=dot Set the addr address to that of the
user's selected text in the window.
clean Mark the window clean as though it
has just been written.
cleartag Remove all text in the tag after the
vertical bar.
del Equivalent to the Del interactive
command.
delete Equivalent to the Delete interactive
command.
dot=addr Set the user's selected text in the
window to the text addressed by the
Page 2 Plan 9 (printed 11/23/24)
ACME(4) ACME(4)
addr address.
dump command Set the command string to recreate
the window from a dump file.
dumpdir directory Set the directory in which to run
the command to recreate the window
from a dump file.
get Equivalent to the Get interactive
command with no arguments; accepts
no arguments.
limit=addr When the ctl file is first opened,
regular expression context searches
in addr addresses examine the whole
file; this message restricts subse-
quent searches to the current addr
address.
mark Cancel nomark, returning the window
to the usual state wherein each mod-
ification to the body must be undone
individually.
name name Set the name of the window to name.
nomark Turn off automatic `marking' of
changes, so a set of related changes
may be undone in a single Undo
interactive command.
noscroll Turn off automatic `scrolling' of
the window to show text written to
the body.
put Equivalent to the Put interactive
command with no arguments; accepts
no arguments.
scroll Cancel a noscroll message, returning
the window to the default state
wherein each write to the body file
causes the window to `scroll' to
display the new text.
show Guarantee at least some of the
selected text is visible on the dis-
play.
noecho Stop echoing characters sent to the
window but indicate their presence
by printing an asterisk.
echo Turns noecho off.
data is used in conjunction with addr for random access to
the contents of the body. The file offset is ignored
when writing the body file, but the character (not
byte) offset may be set with addr and then read from
the data file. Text, which must contain only whole
characters (no `partial runes'), written to data
replaces the characters addressed by the addr file and
sets the address to the null string at the end of the
written text. A read from data returns as many whole
Page 3 Plan 9 (printed 11/23/24)
ACME(4) ACME(4)
characters as the read count will permit starting at
the beginning of the addr address (the end of the
address has no effect) and sets the address to the null
string at the end of the returned characters.
event
When a window's event file is open, changes to the win-
dow occur as always but the actions are also reported
as messages to the reader of the file. Also, user
actions with buttons 2 and 3 (other than chorded Cut
and Paste, which behave normally) have no immediate
effect on the window; it is expected that the program
reading the event file will interpret them. The mes-
sages have a fixed format: a character indicating the
origin or cause of the action, a character indicating
the type of the action, four free-format blank-
terminated decimal numbers, optional text, and a new-
line. The first and second numbers are the character
addresses of the action, the third is a flag, and the
final is a count of the characters in the optional
text, which may itself contain newlines. The origin
characters are E for writes to the body or tag file, F
for actions through the window's other files, K for the
keyboard, and M for the mouse. The type characters are
D for text deleted from the body, d for text deleted
from the tag, I for text inserted to the body, i for
text inserted to the tag, L for a button 3 action in
the body, l for a button 3 action in the tag, X for a
button 2 action in the body, and x for a button 2
action in the tag.
If the relevant text has less than 256 characters, it
is included in the message; otherwise it is elided, the
fourth number is 0, and the program must read it from
the data file if needed. No text is sent on a D or d
message.
For D, d, I, and i the flag is always zero. For X and
x, the flag is a bitwise OR (reported decimally) of the
following: 1 if the text indicated is recognized as an
acme built-in command; 2 if the text indicated is a
null string that has a non-null expansion; if so,
another complete message will follow describing the
expansion exactly as if it had been indicated explic-
itly (its flag will always be 0); 8 if the command has
an extra (chorded) argument; if so, two more complete
messages will follow reporting the argument (with all
numbers 0 except the character count) and where it
originated, in the form of a fully-qualified button 3
style address.
For L and l, the flag is the bitwise OR of the
Page 4 Plan 9 (printed 11/23/24)
ACME(4) ACME(4)
following: 1 if acme can interpret the action without
loading a new file; 2 if a second (post-expansion) mes-
sage follows, analogous to that with X messages; 4 if
the text is a file or window name (perhaps with
address) rather than plain literal text.
For messages with the 1 bit on in the flag, writing the
message back to the event file, but with the flag,
count, and text omitted, will cause the action to be
applied to the file exactly as it would have been if
the event file had not been open.
tag holds contents of the window tag. It may be read at
any byte offset. Text written to tag is always
appended; the file offset is ignored.
SOURCE
/appl/acme
/appl/acme/acme
SEE ALSO
acme(1), cons(3)
Page 5 Plan 9 (printed 11/23/24)