ACME(4) ACME(4)
NAME
acme - control files for text windows
SYNOPSIS
acme [ -ab ] [ -c ncol ] [ -f varfont ] [ -F fixfont ] [ -l
file | 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 /mnt/wsys) and
also /dev; the files mentioned here appear in both those
directories.
Some of these files supply virtual versions of services
available from the underlying environment, in particular the
character terminal files cons(3). (Unlike in rio(1), each
command under acme sees the same set of files; there is not
a distinct /dev/cons for each window.) 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 labeled 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; there is no way to turn off `echo', for exam-
ple, under acme.
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
Page 1 Plan 9 (printed 12/22/24)
ACME(4) ACME(4)
file has multiple zeroxed windows open, only the most
recently used will appear in the index file.
label
is an empty file, writable without effect, present only
for compatibility with rio.
log reports a log of window operations since the opening of
the log file. Each line describes a single operation
using three fields separated by single spaces: the dec-
imal window ID, the operation, and the window name.
Reading from log blocks until there is an operation to
report, so reading the file can be used to monitor edi-
tor activity and react to changes. The reported opera-
tions are `new' (window creation), `zerox' (window cre-
ation via zerox), `get', `put', `del' (window dele-
tion), and `focus' (window focus change). The window
name can be the empty string; in particular it is empty
in `new' log entries corresponding to windows created
by external programs.
new is 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, formatted as 2 decimal numbers m
and n, each formatted in 11 characters plus a blank. M
and n are the character (not byte) offsets of the
beginning and end of the address, which would be
expressed in acme 's input language as #m,#n. 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.
Page 2 Plan 9 (printed 12/22/24)
ACME(4) ACME(4)
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.
dirty Mark the window dirty, the opposite of
clean.
cleartag Remove all text in the tag after the verti-
cal bar.
del Equivalent to the Del interactive command.
delete Equivalent to the Delete interactive com-
mand.
dot=addr Set the user's selected text in the window
to the text addressed by the addr address.
dump command
Set the command string to recreate the win-
dow from a dump file.
dumpdir directory
Set the directory in which to run the com-
mand to recreate the window from a dump
file.
get Equivalent to the Get interactive command
with no arguments; accepts no arguments.
font path Equivalent to the Font interactive command
with a single (required) argument.
limit=addr When the ctl file is first opened, regular
expression context searches in addr
addresses examine the whole file; this mes-
sage restricts subsequent searches to the
current addr address.
mark Cancel nomark, returning the window to the
usual state wherein each modification to
the body must be undone individually.
menu Maintain Undo, Redo, and Put in the left
half of the tag. (This is the default for
file windows.)
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.
nomenu Do not maintain Undo, Redo, and Put in the
left half of the tag. (This is the default
for directory and error windows.)
noscroll Turn off automatic `scrolling' of the win-
dow to show text written to the body.
Page 3 Plan 9 (printed 12/22/24)
ACME(4) ACME(4)
put Equivalent to the Put interactive command
with no arguments; accepts no arguments.
scratch Turn off tracking the `dirty' status, the
window stays clean.
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 display.
data is used in conjunction with addr for random access to
the contents of the body. The file offset is ignored
when writing the data file; instead the location of the
data to be read or written is determined by the state
of the addr 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
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.
errors
Writing to the errors file appends to the body of the
dir/+Errors window, where dir is the directory cur-
rently named in the tag. The window is created if nec-
essary, but not until text is actually written.
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
Page 4 Plan 9 (printed 12/22/24)
ACME(4) ACME(4)
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 follow-
ing: 1 if acme can interpret the action without loading
a new file; 2 if a second (post-expansion) message fol-
lows, 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.
rdsel
holds the contents of the current selection. It may be
read at any byte offset.
wrsel
writing to the wrsel file modifies the text in the
selection. Text written always replaces the text
selected; the file offset is ignored.
xdata
Page 5 Plan 9 (printed 12/22/24)
ACME(4) ACME(4)
The xdata file like data except that reads stop at the
end address.
SOURCE
/sys/src/cmd/acme
SEE ALSO
rio(1), acme(1), cons(3).
Page 6 Plan 9 (printed 12/22/24)