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 virtual 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 commands
run under
acme.
(Input for commands is redirected to
/dev/null.)
Text written to
cons
appears in a window 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 compatibility.
- 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 characters (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 character position 5&215;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
- 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 window. 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 discovered by the
ID
command, by
reading the
ctl
file, or
indirectly 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 compound 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
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 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.
- 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 display.
- 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 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 window 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 messages 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 newline.
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 explicitly (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 following:
1 if
acme
can interpret the action without loading a new file;
2 if a second (post-expansion) message 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.