acme - control files for text windows
acme [ -f varfont ] [ -F
fixfont ] [ file ... ]
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 5×12 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.
/appl/acme
/appl/acme/acme