| 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 virtual console; others control operations of acme itself. When a command is run under acme, a directory holding these files is posted as the 9P service `acme` (using 9pserve(4)).

Some of these files supply virtual versions of services available from the underlying environment, in particular the character terminal files in Plan 9’s cons(3). (Unlike in Plan 9’s 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 commands run under acme. (Input for commands is redirected to `/dev/null`.) Text written to `cons` appears in a window 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 compatibility; there is no way to turn off ‘echo’, for example, 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 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 5x12 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 with `rio`.
`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 two more fields: the width of the window in pixels and the name of the font used in the window. 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 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.

`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 currently named in the tag. The window is created if necessary, but not until text is actually written.

`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.
`xdata`The `xdata` file like `data` except that reads stop at the end address.

SOURCE

| `/usr/local/plan9/src/cmd/acme`

SEE ALSO

| rio(1), acme(1)