ACME(4)                                                   ACME(4)

          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 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

          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 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.

               Is an empty unwritable file present only for compati-

               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.


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     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
               delete             Equivalent to the Delete interactive
               dot=addr           Set the user's selected text in the
                                  window to the text addressed by the

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     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
               mark               Cancel nomark, returning the window
                                  to the usual state wherein each mod-
                                  ification to the body must be undone
               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-
               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

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     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.

               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

               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

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     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.


          acme(1), cons(3)

     Page 5                       Plan 9             (printed 4/19/21)