acme, win, awd – interactive text windows

acme [ –ab ] [ –c ncol ] [ –f varfont ] [ –F fixfont ] [ –l loadfile | file ... ]

win [ command ]

awd [ label ]

Acme manages windows of text that may be edited interactively or by external programs. The interactive interface uses the keyboard and mouse; external programs use a set of files served by acme; these are discussed in acme(4).

Any named files are read into acme windows before acme accepts input. With the –l option, the state of the entire system is loaded from loadfile, which should have been created by a Dump command (q.v.), and subsequent file names are ignored. Plain files display as text; directories display as columnated lists of the names of their components, as in ls –p directory|mc except that the names of subdirectories have a slash appended.

The –f (–F) option sets the main font, usually variable–pitch (alternate, usually fixed–pitch); the default is /lib/font/bit/lucidasans/euro.8.font (.../lucm/unicode.9.font). Tab intervals are set to the width of 4 (or the value of $tabstop) numeral zeros in the appropriate font.

Acme windows are in two parts: a one–line tag above a multi–line body. The body typically contains an image of a file, as in sam(1), or the output of a program, as in an rio(1) window. The tag contains a number of blank–separated words, followed by a vertical bar character, followed by anything. The first word is the name of the window, typically the name of the associated file or directory, and the other words are commands available in that window. Any text may be added after the bar; examples are strings to search for or commands to execute in that window. Changes to the text left of the bar will be ignored, unless the result is to change the name of the window.

If a window holds a directory, the name (first word of the tag) will end with a slash.

Each window has a scroll bar to the left of the body. The scroll bar behaves much as in sam(1) or rio(1) except that scrolling occurs when the button is pressed, rather than released, and continues as long as the mouse button is held down in the scroll bar. For example, to scroll slowly through a file, hold button 3 down near the top of the scroll bar. Moving the mouse down the scroll bar speeds up the rate of scrolling.

Acme windows are arranged in columns. By default, it creates two columns when starting; this can be overridden with the –c option. Placement is automatic but may be adjusted using the layout box in the upper left corner of each window and column. Pressing and holding any mouse button in the box drags the associated window or column. For windows, just clicking in the layout box grows the window in place: button 1 grows it a little, button 2 grows it as much as it can, still leaving all other tags in that column visible, and button 3 takes over the column completely, temporarily hiding other windows in the column. (They will return en masse if any of them needs attention.) The layout box in a window is normally white; when it is black in the center, it records that the file is `dirty': acme believes it is modified from its original contents.

Tags exist at the top of each column and across the whole display. Acme pre–loads them with useful commands. Also, the tag across the top maintains a list of executing long–running commands.

The behavior of typed text is similar to that in rio(1) except that the characters are delivered to the tag or body under the mouse; there is no `click to type'. (The experimental option –b causes typing to go to the most recently clicked–at or made window.) The usual backspacing conventions apply. As in sam(1) but not rio, the ESC key selects the text typed since the last mouse action, a feature particularly useful when executing commands. A side effect is that typing ESC with text already selected is identical to a Cut command (q.v.).

Most text, including the names of windows, may be edited uniformly. The only exception is that the command names to the left of the bar in a tag are maintained automatically; changes to them are repaired by acme.

When a window is in autoindent mode (see the Indent command below) and a newline character is typed, acme copies leading white space on the current line to the new line. The option –a causes each window to start in autoindent mode.

Directory context
Each window's tag names a directory: explicitly if the window holds a directory; implicitly if it holds a regular file (e.g. the directory /adm if the window holds /adm/users). This directory provides a context for interpreting file names in that window. For example, the string users in a window labeled /adm/ or /adm/keys will be interpreted as the file name /adm/users. The directory is defined purely textually, so it can be a non–existent directory or a real directory associated with a non–existent file (e.g. /adm/not–a–file). File names beginning with a slash are assumed to be absolute file names.

Windows whose names begin with – or + conventionally hold diagnostics and other data not directly associated with files. A window labeled +Errors receives all diagnostics produced by acme itself. Diagnostics from commands run by acme appear in a window named directory/+Errors where directory is identified by the context of the command. These error windows are created when needed.

Mouse button 1
Mouse button 1 selects text just as in sam(1) or rio(1), including the usual double–clicking conventions.

Mouse button 2
By an action similar to selecting text with button 1, button 2 indicates text to execute as a command. If the indicated text has multiple white–space–separated words, the first is the command name and the second and subsequent are its arguments. If button 2 is `clicked'--indicates a null string--acme expands the indicated text to find a command to run: if the click is within button–1–selected text, acme takes that selection as the command; otherwise it takes the largest string of valid file name characters containing the click. Valid file name characters are alphanumerics and _ . – + /. This behavior is similar to double–clicking with button 1 but, because a null command is meaningless, only a single click is required.

Some commands, all by convention starting with a capital letter, are built–ins that are executed directly by acme:
Cut   Delete most recently selected text and place in snarf buffer.
Del   Delete window. If window is dirty, instead print a warning; a second Del will succeed.
Delete column and all its windows, after checking that windows are not dirty.
Delete window without checking for dirtiness.
DumpWrite the state of acme to the file name, if specified, or $home/acme.dump by default.
EditTreat the argument as a text editing command in the style of sam(1). The full Sam language is implemented except for the commands k, n, q, and !. The = command is slightly different: it includes the file name and gives only the line address unless the command is explicitly =#. The `current window' for the
command is the body of the window in which the Edit command is executed. Usually the Edit command would be typed in a tag; longer commands may be prepared in a scratch window and executed, with Edit itself in the current window, using the 2–1 chord described below.
ExitExit acme after checking that windows are not dirty.
FontWith no arguments, change the font of the associated window from fixed–spaced to proportional–spaced or vice versa. Given a file name argument, change the font of the window to that stored in the named file. If the file name argument is prefixed by var (fix), also set the default proportional–spaced
(fixed–spaced) font for future use to that font. Other existing windows are unaffected.
Get   Load file into window, replacing previous contents (after checking for dirtiness as in Del). With no argument, use the existing file name of the window. Given an argument, use that file but do not change the window's file name.
ID    Print window ID number (q.v.).
InclWhen opening `include' files (those enclosed in <>) with button 3, acme searches in directories /$objtype/include and /sys/include. Incl adds its arguments to a supplementary list of include directories, analogous to the –I option to the compilers. This list is per–window and is inherited when
windows are created by actions in that window, so Incl is most usefully applied to a directory containing relevant source. With no arguments, Incl prints the supplementary list. This command is largely superseded by plumbing (see plumb(6)).
Set the autoindent mode according to the argument: on and off set the mode for the current window; ON and OFF set the mode for all existing and future windows.
KillSend a kill note to acme–initiated commands named as arguments.
LoadRestore the state of acme from a file (default $home/acme.dump) created by the Dump command.
When prefixed to a command run the command in the same file name space and environment variable group as acme. The environment of the command is restricted but is sufficient to run bind(1), 9fs (see srv(4)), import(4), etc., and to set environment variables such as $objtype.
LookSearch in body for occurrence of literal text indicated by the argument or, if none is given, by the selected text in the body.
New   Make new window. With arguments, load the named files into windows.
Make new column.
Replace most recently selected text with contents of snarf buffer.
Put   Write window to the named file. With no argument, write to the file named in the tag of the window.
Write all dirty windows whose names indicate existing regular files.
RedoComplement of Undo.
SendAppend selected text or snarf buffer to end of body; used mainly with win.
Place selected text in snarf buffer.
SortArrange the windows in the column from top to bottom in lexicographical order based on their names.
Tab   Set the width of tab stops for this window to the value of the argument, in units of widths of the zero character. With no arguments, it prints the current value.
UndoUndo last textual change or set of changes.
Create a copy of the window containing most recently selected text.
|>   If a regular shell command is preceded by a <, |, or > character, the selected text in the body of the window is affected by the I/O from the command. The < character causes the selection to be replaced by the standard output of the command; > causes the selection to be sent as standard input to the
command; and | does both at once, `piping' the selection through the command and replacing it with the output.

A common place to store text for commands is in the tag; in fact acme maintains a set of commands appropriate to the state of the window to the left of the bar in the tag.

If the text indicated with button 2 is not a recognized built–in, it is executed as a shell command. For example, indicating date with button 2 runs date(1). The standard and error outputs of commands are sent to the error window associated with the directory from which the command was run, which will be created if necessary. For example, in a window /adm/users executing pwd will produce the output /adm in a (possibly newly–created) window labeled /adm/+Errors; in a window containing /sys/src/cmd/sam/sam.c executing mk will run mk(1) in /sys/src/cmd/sam, producing output in a window labeled /sys/src/cmd/sam/+Errors. The environment of such commands contains the variable $% with value set to the filename of the window in which the command is run, and $winid set to the window's id number (see acme(4)).

Mouse button 3
Pointing at text with button 3 instructs acme to locate or acquire the file, string, etc. described by the indicated text and its context. This description follows the actions taken when button 3 is released after sweeping out some text. In the description, text refers to the text of the original sweep or, if it was null, the result of applying the same expansion rules that apply to button 2 actions.

If the text names an existing window, acme moves the mouse cursor to the selected text in the body of that window. If the text names an existing file with no associated window, acme loads the file into a new window and moves the mouse there. If the text is a file name contained in angle brackets, acme loads the indicated include file from the directory appropriate to the suffix of the file name of the window holding the text. (The Incl command adds directories to the standard list.)

If the text begins with a colon, it is taken to be an address, in the style of sam(1), within the body of the window containing the text. The address is evaluated, the resulting text highlighted, and the mouse moved to it. Thus, in acme, one must type :/regexp or :127 not just /regexp or 127. (There is an easier way to locate literal text; see below.)

If the text is a file name followed by a colon and an address, acme loads the file and evaluates the address. For example, clicking button 3 anywhere in the text file.c:27 will open file.c, select line 27, and put the mouse at the beginning of the line. The rules about Error files, directories, and so on all combine to make this an efficient way to investigate errors from compilers, etc.

If the text is not an address or file, it is taken to be literal text, which is then searched for in the body of the window in which button 3 was clicked. If a match is found, it is selected and the mouse is moved there. Thus, to search for occurrences of a word in a file, just click button 3 on the word. Because of the rule of using the selection as the button 3 action, subsequent clicks will find subsequent occurrences without moving the mouse.

In all these actions, the mouse motion is not done if the text is a null string within a non–null selected string in the tag, so that (for example) complex regular expressions may be selected and applied repeatedly to the body by just clicking button 3 over them.

Chords of mouse buttons
Several operations are bound to multiple–button actions. After selecting text, with button 1 still down, pressing button 2 executes Cut and button 3 executes Paste. After clicking one button, the other undoes the first; thus (while holding down button 1) 2 followed by 3 is a Snarf that leaves the file undirtied; 3 followed by 2 is a no–op. These actions also apply to text selected by double–clicking because the double–click expansion is made when the second click starts, not when it ends.

Commands may be given extra arguments by a mouse chord with buttons 2 and 1. While holding down button 2 on text to be executed as a command, clicking button 1 appends the text last pointed to by button 1 as a distinct final argument. For example, to search for literal text one may execute Look text with button 2 or instead point at text with button 1 in any window, release button 1, then execute Look, clicking button 1 while 2 is held down.

When an external command (e.g. echo(1)) is executed this way, the extra argument is passed as expected and an environment variable $acmeaddr is created that holds, in the form interpreted by button 3, the fully–qualified address of the extra argument.

Support programs
Win creates a new acme window and runs a command (default /bin/rc) in it, turning the window into something analogous to an rio(1) window. Executing text in a win window with button 2 is similar to using Send.

Awd loads the tag line of its window with the directory in which it's running, suffixed –label (default rc); it is intended to be executed by a cd function for use in win windows. An example definition is
fn cd { builtin cd $1 && awd $sysname }

Applications and guide files
In the directory /acme live several subdirectories, each corresponding to a program or set of related programs that employ acme's user interface. Each subdirectory includes source, binaries, and a readme file for further information. It also includes a guide, a text file holding sample commands to invoke the programs. The idea is to find an example in the guide that best matches the job at hand, edit it to suit, and execute it.

Whenever a command is executed by acme, the default search path includes the directory of the window containing the command and its subdirectory $cputype. The program directories in /acme contain appropriately labeled subdirectories of binaries, so commands named in the guide files will be found automatically when run. Also, acme binds the directories /acme/bin and /acme/bin/$cputype to the beginning of /bin when it starts; this is where acme–specific programs such as win and awd reside.

$home/acme.dump   default file for Dump and Load; also where state is written if acme dies or is killed unexpectedly, e.g. by deleting its window.
/acme/*/guide     template files for applications
/acme/*/readme    informal documentation for applications
/acme/*/src       source for applications
/acme/*/mips      MIPS–specific binaries for applications


Rob Pike, Acme: A User Interface for Programmers.

With the –l option or Load command, the recreation of windows under control of external programs such as win is just to rerun the command; information may be lost.
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