Nirvana Editor (NEdit) Help Documentation

Table of Contents

    Getting Started                    

    Basic Operation                     Macro/Shell Extensions
      Selecting Text                      Shell Commands and Filters
      Finding and Replacing Text          Learn/Replay
      Cut and Paste                       Macro Language
      Using the Mouse                     Macro Subroutines
      Keyboard Shortcuts                  Action Routines
      Shifting and Filling
      File Format
                                        Customizing
    Features for Programming              Customizing NEdit
      Programming with NEdit              Preferences
      Tabs/Emulated Tabs                  X Resources
      Auto/Smart Indent                   Key Binding
      Syntax Highlighting                 Highlighting Patterns
      Finding Declarations (ctags)        Smart Indent Macros

    Regular Expressions                 NEdit Command Line
      Basic Regular Expression Syntax   Client/Server Mode
      Metacharacters                    Crash Recovery
      Parenthetical Constructs          Version
      Advanced Topics                   Distribution Policy
      Example Regular Expressions       Mailing Lists
                                        Problems/Defects

Getting Started

• Selecting Text
• Finding and Replacing Text
• Cut and Paste
• Using the Mouse
• Keyboard Shortcuts
• Shifting and Filling

Programmers should also read the introductory section under the "Features for Programming" section:

      Programming with NEdit

If you get into trouble, the Undo command in the Edit menu can reverse any modifications that you make. NEdit does not change the file you are editing until you tell it to Save.

Editing an Existing File

To open an existing file, choose Open... from the file menu. Select the file that you want to open in the pop-up dialog that appears and click on OK. You may open any number of files at the same time. Each file will appear in its own editor window. Using Open... rather than re-typing the NEdit command and running additional copies of NEdit, will give you quick access to all of the files you have open via the Windows menu, and ensure that you don't accidentally open the same file twice. NEdit has no "main" window. It remains running as long as at least one editor window is open.

Creating a New File

If you already have an empty (Untitled) window displayed, just begin typing in the window. To create a new Untitled window, choose New from the File menu. To give the file a name and save its contents to the disk, choose Save or Save As... from the File menu.

Backup Files

NEdit maintains periodic backups of the file you are editing so that you can recover the file in the event of a problem such as a system crash, network failure, or X server crash. These files are saved under the name `~filename` (on Unix) or `_filename` (on VMS), where filename is the name of the file you were editing. If an NEdit process is killed, some of these backup files may remain in your directory. (To remove one of these files on Unix, you may have to prefix the `~' (tilde) character with a (backslash) to prevent the shell from interpreting it as a special character.)

Shortcuts

As you become more familiar with NEdit, substitute the control and function keys shown on the right side of the menus for pulling down menus with the mouse.

Dialogs are also streamlined so you can enter information quickly and without using the mouse*. To move the keyboard focus around a dialog, use the tab and arrow keys. One of the buttons in a dialog is usually drawn with a thick, indented, outline. This button can be activated by pressing Return or Enter. The Cancel or Dismiss button can be activated by pressing escape. For example, to replace the string "thing" with "things" type:

      <ctrl-r>thing<tab>things<return>

To open a file named "whole_earth.c", type:

      <ctrl-o>who<return>

(how much of the filename you need to type depends on the other files in the directory). See the section called "Keyboard Shortcuts" for more details.

* Users who have set their keyboard focus mode to "pointer" should set "Popups Under Pointer" in the Default Settings menu to avoid the additional step of moving the mouse into the dialog.

Basic Operation

Selecting Text

To select a rectangle or column of text, hold the Ctrl key while dragging the mouse. Rectangular selections can be used in any context that normal selections can be used, including cutting and pasting, filling, shifting, dragging, and searching. Operations on rectangular selections automatically fill in tabs and spaces to maintain alignment of text within and to the right of the selection. Note that the interpretation of rectangular selections by Fill Paragraph is slightly different from that of other commands, the section titled "Shifting and Filling" has details.

The middle mouse button can be used to make an additional selection (called the secondary selection). As soon as the button is released, the contents of this selection will be copied to the insert position of the window where the mouse was last clicked (the destination window). This position is marked by a caret shaped cursor when the mouse is outside of the destination window. If there is a (primary) selection, adjacent to the cursor in the window, the new text will replace the selected text. Holding the shift key while making the secondary selection will move the text, deleting it at the site of the secondary selection, rather than copying it.

Selected text can also be dragged to a new location in the file using the middle mouse button. Holding the shift key while dragging the text will copy the selected text, leaving the original text in place. Holding the control key will drag the text in overlay mode.

Normally, dragging moves text by removing it from the selected position at the start of the drag, and inserting it at a new position relative to to the mouse. Dragging a block of text over existing characters, displaces the characters to the end of the selection. In overlay mode, characters which are occluded by blocks of text being dragged are simply removed. When dragging non-rectangular selections, overlay mode also converts the selection to rectangular form, allowing it to be dragged outside of the bounds of the existing text.

The section "Using the Mouse" sumarizes the mouse commands for making primary and secondary selections. Primary selections can also be made via keyboard commands, see "Keyboard Shortcuts".

Finding and Replacing Text

Find Selection searches for the text contained in the current primary selection (see Selecting Text). The selected text does not have to be in the current editor window, it may even be in another program. For example, if the word dog appears somewhere in a window on your screen, and you want to find it in the file you are editing, select the word dog by dragging the mouse across it, switch to your NEdit window and choose Find Selection from the Search menu.

Find Incremental is yet another variation on searching, where every character typed triggers a new search. Incremental searching is generally the quickest way to find something in a file, because it gives you the immediate feedback of seeing how your search is progressing, so you never need to type more than the minimally sufficient search string to reach your target.

Searching Backwards

Holding down the shift key while choosing any of the search or replace commands from the menu (or using the keyboard shortcut), will search in the reverse direction. Users who have set the search direction using the buttons in the search dialog, may find it a bit confusing that Find Again and Replace Again don't continue in the same direction as the original search (for experienced users, consistency of the direction implied by the shift key is more important).

Selective Replacement

To replace only some occurrences of a string within a file, choose Replace... from the Search menu, enter the string to search for and the string to substitute, and finish by pressing the Find button. When the first occurrence is highlighted, use either Replace Again (^T) to replace it, or Find Again (^G) to move to the next occurrence without replacing it, and continue in such a manner through all occurrences of interest.

To replace all occurrences of a string within some range of text, select the range (see Selecting Text), choose Replace... from the Search menu, type the string to search for and the string to substitute, and press the "R. in Selection" button in the dialog. Note that selecting text in the Replace... dialog will unselect the text in the window.

Cut and Paste

The easiest way to copy and move text around in your file or between windows, is to use the clipboard, an imaginary area that temporarily stores text and data. The Cut command removes the selected text (see Selecting Text) from your file and places it in the clipboard. Once text is in the clipboard, the Paste command will copy it to the insert position in the current window. For example, to move some text from one place to another, select it by dragging the mouse over it, choose Cut to remove it, click the pointer to move the insert point where you want the text inserted, then choose Paste to insert it. Copy copies text to the clipboard without deleting it from your file. You can also use the clipboard to transfer text to and from other Motif programs and X programs which make proper use of the clipboard.

There are many other methods for copying and moving text within NEdit windows and between NEdit and other programs. The most common such method is clicking the middle mouse button to copy the primary selection (to the clicked position). Copying the selection by clicking the middle mouse button in many cases is the only way to transfer data to and from many X programs. Holding the Shift key while clicking the middle mouse button moves the text, deleting it from its original position, rather than copying it. Other methods for transferring text include secondary selections, primary selection dragging, keyboard-based selection copying, and drag and drop. These are described in detail in the sections: "Selecting Text", "Using the Mouse", and "Keyboard Shortcuts".

Using the Mouse

This section will make more sense if you also read the section called, "Selecting Text", which explains the terminology of selections, that is, what is meant by primary, secondary, rectangular, etc.

Button and Modifier Key Summary

General meaning of mouse buttons and modifier keys:

Buttons

      Button 1 (left)    Cursor position and primary selection

      Button 2 (middle)  Secondary selections, and dragging and
                         copying the primary selection

      Button 3 (right)   Quick-access programmable menu and pan
                         scrolling

Modifier keys

      Shift   On primary selections, (left mouse button):
                 Extends selection to the mouse pointer
              On secondary and copy operations, (middle):
                 Toggles between move and copy

      Ctrl    Makes selection rectangular or insertion
              columnar

      Alt*    (on release) Exchange primary and secondary
              selections.

Left Mouse Button

The left mouse button is used to position the cursor and to make primary selections.

    Click         Moves the cursor

    Double Click  Selects a whole word

    Triple Click  Selects a whole line

    Quad Click    Selects the whole file

    Shift Click   Adjusts (extends or shrinks) the
                  selection, or if there is no existing
                  selection, begins a new selection
                  between the cursor and the mouse.

    Ctrl+Shift+   Adjusts (extends or shrinks) the
    Click         selection rectangularly.

    Drag          Selects text between where the mouse
                  was pressed and where it was released.

    Ctrl+Drag     Selects rectangle between where the
                  mouse was pressed and where it was
                  released.

Right Mouse Button

The right mouse button posts a programmable menu for frequently used commands.

    Click/Drag    Pops up the background menu (programmed
                  from Preferences -> Default Settings ->
                  Customize Menus -> Window Background).

    Ctrl+Drag     Pan scrolling.  Scrolls the window
                  both vertically and horizontally, as if
                  you had grabbed it with your mouse.

Middle Mouse Button

The middle mouse button is for making secondary selections, and copying and dragging the primary selection.

    Click         Copies the primary selection to the
                  clicked position.

    Shift+Click   Moves the primary selection to the
                  clicked position, deleting it from its
                  original position.

    Drag          1) Outside of the primary selection:
                      Begins a secondary selection.
                  2) Inside of the primary selection:
                      Moves the selection by dragging.

    Ctrl+Drag     1) Outside of the primary selection:
                      Begins a rectangular secondary
                      selection.
                  2) Inside of the primary selection:
                      Drags the selection in overlay
                      mode (see below).

When the mouse button is released after creating a secondary selection:

    No Modifiers  If there is a primary selection,
                  replaces it with the secondary
                  selection.  Otherwise, inserts the
                  secondary selection at the cursor
                  position.

    Shift         Move the secondary selection, deleting
                  it from its original position.  If
                  there is a primary selection, the move
                  will replace the primary selection
                  with the secondary selection.
                  Otherwise, moves the secondary
                  selection to to the cursor position.

    Alt*          Exchange the primary and secondary
                  selections.

While moving the primary selection by dragging with the middle mouse button:

    Shift         Leaves a copy of the original
                  selection in place rather than
                  removing it or blanking the area.

    Ctrl          Changes from insert mode to overlay
                  mode (see below).

    Escape        Cancels drag in progress.

Overlay Mode: Normally, dragging moves text by removing it from the selected position at the start of the drag, and inserting it at a new position relative to to the mouse. When you drag a block of text over existing characters, the existing characters are displaced to the end of the selection. In overlay mode, characters which are occluded by blocks of text being dragged are simply removed. When dragging non-rectangular selections, overlay mode also converts the selection to rectangular form, allowing it to be dragged outside of the bounds of the existing text.

Mouse buttons 4 and 5 are usually represented by a mouse wheel nowadays. They are used to scroll up or down in the text window.

* The Alt key may be labeled Meta or Compose-Character on some keyboards. Some window managers, including default configurations of mwm, bind combinations of the Alt key and mouse buttons to window manager operations. In NEdit, Alt is only used on button release, so regardless of the window manager bindings for Alt-modified mouse buttons, you can still do the corresponding NEdit operation by using the Alt key AFTER the initial mouse press, so that Alt is held while you release the mouse button. If you find this difficult or annoying, you can re-configure most window managers to skip this binding, or you can re-configure NEdit to use a different key combination.

Keyboard Shortcuts

Under X and Motif, there are several levels of translation between keyboard keys and the actions they perform in a program. The "Customizing NEdit", and "X Resources" sections of the Help menu have more information on this subject. Because of all of this configurability, and since keyboards and standards for the meaning of some keys vary from machine to machine, the mappings may be changed from the defaults listed below.

Modifier Keys (in general)

    Ctrl   Extends the scope of the action that the key
           would otherwise perform.  For example, Home
           normally moves the insert cursor to the beginning
           of a line. Ctrl+Home moves it to the beginning of
           the file.  Backspace deletes one character, Ctrl+
           Backspace deletes one word.

    Shift  Extends the selection to the cursor position. If
           there's no selection, begins one between the old
           and new cursor positions.

    Alt    When modifying a selection, makes the selection
           rectangular.

(For the effects of modifier keys on mouse button presses, see the section titled "Using the Mouse")

All Keyboards

    Escape        Cancels operation in progress: menu
                  selection, drag, selection, etc.  Also
                  equivalent to cancel button in dialogs.

    Backspace     Delete the character before the cursor

    Ctrl+BS       Delete the word before the cursor

    Arrows --

      Left        Move the cursor to the left one character

      Ctrl+Left   Move the cursor backward one word
                  (Word delimiters are settable, see
                  "Customizing NEdit", and "X Resources")

      Right       Move the cursor to the right one character

      Ctrl+Right  Move the cursor forward one word

      Up          Move the cursor up one line

      Ctrl+Up     Move the cursor up one paragraph.
                  (Paragraphs are delimited by blank lines)

      Down        Move the cursor down one line.

      Ctrl+Down   Move the cursor down one paragraph.

    Ctrl+Return   Return with automatic indent, regardless
                  of the setting of Auto Indent.

    Shift+Return  Return without automatic indent,
                  regardless of the setting of Auto Indent.

    Ctrl+Tab      Insert an ASCII tab character, without
                  processing emulated tabs.

    Alt+Ctrl+<c>  Insert the control-code equivalent of
                  a key <c>

    Ctrl+/        Select everything (same as Select
                  All menu item or ^A)

    Ctrl+\        Unselect

    Ctrl+U        Delete to start of line

PC Standard Keyboard

    Ctrl+Insert   Copy the primary selection to the
                  clipboard (same as Copy menu item or ^C)
                  for compatibility with Motif standard key
                  binding
    Shift+Ctrl+
    Insert        Copy the primary selection to the cursor
                  location.

    Delete        Delete the character before the cursor.
                  (Can be configured to delete the character
                  after the cursor, see "Customizing NEdit",
                  and "X Resources")

    Ctrl+Delete   Delete to end of line.

    Shift+Delete  Cut, remove the currently selected text
                  and place it in the clipboard. (same as
                  Cut menu item or ^X) for compatibility
                  with Motif standard key binding
    Shift+Ctrl+
    Delete        Cut the primary selection to the cursor
                  location.

    Home          Move the cursor to the beginning of the
                  line

    Ctrl+Home     Move the cursor to the beginning of the
                  file

    End           Move the cursor to the end of the line

    Ctrl+End      Move the cursor to the end of the file

    PageUp        Scroll and move the cursor up by one page.

    Ctrl+PageUp   Scroll and move the cursor left by one
                  page.
    PageDown      Scroll and move the cursor down by one
                  page.

    Ctrl+PageDown Scroll and move the cursor right by one
                  page.

    F10           Make the menu bar active for keyboard
                  input (Arrow Keys, Return, Escape,
                  and the Space Bar)

Specialty Keyboards

On machines with different styles of keyboards, generally, text editing actions are properly matched to the labeled keys, such as Remove, Next-screen, etc.. If you prefer different key bindings, see the section titled "Key Binding" under the Customizing heading in the Help menu.

Shifting and Filling

File Format

Features for Programming

Programming with NEdit

Though general in appearance, NEdit has many features intended specifically for programmers. Major programming-related topics are listed in separate sections under the heading: "Features for Programming": Syntax Highlighting, Tabs/Emulated Tabs, Finding Declarations (ctags), and Auto/Smart Indent. Minor topics related to programming are discussed below:

Language Modes

When NEdit initially reads a file, it attempts to determine whether the file is in one of the computer languages that it knows about. Knowing what language a file is written in allows NEdit to assign highlight patterns and smart indent macros, and to set language specific preferences like word delimiters, tab emulation, and auto-indent. Language mode can be recognized from both the file name and from the first 200 characters of content. Language mode recognition and language-specific preferences are configured in: Preferences -> Default Settings -> Language Modes....

You can set the language mode manually for a window, by selecting it from the menu: Preferences -> Language Modes.

Line Numbers

To find a particular line in a source file by line number, choose Goto Line #... from the Search menu. You can also directly select the line number text in the compiler message in the terminal emulator window (xterm, decterm, winterm, etc.) where you ran the compiler, and choose Goto Selected from the Search menu.

To find out the line number of a particular line in your file, turn on Statistics Line in the Preferences menu and position the insertion point anywhere on the line. The statistics line continuously updates the line number of the line containing the cursor.

Matching Parentheses

To help you inspect nested parentheses, brackets, braces, quotes, and other characters, NEdit has both an automatic parenthesis matching mode, and a Goto Matching command. Automatic parenthesis matching is activated when you type, or move the insertion cursor after a parenthesis, bracket, or brace. It momentarily highlights either the opposite character ('Delimiter') or the entire expression ('Range') when the opposite character is visible in the window. To find a matching character anywhere in the file, select it or position the cursor after it, and choose Goto Matching from the Search menu. If the character matches itself, such as a quote or slash, select the first character of the pair. NEdit will match {, (, [, <, ", ', `, /, and \. Holding the Shift key while typing the accelerator key (Shift+Ctrl+M, by default), will select all of the text between the matching characters.

When syntax highlighting is enabled, the matching routines can optionally make use of the syntax information for improved accuracy. In that case, a brace inside a highlighted string will not match a brace inside a comment, for instance.

Opening Included Files

The Open Selected command in the File menu understands the C preprocessor's #include syntax, so selecting an #include line and invoking Open Selected will generally find the file referred to, unless doing so depends on the settings of compiler switches or other information not available to NEdit.

Interface to Programming Tools

Integrated software development environments such as SGI's CaseVision and Centerline Software's Code Center, can be interfaced directly with NEdit via the client server interface. These tools allow you to click directly on compiler and runtime error messages and request NEdit to open files, and select lines of interest. The easiest method is usually to use the tool's interface for character-based editors like vi, to invoke nc, but programmatic interfaces can also be derived using the source code for nc.

There are also some simple compile/review, grep, ctree, and ctags browsers available in the NEdit contrib directory on ftp.nedit.org.

Tabs/Emulated Tabs

Auto/Smart Indent

Syntax Highlighting

If no highlighting patterns are available for the language that you want to use, you can create new patterns relatively quickly. The Help section "Highlighting Patterns" under "Customizing", has details.

If you are satisfied with what NEdit is highlighting, but would like it to use different colors or fonts, you can change these by selecting Preferences -> Default Settings -> Syntax Highlighting -> Text Drawing Styles. Highlighting patterns are connected with font and color information through a common set of styles so that colorings defined for one language will be similar across others, and patterns within the same language which are meant to appear identical can be changed in the same place. To understand which styles are used to highlight the language you are interested in, you may need to look at "Highlighting Patterns" section, as well.

Syntax highlighting is CPU intensive, and under some circumstances can affect NEdit's responsiveness. If you have a particularly slow system, or work with very large files, you may not want to use it all of the time. Syntax highlighting introduces two kinds of delays. The first is an initial parsing delay, proportional to the size of the file. This delay is also incurred when pasting large sections of text, filtering text through shell commands, and other circumstances involving changes to large amounts of text. The second kind of delay happens when text which has not previously been visible is scrolled in to view. Depending on your system, and the highlight patterns you are using, this may or may not be noticeable. A typing delay is also possible, but unlikely if you are only using the built-in patterns.

Finding Declarations (ctags)

NEdit can process tags files generated using the Unix ctags command or the Exuberant Ctags program. Ctags creates index files correlating names of functions and declarations with their locations in C, Fortran, or Pascal source code files. (See the ctags manual page for more information). Ctags produces a file called "tags" which can be loaded by NEdit. NEdit can manage any number of tags files simultaneously. Tag collisions are handled with a popup menu to let the user decide which tag to use. In 'Smart' mode NEdit will automatically choose the desired tag based on the scope of the file or module. Once loaded, the information in the tags file enables NEdit to go directly to the declaration of a highlighted function or data structure name with a single command. To load a tags file, select "Load Tags File" from the File menu and choose a tags file to load, or specify the name of the tags file on the NEdit command line:

      nedit -tags tags

NEdit can also be set to load a tags file automatically when it starts up. Setting the X resource nedit.tagFile to the name of a tag file tells NEdit to look for that file at startup time (see "Customizing NEdit"). The file name can be either a complete path name, in which case NEdit will always load the same tags file, or a file name without a path or with a relative path, in which case NEdit will load it starting from the current directory. The second option allows you to have different tags files for different projects, each automatically loaded depending on the directory you're in when you start NEdit. Setting the name to "tags" is an obvious choice since this is the name that ctags uses. NEdit normally evaluates relative path tag file specifications every time a file is opened. All accessible tag files are loaded at this time. To disable the automatic loading of tag files specified as relative paths, set the X resource nedit.alwaysCheckRelativeTagsSpecs to False.

To unload a tags file, select "Un-load Tags File" from the File menu and choose from the list of tags files. NEdit will keep track of tags file updates by checking the timestamp on the files, and automatically update the tags cache.

To find the definition of a function or data structure once a tags file is loaded, select the name anywhere it appears in your program (see "Selecting Text") and choose "Find Definition" from the Search menu.

Regular Expressions

Basic Regular Expression Syntax

A regex can also be organized into a list of alternatives by separating each alternative with pipe characters, `|'. This is called alternation. A match will be attempted for each alternative listed, in the order specified, until a match results or the list of alternatives is exhausted (see Alternation section below.)

The 'Any' Character

If a dot (`.') appears in a regex, it means to match any character exactly once. By default, dot will not match a newline character, but this behavior can be changed (see help topic Parenthetical Constructs, under the heading, Matching Newlines).

Character Classes

A character class, or range, matches exactly one character of text, but the candidates for matching are limited to those specified by the class. Classes come in two flavors as described below:

     [...]   Regular class, match only characters listed.
     [^...]  Negated class, match only characters NOT listed.

As with the dot token, by default negated character classes do not match newline, but can be made to do so.

The characters that are considered special within a class specification are different than the rest of regex syntax as follows. If the first character in a class is the `]' character (second character if the first character is `^') it is a literal character and part of the class character set. This also applies if the first or last character is `-'. Outside of these rules, two characters separated by `-' form a character range which includes all the characters between the two characters as well. For example, `[^f-j]' is the same as `[^fghij]' and means to match any character that is not `f', `g', `h', `i', or `j'.

Anchors

Anchors are assertions that you are at a very specific position within the search text. NEdit regular expressions support the following anchor tokens:

     ^    Beginning of line
     $    End of line
     <    Left word boundary
     >    Right word boundary
     \B   Not a word boundary

Note that the \B token ensures that the left and right characters are both delimiter characters, or that both left and right characters are non-delimiter characters. Currently word anchors check only one character, e.g. the left word anchor `<' only asserts that the left character is a word delimiter character. Similarly the right word anchor checks the right character.

Quantifiers

Quantifiers specify how many times the previous regular expression atom may be matched in the search text. Some quantifiers can produce a large performance penalty, and can in some instances completely lock up NEdit. To prevent this, avoid nested quantifiers, especially those of the maximal matching type (see below.)

The following quantifiers are maximal matching, or "greedy", in that they match as much text as possible.

     *   Match zero or more
     +   Match one  or more
     ?   Match zero or one

The following quantifiers are minimal matching, or "lazy", in that they match as little text as possible.

     *?   Match zero or more
     +?   Match one  or more
     ??   Match zero or one

One final quantifier is the counting quantifier, or brace quantifier. It takes the following basic form:

     {min,max}  Match from `min' to `max' times the
                previous regular expression atom.

If `min' is omitted, it is assumed to be zero. If `max' is omitted, it is assumed to be infinity. Whether specified or assumed, `min' must be less than or equal to `max'. Note that both `min' and `max' are limited to 65535. If both are omitted, then the construct is the same as `*'. Note that `{,}' and `{}' are both valid brace constructs. A single number appearing without a comma, e.g. `{3}' is short for the `{min,min}' construct, or to match exactly `min' number of times.

The quantifiers `{1}' and `{1,1}' are accepted by the syntax, but are optimized away since they mean to match exactly once, which is redundant information. Also, for efficiency, certain combinations of `min' and `max' are converted to either `*', `+', or `?' as follows:

     {} {,} {0,}    *
     {1,}           +
     {,1} {0,1}     ?

Note that {0} and {0,0} are meaningless and will generate an error message at regular expression compile time.

Brace quantifiers can also be "lazy". For example {2,5}? would try to match 2 times if possible, and will only match 3, 4, or 5 times if that is what is necessary to achieve an overall match.

Alternation

A series of alternative patterns to match can be specified by separating them with vertical pipes, `|'. An example of alternation would be `a|be|sea'. This will match `a', or `be', or `sea'. Each alternative can be an arbitrarily complex regular expression. The alternatives are attempted in the order specified. An empty alternative can be specified if desired, e.g. `a|b|'. Since an empty alternative can match nothingness (the empty string), this guarantees that the expression will match.

Comments

Metacharacters

     \(  \)  \-  \[  \]  \<  \>  \{  \}
     \.  \|  \^  \$  \*  \+  \?  \&  \\

     \a  alert (bell)
     \b  backspace
     \e  ASCII escape character (***)
     \f  form feed (new page)
     \n  newline
     \r  carriage return
     \t  horizontal tab
     \v  vertical tab

     *** For environments that use the EBCDIC character set,
         when compiling NEdit set the EBCDIC_CHARSET compiler
         symbol to get the EBCDIC equivalent escape
         character.)

   \d  digits            0-9
   \l  letters           a-z, A-Z, and locale dependent letters
   \s  whitespace        \t, \r, \v, \f, and space
   \w  word characters   letters, digits, and underscore, `_'

     \y   Word delimiter character
     \Y   Not a word delimiter character

Parenthetical Constructs

     (?i<regex>)   Case insensitive; `AbcD' and `aBCd' are
                   equivalent.

     (?I<regex>)   Case sensitive;   `AbcD' and `aBCd' are
                   different.

     `\d', `\D', `\l', `\L', `\s', `\S', `\w', `\W', `\Y'

     (?n<regex>)  `.', `[^...]', `\s', `\S' match newlines

     (?N<regex>)  `.', `[^...]', `\s', `\S' don't match
                                            newlines

Advanced Topics

     Search string:   `get_x *\( *([^ ,]*), *([^\)]*)\)'
     Replace string:  `new_get_x(\2, \1, NULL)'

          "Mastering Regular Expressions"
          Jeffrey E. F. Friedl
          (c) 1997, O'Reilly & Associates
          ISBN 1-56592-257-3

Example Regular Expressions

        ^.*$
 

        ^$
 

        \s+
 

        (?n\s+)
 

        (?n\s*?\n\s*)
 

        (?:\d{1,3}(?:\.\d{1,3}){3})
 

        [ACDF-IK-PR-W][A-Z]
 

        (?:http://)?www\.\S+
 

        (?i(?n<(\S+)\s+\1>))
 

        <[A-Z][^a-z\s]*>

Macro/Shell Extensions

Shell Commands and Filters

The X resource called nedit.shell (See "Customizing NEdit") determines which Unix shell is used to execute commands. The default value for this resource is /bin/csh.

Learn/Replay

Macro Language

NEdit's macro language is a simple interpreter with integer arithmetic, dynamic strings, and C-style looping constructs (very similar to the procedural portion of the Unix awk program). From the macro language, you can call the same action routines which are bound to keyboard keys and menu items, as well additional subroutines for accessing and manipulating editor data, which are specific to the macro language (these are listed in the sections titled "Macro Subroutines", and "Action Routines").

Syntax

An NEdit macro language program consists of a list of statements, each terminated by a newline. Groups of statements which are executed together conditionally, such as the body of a loop, are surrounded by curly braces "{}".

Blank lines and comments are also allowed. Comments begin with a "#" and end with a newline, and can appear either on a line by themselves, or at the end of a statement.

Statements which are too long to fit on a single line may be split across several lines, by placing a backslash "\" character at the end of each line to be continued.

Data Types

The NEdit macro language recognizes only three data types, dynamic character strings, integer values and associative arrays. In general strings and integers can be used interchangeably. If a string represents an integer value, it can be used as an integer. Integers can be compared and concatenated with strings. Arrays may contain integers, strings, or arrays. Arrays are stored key/value pairs. Keys are always stored as strings.

Integer Constants

Integers are non-fractional numbers in the range of -2147483647 to 2147483647. Integer constants must be in decimal. For example:

    a = -1
    b = 1000

Character String Constants

Character string constants are enclosed in double quotes. For example:

     a = "a string"
     dialog("Hi there!", "Dismiss")

Strings may also include C-language style escape sequences:

     \\ Backslash     \t Tab              \f Form feed
     \" Double quote  \b Backspace        \a Alert
     \n Newline       \r Carriage return  \v Vertical tab

For example, to send output to the terminal from which NEdit was started, a newline character is necessary because, like printf, t_print requires explicit newlines, and also buffers its output on a per-line basis:

     t_print("a = " a "\n")

Variables

Variable names must begin either with a letter (local variables), or a $ (global variables). Beyond the first character, variables may also contain numbers and underscores `_'. Variables are called in to existence just by setting them (no explicit declarations are necessary).

Local variables are limited in scope to the subroutine (or menu item definition) in which they appear. Global variables are accessible from all routines, and their values persist beyond the call which created them, until reset.

Built-in Variables

NEdit has a number of permanently defined variables, which are used to access global editor information and information about the the window in which the macro is executing. These are listed along with the built in functions in the section titled "Macro Subroutines".

Functions and Subroutines

The syntax of a function or subroutine call is:

     function_name(arg1, arg2, ...)

where arg1, arg2, etc. represent up to 9 argument values which are passed to the routine being called. A function or subroutine call can be on a line by itself, as above, or if it returns a value, can be invoked within a character or numeric expression:

     a = fn1(b, c) + fn2(d)
     dialog("fn3 says: " fn3())

Arguments are passed by value. This means that you can not return values via the argument list, only through the function value or indirectly through agreed-upon global variables.

Built-in Functions

NEdit has a wide range of built in functions which can be called from the macro language. These routines are divided into two classes, macro-language functions, and editor action routines. Editor action routines are more flexible, in that they may be called either from the macro language, or bound directly to keys via translation tables. They are also limited, however, in that they can not return values. Macro language routines can return values, but can not be bound to keys in translation tables.

Nearly all of the built-in subroutines operate on an implied window, which is initially the window from which the macro was started. To manipulate the contents of other windows, use the focus_window subroutine to change the focus to the ones you wish to modify. focus_window can also be used to iterate over all of the currently open windows, using the special keyword names, "last" and "next".

For backwards compatibility, hyphenated action routine names are allowed, and most of the existing action routines names which contain underscores have an equivalent version containing hyphens ('-') instead of underscores. Use of these names is discouraged. The macro parser resolves the ambiguity between '-' as the subtraction/negation operator, and - as part of an action routine name by assuming subtraction unless the symbol specifically matches an action routine name.

User Defined Functions

Users can define their own macro subroutines, using the define keyword:

     define subroutine_name {
        < body of subroutine >
     }

Macro definitions can not appear within other definitions, or within macro menu item definitions (usually they are found in the .neditmacro file).

The arguments with which a user-defined subroutine or function was invoked, are presented as $1, $2, ... , $9. The number of arguments can be read from $n_args.

To return a value from a subroutine, and/or to exit from the subroutine before the end of the subroutine body, use the return statement:

     return <value to return>

Operators and Expressions

Operators have the same meaning and precedence that they do in C, except for ^, which raises a number to a power (y^x means y to the x power), rather than bitwise exclusive OR. The table below lists operators in decreasing order of precedence.

     Operators                Associativity
     ()
     ^                        right to left
     - ! ++ --                (unary)
     * / %                    left to right
     + -                      left to right
     > >= < <= == !=          left to right
     &                        left to right
     |                        left to right
     &&                       left to right
     ||                       left to right
     (concatenation)          left to right
     = += -= *= /= %=, &= |=  right to left

The order in which operands are evaluated in an expression is undefined, except for && and ||, which like C, evaluate operands left to right, but stop when further evaluation would no longer change the result.

Numerical Operators

The numeric operators supported by the NEdit macro language are listed below:

     + addition
     - subtraction or negation
     * multiplication
     / division
     % modulo
     ^ power
     & bitwise and
     | bitwise or

Increment (++) and decrement (--) operators can also be appended or prepended to variables within an expression. Prepended increment/decrement operators act before the variable is evaluated. Appended increment/decrement operators act after the variable is evaluated.

Logical and Comparison Operators

Logical operations produce a result of 0 (for false) or 1 (for true). In a logical operation, any non-zero value is recognized to mean true. The logical and comparison operators allowed in the NEdit macro language are listed below:

     && logical and
     || logical or
     !  not
     >  greater
     <  less
     >= greater or equal
     <= less or equal
     == equal (integers and/or strings)
     != not equal (integers and/or strings)

Character String Operators

The "operator" for concatenating two strings is the absence of an operator. Adjoining character strings with no operator in between means concatenation:

     d = a b "string" c
     t_print("the value of a is: " a)

Comparison between character strings is done with the == and != operators, (as with integers). There are a number of useful built-in routines for working with character strings, which are listed in the section called "Macro Subroutines".

Arrays and Array Operators

Arrays may contain either strings, integers, or other arrays. Arrays are associative, which means that they relate two pieces of information, the key and the value. The key is always a string; if you use integers they are converted to strings.

To determine if a given key is in an array, use the in keyword.

      if ("6" in x)
          <body>

If the left side of the in keyword is an array, the result is true if every key in the left array is in the right array. Array values are not compared.

To iterate through all the keys of an array use the for looping construct. Keys are not guaranteed in any particular order:

      for (aKey in x)
          <body>

Elements can be removed from an array using the delete command:

      delete x[3] # deletes element with key 3
      delete x[]  # deletes all elements

The number of elements in an array can be determined by referencing the array with no indices:

      dialog("array x has " x[] " elements", "OK")

Arrays can be combined with some operators. All the following operators only compare the keys of the arrays.

      result = x + y   (Merge arrays)

The 'result' is a new array containing keys from both x and y. If duplicates are present values from y are used.

      result = x - y   (Remove keys)

The 'result' is a new array containing all keys from x that are not in y.

      result = x & y   (Common keys)

The 'result' is a new array containing all keys which are in both x and y. The values from y are used.

      result = x | y   (Unique keys)

The 'result' is a new array containing keys which exist in either x or y, but not both.

When duplicate keys are encountered using the + and & operators, the values from the array on the right side of the operators are used for the result. All of the above operators are array only, meaning both the left and right sides of the operator must be arrays. The results are also arrays.

Array keys can also contain multiple dimensions:

      x[1, 1, 1] = "string"

These are used in the expected way, e.g.:

      for (i = 1; i < 3; i++)
      {
          for (j = 1; j < 3; j++)
          {
              x[i, j] = k++
          }
      }

gives the following array:

      x[1, 1] = 0
      x[1, 2] = 1
      x[2, 1] = 2
      x[2, 2] = 3

Internally all indices are part of one string, separated by the string $sub_sep (ASCII 0x18). The first key in the above example is in fact

      ["1" $sub_sep "1"]

If you need to extract one of the keys, you can use split(), using $sub_sep as the separator.

You can also check for the existence of multi-dimensional array by looking for $sub_sep in the key.

Last, you need $sub_sep if you want to use the 'in' keyword.

      if ((1,2) in myArray)
      {..}

doesn't work, but

      if (("1" $sub_sep "2") in myArray)
      {..}

does work.

Looping and Conditionals

NEdit supports looping constructs: for and while, and conditional statements: if and else, with essentially the same syntax as C:

     for (<init>, ...; <condition>; <increment>, ...) <body>

     while (<condition>) <body>

     if (<condition>) <body>

     if (<condition>) <body> else <body>

<body>, as in C, can be a single statement, or a list of statements enclosed in curly braces ({}). <condition> is an expression which must evaluate to true for the statements in <body> to be executed. for loops may also contain initialization statements, <init>, executed once at the beginning of the loop, and increment/decrement statements (or any arbitrary statement), which are executed at the end of the loop, before the condition is evaluated again.

Examples:

    for (i=0; i<100; i++)
       j = i * 2

    for (i=0, j=20; i<20; i++, j--) {
       k = i * j
       t_print(i, j, k)
    }

    while (k > 0)
    {
       k = k - 1
       t_print(k)
    }

    for (;;) {
       if (i-- < 1)
           break
    }

Loops may contain break and continue statements. A break statement causes an exit from the innermost loop, a continue statement transfers control to the end of the loop.

Macro Subroutines

$active_pane

$auto_indent

$cursor

$column

$display_width

$em_tab_dist

$empty_array

$file_format

$file_name

$file_path

$font_name

$font_name_bold

$font_name_bold_italic

$font_name_italic

$highlight_syntax

$incremental_backup

$incremental_search_line

$language_mode

$line

$locked

$make_backup_copy

$max_font_width

$min_font_width

$modified

$n_display_lines

$n_panes

$overtype_mode

$read_only

$selection_start, $selection_end   

$selection_left, $selection_right  

$server_name

$show_line_numbers

$show_matching

$match_syntax_based

$statistics_line

$sub_sep

$tab_dist

$text_length

$top_line

$use_tabs

$wrap_margin

$wrap_text

append_file( string, filename )

beep()

clipboard_to_string()  

dialog( message, btn_1_label, btn_2_label, ... )  

focus_window( window_name )  

get_character( position )  

get_range( start, end )  

get_selection()  

getenv( name )

length( string )

list_dialog( message, text, btn_1_label, btn_2_label, ... )  

max( n1, n2, ... )

min( n1, n2, ... )

read_file( filename )  

replace_in_string( string, search_for, replace_with [, type] )  

replace_range( start, end, string )  

replace_selection( string )  

replace_substring( string, start, end, replace_with )  

search( search_for, start [, search_type, wrap, direction] )  

search_string( string, search_for, start [, search_type, direction] ) 

select( start, end )  

select_rectangle( start, end, left, right )  

set_cursor_pos( position )

shell_command( command, input_string )  

split(string, separation_string [, search_type])

string_dialog( message, btn_1_label, btn_2_label, ... )  

string_compare(string1, string2 [, consider-case])

string_to_clipboard( string )  

substring( string, start, end )  

t_print( string1, string2, ... )  

tolower( string )

toupper( string )

write_file( string, filename )  

Action Routines

All of the editing capabilities of NEdit are represented as a special type of subroutine, called an action routine, which can be invoked from both macros and translation table entries (see "Key Binding" in the Customizing section of the Help menu).

Actions Representing Menu Commands

    File Menu                 Search Menu
    -----------------------   -------------------------
    new()                     find()
    open()                    find_dialog()
    open_dialog()             find_again()
    open_selected()           find_selection()
    close()                   replace()
    save()                    replace_dialog()
    save_as()                 replace_all()
    save_as_dialog()          replace_in_selection()
    revert_to_saved()         replace_again()
    include_file()            goto_line_number()
    include_file_dialog()     goto_line_number_dialog()
    load_macro_file()         goto_selected()
    load_macro_file_dialog()  mark()
    load_tags_file()          mark_dialog()
    load_tags_file_dialog()   goto_mark()
    unload_tags_file()        goto_mark_dialog()
    print()                   goto_matching()
    print_selection()         select_to_matching()
    exit()                    find_definition()

    Edit Menu                 Shell Menu
    -----------------------   -------------------------
    undo()                    filter_selection_dialog()
    redo()                    filter_selection()
    delete()                  execute_command()
    select_all()              execute_command_dialog()
    shift_left()              execute_command_line()
    shift_left_by_tab()       shell_menu_command()
    shift_right()
    shift_right_by_tab()      Macro Menu
    uppercase()               -------------------------
    lowercase()               macro_menu_command()
    fill_paragraph()          repeat_macro()
    control_code_dialog()     repeat_dialog()

                              Windows Menu
                              -------------------------
                              split_window()
                              close_pane()

An action representing a menu command is named the same as its corresponding menu item except that all punctuation is removed, all letters are changed to lower case, and spaces are replaced with underscores. To present a dialog to ask the user for input, use the actions with the `_dialog` suffix. Actions without the `_dialog` suffix take the information from the routine's arguments (see below).

Menu Action Routine Arguments

Arguments are text strings enclosed in quotes. Below are the menu action routines which take arguments. Optional arguments are enclosed in [].

    close( ["prompt" | "save" | "nosave"] )

    execute_command( shell-command )

    filter_selection( shell-command )

    find( search-string [, search-direction] [, search-type] 
       [, search-wrap] )

    find_again( [search-direction] [, search-wrap] )

    find_definition( [tag-name] )

    find_dialog( [search-direction] [, search-type] 
       [, keep-dialog] )

    find_selection( [search-direction] [, search-wrap] 
       [, non-regex-search-type] )

    goto_line_number( [line-number] )

    goto_mark( mark-letter )

    include_file( filename )

    load_tags_file( filename )

    macro_menu_command( macro-menu-item-name )

    mark( mark-letter )

    open( filename )

    replace( search-string, replace-string, 
       [, search-direction] [, search-type] [, search-wrap] )

    replace_again( [search-direction] [, search-wrap] )

    replace_dialog( [search-direction] [, search-type]
       [, keep-dialog] )

    replace_in_selection( search-string, 
       replace-string [, search-type] )

    save_as( filename )

    shell_menu_command( shell-menu-item-name )

    unload_tags_file( filename )

    ----------- Some notes on argument types above -----------

    filename       Path names are relative to the directory from
                   which NEdit was started. Shell interpreted 
                   wildcards and `~' are not expanded.

    keep-dialog    Either "keep" or "nokeep".

    mark-letter    The mark command limits users to single 
                   letters. Inside of macros, numeric marks are
                   allowed, which won't interfere with marks set
                   by the user.

    macro-menu-item-name
                   Name of the command exactly as specified in 
                   the Macro Menu dialogs.

    non-regex-search-type 
                   Either "literal", "case", "word", or 
                   "caseWord".

    search-direction
                   Either "forward" or "backward".

    search-type    Either "literal", "case", "word", 
                   "caseWord", "regex", or "regexNoCase".

    search-wrap    Either "wrap" or "nowrap".

    shell-menu-item-name
                   Name of the command exactly as specified in 
                   the Shell Menu dialogs.

Window Preferences Actions

set_auto_indent( "off" | "on" | "smart" )

set_em_tab_dist( em-tab-distance )

set_fonts( font-name, italic-font-name, bold-font-name, bold-italic-font-name )

set_highlight_syntax( [0 | 1] )

set_incremental_backup( [0 | 1] )

set_incremental_search_line( [0 | 1] )

set_language_mode( language-mode )

set_locked( [0 | 1] )

set_make_backup_copy( [0 | 1] )

set_overtype_mode( [0 | 1] )

set_show_line_numbers( [0 | 1] )

set_show_matching( "off" | "delimiter" | "range" )

set_match_syntax_based( [0 | 1] )

set_statistics_line( [0 | 1] )

set_tab_dist( tab-distance )

set_use_tabs( [0 | 1] )

set_wrap_margin( wrap-width )

set_wrap_text( "none" | "auto" | "continuous" )

Keyboard-Only Actions

In addition to the arguments listed in the call descriptions below, any routine involving cursor movement can take the argument "extend", meaning, adjust the primary selection to the new cursor position. Routines which take the "extend" argument as well as mouse dragging operations for both primary and secondary selections can take the optional keyword "rect", meaning, make the selection rectangular. Any routine that accepts the "scrollbar" argument will move the display but not the cursor or selection. Routines that accept the "nobell" argument will fail silently without beeping, when that argument is supplied.

backward_character( ["nobell"] )

backward_paragraph(["nobell"] )

backward_word( ["nobell"] )

beginning_of_file( ["scrollbar"] )

beginning_of_line()

beginning_of_selection()

copy_clipboard()

copy_primary()

copy_to()

copy_to_or_end_drag()

cut_clipboard()

cut_primary()

delete_selection()

delete_next_character( ["nobell"] )

delete_previous_character( ["nobell"] )

delete_next_word( ["nobell"] )

delete_previous_word( ["nobell"] )

delete_to_start_of_line( ["nobell"] )

delete_to_end_of_line( ["nobell"] )

deselect_all()

end_of_file( ["scrollbar"] )

end_of_line()

end_of_selection()

exchange( ["nobell"] )

extend_adjust()

extend_end()

extend_start()

focus_pane( [relative-pane] | [positive-index] | [negative-index] )

forward_character()

forward_paragraph( ["nobell"] )

forward_word( ["tail"] ["nobell"] )

grab_focus()

insert_string( "string" )

key_select( "direction" [,"nobell"] )

move-destination()

move_to()

move_to_or_end_drag()

newline()

newline_and_indent()

newline_no_indent()

next_page( ["stutter"] ["column"] ["scrollbar"] ["nobell"] )

page_left( ["scrollbar"] ["nobell"] )

page_right( ["scrollbar"] ["nobell"] )

paste_clipboard()

previous_page( ["stutter"] ["column"] ["scrollbar"] ["nobell"] )

process_bdrag()

process_cancel()

process_down( ["nobell"] )

process_return()

process_shift_down( ["nobell"] )

process_shift_up( ["nobell"] )

process_tab()

process_up( ["nobell"] )

raise_window([relative-window] | [positive-index] | [negative-index])

scroll_down(nLines)

scroll_left( nPixels )

scroll_right( nPixels )

scroll_up( nLines )

scroll_to_line( lineNum )

secondary_adjust()

secondary_or_drag_adjust()

secondary_or_drag_start()

secondary_start()

select_all()

self_insert()

Customizing

Customizing NEdit

NEdit can be customized many different ways. The most important user-settable options are presented in the Preferences menu, including all options that users might need to change during an editing session. Options set in the Default Settings sub-menu of the Preferences menu can be preserved between sessions by selecting Save Defaults, which writes a file called .nedit in the user's home directory. See the section titled "Preferences" for more details.

User defined commands can be added to NEdit's Shell, Macro, and window background menus. Dialogs for creating items in these menus can be found under Customize Menus in the Default Settings sub menu of the Preferences menu.

For users who depend on NEdit every day and want to tune every excruciating detail, there are also X resources for tuning a vast number of such details, down to the color of each individual button. See the section "X Resources" for more information, as well as a list of selected resources.

The most common reason customizing your X resources for NEdit, however, is key binding. While limited key binding can be done through Preferences settings (Preferences -> Default Settings -> Customize Menus), you can really only add keys this way, and each key must have a corresponding menu item. Any significant changes to key binding should be made via the Translations resource and menu accelerator resources. The sections titled "Key Binding" and "X Resources" have more information.

Preferences