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diff --git a/doc/ncurses-intro.doc b/doc/ncurses-intro.doc index b44800503a32..4e752ed0fc54 100644 --- a/doc/ncurses-intro.doc +++ b/doc/ncurses-intro.doc @@ -132,20 +132,36 @@ A Brief History of Curses Historically, the first ancestor of curses was the routines written to - provide screen-handling for the game rogue; these used the - already-existing termcap database facility for describing terminal + provide screen-handling for the vi editor; these used the termcap + database facility (both released in 3BSD) for describing terminal capabilities. These routines were abstracted into a documented library - and first released with the early BSD UNIX versions. - - System III UNIX from Bell Labs featured a rewritten and much-improved - curses library. It introduced the terminfo format. Terminfo is based - on Berkeley's termcap database, but contains a number of improvements - and extensions. Parameterized capabilities strings were introduced, - making it possible to describe multiple video attributes, and colors - and to handle far more unusual terminals than possible with termcap. - In the later AT&T System V releases, curses evolved to use more - facilities and offer more capabilities, going far beyond BSD curses in - power and flexibility. + and first released with the early BSD UNIX versions. All of this work + was done by students at the University of California (Berkeley + campus). The curses library was first published in 4.0BSD, a year + after 3BSD (i.e., late 1980). + + After graduation, one of those students went to work at AT&T Bell + Labs, and made an improved termcap library called terminfo (i.e., + "libterm"), and adapted the curses library to use this. That was + subsequently released in System V Release 2 (early 1984). Thereafter, + other developers added to the curses and terminfo libraries. For + instance, a student at Cornell University wrote an improved terminfo + library as well as a tool (tic) to compile the terminal descriptions. + As a general rule, AT&T did not identify the developers in the + source-code or documentation; the tic and infocmp programs are the + exceptions. + + System V Release 3 (System III UNIX) from Bell Labs featured a + rewritten and much-improved curses library, along with the tic program + (late 1986). + + To recap, terminfo is based on Berkeley's termcap database, but + contains a number of improvements and extensions. Parameterized + capabilities strings were introduced, making it possible to describe + multiple video attributes, and colors and to handle far more unusual + terminals than possible with termcap. In the later AT&T System V + releases, curses evolved to use more facilities and offer more + capabilities, going far beyond BSD curses in power and flexibility. Scope of This Document @@ -153,7 +169,7 @@ Scope of This Document curses API with some clearly marked extensions. It includes the following System V curses features: * Support for multiple screen highlights (BSD curses could only - handle one `standout' highlight, usually reverse-video). + handle one "standout" highlight, usually reverse-video). * Support for line- and box-drawing using forms characters. * Recognition of function keys on input. * Color support. @@ -164,7 +180,7 @@ Scope of This Document character features of terminals so equipped, and determines how to optimally use these features with no help from the programmer. It allows arbitrary combinations of video attributes to be displayed, - even on terminals that leave ``magic cookies'' on the screen to mark + even on terminals that leave "magic cookies" on the screen to mark changes in attributes. The ncurses package can also capture and use event reports from a @@ -242,8 +258,8 @@ An Overview of Curses standard screen) is provided by default to make changes on. A window is a purely internal representation. It is used to build and - store a potential image of a portion of the terminal. It doesn't bear - any necessary relation to what is really on the terminal screen; it's + store a potential image of a portion of the terminal. It does not bear + any necessary relation to what is really on the terminal screen; it is more like a scratchpad or write buffer. To make the section of physical screen corresponding to a window @@ -253,7 +269,7 @@ An Overview of Curses A given physical screen section may be within the scope of any number of overlapping windows. Also, changes can be made to windows in any order, without regard to motion efficiency. Then, at will, the - programmer can effectively say ``make it look like this,'' and let the + programmer can effectively say "make it look like this," and let the package implementation determine the most efficient way to repaint the screen. @@ -269,8 +285,8 @@ An Overview of Curses Many functions are defined to use stdscr as a default screen. For example, to add a character to stdscr, one calls addch() with the desired character as argument. To write to a different window. use the - routine waddch() (for `w'indow-specific addch()) is provided. This - convention of prepending function names with a `w' when they are to be + routine waddch() (for window-specific addch()) is provided. This + convention of prepending function names with a "w" when they are to be applied to specific windows is consistent. The only routines which do not follow it are those for which a window must always be specified. @@ -278,7 +294,7 @@ An Overview of Curses another, the routines move() and wmove() are provided. However, it is often desirable to first move and then perform some I/O operation. In order to avoid clumsiness, most I/O routines can be preceded by the - prefix 'mv' and the desired (y, x) coordinates prepended to the + prefix "mv" and the desired (y, x) coordinates prepended to the arguments to the function. For example, the calls move(y, x); addch(ch); @@ -310,13 +326,13 @@ An Overview of Curses general usefulness: bool - boolean type, actually a `char' (e.g., bool doneit;) + boolean type, actually a "char" (e.g., bool doneit;) TRUE - boolean `true' flag (1). + boolean "true" flag (1). FALSE - boolean `false' flag (0). + boolean "false" flag (0). ERR error flag returned by routines on a failure (-1). @@ -332,7 +348,7 @@ Using the Library function names and parameters as mentioned above. Here is a sample program to motivate the discussion: -#include <curses.h> +#include <stdlib.h> #include <curses.h> #include <signal.h> @@ -381,7 +397,7 @@ main(int argc, char *argv[]) /* process the command keystroke */ } - finish(0); /* we're done */ + finish(0); /* we are done */ } static void finish(int sig) @@ -411,7 +427,7 @@ static void finish(int sig) Once the screen windows have been allocated, you can set them up for your program. If you want to, say, allow a screen to scroll, use scrollok(). If you want the cursor to be left in place after the last - change, use leaveok(). If this isn't done, refresh() will move the + change, use leaveok(). If this is not done, refresh() will move the cursor to the window's current (y, x) coordinates after updating it. You can create new windows of your own using the functions newwin(), @@ -454,8 +470,8 @@ static void finish(int sig) set, will call addch() to echo the character. Since the screen package needs to know what is on the terminal at all times, if characters are to be echoed, the tty must be in raw or cbreak mode. Since initially - the terminal has echoing enabled and is in ordinary ``cooked'' mode, - one or the other has to changed before calling getch(); otherwise, the + the terminal has echoing enabled and is in ordinary "cooked" mode, one + or the other has to changed before calling getch(); otherwise, the program's output will be unpredictable. When you need to accept line-oriented input in a window, the functions @@ -499,7 +515,7 @@ static void finish(int sig) of the highlights you want into the character argument of an addch() call, or any other output call that takes a chtype argument. - The other is to set the current-highlight value. This is logical-or'ed + The other is to set the current-highlight value. This is logical-ORed with any highlight you specify the first way. You do this with the functions attron(), attroff(), and attrset(); see the manual pages for details. Color is a special kind of highlight. The package actually @@ -510,8 +526,8 @@ static void finish(int sig) range of eight non-conflicting values could have been used as the first arguments of the init_pair() values. - Once you've done an init_pair() that creates color-pair N, you can use - COLOR_PAIR(N) as a highlight that invokes that particular color + Once you have done an init_pair() that creates color-pair N, you can + use COLOR_PAIR(N) as a highlight that invokes that particular color combination. Note that COLOR_PAIR(N), for constant N, is itself a compile-time constant and can be used in initializers. @@ -550,11 +566,11 @@ static void finish(int sig) otherwise another mouse event might come in and make the first one inaccessible). - Each call to getmouse() fills a structure (the address of which you'll - pass it) with mouse event data. The event data includes zero-origin, - screen-relative character-cell coordinates of the mouse pointer. It - also includes an event mask. Bits in this mask will be set, - corresponding to the event type being reported. + Each call to getmouse() fills a structure (the address of which you + will pass it) with mouse event data. The event data includes + zero-origin, screen-relative character-cell coordinates of the mouse + pointer. It also includes an event mask. Bits in this mask will be + set, corresponding to the event type being reported. The mouse structure contains two additional fields which may be significant in the future as ncurses interfaces to new kinds of @@ -567,7 +583,7 @@ static void finish(int sig) The class of visible events may be changed at any time via mousemask(). Events that can be reported include presses, releases, single-, double- and triple-clicks (you can set the maximum - button-down time for clicks). If you don't make clicks visible, they + button-down time for clicks). If you do not make clicks visible, they will be reported as press-release pairs. In some environments, the event mask may include bits reporting the state of shift, alt, and ctrl keys on the keyboard during the event. @@ -701,7 +717,7 @@ Function Descriptions more terminals at once. Setupterm() also stores the names section of the terminal description in the global character array ttytype[]. Subsequent calls to setupterm() will overwrite - this array, so you'll have to save it yourself if need be. + this array, so you will have to save it yourself if need be. Debugging @@ -710,7 +726,7 @@ Function Descriptions trace() This function can be used to explicitly set a trace level. If the trace level is nonzero, execution of your program will - generate a file called `trace' in the current working directory + generate a file called "trace" in the current working directory containing a report on the library's actions. Higher trace levels enable more detailed (and verbose) reporting -- see comments attached to TRACE_ defines in the curses.h file for @@ -740,7 +756,7 @@ Hints, Tips, and Tricks Some Notes of Caution If you find yourself thinking you need to use noraw() or nocbreak(), - think again and move carefully. It's probably better design to use + think again and move carefully. It is probably better design to use getstr() or one of its relatives to simulate cooked mode. The noraw() and nocbreak() functions try to restore cooked mode, but they may end up clobbering some control bits set before you started your @@ -748,7 +764,7 @@ Hints, Tips, and Tricks likely to hurt your application's usability with other curses libraries. - Bear in mind that refresh() is a synonym for wrefresh(stdscr). Don't + Bear in mind that refresh() is a synonym for wrefresh(stdscr). Do not try to mix use of stdscr with use of windows declared by newwin(); a refresh() call will blow them off the screen. The right way to handle this is to use subwin(), or not touch stdscr at all and tile your @@ -774,7 +790,7 @@ Hints, Tips, and Tricks Temporarily Leaving NCURSES Mode Sometimes you will want to write a program that spends most of its - time in screen mode, but occasionally returns to ordinary `cooked' + time in screen mode, but occasionally returns to ordinary "cooked" mode. A common reason for this is to support shell-out. This behavior is simple to arrange in ncurses. @@ -839,8 +855,8 @@ Hints, Tips, and Tricks tigetflag(), tigetnum(), and tigetstr() to do your testing. A particularly useful case of this often comes up when you want to - test whether a given terminal type should be treated as `smart' - (cursor-addressable) or `stupid'. The right way to test this is to see + test whether a given terminal type should be treated as "smart" + (cursor-addressable) or "stupid". The right way to test this is to see if the return value of tigetstr("cup") is non-NULL. Alternatively, you can include the term.h file and test the value of the macro cursor_address. @@ -848,8 +864,8 @@ Hints, Tips, and Tricks Tuning for Speed Use the addchstr() family of functions for fast screen-painting of - text when you know the text doesn't contain any control characters. - Try to make attribute changes infrequent on your screens. Don't use + text when you know the text does not contain any control characters. + Try to make attribute changes infrequent on your screens. Do not use the immedok() option! Special Features of NCURSES @@ -913,7 +929,7 @@ Compatibility with Older Versions they do change copy or entire copy. We know that System V release 3 curses has logic in it that looks like an attempt to do change copy, but the surrounding logic and data representations are sufficiently - complex, and our knowledge sufficiently indirect, that it's hard to + complex, and our knowledge sufficiently indirect, that it is hard to know whether this is reliable. It is not clear what the SVr4 documentation and XSI standard intend. The XSI Curses standard barely mentions wnoutrefresh(); the SVr4 documents seem to be describing @@ -997,8 +1013,8 @@ Overview of Panels in the proper order to resolve overlaps. The standard window, stdscr, is considered below all panels. - Details on the panels functions are available in the man pages. We'll - just hit the highlights here. + Details on the panels functions are available in the man pages. We + will just hit the highlights here. You create a panel from a window by calling new_panel() on a window pointer. It then becomes the top of the deck. The panel's window is @@ -1009,11 +1025,11 @@ Overview of Panels This will not deallocate the associated window; you have to do that yourself. You can replace a panel's window with a different window by calling replace_window. The new window may be of different size; the - panel code will re-compute all overlaps. This operation doesn't change - the panel's position in the deck. + panel code will re-compute all overlaps. This operation does not + change the panel's position in the deck. To move a panel's window, use move_panel(). The mvwin() function on - the panel's window isn't sufficient because it doesn't update the + the panel's window is not sufficient because it does not update the panels library's representation of where the windows are. This operation leaves the panel's depth, contents, and size unchanged. @@ -1028,12 +1044,12 @@ Overview of Panels Typically, you will want to call update_panels() and doupdate() just before accepting command input, once in each cycle of interaction with the user. If you call update_panels() after each and every panel - write, you'll generate a lot of unnecessary refresh activity and + write, you will generate a lot of unnecessary refresh activity and screen flicker. Panels, Input, and the Standard Screen - You shouldn't mix wnoutrefresh() or wrefresh() operations with panels + You should not mix wnoutrefresh() or wrefresh() operations with panels code; this will work only if the argument window is either in the top panel or unobscured by any other panels. @@ -1051,7 +1067,7 @@ Panels, Input, and the Standard Screen Hiding Panels - It's possible to remove a panel from the deck temporarily; use + It is possible to remove a panel from the deck temporarily; use hide_panel for this. Use show_panel() to render it visible again. The predicate function panel_hidden tests whether or not a panel is hidden. @@ -1062,7 +1078,7 @@ Hiding Panels Miscellaneous Other Facilities - It's possible to navigate the deck using the functions panel_above() + It is possible to navigate the deck using the functions panel_above() and panel_below. Handed a panel pointer, they return the panel above or below that panel. Handed NULL, they return the bottom-most or top-most panel. @@ -1156,7 +1172,7 @@ Menu Display The actual menu page may be smaller than the format size. This depends on the item number and size and whether O_ROWMAJOR is on. This option - (on by default) causes menu items to be displayed in a `raster-scan' + (on by default) causes menu items to be displayed in a "raster-scan" pattern, so that if more than one item will fit horizontally the first couple of items are side-by-side in the top row. The alternative is column-major display, which tries to put the first several items in @@ -1222,7 +1238,7 @@ Processing Menu Input REQ_SCR_DPAGE, and REQ_SCR_UPAGE. The REQ_TOGGLE_ITEM selects or deselects the current item. It is for - use in multi-valued menus; if you use it with O_ONEVALUE on, you'll + use in multi-valued menus; if you use it with O_ONEVALUE on, you will get an error return (E_REQUEST_DENIED). Each menu has an associated pattern buffer. The menu_driver() logic @@ -1326,7 +1342,7 @@ Overview of Forms obviously designed to resemble that of the menu library wherever possible. - In forms programs, however, the `process user requests' is somewhat + In forms programs, however, the "process user requests" is somewhat more complicated than for menus. Besides menu-like navigation operations, the menu driver loop has to support field editing and data validation. @@ -1348,7 +1364,7 @@ FIELD *new_field(int height, int width, /* new field size */ the screen (the third and fourth arguments, which must be zero or greater). Note that these coordinates are relative to the form subwindow, which will coincide with stdscr by default but need not be - stdscr if you've done an explicit set_form_win() call. + stdscr if you have done an explicit set_form_win() call. The fifth argument allows you to specify a number of off-screen rows. If this is zero, the entire field will always be displayed. If it is @@ -1593,7 +1609,7 @@ int field_status(FIELD *field); /* fetch mode of field */ Calling field_status() on a field not currently selected for input will return a correct value. Calling field_status() on a field that is currently selected for input may not necessarily give a correct field - status value, because entered data isn't necessarily copied to buffer + status value, because entered data is not necessarily copied to buffer zero before the exit validation check. To guarantee that the returned status value reflects reality, call field_status() either (1) in the field's exit validation check routine, (2) from the field's or form's @@ -1662,7 +1678,7 @@ Field Validation By default, a field will accept any data that will fit in its input buffer. However, it is possible to attach a validation type to a field. If you do this, any attempt to leave the field while it - contains data that doesn't match the validation type will fail. Some + contains data that does not match the validation type will fail. Some validation types also have a character-validity check for each time a character is entered in the field. @@ -1696,10 +1712,10 @@ int set_field_type(FIELD *field, /* field to alter */ TYPE_ALPHA, /* type to associate */ int width); /* maximum width of field */ - The width argument sets a minimum width of data. Typically you'll want - to set this to the field width; if it's greater than the field width, - the validation check will always fail. A minimum width of zero makes - field completion optional. + The width argument sets a minimum width of data. Typically you will + want to set this to the field width; if it is greater than the field + width, the validation check will always fail. A minimum width of zero + makes field completion optional. TYPE_ALNUM @@ -1711,9 +1727,9 @@ int set_field_type(FIELD *field, /* field to alter */ int width); /* maximum width of field */ The width argument sets a minimum width of data. As with TYPE_ALPHA, - typically you'll want to set this to the field width; if it's greater - than the field width, the validation check will always fail. A minimum - width of zero makes field completion optional. + typically you will want to set this to the field width; if it is + greater than the field width, the validation check will always fail. A + minimum width of zero makes field completion optional. TYPE_ENUM @@ -1802,7 +1818,7 @@ char *field_buffer(FIELD *field, /* field to query */ int bufindex); /* number of buffer to query */ Normally, the state of the zero-numbered buffer for each field is set - by the user's editing actions on that field. It's sometimes useful to + by the user's editing actions on that field. It is sometimes useful to be able to set the value of the zero-numbered (or some other) buffer from your application: int set_field_buffer(FIELD *field, /* field to alter */ @@ -1817,7 +1833,7 @@ int set_field_buffer(FIELD *field, /* field to alter */ Calling field_buffer() on a field not currently selected for input will return a correct value. Calling field_buffer() on a field that is currently selected for input may not necessarily give a correct field - buffer value, because entered data isn't necessarily copied to buffer + buffer value, because entered data is not necessarily copied to buffer zero before the exit validation check. To guarantee that the returned buffer value reflects on-screen reality, call field_buffer() either (1) in the field's exit validation check routine, (2) from the field's @@ -1877,7 +1893,7 @@ Control of Form Display erased at post/unpost time. The inner window or subwindow is where the current form page is actually displayed. - In order to declare your own frame window for a form, you'll need to + In order to declare your own frame window for a form, you will need to know the size of the form's bounding rectangle. You can get this information with: int scale_form(FORM *form, /* form to query */ @@ -2389,13 +2405,12 @@ FIELD *link_fieldtype(FIELDTYPE *type1, entered. * A field-validation function to be applied on exit from the field. - Here's how you do that: + Here is how you do that: typedef int (*HOOK)(); /* pointer to function returning int */ FIELDTYPE *new_fieldtype(HOOK f_validate, /* field validator */ HOOK c_validate) /* character validator */ - int free_fieldtype(FIELDTYPE *ftype); /* type to free */ At least one of the arguments of new_fieldtype() must be non-NULL. The @@ -2419,7 +2434,7 @@ int free_fieldtype(FIELDTYPE *ftype); /* type to free */ Your field- and character- validation functions will be passed a second argument as well. This second argument is the address of a - structure (which we'll call a pile) built from any of the + structure (which we will call a pile) built from any of the field-type-specific arguments passed to set_field_type(). If no such arguments are defined for the field type, this pile pointer argument will be NULL. @@ -2469,7 +2484,7 @@ int set_fieldtype_arg(FIELDTYPE *type, /* type to alter */ Some custom field types are simply ordered in the same well-defined way that TYPE_ENUM is. For such types, it is possible to define successor and predecessor functions to support the REQ_NEXT_CHOICE and - REQ_PREV_CHOICE requests. Here's how: + REQ_PREV_CHOICE requests. Here is how: typedef int (*INTHOOK)(); /* pointer to function returning int */ int set_fieldtype_arg(FIELDTYPE *type, /* type to alter */ |