X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_initscr.3x.html;h=3c47ac6c2ce3f12c3cbc39f71609ab618e059b4c;hp=f5fd5441747dff91e4c70133acc540c4327edc30;hb=b9a2bd87a73d976d1c916815e2d370bf1090d1b2;hpb=55ccd2b959766810cf7db8d1c4462f338ce0afc8 diff --git a/doc/html/man/curs_initscr.3x.html b/doc/html/man/curs_initscr.3x.html index f5fd5441..3c47ac6c 100644 --- a/doc/html/man/curs_initscr.3x.html +++ b/doc/html/man/curs_initscr.3x.html @@ -1,7 +1,6 @@ - +
+ +- curs_initscr(3x) curs_initscr(3x)-
+NAME
initscr, newterm, endwin, isendwin, set_term, delscreen - curses screen initialization and manipulation routines-SYNOPSIS
+SYNOPSIS
#include <curses.h> WINDOW *initscr(void); int endwin(void); bool isendwin(void); - SCREEN *newterm(char *type, FILE *outfd, FILE *infd); - SCREEN *set_term(SCREEN *new); - void delscreen(SCREEN* sp); + SCREEN *newterm(char *type, FILE *outfd, FILE *infd); + SCREEN *set_term(SCREEN *new); + void delscreen(SCREEN* sp);-DESCRIPTION
+DESCRIPTION
+ ++initscr
initscr is normally the first curses routine to call when initializing a program. A few special routines sometimes need to be called before it; these are slk_init, filter, @@ -78,6 +81,9 @@ dard error and exits; otherwise, a pointer is returned to stdscr. + ++newterm
A program that outputs to more than one terminal should use the newterm routine for each terminal instead of initscr. A program that needs to inspect capabilities, so @@ -86,27 +92,48 @@ use newterm. The routine newterm should be called once for each terminal. It returns a variable of type SCREEN * which should be saved as a reference to that terminal. - The arguments are the type of the terminal to be used in - place of $TERM, a file pointer for output to the terminal, - and another file pointer for input from the terminal (if - type is NULL, $TERM will be used). The program must also - call endwin for each terminal being used before exiting - from curses. If newterm is called more than once for the - same terminal, the first terminal referred to must be the - last one for which endwin is called. - - A program should always call endwin before exiting or es- - caping from curses mode temporarily. This routine re- - stores tty modes, moves the cursor to the lower left-hand - corner of the screen and resets the terminal into the - proper non-visual mode. Calling refresh or doupdate after - a temporary escape causes the program to resume visual - mode. + newterm's arguments are + + o the type of the terminal to be used in place of $TERM, + + o a file pointer for output to the terminal, and + + o another file pointer for input from the terminal + + If the type parameter is NULL, $TERM will be used. + + ++endwin
+ The program must also call endwin for each terminal being + used before exiting from curses. If newterm is called + more than once for the same terminal, the first terminal + referred to must be the last one for which endwin is + called. + + A program should always call endwin before exiting or es- + caping from curses mode temporarily. This routine + o restores tty modes, + + o moves the cursor to the lower left-hand corner of the + screen and + + o resets the terminal into the proper non-visual mode. + + Calling refresh or doupdate after a temporary escape caus- + es the program to resume visual mode. + + ++isendwin
The isendwin routine returns TRUE if endwin has been called without any subsequent calls to wrefresh, and FALSE otherwise. + ++set_term
The set_term routine is used to switch between different terminals. The screen reference new becomes the new cur- rent terminal. The previous terminal is returned by the @@ -114,6 +141,9 @@ SCREEN pointers; all other routines affect only the cur- rent terminal. + ++delscreen
The delscreen routine frees storage associated with the SCREEN data structure. The endwin routine does not do this, so delscreen should be called after endwin if a par- @@ -121,47 +151,164 @@-RETURN VALUE
+RETURN VALUE
endwin returns the integer ERR upon failure and OK upon successful completion. Routines that return pointers always return NULL on error. - X/Open defines no error conditions. In this implementa- - tion endwin returns an error if the terminal was not ini- - tialized. + X/Open defines no error conditions. In this implementa- + tion + + o endwin returns an error if the terminal was not ini- + tialized. + + o newterm returns an error if it cannot allocate the da- + ta structures for the screen, or for the top-level + windows within the screen, i.e., curscr, newscr, or + stdscr. + + o set_term returns no error.-NOTES
+NOTES
Note that initscr and newterm may be macros.-PORTABILITY
- These functions are described in the XSI Curses standard, - Issue 4. It specifies that portable applications must not - call initscr more than once. +PORTABILITY
+ These functions were described in the XSI Curses standard, + Issue 4. As of 2015, the current document is X/Open Curs- + es, Issue 7. + + ++Differences
+ X/Open specifies that portable applications must not call + initscr more than once: + + o The portable way to use initscr is once only, using + refresh (see curs_refresh(3x)) to restore the screen + after endwin. + + o This implementation allows using initscr after endwin. Old versions of curses, e.g., BSD 4.4, may have returned a - null pointer from initscr when an error is detected, - rather than exiting. It is safe but redundant to check + null pointer from initscr when an error is detected, + rather than exiting. It is safe but redundant to check the return value of initscr in XSI Curses.-SEE ALSO
+Unset TERM Variable
+ If the TERM variable is missing or empty, initscr uses the + value "unknown", which normally corresponds to a terminal + entry with the generic (gn) capability. Generic entries + are detected by setupterm (see curs_terminfo(3x)) and can- + not be used for full-screen operation. Other implementa- + tions may handle a missing/empty TERM variable different- + ly. + + ++Signal Handlers
+ Quoting from X/Open Curses, section 3.1.1: + + Curses implementations may provide for special han- + dling of the SIGINT, SIGQUIT and SIGTSTP signals if + their disposition is SIG_DFL at the time initscr() is + called ... + + Any special handling for these signals may remain in + effect for the life of the process or until the + process changes the disposition of the signal. + + None of the Curses functions are required to be safe + with respect to signals ... + + This implementation establishes signal handlers during + initialization, e.g., initscr or newterm. Applications + which must handle these signals should set up the corre- + sponding handlers after initializing the library: + + SIGINT + The handler attempts to cleanup the screen on exit. + Although it usually works as expected, there are lim- + itations: + + o Walking the SCREEN list is unsafe, since all list + management is done without any signal blocking. + + o On systems which have REENTRANT turned on, + set_term uses functions which could deadlock or + misbehave in other ways. + + o endwin calls other functions, many of which use + stdio or other library functions which are clear- + ly unsafe. + + SIGTERM + This uses the same handler as SIGINT, with the same + limitations. It is not mentioned in X/Open Curses, + but is more suitable for this purpose than SIGQUIT + (which is used in debugging). + + SIGTSTP + This handles the stop signal, used in job control. + When resuming the process, this implementation dis- + cards pending input with flushinput (see + curs_util(3x)), and repaints the screen assuming that + it has been completely altered. It also updates the + saved terminal modes with def_shell_mode (see + curs_kernel(3x)). + + SIGWINCH + This handles the window-size changes which were ini- + tially ignored in the standardization efforts. The + handler sets a (signal-safe) variable which is later + tested in wgetch (see curs_getch(3x)). If keypad has + been enabled for the corresponding window, wgetch re- + turns the key symbol KEY_RESIZE. At the same time, + wgetch calls resizeterm to adjust the standard screen + stdscr, and update other data such as LINES and COLS. + + ++SEE ALSO
curses(3x), curs_kernel(3x), curs_refresh(3x), - curs_slk(3x), curs_util(3x) + curs_slk(3x), curs_terminfo(3x), curs_util(3x), curs_vari- + ables(3x). curs_initscr(3x)-
- -Man(1) output converted with -man2html - +