X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_getstr.3x.html;h=76b23fa80c4a0686e992dc7e217a78d3a638fec9;hb=265e45e43e9917e8b9ecc2bf9d23867a3ede2ecd;hp=4c9de8839d15a567d18ad1a003153984ad57f018;hpb=2560bc3dae7f4919060c02c91a593566c908091c;p=ncurses.git diff --git a/doc/html/man/curs_getstr.3x.html b/doc/html/man/curs_getstr.3x.html index 4c9de883..76b23fa8 100644 --- a/doc/html/man/curs_getstr.3x.html +++ b/doc/html/man/curs_getstr.3x.html @@ -1,6 +1,7 @@
- +#include <curses.h> - int getstr(char *str); - int getnstr(char *str, int n); - int wgetstr(WINDOW *win, char *str); - int wgetnstr(WINDOW *win, char *str, int n); - int mvgetstr(int y, int x, char *str); - int mvwgetstr(WINDOW *win, int y, int x, char *str); - int mvgetnstr(int y, int x, char *str, int n); - int mvwgetnstr(WINDOW *, int y, int x, char *str, int n); + int getstr(char *str); + int getnstr(char *str, int n); + int wgetstr(WINDOW *win, char *str); + int wgetnstr(WINDOW *win, char *str, int n); + + int mvgetstr(int y, int x, char *str); + int mvwgetstr(WINDOW *win, int y, int x, char *str); + int mvgetnstr(int y, int x, char *str, int n); + int mvwgetnstr(WINDOW *win, int y, int x, char *str, int n);
The function getstr is equivalent to a series of calls to getch, until a newline or carriage return is received (the terminating character is not included in the returned string). The resulting value is placed in - the area pointed to by the character pointer str. + the area pointed to by the character pointer str, followed by a NUL. + + The getnstr function reads from the stdscr default window. The other + functions, such as wgetnstr, read from the window given as a parameter. + + getnstr reads at most n characters, thus preventing a possible overflow + of the input buffer. Any attempt to enter more characters (other than + the terminating newline or carriage return) causes a beep. Function + keys also cause a beep and are ignored. + + The user's erase and kill characters are interpreted: - wgetnstr reads at most n characters, thus preventing a possible over- - flow of the input buffer. Any attempt to enter more characters (other - than the terminating newline or carriage return) causes a beep. Func- - tion keys also cause a beep and are ignored. The getnstr function - reads from the stdscr default window. + o The erase character (e.g., ^H) erases the character at the end of + the buffer, moving the cursor to the left. - The user's erase and kill characters are interpreted. If keypad mode - is on for the window, KEY_LEFT and KEY_BACKSPACE are both considered - equivalent to the user's kill character. + If keypad mode is on for the window, KEY_LEFT and KEY_BACKSPACE are + both considered equivalent to the user's erase character. - Characters input are echoed only if echo is currently on. In that - case, backspace is echoed as deletion of the previous character (typi- + o The kill character (e.g., ^U) erases the entire buffer, leaving the + cursor at the beginning of the buffer. + + Characters input are echoed only if echo is currently on. In that + case, backspace is echoed as deletion of the previous character (typi- cally a left motion).
All routines return the integer ERR upon failure and an OK (SVr4 speci- - fies only "an integer value other than ERR") upon successful comple- + fies only "an integer value other than ERR") upon successful comple- tion. X/Open defines no error conditions. - In this implementation, these functions return an error if the window + In this implementation, these functions return an error if the window pointer is null, or if its timeout expires without having any data. - This implementation provides an extension as well. If a SIGWINCH in- + This implementation provides an extension as well. If a SIGWINCH in- terrupts the function, it will return KEY_RESIZE rather than OK or ERR. - Functions with a "mv" prefix first perform a cursor movement using + Functions with a "mv" prefix first perform a cursor movement using wmove, and return an error if the position is outside the window, or if the window pointer is null. @@ -107,24 +121,101 @@
- These functions are described in the XSI Curses standard, Issue 4. - They read single-byte characters only. The standard does not define - any error conditions. This implementation returns ERR if the window - pointer is null, or if the lower-level wgetch(3x) call returns an ERR. - - SVr3 and early SVr4 curses implementations did not reject function - keys; the SVr4.0 documentation claimed that "special keys" (such as - function keys, "home" key, "clear" key, etc.) are "interpreted", with- - out giving details. It lied. In fact, the "character" value appended - to the string by those implementations was predictable but not useful + These functions are described in the XSI Curses standard, Issue 4. + They read single-byte characters only. The standard does not define + any error conditions. This implementation returns ERR if the window + pointer is null, or if the lower-level wgetch(3x) call returns an ERR. + + SVr3 and early SVr4 curses implementations did not reject function + keys; the SVr4.0 documentation claimed that "special keys" (such as + function keys, "home" key, "clear" key, etc.) are "interpreted", with- + out giving details. It lied. In fact, the "character" value appended + to the string by those implementations was predictable but not useful (being, in fact, the low-order eight bits of the key's KEY_ value). - The functions getnstr, mvgetnstr, and mvwgetnstr were present but not + The functions getnstr, mvgetnstr, and mvwgetnstr were present but not documented in SVr4. + X/Open Curses, Issue 5 (2007) stated that these functions "read at most + n bytes" but did not state whether the terminating NUL is counted in + that limit. X/Open Curses, Issue 7 (2009) changed that to say they + "read at most n-1 bytes" to allow for the terminating NUL. As of 2018, + some implementations do, some do not count it: + + o ncurses 6.1 and PDCurses do not count the NUL in the given limit, + while + + o Solaris SVr4 and NetBSD curses count the NUL as part of the limit. + + o Solaris xcurses provides both: its wide-character wget_nstr re- + serves a NUL, but its wgetnstr does not count the NUL consistently. + + In SVr4 curses, a negative value of n tells wgetnstr to assume that the + caller's buffer is large enough to hold the result, i.e., to act like + wgetstr. X/Open Curses does not mention this (or anything related to + negative or zero values of n), however most implementations use the + feature, with different limits: + + o Solaris SVr4 curses and PDCurses limit the result to 255 bytes. + Other Unix systems than Solaris are likely to use the same limit. + + o Solaris xcurses limits the result to LINE_MAX bytes. + + o NetBSD 7 assumes no particular limit for the result from wgetstr. + However, it limits the wgetnstr parameter n to ensure that it is + greater than zero. + + A comment in NetBSD's source code states that this is specified in + SUSv2. + + o ncurses (before 6.2) assumes no particular limit for the result + from wgetstr, and treats the n parameter of wgetnstr like SVr4 + curses. + + o ncurses 6.2 uses LINE_MAX, or a larger (system-dependent) value + which the sysconf function may provide. If neither LINE_MAX or + sysconf is available, ncurses uses the POSIX value for LINE_MAX (a + 2048 byte limit). In either case, it reserves a byte for the ter- + minating NUL. + + Although getnstr is equivalent to a series of calls to getch, it also + makes changes to the curses modes to allow simple editing of the input + buffer: + + o getnstr saves the current value of the nl, echo, raw and cbreak + modes, and sets nl, noecho, noraw, and cbreak. + + getnstr handles the echoing of characters, rather than relying on + the caller to set an appropriate mode. + + o It also obtains the erase and kill characters from erasechar and + killchar, respectively. + + o On return, getnstr restores the modes to their previous values. + + Other implementations differ in their treatment of special characters: + + o While they may set the echo mode, other implementations do not mod- + ify the raw mode, They may take the cbreak mode set by the caller + into account when deciding whether to handle echoing within getnstr + or as a side-effect of the getch calls. + + o The original ncurses (as pcurses in 1986) set noraw and cbreak when + accepting input for getnstr. That may have been done to make func- + tion- and cursor-keys work; it is not necessary with ncurses. + + Since 1995, ncurses has provided signal handlers for INTR and QUIT + (e.g., ^C or ^\). With the noraw and cbreak settings, those may + catch a signal and stop the program, where other implementations + allow one to enter those characters in the buffer. + + o Starting in 2021 (ncurses 6.3), getnstr sets raw, rather than noraw + and cbreak for better compatibility with SVr4-curses, e.g., allow- + ing one to enter a ^C into the buffer. +
- curses(3x), curs_getch(3x), curs_variables(3x). + curses(3x), curs_getch(3x), curs_termattrs(3x), curs_variables(3x).