X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_getstr.3x.html;h=8c4c7bca864f8e8ddbb9ab743b349c908391646a;hb=c55d387cebf1cee4757ca2c2ef4fbeae59ee4175;hp=0141f63dca27e801244432d019f02ad8c9f1667e;hpb=6208c89f98f1cf9fe0980bd8e791846ce007a13d;p=ncurses.git diff --git a/doc/html/man/curs_getstr.3x.html b/doc/html/man/curs_getstr.3x.html index 0141f63d..8c4c7bca 100644 --- a/doc/html/man/curs_getstr.3x.html +++ b/doc/html/man/curs_getstr.3x.html @@ -1,6 +1,6 @@
- +-curs_getstr(3x) curs_getstr(3x) +curs_getstr(3x) curs_getstr(3x)
- getstr, getnstr, wgetstr, wgetnstr, mvgetstr, mvgetnstr, - mvwgetstr, mvwgetnstr - accept character strings from - curses terminal keyboard + getstr, getnstr, wgetstr, wgetnstr, mvgetstr, mvgetnstr, mvwgetstr, + mvwgetnstr - accept character strings from curses terminal keyboard
@@ -65,47 +67,42 @@
- 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 point- - ed to by the character pointer str. + 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, followed by a NUL. - wgetnstr reads at most n characters, thus preventing a - possible overflow of the input buffer. Any attempt to en- - ter more characters (other than the terminating newline or - carriage return) causes a beep. Function keys also cause - a beep and are ignored. The getnstr function reads from - the stdscr default window. + 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. - 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. + 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. - Characters input are echoed only if echo is currently on. - In that case, backspace is echoed as deletion of the pre- - vious character (typically a left motion). + 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 specifies only "an integer value other than ERR") - upon successful completion. + All routines return the integer ERR upon failure and an OK (SVr4 speci- + 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 pointer is null, or if its timeout expires - without having any data. + 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 interrupts the function, it will return KEY_RE- - SIZE rather than OK or ERR. + 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 move- - ment using wmove, and return an error if the position is - outside the window, or if the window pointer is null. + 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.
@@ -113,23 +110,62 @@
- 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 im- - plementation returns ERR if the window pointer is null, or - if the lower-level wgetch call returns an ERR. + 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 "spe- - cial keys" (such as function keys, "home" key, "clear" - key, etc.) are "interpreted", without 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). + 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 documented in SVr4. + 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.
@@ -137,7 +173,7 @@ - curs_getstr(3x) + curs_getstr(3x)