curs_getstr(3x) — Linux manual page


curs_getstr(3X)                                          curs_getstr(3X)

NAME         top

       getstr, getnstr, wgetstr, wgetnstr, mvgetstr, mvgetnstr,
       mvwgetstr, mvwgetnstr - accept character strings from curses
       terminal keyboard

SYNOPSIS         top

       #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 *win, int y, int x, char *str, int n);

DESCRIPTION         top

       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.

       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

       The user's erase and kill characters are interpreted:

       •   The erase character (e.g., ^H) erases the character at the
           end of the buffer, moving the cursor to the left.

           If keypad mode is on for the window, KEY_LEFT and
           KEY_BACKSPACE are both considered equivalent to the user's
           erase character.

       •   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 (typically a left motion).

RETURN VALUE         top

       All routines return the integer ERR upon failure and an OK (SVr4
       specifies only “an integer value other than ERR”) upon successful

       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.

       This implementation provides an extension as well.  If a SIGWINCH
       interrupts the function, it will return KEY_RESIZE rather than OK
       or ERR.

       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.

NOTES         top

       Note that getstr, mvgetstr, and mvwgetstr may be macros.

PORTABILITY         top

       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”, 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).

       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:

       •   ncurses 6.1 and PDCurses do not count the NUL in the given
           limit, while

       •   Solaris SVr4 and NetBSD curses count the NUL as part of the

       •   Solaris xcurses provides both: its wide-character wget_nstr
           reserves a NUL, but its wgetnstr does not count the NUL

       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:

       •   Solaris SVr4 curses and PDCurses limit the result to 255
           bytes.  Other Unix systems than Solaris are likely to use the
           same limit.

       •   Solaris xcurses limits the result to LINE_MAX bytes.

       •   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.

       •   ncurses (before 6.2) assumes no particular limit for the
           result from wgetstr, and treats the n parameter of wgetnstr
           like SVr4 curses.

       •   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 terminating 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:

       •   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.

       •   It also obtains the erase and kill characters from erasechar
           and killchar, respectively.

       •   On return, getnstr restores the modes to their previous

       Other implementations differ in their treatment of special

       •   While they may set the echo mode, other implementations do
           not modify 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

       •   The original ncurses (as pcurses in 1986) set noraw and
           cbreak when accepting input for getnstr.  That may have been
           done to make function- 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

       •   Starting in 2021 (ncurses 6.3), getnstr sets raw, rather than
           noraw and cbreak for better compatibility with SVr4-curses,
           e.g., allowing one to enter a ^C into the buffer.

SEE ALSO         top

       curses(3X), curs_getch(3X), curs_termattrs(3X),

COLOPHON         top

       This page is part of the ncurses (new curses) project.
       Information about the project can be found at 
       ⟨⟩.  If you have
       a bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git mirror of the CVS repository
       ⟨⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-03-12.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to