instr(3NCURSES) Library calls instr(3NCURSES)
NAME
instr, winstr, mvinstr, mvwinstr, innstr, winnstr, mvinnstr, mvwinnstr -
get a string from a curses window
SYNOPSIS
#include <curses.h>
int instr(char * str);
int winstr(WINDOW * win, char * str);
int mvinstr(int y, int x, char * str);
int mvwinstr(WINDOW * win, int y, int x, char * str);
int innstr(char * str, int n);
int winnstr(WINDOW * win, char * str, int n);
int mvinnstr(int y, int x, char * str, int n);
int mvwinnstr(WINDOW * win, int y, int x, char * str,
int n);
DESCRIPTION
winstr extracts a string from a curses window win, starting at the cur-
sor and stopping at the end of the line, and stores it in str, terminat-
ing it with a null character and omitting any attributes and color pair
identifier that curses associates with each character. winnstr does the
same, but copies at most n characters from win. A negative n implies no
limit; winnstr then works like winstr. ncurses(3NCURSES) describes the
variants of these functions.
RETURN VALUE
These functions return the count of characters copied from win to str,
or ERR upon failure.
In ncurses, they return ERR if
• win is NULL or
• str is NULL.
Functions prefixed with “mv” first perform cursor movement and fail if
the position (y, x) is outside the window boundaries.
NOTES
All of these functions except winnstr may be implemented as macros.
Reading a line that overflows the array pointed to by str with instr,
winstr, mvinstr, or mvwinstr causes undefined results. Use of innstr,
winnstr, mvinnstr, and mvwinnstr is recommended instead.
EXTENSIONS
innstr, winnstr, mvinnstr, and mvwinnstr's acceptance of negative n val-
ues is an ncurses extension.
PORTABILITY
Applications employing ncurses extensions should condition their use on
the visibility of the NCURSES_VERSION preprocessor macro.
X/Open Curses Issue 4 describes these functions. It specifies no error
conditions for them.
X/Open Curses Issues 4 and 7 both state that instr, winstr, mvinstr, and
mvwinstr return OK rather than a character count. This is likely an er-
ratum.
• SVr3.1 and SVr4 implemented winstr as a wrapper around winnstr, re-
turning the latter's return value. X/Open Curses's specification
thus may have been an editorial solecism copied from System V's doc-
umentation (see below) by X/Open, rather than an intentional change.
• ncurses retains compatibility with System V curses behavior.
SVr4 describes a successful return value only as “an integer value other
than ERR”.
SVr4 does not document whether n counts the null terminator that these
functions write to str.
HISTORY
SVr3.1 (1987) introduced these functions. winstr, winnstr, and their
variants.
SEE ALSO
inwstr(3NCURSES) describes comparable functions of the ncurses library
in its wide-character configuration (ncursesw).
ncurses(3NCURSES), inch(3NCURSES), inchstr(3NCURSES)
ncurses 6.5 2025-02-01 instr(3NCURSES)
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