guy@sun.uucp (Guy Harris) (04/11/86)
Index: usr.lib/libcurses/getch.c 4.2BSD
Description:
According to the documentation on "curses", "getch" and
"wgetch" will turn on "cbreak" mode if neither "noecho",
"raw", nor "cbreak" are already set, and will restore the mode
when the character is read.
It actually turns on "raw" mode, not "cbreak" mode. This means,
for example, that if a program calls "getstr" or "wgetstr" without
setting "cbreak" mode, "raw" mode is set, which means that if the
user's terminal has a RETURN key which transmits <CR>, that key
will NOT act as an input terminator; they must type the LINE
FEED key instead.
Repeat-By:
Try running the following program:
#include <curses.h>
main()
{
char source[80];
WINDOW *win1;
initscr();
win1=newwin(0,0,0,0);
wmove(win1,1,1);
waddstr(win1,"Input: ");
wmove(win1,1,8);
wrefresh(win1);
/* Terminal will hang after input if the lines containing
crmode() and nocrmode() are removed. */
crmode(); /* Set terminal to cbreak mode */
wscanw(win1,"%s",source);
nocrmode(); /* Unset terminal from cbreak mode */
wmove(win1,2,1);
wprintw(win1,"You typed: %s",source);
wmove(win1,3,1);
wrefresh(win1);
endwin();
exit(0);
}
and then try running it with the two lines in question deleted. Try typing
"foo<RETURN>" at it both times. The first time, it should say
"You typed: foo" and exit; the second time, it should still be waiting and
only finish if you type the LINE FEED key.
Fix:
Fix "getch.c" like this:
*** getch.c.orig Fri Apr 11 13:06:25 1986
--- getch.c Fri Apr 11 13:06:47 1986
***************
*** 18,24 ****
fprintf(outf, "WGETCH: _echoit = %c, _rawmode = %c\n", _echoit ? 'T' : 'F', _rawmode ? 'T' : 'F');
# endif
if (_echoit && !_rawmode) {
! raw();
weset++;
}
inp = getchar();
--- 18,24 ----
fprintf(outf, "WGETCH: _echoit = %c, _rawmode = %c\n", _echoit ? 'T' : 'F', _rawmode ? 'T' : 'F');
# endif
if (_echoit && !_rawmode) {
! cbreak();
weset++;
}
inp = getchar();
***************
*** 30,35 ****
waddch(win, inp);
}
if (weset)
! noraw();
return inp;
}
--- 30,35 ----
waddch(win, inp);
}
if (weset)
! nocbreak();
return inp;
}
--
Guy Harris
{ihnp4, decvax, seismo, decwrl, ...}!sun!guy
guy@sun.arpa (yes, really)