less: fall back to using fd #1 for keyboard reading. Closes 9231

function                                             old     new   delta
less_main                                           2535    2540      +5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-09-13 20:53:38 +02:00
parent 20a3262cd7
commit 3c0e579a06

View File

@ -1797,9 +1797,10 @@ int less_main(int argc, char **argv)
/* Some versions of less can survive w/o controlling tty,
* try to do the same. This also allows to specify an alternative
* tty via "less 1<>TTY".
* We don't try to use STDOUT_FILENO directly,
*
* We prefer not to use STDOUT_FILENO directly,
* since we want to set this fd to non-blocking mode,
* and not bother with restoring it on exit.
* and not interfere with other processes which share stdout with us.
*/
tty_name = xmalloc_ttyname(STDOUT_FILENO);
if (tty_name) {
@ -1811,8 +1812,15 @@ int less_main(int argc, char **argv)
/* Try controlling tty */
try_ctty:
tty_fd = open(CURRENT_TTY, O_RDONLY);
if (tty_fd < 0)
return bb_cat(argv);
if (tty_fd < 0) {
/*
* If all else fails, less 481 uses stdout. Mimic that.
* Testcase where usually both ttyname(STDOUT_FILENO)
* and open(CURRENT_TTY) fail:
* su -s /bin/sh -c 'busybox less FILE' - nobody
*/
tty_fd = STDOUT_FILENO;
}
}
ndelay_on(tty_fd);
kbd_fd = tty_fd; /* save in a global */