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/* vi: set sw=4 ts=4: */
/*
* Ask for a password
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
/* do nothing signal handler */
static void askpass_timeout(int UNUSED_PARAM ignore)
{
}
char* FAST_FUNC bb_ask_noecho(int fd, int timeout, const char *prompt)
{
#define MAX_LINE 0xfff
char *ret;
int i;
struct sigaction sa, oldsa;
struct termios tio, oldtio;
tcflush(fd, TCIFLUSH);
/* Was buggy: was printing prompt *before* flushing input,
* which was upsetting "expect" based scripts of some users.
*/
fputs_stdout(prompt);
fflush_all();
tcgetattr(fd, &oldtio);
tio = oldtio;
/* Switch off echo. ECHOxyz meaning:
* ECHO echo input chars
* ECHOE echo BS-SP-BS on erase character
* ECHOK echo kill char specially, not as ^c (ECHOKE controls how exactly)
* ECHOKE erase all input via BS-SP-BS on kill char (else go to next line)
* ECHOCTL Echo ctrl chars as ^c (else echo verbatim:
* e.g. up arrow emits "ESC-something" and thus moves cursor up!)
* ECHONL Echo NL even if ECHO is not set
* ECHOPRT On erase, echo erased chars
* [qwe<BS><BS><BS> input looks like "qwe\ewq/" on screen]
*/
tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL);
tcsetattr(fd, TCSANOW, &tio);
memset(&sa, 0, sizeof(sa));
/* sa.sa_flags = 0; - no SA_RESTART! */
/* SIGINT and SIGALRM will interrupt reads below */
sa.sa_handler = askpass_timeout;
sigaction(SIGINT, &sa, &oldsa);
if (timeout) {
sigaction_set(SIGALRM, &sa);
alarm(timeout);
}
ret = NULL;
i = 0;
while (1) {
int r;
/* User input is uber-slow, no need to optimize reallocs.
* Grow it on every char.
*/
ret = xrealloc(ret, i + 2);
r = read(fd, &ret[i], 1);
if ((i == 0 && r == 0) /* EOF (^D) with no password */
|| r < 0 /* read is interrupted by timeout or ^C */
) {
ret[i] = '\0'; /* paranoia */
nuke_str(ret); /* paranoia */
free(ret);
ret = NULL;
break;
}
if (r == 0 /* EOF */
|| ret[i] == '\r' || ret[i] == '\n' /* EOL */
|| ++i == MAX_LINE /* line limit */
) {
ret[i] = '\0';
break;
}
}
if (timeout) {
alarm(0);
}
sigaction_set(SIGINT, &oldsa);
tcsetattr(fd, TCSANOW, &oldtio);
bb_putchar('\n');
fflush_all();
return ret;
}
char* FAST_FUNC bb_ask_noecho_stdin(const char *prompt)
{
return bb_ask_noecho(STDIN_FILENO, 0, prompt);
}
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