/* 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(prompt, stdout); 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); }