void
restore_rl_state()
{
char *newprompt;
move_cursor_to_start_of_prompt(impatient_prompt ? ERASE : DONT_ERASE);
cook_prompt_if_necessary();
newprompt = mark_invisible(saved_rl_state.cooked_prompt); /* bracket (colour) control sequences with \001 and \002 */
rl_expand_prompt(newprompt);
mirror_slaves_echo_mode(); /* don't show passwords etc */
DPRINTF1(DEBUG_READLINE,"newprompt now %s", mangle_string_for_debug_log(newprompt,MANGLE_LENGTH));
rl_callback_handler_install(newprompt, &line_handler);
DPRINTF0(DEBUG_AD_HOC, "freeing newprompt");
free(newprompt); /* readline docs don't say it, but we can free newprompt now (readline apparently
uses its own copy) */
rl_insert_text(saved_rl_state.input_buffer);
rl_point = saved_rl_state.point;
saved_rl_state.already_saved = 0;
DPRINTF0(DEBUG_AD_HOC, "Starting redisplay");
rl_redisplay();
rl_prep_terminal(1);
prompt_is_still_uncooked = FALSE; /* has been done right now */
}
static void
handle_sigTSTP(int signo)
{
sigset_t all_signals;
int error, saved_errno = errno;
DEBUG_RANDOM_SLEEP;
sigfillset(&all_signals);
DPRINTF2(DEBUG_SIGNALS, "got %s, sending it to pgid %d", signal_name(signo), command_pid);
zero_select_timeout();
/* Hand the SIGTSTP down to command and its process group */
if (command_pid && (error = kill(-command_pid, SIGTSTP))) {
myerror(FATAL|USE_ERRNO, "Failed to deliver SIGTSTP");
}
if (within_line_edit)
save_rl_state();
mysignal(SIGTSTP, SIG_DFL); /* reset disposition to default (i.e. suspend) */
sigprocmask(SIG_UNBLOCK, &all_signals, NULL); /* respond to sleep- and wake-up signals */
kill(getpid(), SIGTSTP); /* suspend */
/* keyboard gathers dust, kingdoms crumble,.... */
/* .... */
/* Beautiful princess types "fg", (or her father tries to kill us...) and we wake up HERE: */
sigprocmask(SIG_BLOCK, &all_signals, NULL);
mysignal(SIGTSTP, &handle_sigTSTP);
DPRINTF0(DEBUG_SIGNALS, "woken up");
/* On most systems, command's process group will have been woken up by the handler of
the signal that woke us up. This doesn't seem to happen for SIGCONT on QNX, so here goes: */
#ifdef __QNX__
if (command_pid && (error = kill(-command_pid, SIGCONT))) {
myerror(FATAL|USE_ERRNO, "Failed to deliver SIGCONT");
}
#endif
if (within_line_edit) {
restore_rl_state();
} else {
set_echo(FALSE);
cr();
if (skip_rlwrap())
return;
move_cursor_to_start_of_prompt(ERASE);
cook_prompt_if_necessary();
my_putstr(saved_rl_state.cooked_prompt);
}
adapt_tty_winsize(STDIN_FILENO, master_pty_fd); /* just in case */
errno = saved_errno;
sigprocmask(SIG_UNBLOCK, &all_signals, NULL);
}
/*
* main loop: listen on stdin (for user input) and master pty (for command output),
* and try to write output_queue to master_pty (if it is not empty)
* This function never returns.
*/
void
main_loop()
{
int nfds;
fd_set readfds;
fd_set writefds;
int nread;
char buf[BUFFSIZE], *timeoutstr, *old_raw_prompt, *new_output_minus_prompt;
int promptlen = 0;
int leave_prompt_alone;
sigset_t no_signals_blocked;
struct timespec select_timeout, *select_timeoutptr;
struct timespec immediately = { 0, 0 }; /* zero timeout when child is dead */
struct timespec wait_a_little = {0, 0xBadf00d }; /* tv_usec field will be filled in when initialising */
struct timespec *forever = NULL;
wait_a_little.tv_nsec = 1000 * 1000 * wait_before_prompt;
sigemptyset(&no_signals_blocked);
init_readline("");
last_minute_checks();
pass_through_filter(TAG_OUTPUT,""); /* If something is wrong with filter, get the error NOW */
set_echo(FALSE); /* This will also put the terminal in CBREAK mode */
test_main();
/* ------------------------------ main loop -------------------------------*/
while (TRUE) {
/* listen on both stdin and pty_fd */
FD_ZERO(&readfds);
FD_SET(STDIN_FILENO, &readfds);
FD_SET(master_pty_fd, &readfds);
/* try to write output_queue to master_pty (but only if it is nonempty) */
FD_ZERO(&writefds);
if (output_queue_is_nonempty())
FD_SET(master_pty_fd, &writefds);
DPRINTF1(DEBUG_AD_HOC, "prompt_is_still_uncooked = %d", prompt_is_still_uncooked);
if (command_is_dead || ignore_queued_input) {
select_timeout = immediately;
select_timeoutptr = &select_timeout;
timeoutstr = "immediately";
} else if (prompt_is_still_uncooked) {
select_timeout = wait_a_little;
select_timeoutptr = &select_timeout;
timeoutstr = "wait_a_little";
} else {
select_timeoutptr = forever; /* NULL */
timeoutstr = "forever";
}
DPRINTF1(DEBUG_TERMIO, "calling select() with timeout %s", timeoutstr);
nfds = my_pselect(1 + master_pty_fd, &readfds, &writefds, NULL, select_timeoutptr, &no_signals_blocked);
DPRINTF3(DEBUG_TERMIO, "select() returned %d (stdin|pty in|pty out = %03d), within_line_edit=%d", nfds,
100*(FD_ISSET(STDIN_FILENO, &readfds)?1:0) + 10*(FD_ISSET(master_pty_fd, &readfds)?1:0) + (FD_ISSET(master_pty_fd, &writefds)?1:0),
within_line_edit);
assert(!filter_pid || filter_is_dead || kill(filter_pid,0) == 0);
assert(command_is_dead || kill(command_pid,0) == 0);
/* check flags that may have been set by signal handlers */
if (filter_is_dead)
filters_last_words(); /* will call myerror with last words */
if (received_WINCH) { /* received_WINCH flag means we've had a WINCH while within_line_edit was FALSE */
DPRINTF0(DEBUG_READLINE, "Starting line edit as a result of WINCH ");
within_line_edit = TRUE;
restore_rl_state();
received_WINCH = FALSE;
continue;
}
if (nfds < 0) { /* exception */
if (errno == EINTR) { /* interrupted by signal */
continue;
} else
myerror("select received exception");
} else if (nfds == 0) {
/* timeout, which can only happen when .. */
if (ignore_queued_input) { /* ... we have read all the input keystrokes that should
be ignored (i.e. those that accumulated on stdin while we
were calling an external editor) */
ignore_queued_input = FALSE;
continue;
} else if (command_is_dead) { /* ... or else, if child is dead, ... */
DPRINTF2(DEBUG_SIGNALS,
"select returned 0, command_is_dead=%d, commands_exit_status=%d",
command_is_dead, commands_exit_status);
cleanup_rlwrap_and_exit(EXIT_SUCCESS);
} else if (prompt_is_still_uncooked) { /* cooking time? */
if (we_just_got_a_signal_or_EOF) {
we_just_got_a_signal_or_EOF = FALSE; /* 1. If we got a signal/EOF before cooking time, we don't need special action
to preserve the cooked prompt.
2. Reset we_just_got_a_signal_or_EOF after a signal or EOF that didn't kill command */
continue;
}
if (!skip_rlwrap()) { /* ... or else, it is time to cook the prompt */
if (pre_given && accepted_lines == 0) {
saved_rl_state.input_buffer = mysavestring(pre_given); /* stuff pre-given text into edit buffer */
saved_rl_state.point = strlen(pre_given);
DPRINTF0(DEBUG_READLINE, "Starting line edit (because of -P option)");
within_line_edit = TRUE;
restore_rl_state();
continue;
}
if (accepted_lines == 1 && one_shot_rlwrap)
cleanup_rlwrap_and_exit(EXIT_SUCCESS);
move_cursor_to_start_of_prompt(ERASE); /* cooked prompt may be shorter than raw prompt, hence the ERASE */
/* move and erase before cooking, as we need to move/erase according
to the raw prompt */
cook_prompt_if_necessary();
DPRINTF2(DEBUG_READLINE,"After cooking, raw_prompt=%s, cooked=%s",
mangle_string_for_debug_log(saved_rl_state.raw_prompt, MANGLE_LENGTH),
mangle_string_for_debug_log(saved_rl_state.cooked_prompt, MANGLE_LENGTH));
my_putstr(saved_rl_state.cooked_prompt);
rlwrap_already_prompted = TRUE;
}
prompt_is_still_uncooked = FALSE;
} else {
myerror("unexpected select() timeout");
}
} else if (nfds > 0) { /* Hah! something to read or write */
/* -------------------------- read pty --------------------------------- */
if (FD_ISSET(master_pty_fd, &readfds)) { /* there is something to read on master pty: */
if ((nread = read(master_pty_fd, buf, BUFFSIZE - 1)) <= 0) { /* read it */
if (command_is_dead || nread == 0) { /* child is dead or has closed its stdout */
if (promptlen > 0) /* commands dying words were not terminated by \n ... */
my_putchar('\n'); /* provide the missing \n */
cleanup_rlwrap_and_exit(EXIT_SUCCESS);
} else if (errno == EINTR) /* interrupted by signal ...*/
continue; /* ... don't worry */
else
myerror("read error on master pty");
}
completely_mirror_slaves_output_settings(); /* some programs (e.g. joe) need this. Gasp!! */
if (skip_rlwrap()) { /* Race condition here! The client may just have finished an emacs session and
returned to cooked mode, while its ncurses-riddled output is stil waiting for us to be processed. */
write_patiently(STDOUT_FILENO, buf, nread, "to stdout");
DPRINTF2(DEBUG_TERMIO, "read from pty and wrote to stdout %d bytes in direct mode <%s>",
nread, mangle_string_for_debug_log((buf[nread]='\0', buf), MANGLE_LENGTH));
yield();
continue;
}
DPRINTF2(DEBUG_TERMIO, "read %d bytes from pty into buffer: %s", nread, mangle_string_for_debug_log((buf[nread]='\0', buf), MANGLE_LENGTH));
remove_padding_and_terminate(buf, nread);
write_logfile(buf);
if (within_line_edit) /* client output arrives while we're editing keyboard input: */
save_rl_state(); /* temporarily disable readline and restore the screen state before readline was called */
assert(saved_rl_state.raw_prompt != NULL);
/* We *always* compute the printable part and the new raw prompt, and *always* print the printable part
There are four possibilities:
1. impatient before cooking. The raw prompt has been printed, write the new output after it
2. patient before cooking No raw prompt has been printed yet, don't print anything
3. impatient after cooking
3a no current prompt print the new output
3b some current prompt erase it, replace by current raw prompt and print new output
4. patient after cooking don't print anything
*/
/* sometimes we want to leave the prompt standing, e.g. after accepting a line, or when a signal arrived */
leave_prompt_alone =
*saved_rl_state.raw_prompt == '\0' /* saved_rl_state.raw_prompt = "" in two distinct cases: when there is actually no prompt,
or just after accepting a line, when the cursor is at the end of the prompt. In both
cases, we dont't want to move the cursor */
|| prompt_is_still_uncooked /* in this case no prompt has been displayed yet */
|| command_is_dead
|| (we_just_got_a_signal_or_EOF && strrchr(buf, '\n')); /* a signal followed by output with a newline in it: treat it as
response to user input, so leave the prompt alone */
DPRINTF3(DEBUG_READLINE, "leave_prompt_alone: %s (raw prompt: %s, prompt_is_still_uncooked: %d)",
(leave_prompt_alone? "yes" : "no"), mangle_string_for_debug_log(saved_rl_state.raw_prompt, MANGLE_LENGTH), prompt_is_still_uncooked);
if (!leave_prompt_alone) /* && (!impatient_prompt || !saved_rl_state.cooked_prompt)) */
move_cursor_to_start_of_prompt(ERASE);
else if (we_just_got_a_signal_or_EOF) {
free (saved_rl_state.raw_prompt);
saved_rl_state.raw_prompt = mysavestring(""); /* prevent reprinting the prompt */
}
if (impatient_prompt && !leave_prompt_alone)
old_raw_prompt = mysavestring(saved_rl_state.raw_prompt);
new_output_minus_prompt = process_new_output(buf, &saved_rl_state); /* chop off the part after the last newline and put this in
saved_rl_state.raw_prompt (or append buf if no newline found)*/
if (impatient_prompt) { /* in impatient mode, ALL command output is passed through the OUTPUT filter, including the prompt The
prompt, however, is filtered separately at cooking time and then displayed */
char *filtered = pass_through_filter(TAG_OUTPUT, buf);
if(!leave_prompt_alone) {
my_putstr(old_raw_prompt);
free(old_raw_prompt);
}
my_putstr(filtered);
free (filtered);
rlwrap_already_prompted = TRUE;
} else {
my_putstr(new_output_minus_prompt);
rlwrap_already_prompted = FALSE;
}
free(new_output_minus_prompt);
prompt_is_still_uncooked = TRUE;
if (within_line_edit)
restore_rl_state();
yield(); /* wait for what client has to say .... */
continue; /* ... and don't attempt to process keyboard input as long as it is talking ,
in order to avoid re-printing the current prompt (i.e. unfinished output line) */
}
/* ----------------------------- key pressed: read stdin -------------------------*/
if (FD_ISSET(STDIN_FILENO, &readfds)) { /* key pressed */
unsigned char byte_read; /* the readline function names and documentation talk about "characters" and "keys",
but we're reading bytes (i.e. unsigned chars) here, and those may very well be
part of a multi-byte character. Example: hebrew "aleph" in utf-8 is 0xd790; pressing this key
will make us read 2 bytes 0x90 and then 0xd7, (or maybe the other way round depending on endianness??)
The readline library hides all this complexity and allows one to just "pass the bytes around" */
nread = read(STDIN_FILENO, &byte_read, 1); /* read next byte of input */
assert(sizeof(unsigned char) == 1); /* gets optimised away */
if (nread <= 0)
DPRINTF1(DEBUG_TERMIO, "read from stdin returned %d", nread);
if (nread < 0)
if (errno == EINTR)
continue;
else
myerror("Unexpected error");
else if (nread == 0) /* EOF on stdin */
cleanup_rlwrap_and_exit(EXIT_SUCCESS);
else if (ignore_queued_input)
continue; /* do nothing with it*/
assert(nread == 1);
DPRINTF2(DEBUG_TERMIO, "read from stdin: byte 0x%02x (%s)", byte_read, mangle_char_for_debug_log(byte_read, TRUE));
if (skip_rlwrap()) { /* direct mode, just pass it on */
/* remote possibility of a race condition here: when the first half of a multi-byte char is read in
direct mode and the second half in readline mode. Oh well... */
DPRINTF0(DEBUG_TERMIO, "passing it on (in transparent mode)");
completely_mirror_slaves_terminal_settings(); /* this is of course 1 keypress too late: we should
mirror the terminal settings *before* the user presses a key.
(maybe using rl_event_hook??) @@@FIXME @@@ HOW?*/
write_patiently(master_pty_fd, &byte_read, 1, "to master pty");
} else { /* hand it over to readline */
if (!within_line_edit) { /* start a new line edit */
DPRINTF0(DEBUG_READLINE, "Starting line edit");
within_line_edit = TRUE;
restore_rl_state();
}
if (term_eof && byte_read == term_eof && strlen(rl_line_buffer) == 0) { /* hand a term_eof (usually CTRL-D) directly to command */
char *sent_EOF = mysavestring("?");
*sent_EOF = term_eof;
put_in_output_queue(sent_EOF);
we_just_got_a_signal_or_EOF = TRUE;
free(sent_EOF);
}
else {
rl_stuff_char(byte_read); /* stuff it back in readline's input queue */
DPRINTF0(DEBUG_TERMIO, "passing it to readline");
DPRINTF2(DEBUG_READLINE, "rl_callback_read_char() (_rl_eof_char=%d, term_eof=%d)", _rl_eof_char, term_eof);
rl_callback_read_char();
}
}
}
/* -------------------------- write pty --------------------------------- */
if (FD_ISSET(master_pty_fd, &writefds)) {
flush_output_queue();
yield(); /* give slave command time to respond. If we don't do this,
nothing bad will happen, but the "dialogue" on screen will be
out of order */
}
} /* if (ndfs > 0) */
} /* while (1) */
} /* void main_loop() */
