static void flag_change(void)
{
int keypress;
clear_line();
bb_putchar('-');
keypress = less_getch(1);
switch (keypress) {
case 'M':
option_mask32 ^= FLAG_M;
break;
case 'm':
option_mask32 ^= FLAG_m;
break;
case 'E':
option_mask32 ^= FLAG_E;
break;
case '~':
option_mask32 ^= FLAG_TILDE;
break;
case 'S':
option_mask32 ^= FLAG_S;
buffer_fill_and_print();
break;
#if ENABLE_FEATURE_LESS_LINENUMS
case 'N':
option_mask32 ^= FLAG_N;
re_wrap();
buffer_fill_and_print();
break;
#endif
}
}
static void buffer_up(int nlines)
{
cur_fline -= nlines;
if (cur_fline < 0) cur_fline = 0;
read_lines();
buffer_fill_and_print();
}
/* Move the buffer up and down in the file in order to scroll */
static void buffer_down(int nlines)
{
cur_fline += nlines;
read_lines();
cap_cur_fline(nlines);
buffer_fill_and_print();
}
static void buffer_line(int linenum)
{
if (linenum < 0)
linenum = 0;
cur_fline = linenum;
read_lines();
if (linenum + max_displayed_line > max_fline)
linenum = max_fline - max_displayed_line + TILDES;
if (linenum < 0)
linenum = 0;
cur_fline = linenum;
buffer_fill_and_print();
}
/* Reinitialize everything for a new file - free the memory and start over */
static void reinitialize(void)
{
unsigned i;
if (flines) {
for (i = 0; i <= max_fline; i++)
free(MEMPTR(flines[i]));
free(flines);
flines = NULL;
}
max_fline = -1;
cur_fline = 0;
max_lineno = 0;
open_file_and_read_lines();
buffer_fill_and_print();
}
static ssize_t getch_nowait(char* input, int sz)
{
ssize_t rd;
struct pollfd pfd[2];
pfd[0].fd = STDIN_FILENO;
pfd[0].events = POLLIN;
pfd[1].fd = kbd_fd;
pfd[1].events = POLLIN;
again:
tcsetattr(kbd_fd, TCSANOW, &term_less);
/* NB: select/poll returns whenever read will not block. Therefore:
* if eof is reached, select/poll will return immediately
* because read will immediately return 0 bytes.
* Even if select/poll says that input is available, read CAN block
* (switch fd into O_NONBLOCK'ed mode to avoid it)
*/
rd = 1;
if (max_fline <= cur_fline + max_displayed_line
&& eof_error > 0 /* did NOT reach eof yet */
) {
/* We are interested in stdin */
rd = 0;
}
/* position cursor if line input is done */
if (less_gets_pos >= 0)
move_cursor(max_displayed_line + 2, less_gets_pos + 1);
fflush(stdout);
safe_poll(pfd + rd, 2 - rd, -1);
input[0] = '\0';
rd = safe_read(kbd_fd, input, sz); /* NB: kbd_fd is in O_NONBLOCK mode */
if (rd < 0 && errno == EAGAIN) {
/* No keyboard input -> we have input on stdin! */
read_lines();
buffer_fill_and_print();
goto again;
}
set_tty_cooked();
return rd;
}
static int getch_nowait(void)
{
int rd;
struct pollfd pfd[2];
pfd[0].fd = STDIN_FILENO;
pfd[0].events = POLLIN;
pfd[1].fd = kbd_fd;
pfd[1].events = POLLIN;
again:
tcsetattr(kbd_fd, TCSANOW, &term_less);
/* NB: select/poll returns whenever read will not block. Therefore:
* if eof is reached, select/poll will return immediately
* because read will immediately return 0 bytes.
* Even if select/poll says that input is available, read CAN block
* (switch fd into O_NONBLOCK'ed mode to avoid it)
*/
rd = 1;
/* Are we interested in stdin? */
//TODO: reuse code for determining this
if (!(option_mask32 & FLAG_S)
? !(max_fline > cur_fline + max_displayed_line)
: !(max_fline >= cur_fline
&& max_lineno > LINENO(flines[cur_fline]) + max_displayed_line)
) {
if (eof_error > 0) /* did NOT reach eof yet */
rd = 0; /* yes, we are interested in stdin */
}
/* Position cursor if line input is done */
if (less_gets_pos >= 0)
move_cursor(max_displayed_line + 2, less_gets_pos + 1);
fflush_all();
if (kbd_input[0] == 0) { /* if nothing is buffered */
#if ENABLE_FEATURE_LESS_WINCH
while (1) {
int r;
/* NB: SIGWINCH interrupts poll() */
r = poll(pfd + rd, 2 - rd, -1);
if (/*r < 0 && errno == EINTR &&*/ winch_counter)
return '\\'; /* anything which has no defined function */
if (r) break;
}
#else
safe_poll(pfd + rd, 2 - rd, -1);
#endif
}
/* We have kbd_fd in O_NONBLOCK mode, read inside read_key()
* would not block even if there is no input available */
rd = read_key(kbd_fd, kbd_input, /*timeout off:*/ -2);
if (rd == -1) {
if (errno == EAGAIN) {
/* No keyboard input available. Since poll() did return,
* we should have input on stdin */
read_lines();
buffer_fill_and_print();
goto again;
}
/* EOF/error (ssh session got killed etc) */
less_exit(0);
}
set_tty_cooked();
return rd;
}
int less_main(int argc, char **argv)
{
int keypress;
INIT_G();
/* TODO: -x: do not interpret backspace, -xx: tab also */
/* -xxx: newline also */
/* -w N: assume width N (-xxx -w 32: hex viewer of sorts) */
getopt32(argv, "EMmN~I" IF_FEATURE_LESS_DASHCMD("S"));
argc -= optind;
argv += optind;
num_files = argc;
files = argv;
/* Another popular pager, most, detects when stdout
* is not a tty and turns into cat. This makes sense. */
if (!isatty(STDOUT_FILENO))
return bb_cat(argv);
if (!num_files) {
if (isatty(STDIN_FILENO)) {
/* Just "less"? No args and no redirection? */
bb_error_msg("missing filename");
bb_show_usage();
}
} else {
filename = xstrdup(files[0]);
}
if (option_mask32 & FLAG_TILDE)
empty_line_marker = "";
kbd_fd = open(CURRENT_TTY, O_RDONLY);
if (kbd_fd < 0)
return bb_cat(argv);
ndelay_on(kbd_fd);
tcgetattr(kbd_fd, &term_orig);
term_less = term_orig;
term_less.c_lflag &= ~(ICANON | ECHO);
term_less.c_iflag &= ~(IXON | ICRNL);
/*term_less.c_oflag &= ~ONLCR;*/
term_less.c_cc[VMIN] = 1;
term_less.c_cc[VTIME] = 0;
get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
/* 20: two tabstops + 4 */
if (width < 20 || max_displayed_line < 3)
return bb_cat(argv);
max_displayed_line -= 2;
/* We want to restore term_orig on exit */
bb_signals(BB_FATAL_SIGS, sig_catcher);
#if ENABLE_FEATURE_LESS_WINCH
signal(SIGWINCH, sigwinch_handler);
#endif
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
reinitialize();
while (1) {
#if ENABLE_FEATURE_LESS_WINCH
while (WINCH_COUNTER) {
again:
winch_counter--;
get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
/* 20: two tabstops + 4 */
if (width < 20)
width = 20;
if (max_displayed_line < 3)
max_displayed_line = 3;
max_displayed_line -= 2;
free(buffer);
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
/* Avoid re-wrap and/or redraw if we already know
* we need to do it again. These ops are expensive */
if (WINCH_COUNTER)
goto again;
re_wrap();
if (WINCH_COUNTER)
goto again;
buffer_fill_and_print();
/* This took some time. Loop back and check,
* were there another SIGWINCH? */
}
#endif
keypress = less_getch(-1); /* -1: do not position cursor */
keypress_process(keypress);
}
}
