//config: this option makes less perform a last-ditch effort to find it:
//config: position cursor to 999,999 and ask terminal to report real
//config: cursor position using "ESC [ 6 n" escape sequence, then read stdin.
-//config:
//config: This is not clean but helps a lot on serial lines and such.
//config:
//config:config FEATURE_LESS_DASHCMD
//config: less itself ('-' keyboard command).
//config:
//config:config FEATURE_LESS_LINENUMS
-//config: bool "Enable dynamic switching of line numbers"
+//config: bool "Enable -N (dynamic switching of line numbers)"
//config: default y
//config: depends on FEATURE_LESS_DASHCMD
-//config: help
-//config: Enables "-N" command.
+
+//applet:IF_LESS(APPLET(less, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_LESS) += less.o
//usage:#define less_trivial_usage
//usage: "[-E" IF_FEATURE_LESS_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm")
#include <sched.h> /* sched_yield() */
#include "libbb.h"
+#include "common_bufsiz.h"
#if ENABLE_FEATURE_LESS_REGEXP
#include "xregex.h"
#endif
enum { pattern_valid = 0 };
#endif
-enum {
- READING_FILE = -1,
- READING_STDIN = -2,
- READING_NONREG = -3
-};
-
struct globals {
int cur_fline; /* signed */
int kbd_fd; /* fd to get input from */
+ int kbd_fd_orig_flags;
int less_gets_pos;
/* last position in last line, taking into account tabs */
size_t last_line_pos;
char *filename;
char **files;
#if ENABLE_FEATURE_LESS_FLAGS
- int num_lines; /* input source if < 0, line count if >= 0 */
+ int num_lines; /* a flag if < 0, line count if >= 0 */
+# define REOPEN_AND_COUNT (-1)
+# define REOPEN_STDIN (-2)
+# define NOT_REGULAR_FILE (-3)
#endif
#if ENABLE_FEATURE_LESS_MARKS
unsigned num_marks;
static void less_exit(int code)
{
set_tty_cooked();
+ if (!(G.kbd_fd_orig_flags & O_NONBLOCK))
+ ndelay_off(kbd_fd);
clear_line();
if (code < 0)
kill_myself_with_sig(- code); /* does not return */
*/
static void read_lines(void)
{
-#define readbuf bb_common_bufsiz1
char *current_line, *p;
int w = width;
char last_terminated = terminated;
unsigned old_max_fline = max_fline;
#endif
+#define readbuf bb_common_bufsiz1
+ setup_common_bufsiz();
+
/* (careful: max_fline can be -1) */
if (max_fline + 1 > MAXLINES)
return;
if (option_mask32 & FLAG_N)
w -= 8;
- p = current_line = ((char*)xmalloc(w + 4)) + 4;
+ p = current_line = ((char*)xmalloc(w + 5)) + 4;
if (!last_terminated) {
const char *cp = flines[max_fline];
p = stpcpy(p, cp);
time_t t;
errno = 0;
- eof_error = safe_read(STDIN_FILENO, readbuf, sizeof(readbuf));
+ eof_error = safe_read(STDIN_FILENO, readbuf, COMMON_BUFSIZE);
if (errno != EAGAIN)
break;
t = time(NULL);
*--p = '\0';
continue;
}
+ {
+ size_t new_last_line_pos = last_line_pos + 1;
+ if (c == '\t') {
+ new_last_line_pos += 7;
+ new_last_line_pos &= (~7);
+ }
+ if ((int)new_last_line_pos > w)
+ break;
+ last_line_pos = new_last_line_pos;
+ }
/* ok, we will eat this char */
readpos++;
if (c == '\n') {
if (c == '\0') c = '\n';
*p++ = c;
*p = '\0';
- {
- size_t new_last_line_pos = last_line_pos + 1;
- if (c == '\t') {
- new_last_line_pos += 7;
- new_last_line_pos &= (~7);
- }
- if ((int)new_last_line_pos >= w)
- break;
- last_line_pos = new_last_line_pos;
- }
} /* end of "read chars until we have a line" loop */
#if 0
//BUG: also triggers on this:
break;
}
max_fline++;
- current_line = ((char*)xmalloc(w + 4)) + 4;
+ current_line = ((char*)xmalloc(w + 5)) + 4;
p = current_line;
last_line_pos = 0;
} /* end of "read lines until we reach cur_fline" loop */
static void update_num_lines(void)
{
int count, fd;
+ struct stat stbuf;
ssize_t len, i;
char buf[4096];
/* only do this for regular files */
- if (num_lines == READING_FILE) {
+ if (num_lines == REOPEN_AND_COUNT || num_lines == REOPEN_STDIN) {
count = 0;
- fd = open(filename, O_RDONLY);
+ fd = open("/proc/self/fd/0", O_RDONLY);
+ if (fd < 0 && num_lines == REOPEN_AND_COUNT) {
+ /* "filename" is valid only if REOPEN_AND_COUNT */
+ fd = open(filename, O_RDONLY);
+ }
if (fd < 0) {
/* somebody stole my file! */
- num_lines = READING_NONREG;
+ num_lines = NOT_REGULAR_FILE;
return;
}
+ if (fstat(fd, &stbuf) != 0 || !S_ISREG(stbuf.st_mode)) {
+ num_lines = NOT_REGULAR_FILE;
+ goto do_close;
+ }
while ((len = safe_read(fd, buf, sizeof(buf))) > 0) {
for (i = 0; i < len; ++i) {
if (buf[i] == '\n' && ++count == MAXLINES)
}
done:
num_lines = count;
+ do_close:
close(fd);
}
}
char *growline;
regmatch_t match_structs;
- char buf[width];
+ char buf[width+1];
const char *str = line;
char *p = buf;
size_t n;
static void print_ascii(const char *str)
{
- char buf[width];
+ char buf[width+1];
char *p;
size_t n;
static void open_file_and_read_lines(void)
{
if (filename) {
+ xmove_fd(xopen(filename, O_RDONLY), STDIN_FILENO);
#if ENABLE_FEATURE_LESS_FLAGS
- struct stat stbuf;
-
- xstat(filename, &stbuf);
- if (!S_ISREG(stbuf.st_mode))
- num_lines = READING_NONREG;
+ num_lines = REOPEN_AND_COUNT;
#endif
- xmove_fd(xopen(filename, O_RDONLY), STDIN_FILENO);
} else {
/* "less" with no arguments in argv[] */
/* For status line only */
filename = xstrdup(bb_msg_standard_input);
+#if ENABLE_FEATURE_LESS_FLAGS
+ num_lines = REOPEN_STDIN;
+#endif
}
readpos = 0;
readeof = 0;
max_fline = -1;
cur_fline = 0;
max_lineno = 0;
-#if ENABLE_FEATURE_LESS_FLAGS
- num_lines = filename ? READING_FILE : READING_STDIN;
-#endif
open_file_and_read_lines();
#if ENABLE_FEATURE_LESS_ASK_TERMINAL
if (G.winsize_err)
static void match_right_bracket(char bracket)
{
- unsigned i;
+ unsigned i = cur_fline;
- if (strchr(flines[cur_fline], bracket) == NULL) {
+ if (i >= max_fline
+ || strchr(flines[i], bracket) == NULL
+ ) {
print_statusline("No bracket in top line");
return;
}
+
bracket = opp_bracket(bracket);
- for (i = cur_fline + 1; i < max_fline; i++) {
+ for (; i < max_fline; i++) {
if (strchr(flines[i], bracket) != NULL) {
- buffer_line(i);
+ /*
+ * Line with matched right bracket becomes
+ * last visible line
+ */
+ buffer_line(i - max_displayed_line);
return;
}
}
static void match_left_bracket(char bracket)
{
- int i;
+ int i = cur_fline + max_displayed_line;
- if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) {
+ if (i >= max_fline
+ || strchr(flines[i], bracket) == NULL
+ ) {
print_statusline("No bracket in bottom line");
return;
}
bracket = opp_bracket(bracket);
- for (i = cur_fline + max_displayed_line; i >= 0; i--) {
+ for (; i >= 0; i--) {
if (strchr(flines[i], bracket) != NULL) {
+ /*
+ * Line with matched left bracket becomes
+ * first visible line
+ */
buffer_line(i);
return;
}
/* 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) {
/* 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 */
+ tty_fd = STDOUT_FILENO;
+ }
}
- ndelay_on(tty_fd);
+ G.kbd_fd_orig_flags = ndelay_on(tty_fd);
kbd_fd = tty_fd; /* save in a global */
tcgetattr(kbd_fd, &term_orig);
projects / oweals / busybox.git / blobdiff