*
* Copyright (C) 2005 by Rob Sullivan <cogito.ergo.cogito@gmail.com>
*
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/*
* redirected input has been read from stdin
*/
-#include <sched.h> /* sched_yield() */
+//config:config LESS
+//config: bool "less"
+//config: default y
+//config: help
+//config: 'less' is a pager, meaning that it displays text files. It possesses
+//config: a wide array of features, and is an improvement over 'more'.
+//config:
+//config:config FEATURE_LESS_MAXLINES
+//config: int "Max number of input lines less will try to eat"
+//config: default 9999999
+//config: depends on LESS
+//config:
+//config:config FEATURE_LESS_BRACKETS
+//config: bool "Enable bracket searching"
+//config: default y
+//config: depends on LESS
+//config: help
+//config: This option adds the capability to search for matching left and right
+//config: brackets, facilitating programming.
+//config:
+//config:config FEATURE_LESS_FLAGS
+//config: bool "Enable -m/-M"
+//config: default y
+//config: depends on LESS
+//config: help
+//config: The -M/-m flag enables a more sophisticated status line.
+//config:
+//config:config FEATURE_LESS_MARKS
+//config: bool "Enable marks"
+//config: default y
+//config: depends on LESS
+//config: help
+//config: Marks enable positions in a file to be stored for easy reference.
+//config:
+//config:config FEATURE_LESS_REGEXP
+//config: bool "Enable regular expressions"
+//config: default y
+//config: depends on LESS
+//config: help
+//config: Enable regular expressions, allowing complex file searches.
+//config:
+//config:config FEATURE_LESS_WINCH
+//config: bool "Enable automatic resizing on window size changes"
+//config: default y
+//config: depends on LESS
+//config: help
+//config: Makes less track window size changes.
+//config:
+//config:config FEATURE_LESS_ASK_TERMINAL
+//config: bool "Use 'tell me cursor position' ESC sequence to measure window"
+//config: default y
+//config: depends on FEATURE_LESS_WINCH
+//config: help
+//config: Makes less track window size changes.
+//config: If terminal size can't be retrieved and $LINES/$COLUMNS are not set,
+//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: bool "Enable flag changes ('-' command)"
+//config: default y
+//config: depends on LESS
+//config: help
+//config: This enables the ability to change command-line flags within
+//config: less itself ('-' keyboard command).
+//config:
+//config:config FEATURE_LESS_LINENUMS
+//config: bool "Enable dynamic switching of line numbers"
+//config: default y
+//config: depends on FEATURE_LESS_DASHCMD
+//config: help
+//config: Enables "-N" command.
+
+//usage:#define less_trivial_usage
+//usage: "[-E" IF_FEATURE_LESS_FLAGS("Mm") "Nh~I?] [FILE]..."
+//usage:#define less_full_usage "\n\n"
+//usage: "View FILE (or stdin) one screenful at a time\n"
+//usage: "\n -E Quit once the end of a file is reached"
+//usage: IF_FEATURE_LESS_FLAGS(
+//usage: "\n -M,-m Display status line with line numbers"
+//usage: "\n and percentage through the file"
+//usage: )
+//usage: "\n -N Prefix line number to each line"
+//usage: "\n -I Ignore case in all searches"
+//usage: "\n -~ Suppress ~s displayed past EOF"
+
+#include <sched.h> /* sched_yield() */
#include "libbb.h"
#if ENABLE_FEATURE_LESS_REGEXP
#include "xregex.h"
#endif
+
+#define ESC "\033"
/* The escape codes for highlighted and normal text */
-#define HIGHLIGHT "\033[7m"
-#define NORMAL "\033[0m"
-/* The escape code to clear the screen */
-#define CLEAR "\033[H\033[J"
-/* The escape code to clear to end of line */
-#define CLEAR_2_EOL "\033[K"
+#define HIGHLIGHT ESC"[7m"
+#define NORMAL ESC"[0m"
+/* The escape code to home and clear to the end of screen */
+#define CLEAR ESC"[H\033[J"
+/* The escape code to clear to the end of line */
+#define CLEAR_2_EOL ESC"[K"
enum {
/* Absolute max of lines eaten */
regex_t pattern;
smallint pattern_valid;
#endif
+#if ENABLE_FEATURE_LESS_ASK_TERMINAL
+ smallint winsize_err;
+#endif
smallint terminated;
- smalluint kbd_input_size;
struct termios term_orig, term_less;
char kbd_input[KEYCODE_BUFFER_SIZE];
};
#define terminated (G.terminated )
#define term_orig (G.term_orig )
#define term_less (G.term_less )
-#define kbd_input_size (G.kbd_input_size )
#define kbd_input (G.kbd_input )
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
current_file = 1; \
eof_error = 1; \
terminated = 1; \
- USE_FEATURE_LESS_REGEXP(wanted_match = -1;) \
+ IF_FEATURE_LESS_REGEXP(wanted_match = -1;) \
} while (0)
/* flines[] are lines read from stdin, each in malloc'ed buffer.
/* Reset terminal input to normal */
static void set_tty_cooked(void)
{
- fflush(stdout);
+ fflush_all();
tcsetattr(kbd_fd, TCSANOW, &term_orig);
}
top-left corner of the console */
static void move_cursor(int line, int row)
{
- printf("\033[%u;%uH", line, row);
+ printf(ESC"[%u;%uH", line, row);
}
static void clear_line(void)
{
- printf("\033[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
+ printf(ESC"[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
}
static void print_hilite(const char *str)
if (option_mask32 & FLAG_N)
w -= 8;
- USE_FEATURE_LESS_REGEXP(again0:)
+ IF_FEATURE_LESS_REGEXP(again0:)
p = current_line = ((char*)xmalloc(w + 4)) + 4;
max_fline += last_terminated;
* immediately */
eof_error = 1;
} else {
- print_statusline("read error");
+ print_statusline(bb_msg_read_error);
}
}
#if !ENABLE_FEATURE_LESS_REGEXP
{
int percentage;
- if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
+ if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
return;
clear_line();
{
const char *p;
- if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
+ if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
return;
/* Change the status if flags have been set */
cur_fline = 0;
diff = max_fline - (cur_fline + max_displayed_line) + TILDES;
/* As the number of lines requested was too large, we just move
- to the end of the file */
+ * to the end of the file */
if (diff > 0)
cur_fline += diff;
}
"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
"\x7f\x9b"; /* DEL and infamous Meta-ESC :( */
static const char ctrlconv[] ALIGN1 =
- /* '\n': it's a former NUL - subst with '@', not 'J' */
+ /* why 40 instead of 4a below? - it is a replacement for '\n'.
+ * '\n' is a former NUL - we subst it with @, not J */
"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f"
"\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f";
/* buf[] holds quarantined version of str */
/* Each part of the line that matches has the HIGHLIGHT
- and NORMAL escape sequences placed around it.
- NB: we regex against line, but insert text
- from quarantined copy (buf[]) */
+ * and NORMAL escape sequences placed around it.
+ * NB: we regex against line, but insert text
+ * from quarantined copy (buf[]) */
str = buf;
growline = NULL;
eflags = 0;
while (match_status == 0) {
char *new = xasprintf("%s%.*s"HIGHLIGHT"%.*s"NORMAL,
- growline ? : "",
- match_structs.rm_so, str,
- match_structs.rm_eo - match_structs.rm_so,
+ growline ? growline : "",
+ (int)match_structs.rm_so, str,
+ (int)(match_structs.rm_eo - match_structs.rm_so),
str + match_structs.rm_so);
free(growline);
growline = new;
cur_fline = 0;
max_lineno = 0;
open_file_and_read_lines();
+#if ENABLE_FEATURE_LESS_ASK_TERMINAL
+ if (G.winsize_err)
+ printf("\033[999;999H" "\033[6n");
+#endif
buffer_fill_and_print();
}
-static ssize_t getch_nowait(void)
+static int64_t getch_nowait(void)
{
int rd;
+ int64_t key64;
struct pollfd pfd[2];
pfd[0].fd = STDIN_FILENO;
/* Position cursor if line input is done */
if (less_gets_pos >= 0)
move_cursor(max_displayed_line + 2, less_gets_pos + 1);
- fflush(stdout);
+ fflush_all();
- if (kbd_input_size == 0) {
+ if (kbd_input[0] == 0) { /* if nothing is buffered */
#if ENABLE_FEATURE_LESS_WINCH
while (1) {
int r;
/* 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_size, kbd_input);
- if (rd == -1) {
+ key64 = read_key(kbd_fd, kbd_input, /*timeout off:*/ -2);
+ if ((int)key64 == -1) {
if (errno == EAGAIN) {
/* No keyboard input available. Since poll() did return,
* we should have input on stdin */
less_exit(0);
}
set_tty_cooked();
- return rd;
+ return key64;
}
-/* Grab a character from input without requiring the return key. If the
- * character is ASCII \033, get more characters and assign certain sequences
- * special return codes. Note that this function works best with raw input. */
-static int less_getch(int pos)
+/* Grab a character from input without requiring the return key.
+ * May return KEYCODE_xxx values.
+ * Note that this function works best with raw input. */
+static int64_t less_getch(int pos)
{
- int i;
+ int64_t key64;
+ int key;
again:
less_gets_pos = pos;
- i = getch_nowait();
+ key = key64 = getch_nowait();
less_gets_pos = -1;
- /* Discard Ctrl-something chars */
- if (i >= 0 && i < ' ' && i != 0x0d && i != 8)
+ /* Discard Ctrl-something chars.
+ * (checking only lower 32 bits is a size optimization:
+ * upper 32 bits are used only by KEYCODE_CURSOR_POS)
+ */
+ if (key >= 0 && key < ' ' && key != 0x0d && key != 8)
goto again;
- return i;
+
+ return key64;
}
static char* less_gets(int sz)
break;
#endif
case 'r': case 'R':
+ /* TODO: (1) also bind ^R, ^L to this?
+ * (2) re-measure window size?
+ */
buffer_print();
break;
/*case 'R':
int less_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int less_main(int argc, char **argv)
{
- int keypress;
+ char *tty_name;
+ int tty_fd;
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" USE_FEATURE_LESS_DASHCMD("S"));
+ getopt32(argv, "EMmN~I" IF_FEATURE_LESS_DASHCMD("S"));
argc -= optind;
argv += optind;
num_files = argc;
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);
+ /* 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,
+ * since we want to set this fd to non-blocking mode,
+ * and not bother with restoring it on exit.
+ */
+ tty_name = xmalloc_ttyname(STDOUT_FILENO);
+ if (tty_name) {
+ tty_fd = open(tty_name, O_RDONLY);
+ free(tty_name);
+ if (tty_fd < 0)
+ goto try_ctty;
+ } else {
+ /* Try controlling tty */
+ try_ctty:
+ tty_fd = open(CURRENT_TTY, O_RDONLY);
+ if (tty_fd < 0)
+ return bb_cat(argv);
+ }
+ ndelay_on(tty_fd);
+ kbd_fd = tty_fd; /* save in a global */
tcgetattr(kbd_fd, &term_orig);
term_less = term_orig;
term_less.c_cc[VMIN] = 1;
term_less.c_cc[VTIME] = 0;
- get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
+ IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) 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);
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
reinitialize();
while (1) {
+ int64_t keypress;
+
#if ENABLE_FEATURE_LESS_WINCH
while (WINCH_COUNTER) {
again:
winch_counter--;
- get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
+ IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
+ IF_FEATURE_LESS_ASK_TERMINAL(got_size:)
/* 20: two tabstops + 4 */
if (width < 20)
width = 20;
/* This took some time. Loop back and check,
* were there another SIGWINCH? */
}
-#endif
keypress = less_getch(-1); /* -1: do not position cursor */
+# if ENABLE_FEATURE_LESS_ASK_TERMINAL
+ if ((int32_t)keypress == KEYCODE_CURSOR_POS) {
+ uint32_t rc = (keypress >> 32);
+ width = (rc & 0x7fff);
+ max_displayed_line = ((rc >> 16) & 0x7fff);
+ goto got_size;
+ }
+# endif
+#else
+ keypress = less_getch(-1); /* -1: do not position cursor */
+#endif
keypress_process(keypress);
}
}
projects / platform / upstream / busybox.git / blobdiff