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less: add optional line number toggle and resizing on SIGWINCH.

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This commit is contained in:
Denis Vlasenko 2008-10-24 22:43:27 +00:00
parent aa2a1c000c
commit 53c80f0972
4 changed files with 108 additions and 67 deletions
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2
TODO_config_nommu
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@ -575,7 +575,7 @@ CONFIG_LESS=y
CONFIG_FEATURE_LESS_MAXLINES=9999999
CONFIG_FEATURE_LESS_BRACKETS=y
CONFIG_FEATURE_LESS_FLAGS=y
CONFIG_FEATURE_LESS_FLAGCS=y
CONFIG_FEATURE_LESS_DASHCMD=y
CONFIG_FEATURE_LESS_MARKS=y
CONFIG_FEATURE_LESS_REGEXP=y
CONFIG_HDPARM=y

20
miscutils/Config.in
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@ -293,13 +293,13 @@ config FEATURE_LESS_FLAGS
The -M flag enables a more sophisticated status line.
The -m flag enables a simpler status line with a percentage.
config FEATURE_LESS_FLAGCS
bool "Enable flag changes"
config FEATURE_LESS_DASHCMD
bool "Enable flag changes ('-' command)"
default n
depends on LESS
help
This enables the ability to change command-line flags within
less itself.
less itself ('-' keyboard command).
config FEATURE_LESS_MARKS
bool "Enable marks"
@ -315,6 +315,20 @@ config FEATURE_LESS_REGEXP
help
Enable regular expressions, allowing complex file searches.
config FEATURE_LESS_LINENUMS
bool "Enable dynamic switching of line numbers"
default n
depends on LESS
help
Enable "-N" command.
config FEATURE_LESS_WINCH
bool "Enable automatic resizing on window size changes"
default n
depends on LESS
help
Makes less track window size changes.
config HDPARM
bool "hdparm"
default n

151
miscutils/less.c
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@ -28,13 +28,6 @@
#include "xregex.h"
#endif
/* In progress */
#define ENABLE_FEATURE_LESS_REWRAP 0
/* FIXME: currently doesn't work right */
#undef ENABLE_FEATURE_LESS_FLAGCS
#define ENABLE_FEATURE_LESS_FLAGCS 0
/* The escape codes for highlighted and normal text */
#define HIGHLIGHT "\033[7m"
#define NORMAL "\033[0m"
@ -77,14 +70,14 @@ enum {
/* Command line options */
enum {
FLAG_E = 1,
FLAG_E = 1 << 0,
FLAG_M = 1 << 1,
FLAG_m = 1 << 2,
FLAG_N = 1 << 3,
FLAG_TILDE = 1 << 4,
FLAG_I = 1 << 5,
FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_DASHCMD,
/* hijack command line options variable for internal state vars */
LESS_STATE_NO_WRAP = 1 << 14,
LESS_STATE_MATCH_BACKWARDS = 1 << 15,
};
@ -98,10 +91,13 @@ struct globals {
int less_gets_pos;
/* last position in last line, taking into account tabs */
size_t linepos;
unsigned max_displayed_line;
unsigned max_fline;
unsigned max_lineno; /* this one tracks linewrap */
unsigned max_displayed_line;
unsigned width;
#if ENABLE_FEATURE_LESS_WINCH
unsigned winch_counter;
#endif
ssize_t eof_error; /* eof if 0, error if < 0 */
ssize_t readpos;
ssize_t readeof; /* must be signed */
@ -132,10 +128,11 @@ struct globals {
#define kbd_fd (G.kbd_fd )
#define less_gets_pos (G.less_gets_pos )
#define linepos (G.linepos )
#define max_displayed_line (G.max_displayed_line)
#define max_fline (G.max_fline )
#define max_lineno (G.max_lineno )
#define max_displayed_line (G.max_displayed_line)
#define width (G.width )
#define winch_counter (G.winch_counter )
#define eof_error (G.eof_error )
#define readpos (G.readpos )
#define readeof (G.readeof )
@ -218,7 +215,7 @@ static void less_exit(int code)
exit(code);
}
#if ENABLE_FEATURE_LESS_REWRAP
#if ENABLE_FEATURE_LESS_LINENUMS || ENABLE_FEATURE_LESS_WINCH
static void re_wrap(void)
{
int w = width;
@ -297,6 +294,7 @@ static void re_wrap(void)
linepos = 0; // XXX
cur_fline = new_cur_fline;
/* max_lineno is screen-size independent */
pattern_valid = 0;
}
#endif
@ -426,7 +424,11 @@ static void read_lines(void)
eof_error = 0; /* Pretend we saw EOF */
break;
}
if (max_fline > cur_fline + max_displayed_line) {
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 !ENABLE_FEATURE_LESS_REGEXP
break;
#else
@ -719,18 +721,19 @@ static void buffer_print(void)
status_print();
}
#if ENABLE_FEATURE_LESS_REWRAP
static void buffer_fill_and_print(void)
{
unsigned i = 0;
int fpos = cur_fline + i;
unsigned i;
#if ENABLE_FEATURE_LESS_DASHCMD
int fpos = cur_fline;
if (option_mask32 & LESS_STATE_NO_WRAP) {
if (option_mask32 & FLAG_S) {
/* Go back to the beginning of this line */
while (fpos && LINENO(flines[fpos]) == LINENO(flines[fpos-1]))
fpos--;
}
i = 0;
while (i <= max_displayed_line && fpos <= max_fline) {
int lineno = LINENO(flines[fpos]);
buffer[i] = flines[fpos];
@ -738,28 +741,20 @@ static void buffer_fill_and_print(void)
do {
fpos++;
} while ((fpos <= max_fline)
&& (option_mask32 & LESS_STATE_NO_WRAP)
&& (option_mask32 & FLAG_S)
&& lineno == LINENO(flines[fpos])
);
}
for (; i <= max_displayed_line; i++) {
buffer[i] = empty_line_marker;
}
buffer_print();
}
#else
static void buffer_fill_and_print(void)
{
unsigned i;
for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) {
buffer[i] = flines[cur_fline + i];
}
#endif
for (; i <= max_displayed_line; i++) {
buffer[i] = empty_line_marker;
}
buffer_print();
}
#endif
/* Move the buffer up and down in the file in order to scroll */
static void buffer_down(int nlines)
@ -857,7 +852,19 @@ static ssize_t getch_nowait(char* input, int sz)
if (less_gets_pos >= 0)
move_cursor(max_displayed_line + 2, less_gets_pos + 1);
fflush(stdout);
#if ENABLE_FEATURE_LESS_WINCH
while (1) {
int r;
r = poll(pfd + rd, 2 - rd, -1);
if (/*r < 0 && errno == EINTR &&*/ winch_counter) {
input[0] = '\\'; /* anything which has no defined function */
return 1;
}
if (r) break;
}
#else
safe_poll(pfd + rd, 2 - rd, -1);
#endif
input[0] = '\0';
rd = safe_read(kbd_fd, input, sz); /* NB: kbd_fd is in O_NONBLOCK mode */
@ -1114,7 +1121,7 @@ static void regex_process(void)
/* Compile the regex and check for errors */
err = regcomp_or_errmsg(&pattern, uncomp_regex,
option_mask32 & FLAG_I ? REG_ICASE : 0);
(option_mask32 & FLAG_I) ? REG_ICASE : 0);
free(uncomp_regex);
if (err) {
print_statusline(err);
@ -1208,7 +1215,7 @@ static void number_process(int first_digit)
}
}
#if ENABLE_FEATURE_LESS_FLAGCS
#if ENABLE_FEATURE_LESS_DASHCMD
static void flag_change(void)
{
int keypress;
@ -1230,6 +1237,17 @@ static void flag_change(void)
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
}
}
@ -1467,7 +1485,7 @@ static void keypress_process(int keypress)
regex_process();
break;
#endif
#if ENABLE_FEATURE_LESS_FLAGCS
#if ENABLE_FEATURE_LESS_DASHCMD
case '-':
flag_change();
buffer_print();
@ -1487,25 +1505,6 @@ static void keypress_process(int keypress)
case ':':
colon_process();
break;
#if ENABLE_FEATURE_LESS_REWRAP
case '*': /* Should be -N command / option */
option_mask32 ^= FLAG_N;
get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
if (width < 20) /* 20: two tabstops + 4 */
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 *));
re_wrap();
buffer_fill_and_print();
break;
case '&': /* Should be -S command / option */
option_mask32 ^= LESS_STATE_NO_WRAP;
buffer_fill_and_print();
break;
#endif
}
if (isdigit(keypress))
@ -1517,6 +1516,13 @@ static void sig_catcher(int sig)
less_exit(- sig);
}
#if ENABLE_FEATURE_LESS_WINCH
static void sigwinch_handler(int sig UNUSED_PARAM)
{
winch_counter++;
}
#endif
int less_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int less_main(int argc, char **argv)
{
@ -1527,7 +1533,7 @@ int less_main(int argc, char **argv)
/* 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");
getopt32(argv, "EMmN~I" USE_FEATURE_LESS_DASHCMD("S"));
argc -= optind;
argv += optind;
num_files = argc;
@ -1537,10 +1543,6 @@ int less_main(int argc, char **argv)
* is not a tty and turns into cat. This makes sense. */
if (!isatty(STDOUT_FILENO))
return bb_cat(argv);
kbd_fd = open(CURRENT_TTY, O_RDONLY);
if (kbd_fd < 0)
return bb_cat(argv);
ndelay_on(kbd_fd);
if (!num_files) {
if (isatty(STDIN_FILENO)) {
@ -1548,19 +1550,18 @@ int less_main(int argc, char **argv)
bb_error_msg("missing filename");
bb_show_usage();
}
} else
} else {
filename = xstrdup(files[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;
buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
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);
@ -1569,11 +1570,37 @@ int less_main(int argc, char **argv)
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
if (winch_counter) {
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 *));
re_wrap();
buffer_fill_and_print();
}
#endif
keypress = less_getch(-1); /* -1: do not position cursor */
keypress_process(keypress);
}

2
scripts/defconfig
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@ -573,7 +573,7 @@ CONFIG_LESS=y
CONFIG_FEATURE_LESS_MAXLINES=9999999
CONFIG_FEATURE_LESS_BRACKETS=y
CONFIG_FEATURE_LESS_FLAGS=y
CONFIG_FEATURE_LESS_FLAGCS=y
CONFIG_FEATURE_LESS_DASHCMD=y
CONFIG_FEATURE_LESS_MARKS=y
CONFIG_FEATURE_LESS_REGEXP=y
CONFIG_HDPARM=y