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more: hardcode FEATURE_USE_TERMIOS=y in this applet; code shrink

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function                                             old     new   delta
get_wh                                                 -      27     +27
tcsetattr_tty_TCSANOW                                  -      18     +18
gotsig                                                35      27      -8
more_main                                            835     759     -76
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/2 up/down: 45/-84)            Total: -39 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2017-01-11 10:38:52 +01:00
parent 80f806cac9
commit c5891fe1af
1 changed files with 49 additions and 57 deletions
Download Patch File Download Diff File Expand all files Collapse all files

106
util-linux/more.c
View File

@@ -38,32 +38,34 @@
#include "libbb.h"
#include "common_bufsiz.h"
/* Support for FEATURE_USE_TERMIOS */
struct globals {
int cin_fileno;
int tty_fileno;
unsigned terminal_width;
unsigned terminal_height;
struct termios initial_settings;
struct termios new_settings;
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
#define initial_settings (G.initial_settings)
#define new_settings (G.new_settings )
#define cin_fileno (G.cin_fileno )
#define INIT_G() do { setup_common_bufsiz(); } while (0)
#define setTermSettings(fd, argp) \
do { \
if (ENABLE_FEATURE_USE_TERMIOS) \
tcsetattr(fd, TCSANOW, argp); \
} while (0)
#define getTermSettings(fd, argp) tcgetattr(fd, argp)
static void get_wh(void)
{
/* never returns w, h <= 1 */
get_terminal_width_height(G.tty_fileno, &G.terminal_width, &G.terminal_height);
G.terminal_height -= 1;
}
static void tcsetattr_tty_TCSANOW(struct termios *settings)
{
tcsetattr(G.tty_fileno, TCSANOW, settings);
}
static void gotsig(int sig UNUSED_PARAM)
{
/* bb_putchar_stderr doesn't use stdio buffering,
* therefore it is safe in signal handler */
bb_putchar_stderr('\n');
setTermSettings(cin_fileno, &initial_settings);
tcsetattr_tty_TCSANOW(&G.initial_settings);
_exit(EXIT_FAILURE);
}
@@ -73,22 +75,16 @@ int more_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int more_main(int argc UNUSED_PARAM, char **argv)
{
int c = c; /* for compiler */
int lines;
int input = 0;
int spaces = 0;
int please_display_more_prompt;
struct stat st;
FILE *file;
FILE *cin;
int len;
unsigned terminal_width;
unsigned terminal_height;
FILE *tty;
INIT_G();
/* Parse options */
/* Accepted but ignored: */
/* -d Display help instead of ringing bell is pressed */
/* -d Display help instead of ringing bell */
/* -f Count logical lines (IOW: long lines are not folded) */
/* -l Do not pause after any line containing a ^L (form feed) */
/* -s Squeeze blank lines into one */
@@ -100,26 +96,25 @@ int more_main(int argc UNUSED_PARAM, char **argv)
* is not a tty and turns into cat. This makes sense. */
if (!isatty(STDOUT_FILENO))
return bb_cat(argv);
cin = fopen_for_read(CURRENT_TTY);
if (!cin)
tty = fopen_for_read(CURRENT_TTY);
if (!tty)
return bb_cat(argv);
if (ENABLE_FEATURE_USE_TERMIOS) {
cin_fileno = fileno(cin);
getTermSettings(cin_fileno, &initial_settings);
new_settings = initial_settings;
new_settings.c_lflag &= ~(ICANON | ECHO);
new_settings.c_cc[VMIN] = 1;
new_settings.c_cc[VTIME] = 0;
setTermSettings(cin_fileno, &new_settings);
bb_signals(0
+ (1 << SIGINT)
+ (1 << SIGQUIT)
+ (1 << SIGTERM)
, gotsig);
}
G.tty_fileno = fileno(tty);
tcgetattr(G.tty_fileno, &G.initial_settings);
G.new_settings = G.initial_settings;
G.new_settings.c_lflag &= ~(ICANON | ECHO);
G.new_settings.c_cc[VMIN] = 1;
G.new_settings.c_cc[VTIME] = 0;
tcsetattr_tty_TCSANOW(&G.new_settings);
bb_signals(BB_FATAL_SIGS, gotsig);
do {
struct stat st;
FILE *file;
int len;
int lines;
file = stdin;
if (*argv) {
file = fopen_or_warn(*argv, "r");
@@ -129,17 +124,20 @@ int more_main(int argc UNUSED_PARAM, char **argv)
st.st_size = 0;
fstat(fileno(file), &st);
please_display_more_prompt = 0;
/* never returns w, h <= 1 */
get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
terminal_height -= 1;
get_wh();
please_display_more_prompt = 0;
len = 0;
lines = 0;
while (spaces || (c = getc(file)) != EOF) {
for (;;) {
int wrap;
if (spaces)
spaces--;
else {
c = getc(file);
if (c == EOF) break;
}
loop_top:
if (input != 'r' && please_display_more_prompt) {
len = printf("--More-- ");
@@ -151,26 +149,26 @@ int more_main(int argc UNUSED_PARAM, char **argv)
(int) ((uoff_t)ftello(file) / d),
st.st_size);
}
fflush_all();
/*
* We've just displayed the "--More--" prompt, so now we need
* to get input from the user.
*/
for (;;) {
input = getc(cin);
fflush_all();
input = getc(tty);
input = tolower(input);
if (!ENABLE_FEATURE_USE_TERMIOS)
printf("\033[A"); /* cursor up */
/* Erase the last message */
printf("\r%*s\r", len, "");
if (input == 'q')
goto end;
/* Due to various multibyte escape
* sequences, it's not ok to accept
* any input as a command to scroll
* the screen. We only allow known
* commands, else we show help msg. */
if (input == ' ' || input == '\n' || input == 'q' || input == 'r')
if (input == ' ' || input == '\n' || input == 'r')
break;
len = printf("(Enter:next line Space:next page Q:quit R:show the rest)");
}
@@ -178,15 +176,9 @@ int more_main(int argc UNUSED_PARAM, char **argv)
lines = 0;
please_display_more_prompt = 0;
if (input == 'q')
goto end;
/* The user may have resized the terminal.
* Re-read the dimensions. */
if (ENABLE_FEATURE_USE_TERMIOS) {
get_terminal_width_height(cin_fileno, &terminal_width, &terminal_height);
terminal_height -= 1;
}
get_wh();
}
/* Crudely convert tabs into spaces, which are
@@ -206,11 +198,11 @@ int more_main(int argc UNUSED_PARAM, char **argv)
* see if any characters have been hit in the _input_ stream. This
* allows the user to quit while in the middle of a file.
*/
wrap = (++len > terminal_width);
wrap = (++len > G.terminal_width);
if (c == '\n' || wrap) {
/* Then outputting this character
* will move us to a new line. */
if (++lines >= terminal_height || input == '\n')
if (++lines >= G.terminal_height || input == '\n')
please_display_more_prompt = 1;
len = 0;
}
@@ -230,6 +222,6 @@ int more_main(int argc UNUSED_PARAM, char **argv)
fflush_all();
} while (*argv && *++argv);
end:
setTermSettings(cin_fileno, &initial_settings);
tcsetattr_tty_TCSANOW(&G.initial_settings);
return 0;
}