*
* Termios corrects by Vladimir Oleynik <dzo@simtreas.ru>
*
- * Licensed under GPLv2 or later, see file License in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include "busybox.h"
-
-
-#if ENABLE_FEATURE_USE_TERMIOS
-static int cin_fileno;
-#include <termios.h>
-#define setTermSettings(fd, argp) tcsetattr(fd, TCSANOW, argp)
-#define getTermSettings(fd, argp) tcgetattr(fd, argp);
-
-static struct termios initial_settings, new_settings;
-
-static void set_tty_to_initial_mode(void)
+//usage:#define more_trivial_usage
+//usage: "[FILE]..."
+//usage:#define more_full_usage "\n\n"
+//usage: "View FILE (or stdin) one screenful at a time"
+//usage:
+//usage:#define more_example_usage
+//usage: "$ dmesg | more\n"
+
+#include "libbb.h"
+
+/* Support for FEATURE_USE_TERMIOS */
+
+struct globals {
+ int cin_fileno;
+ struct termios initial_settings;
+ struct termios new_settings;
+} FIX_ALIASING;
+#define G (*(struct globals*)bb_common_bufsiz1)
+#define INIT_G() ((void)0)
+#define initial_settings (G.initial_settings)
+#define new_settings (G.new_settings )
+#define cin_fileno (G.cin_fileno )
+
+#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 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);
+ _exit(EXIT_FAILURE);
}
-static void gotsig(int sig)
-{
- putchar('\n');
- exit(EXIT_FAILURE);
-}
-#endif /* FEATURE_USE_TERMIOS */
-
+#define CONVERTED_TAB_SIZE 8
-int more_main(int argc, char **argv);
-int more_main(int argc, char **argv)
+int more_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int more_main(int argc UNUSED_PARAM, char **argv)
{
- int c, lines, input = 0;
- int please_display_more_prompt = 0;
+ 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, page_height;
- int terminal_width;
- int terminal_height;
+ int len;
+ unsigned terminal_width;
+ unsigned terminal_height;
- argc--;
- argv++;
+ INIT_G();
- cin = stdin;
- /* use input from terminal unless we do "more >outfile" */
- if (isatty(STDOUT_FILENO)) {
- cin = fopen(CURRENT_TTY, "r");
- if (!cin)
- cin = xfopen(CONSOLE_DEV, "r");
- please_display_more_prompt = 2;
-#if ENABLE_FEATURE_USE_TERMIOS
+ 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);
+ cin = fopen_for_read(CURRENT_TTY);
+ if (!cin)
+ 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;
- new_settings.c_lflag &= ~ECHO;
+ new_settings.c_lflag &= ~(ICANON | ECHO);
new_settings.c_cc[VMIN] = 1;
new_settings.c_cc[VTIME] = 0;
setTermSettings(cin_fileno, &new_settings);
- atexit(set_tty_to_initial_mode);
- signal(SIGINT, gotsig);
- signal(SIGQUIT, gotsig);
- signal(SIGTERM, gotsig);
-#endif
+ bb_signals(0
+ + (1 << SIGINT)
+ + (1 << SIGQUIT)
+ + (1 << SIGTERM)
+ , gotsig);
}
do {
file = stdin;
- if (argc != 0) {
+ if (*argv) {
file = fopen_or_warn(*argv, "r");
if (!file)
- goto loop;
+ continue;
}
-
st.st_size = 0;
fstat(fileno(file), &st);
- please_display_more_prompt &= ~1;
-
+ please_display_more_prompt = 0;
+ /* never returns w, h <= 1 */
get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
- if (terminal_height > 4)
- terminal_height -= 2;
- if (terminal_width > 0)
- terminal_width -= 1;
+ terminal_height -= 1;
len = 0;
lines = 0;
- page_height = terminal_height;
- while ((c = getc(file)) != EOF) {
-
- if ((please_display_more_prompt & 3) == 3) {
+ while (spaces || (c = getc(file)) != EOF) {
+ int wrap;
+ if (spaces)
+ spaces--;
+ loop_top:
+ if (input != 'r' && please_display_more_prompt) {
len = printf("--More-- ");
- if (file != stdin && st.st_size > 0) {
- len += printf("(%d%% of %"OFF_FMT"d bytes)",
- (int) (ftello(file)*100 / st.st_size),
+ if (st.st_size != 0) {
+ uoff_t d = (uoff_t)st.st_size / 100;
+ if (d == 0)
+ d = 1;
+ len += printf("(%u%% of %"OFF_FMT"u bytes)",
+ (int) ((uoff_t)ftello(file) / d),
st.st_size);
}
- fflush(stdout);
+ fflush_all();
/*
* We've just displayed the "--More--" prompt, so now we need
* to get input from the user.
*/
- input = getc(cin);
-#if !ENABLE_FEATURE_USE_TERMIOS
- printf("\033[A"); /* up cursor */
-#endif
- /* Erase the "More" message */
- printf("\r%*s\r", len, "");
+ for (;;) {
+ input = getc(cin);
+ input = tolower(input);
+ if (!ENABLE_FEATURE_USE_TERMIOS)
+ printf("\033[A"); /* cursor up */
+ /* Erase the last message */
+ printf("\r%*s\r", len, "");
+
+ /* 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')
+ break;
+ len = printf("(Enter:next line Space:next page Q:quit R:show the rest)");
+ }
len = 0;
lines = 0;
- page_height = terminal_height;
- please_display_more_prompt &= ~1;
+ 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;
+ }
+ }
+
+ /* Crudely convert tabs into spaces, which are
+ * a bajillion times easier to deal with. */
+ if (c == '\t') {
+ spaces = ((unsigned)~len) % CONVERTED_TAB_SIZE;
+ c = ' ';
}
/*
* There are two input streams to worry about here:
*
- * c : the character we are reading from the file being "mored"
- * input : a character received from the keyboard
+ * c : the character we are reading from the file being "mored"
+ * input: a character received from the keyboard
*
* If we hit a newline in the _file_ stream, we want to test and
* see if any characters have been hit in the _input_ stream. This
* allows the user to quit while in the middle of a file.
*/
- if (c == '\n') {
- /* increment by just one line if we are at
- * the end of this line */
- if (input == '\n')
- please_display_more_prompt |= 1;
- /* Adjust the terminal height for any overlap, so that
- * no lines get lost off the top. */
- if (len >= terminal_width) {
- int quot, rem;
- quot = len / terminal_width;
- rem = len - (quot * terminal_width);
- if (quot) {
- if (rem)
- page_height -= quot;
- else
- page_height -= (quot - 1);
- }
- }
- if (++lines >= page_height) {
- please_display_more_prompt |= 1;
- }
+ wrap = (++len > terminal_width);
+ if (c == '\n' || wrap) {
+ /* Then outputting this character
+ * will move us to a new line. */
+ if (++lines >= terminal_height || input == '\n')
+ please_display_more_prompt = 1;
len = 0;
}
- /*
- * If we just read a newline from the file being 'mored' and any
- * key other than a return is hit, scroll by one page
- */
- putc(c, stdout);
- len++;
+ if (c != '\n' && wrap) {
+ /* Then outputting this will also put a character on
+ * the beginning of that new line. Thus we first want to
+ * display the prompt (if any), so we skip the putchar()
+ * and go back to the top of the loop, without reading
+ * a new character. */
+ goto loop_top;
+ }
+ /* My small mind cannot fathom backspaces and UTF-8 */
+ putchar(c);
+ die_if_ferror_stdout(); /* if tty was destroyed (closed xterm, etc) */
}
fclose(file);
- fflush(stdout);
- loop:
- argv++;
- } while (--argc > 0);
+ fflush_all();
+ } while (*argv && *++argv);
end:
+ setTermSettings(cin_fileno, &initial_settings);
return 0;
}
projects / oweals / busybox.git / blobdiff