| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini more implementation for busybox |
| * |
| * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. |
| * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| * |
| * Latest version blended together by Erik Andersen <andersen@codepoet.org>, |
| * based on the original more implementation by Bruce, and code from the |
| * Debian boot-floppies team. |
| * |
| * Termios corrects by Vladimir Oleynik <dzo@simtreas.ru> |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| */ |
| //config:config MORE |
| //config: bool "more" |
| //config: default y |
| //config: help |
| //config: more is a simple utility which allows you to read text one screen |
| //config: sized page at a time. If you want to read text that is larger than |
| //config: the screen, and you are using anything faster than a 300 baud modem, |
| //config: you will probably find this utility very helpful. If you don't have |
| //config: any need to reading text files, you can leave this disabled. |
| |
| //applet:IF_MORE(APPLET(more, BB_DIR_BIN, BB_SUID_DROP)) |
| |
| //kbuild:lib-$(CONFIG_MORE) += more.o |
| |
| //usage:#define more_trivial_usage |
| //usage: "[FILE]..." |
| //usage:#define more_full_usage "\n\n" |
| //usage: "View FILE (or stdin) one screenful at a time" |
| //usage: |
| //usage:#define more_example_usage |
| //usage: "$ dmesg | more\n" |
| |
| #include "libbb.h" |
| #include "common_bufsiz.h" |
| |
| struct globals { |
| int tty_fileno; |
| unsigned terminal_width; |
| unsigned terminal_height; |
| struct termios initial_settings; |
| } FIX_ALIASING; |
| #define G (*(struct globals*)bb_common_bufsiz1) |
| #define INIT_G() do { setup_common_bufsiz(); } while (0) |
| |
| 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'); |
| tcsetattr_tty_TCSANOW(&G.initial_settings); |
| _exit(EXIT_FAILURE); |
| } |
| |
| #define CONVERTED_TAB_SIZE 8 |
| |
| 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 input = 0; |
| int spaces = 0; |
| int please_display_more_prompt; |
| FILE *tty; |
| |
| INIT_G(); |
| |
| /* Parse options */ |
| /* Accepted but ignored: */ |
| /* -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 */ |
| /* -u Suppress underlining */ |
| getopt32(argv, "dflsu"); |
| argv += optind; |
| |
| /* 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); |
| tty = fopen_for_read(CURRENT_TTY); |
| if (!tty) |
| return bb_cat(argv); |
| |
| G.tty_fileno = fileno(tty); |
| |
| /* Turn on unbuffered input; turn off echoing */ |
| set_termios_to_raw(G.tty_fileno, &G.initial_settings, 0); |
| 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"); |
| if (!file) |
| continue; |
| } |
| st.st_size = 0; |
| fstat(fileno(file), &st); |
| |
| get_wh(); |
| |
| please_display_more_prompt = 0; |
| len = 0; |
| lines = 0; |
| 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-- "); |
| 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); |
| } |
| |
| /* |
| * We've just displayed the "--More--" prompt, so now we need |
| * to get input from the user. |
| */ |
| for (;;) { |
| fflush_all(); |
| input = getc(tty); |
| input = tolower(input); |
| /* 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 == 'r') |
| break; |
| len = printf("(Enter:next line Space:next page Q:quit R:show the rest)"); |
| } |
| len = 0; |
| lines = 0; |
| please_display_more_prompt = 0; |
| |
| /* The user may have resized the terminal. |
| * Re-read the dimensions. */ |
| get_wh(); |
| } |
| |
| /* 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 |
| * |
| * 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. |
| */ |
| wrap = (++len > G.terminal_width); |
| if (c == '\n' || wrap) { |
| /* Then outputting this character |
| * will move us to a new line. */ |
| if (++lines >= G.terminal_height || input == '\n') |
| please_display_more_prompt = 1; |
| len = 0; |
| } |
| 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_all(); |
| } while (*argv && *++argv); |
| end: |
| tcsetattr_tty_TCSANOW(&G.initial_settings); |
| return 0; |
| } |