/* 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 (6.7 kb)" //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; }