/* 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 tarball for details. */ #include "libbb.h" #if ENABLE_FEATURE_USE_TERMIOS #include <termios.h> #endif /* FEATURE_USE_TERMIOS */ #if ENABLE_FEATURE_USE_TERMIOS struct globals { int cin_fileno; struct termios initial_settings; struct termios new_settings; }; #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) tcsetattr(fd, TCSANOW, argp) #define getTermSettings(fd, argp) tcgetattr(fd, argp) static void gotsig(int sig UNUSED_PARAM) { bb_putchar('\n'); setTermSettings(cin_fileno, &initial_settings); exit(EXIT_FAILURE); } #else /* !FEATURE_USE_TERMIOS */ #define INIT_G() ((void)0) #define setTermSettings(fd, argp) ((void)0) #endif /* FEATURE_USE_TERMIOS */ #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 gcc */ 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; INIT_G(); 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(CURRENT_TTY, "r"); 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_cc[VMIN] = 1; new_settings.c_cc[VTIME] = 0; setTermSettings(cin_fileno, &new_settings); bb_signals(0 + (1 << SIGINT) + (1 << SIGQUIT) + (1 << SIGTERM) , gotsig); #endif do { file = stdin; if (*argv) { file = fopen_or_warn(*argv, "r"); if (!file) continue; } 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; len = 0; lines = 0; while (spaces || (c = getc(file)) != EOF) { int wrap; if (spaces) spaces--; loop_top: if (input != 'r' && please_display_more_prompt) { len = printf("--More-- "); if (st.st_size > 0) { len += printf("(%d%% of %"OFF_FMT"d bytes)", (int) (ftello(file)*100 / st.st_size), st.st_size); } fflush(stdout); /* * We've just displayed the "--More--" prompt, so now we need * to get input from the user. */ for (;;) { input = getc(cin); input = tolower(input); #if !ENABLE_FEATURE_USE_TERMIOS printf("\033[A"); /* up cursor */ #endif /* 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; 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; #endif } /* Crudely convert tabs into spaces, which are * a bajillion times easier to deal with. */ if (c == '\t') { spaces = CONVERTED_TAB_SIZE - 1; 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 > 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 (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); } fclose(file); fflush(stdout); } while (*argv && *++argv); end: setTermSettings(cin_fileno, &initial_settings); return 0; }