1/* vi: set sw=4 ts=4: */ 2/* 3 * Mini more implementation for busybox 4 * 5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. 6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> 7 * 8 * Latest version blended together by Erik Andersen <andersen@codepoet.org>, 9 * based on the original more implementation by Bruce, and code from the 10 * Debian boot-floppies team. 11 * 12 * Termios corrects by Vladimir Oleynik <dzo@simtreas.ru> 13 * 14 * Licensed under GPLv2 or later, see file License in this tarball for details. 15 */ 16 17#include "libbb.h" 18#if ENABLE_FEATURE_USE_TERMIOS 19#include <termios.h> 20#endif /* FEATURE_USE_TERMIOS */ 21 22 23#if ENABLE_FEATURE_USE_TERMIOS 24 25struct globals { 26 int cin_fileno; 27 struct termios initial_settings; 28 struct termios new_settings; 29}; 30#define G (*(struct globals*)bb_common_bufsiz1) 31//#define G (*ptr_to_globals) 32#define INIT_G() ((void)0) 33//#define INIT_G() PTR_TO_GLOBALS = xzalloc(sizeof(G)) 34#define initial_settings (G.initial_settings) 35#define new_settings (G.new_settings ) 36#define cin_fileno (G.cin_fileno ) 37 38#define setTermSettings(fd, argp) tcsetattr(fd, TCSANOW, argp) 39#define getTermSettings(fd, argp) tcgetattr(fd, argp) 40 41static void gotsig(int sig) 42{ 43 putchar('\n'); 44 setTermSettings(cin_fileno, &initial_settings); 45 exit(EXIT_FAILURE); 46} 47 48#else /* !FEATURE_USE_TERMIOS */ 49#define INIT_G() ((void)0) 50#define setTermSettings(fd, argp) ((void)0) 51#endif /* FEATURE_USE_TERMIOS */ 52 53#define CONVERTED_TAB_SIZE 8 54 55int more_main(int argc, char **argv); 56int more_main(int argc, char **argv) 57{ 58 int c = c; /* for gcc */ 59 int lines; 60 int input = 0; 61 int spaces = 0; 62 int please_display_more_prompt; 63 struct stat st; 64 FILE *file; 65 FILE *cin; 66 int len; 67 int terminal_width; 68 int terminal_height; 69 70 INIT_G(); 71 72 argv++; 73 /* Another popular pager, most, detects when stdout 74 * is not a tty and turns into cat. This makes sense. */ 75 if (!isatty(STDOUT_FILENO)) 76 return bb_cat(argv); 77 cin = fopen(CURRENT_TTY, "r"); 78 if (!cin) 79 return bb_cat(argv); 80 81#if ENABLE_FEATURE_USE_TERMIOS 82 cin_fileno = fileno(cin); 83 getTermSettings(cin_fileno, &initial_settings); 84 new_settings = initial_settings; 85 new_settings.c_lflag &= ~ICANON; 86 new_settings.c_lflag &= ~ECHO; 87 new_settings.c_cc[VMIN] = 1; 88 new_settings.c_cc[VTIME] = 0; 89 setTermSettings(cin_fileno, &new_settings); 90 signal(SIGINT, gotsig); 91 signal(SIGQUIT, gotsig); 92 signal(SIGTERM, gotsig); 93#endif 94 95 do { 96 file = stdin; 97 if (*argv) { 98 file = fopen_or_warn(*argv, "r"); 99 if (!file) 100 continue; 101 } 102 st.st_size = 0; 103 fstat(fileno(file), &st); 104 105 please_display_more_prompt = 0; 106 /* never returns w, h <= 1 */ 107 get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height); 108 terminal_height -= 1; 109 110 len = 0; 111 lines = 0; 112 while (spaces || (c = getc(file)) != EOF) { 113 int wrap; 114 if (spaces) 115 spaces--; 116 loop_top: 117 if (input != 'r' && please_display_more_prompt) { 118 len = printf("--More-- "); 119 if (st.st_size > 0) { 120 len += printf("(%d%% of %"OFF_FMT"d bytes)", 121 (int) (ftello(file)*100 / st.st_size), 122 st.st_size); 123 } 124 fflush(stdout); 125 126 /* 127 * We've just displayed the "--More--" prompt, so now we need 128 * to get input from the user. 129 */ 130 for (;;) { 131 input = getc(cin); 132 input = tolower(input); 133#if !ENABLE_FEATURE_USE_TERMIOS 134 printf("\033[A"); /* up cursor */ 135#endif 136 /* Erase the last message */ 137 printf("\r%*s\r", len, ""); 138 139 /* Due to various multibyte escape 140 * sequences, it's not ok to accept 141 * any input as a command to scroll 142 * the screen. We only allow known 143 * commands, else we show help msg. */ 144 if (input == ' ' || input == '\n' || input == 'q' || input == 'r') 145 break; 146 len = printf("(Enter:next line Space:next page Q:quit R:show the rest)"); 147 } 148 len = 0; 149 lines = 0; 150 please_display_more_prompt = 0; 151 152 if (input == 'q') 153 goto end; 154 155 /* The user may have resized the terminal. 156 * Re-read the dimensions. */ 157#if ENABLE_FEATURE_USE_TERMIOS 158 get_terminal_width_height(cin_fileno, &terminal_width, &terminal_height); 159 terminal_height -= 1; 160#endif 161 } 162 163 /* Crudely convert tabs into spaces, which are 164 * a bajillion times easier to deal with. */ 165 if (c == '\t') { 166 spaces = CONVERTED_TAB_SIZE - 1; 167 c = ' '; 168 } 169 170 /* 171 * There are two input streams to worry about here: 172 * 173 * c : the character we are reading from the file being "mored" 174 * input: a character received from the keyboard 175 * 176 * If we hit a newline in the _file_ stream, we want to test and 177 * see if any characters have been hit in the _input_ stream. This 178 * allows the user to quit while in the middle of a file. 179 */ 180 wrap = (++len > terminal_width); 181 if (c == '\n' || wrap) { 182 /* Then outputting this character 183 * will move us to a new line. */ 184 if (++lines >= terminal_height || input == '\n') 185 please_display_more_prompt = 1; 186 len = 0; 187 } 188 if (c != '\n' && wrap) { 189 /* Then outputting this will also put a character on 190 * the beginning of that new line. Thus we first want to 191 * display the prompt (if any), so we skip the putchar() 192 * and go back to the top of the loop, without reading 193 * a new character. */ 194 goto loop_top; 195 } 196 /* My small mind cannot fathom backspaces and UTF-8 */ 197 putchar(c); 198 } 199 fclose(file); 200 fflush(stdout); 201 } while (*argv && *++argv); 202 end: 203 setTermSettings(cin_fileno, &initial_settings); 204 return 0; 205} 206