X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmore.c;h=35957139711f20b89b3c5b793b66f5ccc9a1af0f;hb=70f4320b40b7af83525cebabab2bc437a22c41d2;hp=d00cb40b856b58824b6f441102b0e1620f157dd8;hpb=06af2165288cd6516b89001ec9e24992619230e0;p=oweals%2Fbusybox.git diff --git a/util-linux/more.c b/util-linux/more.c index d00cb40b8..359571397 100644 --- a/util-linux/more.c +++ b/util-linux/more.c @@ -11,168 +11,202 @@ * * Termios corrects by Vladimir Oleynik * - * 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 -#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; }