Bump to version 1.22.1
[platform/upstream/busybox.git] / util-linux / more.c
index ffc79b1..3595713 100644 (file)
 /*
  * 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@lineo.com>,
- * based on the original more implementation by Bruce, and code from the 
+ * 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.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Termios corrects by Vladimir Oleynik <dzo@simtreas.ru>
  *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#include <stdio.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <sys/ioctl.h>
-#include "busybox.h"
-#define BB_DECLARE_EXTERN
-#define bb_need_help
-#include "messages.c"
-
-/* ED: sparc termios is broken: revert back to old termio handling. */
-#ifdef BB_FEATURE_USE_TERMIOS
-#      if #cpu(sparc)
-#              include <termio.h>
-#              define termios termio
-#              define setTermSettings(fd,argp) ioctl(fd,TCSETAF,argp)
-#              define getTermSettings(fd,argp) ioctl(fd,TCGETA,argp)
-#      else
-#              include <termios.h>
-#              define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
-#              define getTermSettings(fd,argp) tcgetattr(fd, argp);
-#      endif
-
-static FILE *cin;
-
-static struct termios initial_settings, new_settings;
-
-static void gotsig(int sig)
+//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)
 {
-       setTermSettings(fileno(cin), &initial_settings);
-       putchar('\n');
-       exit(EXIT_FAILURE);
+       /* 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);
 }
-#endif /* BB_FEATURE_USE_TERMIOS */
-
 
-static int terminal_width = 79;        /* not 80 in case terminal has linefold bug */
-static int terminal_height = 24;
+#define CONVERTED_TAB_SIZE 8
 
-
-extern 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 c = c; /* for compiler */
+       int lines;
+       int input = 0;
+       int spaces = 0;
        int please_display_more_prompt;
        struct stat st;
        FILE *file;
-       int len, page_height;
+       FILE *cin;
+       int len;
+       unsigned terminal_width;
+       unsigned terminal_height;
 
-#if defined BB_FEATURE_AUTOWIDTH && defined BB_FEATURE_USE_TERMIOS
-       struct winsize win = { 0, 0, 0, 0 };
-#endif
+       INIT_G();
 
-       argc--;
        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 | 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);
+       }
 
        do {
-               if (argc == 0) {
-                       file = stdin;
-               } else
-                       file = xfopen(*argv, "r");
-
+               file = stdin;
+               if (*argv) {
+                       file = fopen_or_warn(*argv, "r");
+                       if (!file)
+                               continue;
+               }
+               st.st_size = 0;
                fstat(fileno(file), &st);
 
-#ifdef BB_FEATURE_USE_TERMIOS
-               cin = fopen("/dev/tty", "r");
-               if (!cin)
-                       cin = xfopen("/dev/console", "r");
-               getTermSettings(fileno(cin), &initial_settings);
-               new_settings = initial_settings;
-               new_settings.c_cc[VMIN] = 1;
-               new_settings.c_cc[VTIME] = 0;
-               new_settings.c_lflag &= ~ICANON;
-               new_settings.c_lflag &= ~ECHO;
-               setTermSettings(fileno(cin), &new_settings);
-
-#      ifdef BB_FEATURE_AUTOWIDTH
-               ioctl(fileno(stdout), TIOCGWINSZ, &win);
-               if (win.ws_row > 4)
-                       terminal_height = win.ws_row - 2;
-               if (win.ws_col > 0)
-                       terminal_width = win.ws_col - 1;
-#      endif
-
-               (void) signal(SIGINT, gotsig);
-               (void) signal(SIGQUIT, gotsig);
-               (void) signal(SIGTERM, gotsig);
-
-#endif
-               len=0;
-               lines = 0;
-               page_height = terminal_height;
                please_display_more_prompt = 0;
-               while ((c = getc(file)) != EOF) {
+               /* never returns w, h <= 1 */
+               get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
+               terminal_height -= 1;
 
-                       if (please_display_more_prompt) {
+               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 (file != stdin) {
-#if _FILE_OFFSET_BITS == 64
-                                       len += printf("(%d%% of %lld bytes)",
-                                                  (int) (100 * ((double) ftell(file) /
-                                                  (double) st.st_size)), (long long)st.st_size);
-#else
-                                       len += printf("(%d%% of %ld bytes)",
-                                                  (int) (100 * ((double) ftell(file) /
-                                                  (double) st.st_size)), (long)st.st_size);
-#endif
+                               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);
                                }
-                               len += printf("%s",
-#ifdef BB_FEATURE_USE_TERMIOS
-                                                          ""
-#else
-                                                          "\n"
-#endif
-                                       );
-
-                               fflush(stdout);
+                               fflush_all();
 
                                /*
                                 * We've just displayed the "--More--" prompt, so now we need
                                 * to get input from the user.
                                 */
-#ifdef BB_FEATURE_USE_TERMIOS
-                               input = getc(cin);
-#else
-                               input = getc(stdin);
-#endif
-
-#ifdef BB_FEATURE_USE_TERMIOS
-                               /* Erase the "More" message */
-                               putc('\r', stdout);
-                               while (--len >= 0)
-                                       putc(' ', stdout);
-                               putc('\r', stdout);
-                               fflush(stdout);
-#endif
-                               len=0;
+                               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 = 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) {
-                                       div_t result = div( len, terminal_width); 
-                                       if (result.quot) {
-                                               if (result.rem)
-                                                       page_height-=result.quot;
-                                               else
-                                                       page_height-=(result.quot-1);
-                                       }
-                               }
-                               if (++lines >= page_height) {
+                       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;
+                               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);
-
-               argv++;
-       } while (--argc > 0);
-  end:
-#ifdef BB_FEATURE_USE_TERMIOS
-       setTermSettings(fileno(cin), &initial_settings);
-#endif
+               fflush_all();
+       } while (*argv && *++argv);
+ end:
+       setTermSettings(cin_fileno, &initial_settings);
        return 0;
 }