dd: code shrink
[oweals/busybox.git] / util-linux / more.c
index 1fd6f9ee82c975afe3b8821bc1792a1c9d05b5ba..35957139711f20b89b3c5b793b66f5ccc9a1af0f 100644 (file)
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
+//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 */
@@ -29,16 +37,20 @@ struct globals {
 #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 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('\n');
+       /* 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);
+       _exit(EXIT_FAILURE);
 }
 
 #define CONVERTED_TAB_SIZE 8
@@ -73,8 +85,7 @@ int more_main(int argc UNUSED_PARAM, char **argv)
                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);
@@ -109,9 +120,12 @@ int more_main(int argc UNUSED_PARAM, char **argv)
  loop_top:
                        if (input != 'r' && please_display_more_prompt) {
                                len = printf("--More-- ");
-                               if (st.st_size > 0) {
+                               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) (ftello(file)*100 / st.st_size),
+                                               (int) ((uoff_t)ftello(file) / d),
                                                st.st_size);
                                }
                                fflush_all();
@@ -155,7 +169,7 @@ int more_main(int argc UNUSED_PARAM, char **argv)
                        /* Crudely convert tabs into spaces, which are
                         * a bajillion times easier to deal with. */
                        if (c == '\t') {
-                               spaces = CONVERTED_TAB_SIZE - 1;
+                               spaces = ((unsigned)~len) % CONVERTED_TAB_SIZE;
                                c = ' ';
                        }
 
@@ -187,6 +201,7 @@ int more_main(int argc UNUSED_PARAM, char **argv)
                        }
                        /* 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();