Ticket #268 (Allow using SI-based size prefixes)

* add: switching between old (default) 1024 based "binary" prefixes
           and SI (1000 based) size prefixes when displaying file sizes

Signed-off-by: Ilia Maslakov <il.smind@gmail.com>

    Size in SI units: changed option name and description.

    * Changed option name in 'Configuration options' dialog.
    * Moved description to proper section in man page.
    * Added russian translation.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

doc/man/mc.1.in

@@ -1614,6 +1614,12 @@ Panel Options, Pause after run and Other Options.
 .PP
 .B Panel Options
 .PP
+.I Use SI size units.
+If this option is set, Midnight Commander will use SI units (powers of 1000)
+when displaying any byte sizes. The suffixes (k, m ...) are shown in lowercase.
+If unset (default), Midnight Commander will use binary units (powers of 1024)
+and the suffixes are shown in upper case (K, M ...)
+.PP
 .I Show Backup Files.
 If enabled, the Midnight Commander will show files ending with a tilde.
 Otherwise, they won't be shown (like GNU's ls option -B).

doc/man/ru/mc.1.in

@@ -1771,6 +1771,13 @@ mc на экране.
 .PP
 .B Настройки панелей (Panel Options)
 .PP
+.I Размеры в единицах СИ.
+Если эта опция включена, то Midnight Commander отображает размеры файлов
+и каталогов в единицах СИ (по основанию 1000). Суффиксы к, м, и т. д.
+отображаются в нижнем регистре. По умолчанию опция выключена. В этом случае
+Midnight Commander отображат размеры в двоичных единицах (по снованию
+1024), и суффиксы К, М, и т. д. отображаются в верхнем регистре.
+.PP
 .I Показывать резервные (Backup) файлы.
 По умолчанию программа Midnight Commander не показывает файлы, имена
 которых заканчиваются на '~' (подобно ключу -B команды ls в GNU).

src/dir.c

@@ -45,6 +45,13 @@ int show_backups = 1;
 /* If false then directories are shown separately from files */
 int mix_all_files = 0;
 
+/*
+ * If true, SI units (1000 based) will be used for
+ * larger units (kilobyte, megabyte, ...).
+ * If false binary units (1024 based) will be used.
+ */
+int kilobyte_si = 0;
+
 /* Reverse flag */
 static int reverse = 1;
 

src/dir.h

@@ -83,5 +83,6 @@ int if_link_is_exe (const char *full_name, const file_entry *file);
 extern int show_backups;
 extern int show_dot_files;
 extern int mix_all_files;
+extern int kilobyte_si;
 
 #endif

src/main.c

@@ -883,6 +883,13 @@ toggle_show_hidden (void)
     update_panels (UP_RELOAD, UP_KEEPSEL);
 }
 
+void
+toggle_kilobyte_si (void)
+{
+    kilobyte_si = !kilobyte_si;
+    update_panels (UP_RELOAD, UP_KEEPSEL);
+}
+
 /*
  * Just a hack for allowing url-like pathnames to be accepted from the
  * command line.

src/main.h

@@ -11,6 +11,7 @@ void toggle_fast_reload (void);
 void toggle_mix_all_files (void);
 void toggle_show_backup (void);
 void toggle_show_hidden (void);
+void toggle_kilobyte_si (void);
 
 extern int quote;
 extern volatile int quit;

src/option.c

@@ -78,12 +78,13 @@ static struct {
    {N_("ma&Rk moves down"),   &mark_moves_down,   TOGGLE_VARIABLE,       0 },
    {N_("show &Hidden files"), &show_dot_files,    toggle_show_hidden,    0 },
    {N_("show &Backup files"), &show_backups,      toggle_show_backup,    0 },
+   {N_("Use SI si&ze units"), &kilobyte_si,       toggle_kilobyte_si,    0 },
    { 0, 0, 0, 0 }
 };
 
 /* Make sure this corresponds to the check_options structure */
 #define OTHER_OPTIONS 13
-#define PANEL_OPTIONS 6
+#define PANEL_OPTIONS 7
 
 static WRadio *pause_radio;
 

src/setup.c

@@ -148,6 +148,7 @@ static const struct {
     int  *opt_addr;
 } int_options [] = {
     { "show_backups", &show_backups },
+    { "kilobyte_si", &kilobyte_si },
     { "show_dot_files", &show_dot_files },
     { "verbose", &verbose },
     { "mark_moves_down", &mark_moves_down },

src/util.c

@@ -53,6 +53,7 @@
 #include "strutil.h"
 #include "fileopctx.h"
 #include "file.h"		/* copy_file_file() */
+#include "dir.h"
 
 #ifdef HAVE_CHARSET
 #include "charsets.h"
@@ -271,11 +272,11 @@ size_trunc (double size)
     const char *xtra = "";
     
     if (size > 999999999L){
-	divisor = 1024;
-	xtra = "K";
+	divisor = kilobyte_si?1000:1024;
+	xtra = kilobyte_si?"k":"K";
 	if (size/divisor > 999999999L){
-	    divisor = 1024*1024;
-	    xtra = "M";
+	    divisor = kilobyte_si?(1000*1000):(1024*1024);
+	    xtra = kilobyte_si?"m":"M";
 	}
     }
     g_snprintf (x, sizeof (x), "%.0f%s", (size/divisor), xtra);
@@ -327,12 +328,29 @@ size_trunc_len (char *buffer, int len, off_t size, int units)
 	 1000000000};
     static const char * const suffix [] =
 	{"", "K", "M", "G", "T", "P", "E", "Z", "Y", NULL};
+    static const char * const suffix_lc [] =
+	{"", "k", "m", "g", "t", "p", "e", "z", "y", NULL};
     int j = 0;
+    int size_remain;
 
     /* Don't print more than 9 digits - use suffix.  */
     if (len == 0 || len > 9)
 	len = 9;
 
+    /*
+     * recalculate from 1024 base to 1000 base if units>0
+     * We can't just multiply by 1024 - that might cause overflow
+     * if off_t type is too small
+     */
+    if (units && kilobyte_si) {
+     for (j = 0; j < units; j++) {
+      size_remain=((size % 125)*1024)/1000; /* size mod 125, recalculated */
+      size = size / 125; /* 128/125 = 1024/1000 */
+      size = size * 128; /* This will convert size from multiple of 1024 to multiple of 1000 */
+      size += size_remain; /* Re-add remainder lost by division/multiplication */
+     }
+    }
+
     for (j = units; suffix [j] != NULL; j++) {
 	if (size == 0) {
 	    if (j == units) {
@@ -343,19 +361,23 @@ size_trunc_len (char *buffer, int len, off_t size, int units)
 
 	    /* Use "~K" or just "K" if len is 1.  Use "B" for bytes.  */
 	    g_snprintf (buffer, len + 1, (len > 1) ? "~%s" : "%s",
-			(j > 1) ? suffix[j - 1] : "B");
+			(j > 1) ? (kilobyte_si ? suffix_lc[j - 1] : suffix[j - 1]) : "B");
 	    break;
 	}
 
 	if (size < power10 [len - (j > 0)]) {
-	    g_snprintf (buffer, len + 1, "%lu%s", (unsigned long) size, suffix[j]);
+	    g_snprintf (buffer, len + 1, "%lu%s", (unsigned long) size, kilobyte_si ? suffix_lc[j] : suffix[j]);
 	    break;
 	}
 
-	/* Powers of 1024, with rounding.  */
+	/* Powers of 1000 or 1024, with rounding.  */
+	if (kilobyte_si) {
+	    size = (size + 500) / 1000;
+	} else {
 	    size = (size + 512) >> 10;
 	}
     }
+}
 
 int
 is_exe (mode_t mode)