1 files changed, 87 insertions, 0 deletions
diff --git a/busybox/libbb/human_readable.c b/busybox/libbb/human_readable.c
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+/*
+ * June 30, 2001                 Manuel Novoa III
+ *
+ * All-integer version (hey, not everyone has floating point) of
+ * make_human_readable_str, modified from similar code I had written
+ * for busybox several months ago.
+ *
+ * Notes:
+ *   1) I'm using an unsigned long long to hold the product size * block_size,
+ *      as df (which calls this routine) could request a representation of a
+ *      partition size in bytes > max of unsigned long.  If long longs aren't
+ *      available, it would be possible to do what's needed using polynomial
+ *      representations (say, powers of 1024) and manipulating coefficients.
+ *      The base ten "bytes" output could be handled similarly.
+ *
+ *   2) This routine always outputs a decimal point and a tenths digit when
+ *      display_unit != 0.  Hence, it isn't uncommon for the returned string
+ *      to have a length of 5 or 6.
+ *
+ *      It might be nice to add a flag to indicate no decimal digits in
+ *      that case.  This could be either an additional parameter, or a
+ *      special value of display_unit.  Such a flag would also be nice for du.
+ *
+ *      Some code to omit the decimal point and tenths digit is sketched out
+ *      and "#if 0"'d below.
+ */
+
+#include <stdio.h>
+#include "libbb.h"
+
+const char *make_human_readable_str(unsigned long long size,
+	unsigned long block_size, unsigned long display_unit)
+{
+	/* The code will adjust for additional (appended) units. */
+	static const char zero_and_units[] = { '0', 0, 'k', 'M', 'G', 'T' };
+	static const char fmt[] = "%Lu";
+	static const char fmt_tenths[] = "%Lu.%d%c";
+
+	static char str[21];		/* Sufficient for 64 bit unsigned integers. */
+
+	unsigned long long val;
+	int frac;
+	const char *u;
+	const char *f;
+
+	u = zero_and_units;
+	f = fmt;
+	frac = 0;
+
+	val = size * block_size;
+	if (val == 0) {
+		return u;
+	}
+
+	if (display_unit) {
+		val += display_unit/2;	/* Deal with rounding. */
+		val /= display_unit;	/* Don't combine with the line above!!! */
+	} else {
+		++u;
+		while ((val >= KILOBYTE)
+			   && (u < zero_and_units + sizeof(zero_and_units) - 1)) {
+			f = fmt_tenths;
+			++u;
+			frac = ((((int)(val % KILOBYTE)) * 10) + (KILOBYTE/2)) / KILOBYTE;
+			val /= KILOBYTE;
+		}
+		if (frac >= 10) {		/* We need to round up here. */
+			++val;
+			frac = 0;
+		}
+#if 0
+		/* Sample code to omit decimal point and tenths digit. */
+		if ( /* no_tenths */ 1 ) {
+			if ( frac >= 5 ) {
+				++val;
+			}
+			f = "%Lu%*c" /* fmt_no_tenths */ ;
+			frac = 1;
+		}
+#endif
+	}
+
+	/* If f==fmt then 'frac' and 'u' are ignored. */
+	snprintf(str, sizeof(str), f, val, frac, *u);
+
+	return str;
+}