separate humansize into a util function

also show 1 decimal of human size string like: 4M -> 4.4M

Makefile

@@ -17,6 +17,7 @@ LIB = \
 	util/estrtol.o   \
 	util/fnck.o      \
 	util/getlines.o  \
+	util/human.o     \
 	util/md5.o       \
 	util/mode.o      \
 	util/putword.o   \

du.c

@@ -85,29 +85,11 @@ main(int argc, char *argv[])
 	return 0;
 }
 
-static void
-print_human(long n, char *path)
-{
-	long base = 1024;
-	long power = base;
-	char postfixes[] = {'B', 'K', 'M', 'G', 'T', 'P', 'E'};
-	int i = 0;
-
-	n = n * blksize;
-	while (n > power) {
-		power = power*base;
-		i++;
-	}
-
-	n = i ? n / (power / base) : n;
-	printf("%lu%c\t%s\n", n, postfixes[i], path);
-}
-
 static void
 print(long n, char *path)
 {
 	if (hflag)
-		print_human(n, path);
+		printf("%s\t%s\n", humansize(n * blksize), path);
 	else
 		printf("%lu\t%s\n", n, path);
 }

util.h

@@ -20,6 +20,7 @@ void enprintf(int, const char *, ...);
 double estrtod(const char *);
 long estrtol(const char *, int);
 void fnck(const char *, const char *, int (*)(const char *, const char *));
+char *humansize(double);
 void putword(const char *);
 void recurse(const char *, void (*)(const char *));
 #undef strlcat

util/human.c

@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <string.h>
+
+#include "../util.h"
+
+char *
+humansize(double n)
+{
+	static char buf[16];
+	const char postfixes[] = " KMGTPE";
+	size_t i;
+
+	for(i = 0; n >= 1024 && i < strlen(postfixes); i++)
+		n /= 1024;
+
+	if(!i)
+		snprintf(buf, sizeof(buf), "%lu%c", (unsigned long)n, postfixes[i]);
+	else
+		snprintf(buf, sizeof(buf), "%.1f%c", n, postfixes[i]);
+	return buf;
+}