From 10d81574774acb4d00ae9b9feef9c30e6d0b6c78 Mon Sep 17 00:00:00 2001
From: Jan Vidar Krey <janvidar@extatic.org>
Date: Tue, 2 Oct 2012 23:01:57 +0200
Subject: [PATCH] Added a utility function to convert an arbitrary byte size
 into a human readable string.

E.g. 849484 becomes "829.57 KB".
---
 src/util/misc.c | 17 +++++++++++++++++
 src/util/misc.h | 13 +++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/util/misc.c b/src/util/misc.c
index e3a809a..1fe5c9a 100644
--- a/src/util/misc.c
+++ b/src/util/misc.c
@@ -305,6 +305,23 @@ int is_number(const char* value, int* num)
 }
 
 
+const char* format_size(size_t bytes, char* buf, size_t bufsize)
+{
+	static const char* quant[] = { "B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
+	size_t b = bytes;
+	size_t factor = 0;
+	size_t divisor = 1;
+	while (b > 1024)
+	{
+		factor++;
+		b = (b >> 10);
+		divisor = (divisor << 10);
+	}
+	snprintf(buf, bufsize, "%.2f %s", (double) bytes / (double) divisor, quant[factor]);
+	return buf;
+}
+
+
 const char* uhub_itoa(int val)
 {
 	static char buf[22];
diff --git a/src/util/misc.h b/src/util/misc.h
index 9526d0d..9841c7f 100644
--- a/src/util/misc.h
+++ b/src/util/misc.h
@@ -42,6 +42,19 @@ extern char* strip_off_quotes(char* line);
  */
 extern int is_number(const char* str, int* num);
 
+/**
+ * Convert the 'bytes' number into a formatted byte size string.
+ * E.g. "129012" becomes "125.99 KB".
+ * Note, if the output buffer is not large enough then the output
+ * will be truncated. The buffer will always be \0 terminated.
+ *
+ * @param bytes the number that should be formatted.
+ * @param[out] buf the buffer the string should be formatted into
+ * @param bufsize the size of 'buf'
+ * @return A pointer to buf.
+ */
+extern const char* format_size(size_t bytes, char* buf, size_t bufsize);
+
 extern int file_read_lines(const char* file, void* data, file_line_handler_t handler);
 
 /**