Add dehumanize_number function

Taken from NetBSD.

1 files changed, 114 insertions, 0 deletions

diff --git a/src/dehumanize_number.c b/src/dehumanize_number.c
new file mode 100644
index 0000000..4884422
--- /dev/null
+++ b/src/dehumanize_number.c
@@ -0,0 +1,114 @@
+/*	$NetBSD: dehumanize_number.c,v 1.2 2007/12/14 17:32:47 xtraeme Exp $	*/
+
+/*
+ * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
+ * 2005 program.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: dehumanize_number.c,v 1.2 2007/12/14 17:32:47 xtraeme Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#include <inttypes.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+
+/*
+ * Converts the number given in 'str', which may be given in a humanized
+ * form (as described in humanize_number(3), but with some limitations),
+ * to an int64_t without units.
+ * In case of success, 0 is returned and *size holds the value.
+ * Otherwise, -1 is returned and *size is untouched.
+ *
+ * TODO: Internationalization, SI units.
+ */
+int
+dehumanize_number(const char *str, int64_t *size)
+{
+	char *ep, unit;
+	const char *delimit;
+	long multiplier;
+	long long tmp, tmp2;
+	size_t len;
+
+	len = strlen(str);
+	if (len == 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	multiplier = 1;
+
+	unit = str[len - 1];
+	if (isalpha((unsigned char)unit)) {
+		switch (tolower((unsigned char)unit)) {
+		case 'b':
+			multiplier = 1;
+			break;
+
+		case 'k':
+			multiplier = 1024;
+			break;
+
+		case 'm':
+			multiplier = 1024 * 1024;
+			break;
+
+		case 'g':
+			multiplier = 1024 * 1024 * 1024;
+			break;
+
+		default:
+			errno = EINVAL;
+			return -1; /* Invalid suffix. */
+		}
+
+		delimit = &str[len - 1];
+	} else
+		delimit = NULL;
+
+	errno = 0;
+	tmp = strtoll(str, &ep, 10);
+	if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
+		return -1; /* Not a number. */
+	else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
+		return -1; /* Out of range. */
+
+	tmp2 = tmp * multiplier;
+	tmp2 = tmp2 / multiplier;
+	if (tmp != tmp2) {
+		errno = ERANGE;
+		return -1; /* Out of range. */
+	}
+	*size = tmp * multiplier;
+
+	return 0;
+}