Implement expand_number(3), which is the opposite of humanize_number(3), ie.

a number in human-readable form is converted to int64_t, for example:
123b -> 123
10k -> 10240
16G -> 17179869184

First version submitted by:	Eric Anderson <anderson@freebsd.org>
Approved by:	re (bmah)

4 files changed, 177 insertions, 3 deletions

diff --git a/lib/libutil/Makefile b/lib/libutil/Makefile
index 27e6f9b..773dd74 100644
--- a/lib/libutil/Makefile
+++ b/lib/libutil/Makefile
@@ -8,8 +8,8 @@ SHLIBDIR?= /lib
 LIB=	util
 SHLIB_MAJOR= 7
 
-SRCS=	_secure_path.c auth.c flopen.c fparseln.c humanize_number.c \
-	kld.c login.c login_auth.c login_cap.c login_class.c \
+SRCS=	_secure_path.c auth.c expand_number.c flopen.c fparseln.c \
+	humanize_number.c kld.c login.c login_auth.c login_cap.c login_class.c \
 	login_crypt.c login_ok.c login_times.c login_tty.c logout.c \
 	logwtmp.c pidfile.c property.c pty.c pw_util.c realhostname.c \
 	stub.c trimdomain.c uucplock.c
@@ -27,7 +27,7 @@ MAN+=	kld.3 login.3 login_auth.3 login_tty.3 logout.3 logwtmp.3 pty.3 \
 	login_cap.3 login_class.3 login_times.3 login_ok.3 \
 	_secure_path.3 uucplock.3 property.3 auth.3 realhostname.3 \
 	realhostname_sa.3 trimdomain.3 fparseln.3 humanize_number.3 \
-	pidfile.3 flopen.3
+	pidfile.3 flopen.3 expand_number.3
 MAN+=	login.conf.5 auth.conf.5
 MLINKS+= kld.3 kld_isloaded.3 kld.3 kld_load.3
 MLINKS+= property.3 properties_read.3  property.3 properties_free.3
diff --git a/lib/libutil/expand_number.3 b/lib/libutil/expand_number.3
new file mode 100644
index 0000000..e81a200
--- /dev/null
+++ b/lib/libutil/expand_number.3
@@ -0,0 +1,84 @@
+.\" Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>
+.\" Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" 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 AUTHORS 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 AUTHORS 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.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd April 16, 2007
+.Dt EXPAND_NUMBER 3
+.Os
+.Sh NAME
+.Nm expand_number
+.Nd format a number from human readable form
+.Sh LIBRARY
+.Lb libutil
+.Sh SYNOPSIS
+.In libutil.h
+.Ft int
+.Fo expand_number
+.Fa "char *buf" "int64_t *num"
+.Fc
+.Sh DESCRIPTION
+The
+.Fn expand_number
+function unformats the
+.Fa buf
+string and stores a signed 64-bit quantity at address pointed out by the
+.Fa num
+argument.
+.Pp
+The
+.Fn expand_number
+function
+follows the SI power of two convention.
+.Pp
+The prefixes are:
+.Bl -column "Prefix" "Description" "1000000000000000000" -offset indent
+.It Sy "Prefix" Ta Sy "Description" Ta Sy "Multiplier"
+.It Li k Ta No kilo Ta 1024
+.It Li M Ta No mega Ta 1048576
+.It Li G Ta No giga Ta 1073741824
+.It Li T Ta No tera Ta 1099511627776
+.It Li P Ta No peta Ta 1125899906842624
+.It Li E Ta No exa  Ta 1152921504606846976
+.El
+.Sh RETURN VALUES
+.Rv -std
+.Sh ERRORS
+The
+.Fn expand_number
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The given string contains no digits.
+.It Bq Er EINVAL
+An unrecognized prefix was given.
+.It Bq Er ERANGE
+Result doesn't fit into 64 bits.
+.El
+.Sh HISTORY
+The
+.Fn expand_number
+function first appeared in
+.Fx 7.0 .
diff --git a/lib/libutil/expand_number.c b/lib/libutil/expand_number.c
new file mode 100644
index 0000000..b9ae5d2
--- /dev/null
+++ b/lib/libutil/expand_number.c
@@ -0,0 +1,89 @@
+/*-
+ * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>
+ * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * All rights reserved.
+ *
+ * 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 AUTHORS 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 AUTHORS 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>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <ctype.h>
+#include <errno.h>
+#include <libutil.h>
+#include <stdint.h>
+
+/*
+ * Convert an expression of the following forms to a int64_t.
+ * 	1) A positive decimal number.
+ *	2) A positive decimal number followed by a 'b' or 'B' (mult by 1).
+ *	3) A positive decimal number followed by a 'k' or 'K' (mult by 1 << 10).
+ *	4) A positive decimal number followed by a 'm' or 'M' (mult by 1 << 20).
+ *	5) A positive decimal number followed by a 'g' or 'G' (mult by 1 << 30).
+ *	6) A positive decimal number followed by a 't' or 'T' (mult by 1 << 40).
+ *	7) A positive decimal number followed by a 'p' or 'P' (mult by 1 << 50).
+ *	8) A positive decimal number followed by a 'e' or 'E' (mult by 1 << 60).
+ */
+int
+expand_number(char *buf, int64_t *num)
+{
+	static const char unit[] = "bkmgtpe";
+	char *endptr, s;
+	int64_t number;
+	int i;
+
+	number = strtoimax(buf, &endptr, 0);
+
+	if (endptr == buf) {
+		/* No valid digits. */
+		errno = EINVAL;
+		return (-1);
+	}
+
+	if (*endptr == '\0') {
+		/* No unit. */
+		*num = number;
+		return (0);
+	}
+
+	s = tolower(*endptr);
+	for (i = 0; i < unit[i] != '\0'; i++) {
+		if (s == unit[i])
+			break;
+		if ((number < 0 && (number << 10) > number) ||
+		    (number >= 0 && (number << 10) < number)) {
+			errno = ERANGE;
+			return (-1);
+		}
+		number <<= 10;
+	}
+	if (unit[i] == '\0') {
+		/* Unrecognized unit. */
+		errno = EINVAL;
+		return (-1);
+	}
+
+	*num = number;
+	return (0);
+}
diff --git a/lib/libutil/libutil.h b/lib/libutil/libutil.h
index 51ca3d1..1df9510 100644
--- a/lib/libutil/libutil.h
+++ b/lib/libutil/libutil.h
@@ -82,6 +82,7 @@ int	forkpty(int *_amaster, char *_name,
 		     struct termios *_termp, struct winsize *_winp);
 int	humanize_number(char *_buf, size_t _len, int64_t _number,
 	    const char *_suffix, int _scale, int _flags);
+int	expand_number(char *_buf, int64_t *_num);
 const char *uu_lockerr(int _uu_lockresult);
 int	uu_lock(const char *_ttyname);
 int	uu_unlock(const char *_ttyname);