Add getbsize() function

Import code from DragonFlyBSD and man page from FreeBSD.

include/bsd/stdlib.h

@@ -70,6 +70,8 @@ void *reallocf(void *ptr, size_t size);
 
 long long strtonum(const char *nptr, long long minval, long long maxval,
                    const char **errstr);
+
+char *getbsize(int *headerlenp, long *blocksizep);
 __END_DECLS
 
 #endif

man/Makefile.am

@@ -29,6 +29,7 @@ dist_man_MANS = \
 	fmtcheck.3 \
 	fparseln.3 \
 	funopen.3 \
+	getbsize.3 \
 	getmode.3 \
 	getpeereid.3 \
 	getprogname.3 \

man/getbsize.3

@@ -0,0 +1,95 @@
+.\" Copyright (c) 1993
+.\"	The Regents of the University of California.  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.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+.\"
+.\"     @(#)getbsize.3	8.1 (Berkeley) 6/4/93
+.\" $FreeBSD$
+.\"
+.Dd November 16, 2012
+.Dt GETBSIZE 3
+.Os
+.Sh NAME
+.Nm getbsize
+.Nd get preferred block size
+.Sh LIBRARY
+.ds str-Lb-libbsd Utility functions from BSD systems (libbsd, \-lbsd)
+.Lb libbsd
+.Sh SYNOPSIS
+.In bsd/stdlib.h
+.Ft char *
+.Fn getbsize "int *headerlenp" "long *blocksizep"
+.Sh DESCRIPTION
+The
+.Fn getbsize
+function returns a preferred block size for reporting by system utilities
+.Xr df 1 ,
+.Xr du 1 ,
+.Xr ls 1
+and
+.Xr systat 1 ,
+based on the value of the
+.Ev BLOCKSIZE
+environment variable.
+.Ev BLOCKSIZE
+may be specified directly in bytes, or in multiples of a kilobyte by
+specifying a number followed by ``K'' or ``k'', in multiples of a
+megabyte by specifying a number followed by ``M'' or ``m'' or in
+multiples of a gigabyte by specifying a number followed by ``G'' or
+``g''.
+Multiples must be integers.
+.Pp
+Valid values of
+.Ev BLOCKSIZE
+are 512 bytes to 1 gigabyte.
+Sizes less than 512 bytes are rounded up to 512 bytes, and sizes
+greater than 1 GB are rounded down to 1 GB.
+In each case
+.Fn getbsize
+produces a warning message.
+.Pp
+The
+.Fn getbsize
+function returns a pointer to a null-terminated string describing
+the block size, something like
+.Dq 1K-blocks .
+The memory referenced by
+.Fa headerlenp
+is filled in with the length of the string (not including the
+terminating null).
+The memory referenced by
+.Fa blocksizep
+is filled in with block size, in bytes.
+.Sh SEE ALSO
+.Xr df 1 ,
+.Xr du 1 ,
+.Xr ls 1 ,
+.Xr systat 1 ,
+.Xr environ 7
+.Sh HISTORY
+The
+.Fn getbsize
+function first appeared in
+.Bx 4.4 .

src/Makefile.am

@@ -52,6 +52,7 @@ libbsd_la_SOURCES = \
 	fparseln.c \
 	fpurge.c \
 	funopen.c \
+	getbsize.c \
 	getpeereid.c \
 	hash/md5.c \
 	hash/md5hl.c \

src/getbsize.c

@@ -0,0 +1,102 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ *
+ * @(#)getbsize.c	8.1 (Berkeley) 6/4/93
+ * $FreeBSD: src/lib/libc/gen/getbsize.c,v 1.9 2008/08/04 06:53:13 cperciva Exp $
+ * $DragonFly: src/lib/libc/gen/getbsize.c,v 1.4 2005/11/13 00:07:42 swildner Exp $
+ */
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char *
+getbsize(int *headerlenp, long *blocksizep)
+{
+	static char header[20];
+	long n, max, mul, blocksize;
+	char *ep, *p;
+	const char *form;
+
+#define	KB	(1024L)
+#define	MB	(1024L * 1024L)
+#define	GB	(1024L * 1024L * 1024L)
+#define	MAXB	GB		/* No tera, peta, nor exa. */
+	form = "";
+	if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
+		if ((n = strtol(p, &ep, 10)) < 0)
+			goto underflow;
+		if (n == 0)
+			n = 1;
+		if (*ep && ep[1])
+			goto fmterr;
+		switch (*ep) {
+		case 'G': case 'g':
+			form = "G";
+			max = MAXB / GB;
+			mul = GB;
+			break;
+		case 'K': case 'k':
+			form = "K";
+			max = MAXB / KB;
+			mul = KB;
+			break;
+		case 'M': case 'm':
+			form = "M";
+			max = MAXB / MB;
+			mul = MB;
+			break;
+		case '\0':
+			max = MAXB;
+			mul = 1;
+			break;
+		default:
+fmterr:			warnx("%s: unknown blocksize", p);
+			n = 512;
+			max = MAXB;
+			mul = 1;
+			break;
+		}
+		if (n > max) {
+			warnx("maximum blocksize is %ldG", MAXB / GB);
+			n = max;
+		}
+		if ((blocksize = n * mul) < 512) {
+underflow:		warnx("minimum blocksize is 512");
+			form = "";
+			blocksize = n = 512;
+		}
+	} else
+		blocksize = n = 512;
+
+	snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
+	*headerlenp = strlen(header);
+	*blocksizep = blocksize;
+	return (header);
+}

src/libbsd.map

@@ -112,6 +112,8 @@ LIBBSD_0.6 {
 } LIBBSD_0.5;
 
 LIBBSD_0.7 {
+    getbsize;
+
     funopen;
 
     _time32_to_time;