[src/trunk]: src/lib/libc/gen PR#7540, add a commaize_number function, which ...

[erh <erh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c57c0e20fd0a
branches:  trunk
changeset: 763244:c57c0e20fd0a
user:      erh <erh%NetBSD.org@localhost>
date:      Tue Mar 15 03:47:04 2011 +0000

description:
PR#7540, add a commaize_number function, which inserts comma into a string
 of digits to make it more readable.  This is soon to be used in /bin/ls.

diffstat:

 lib/libc/gen/Makefile.inc      |    8 ++-
 lib/libc/gen/commaize_number.3 |   83 +++++++++++++++++++++++++++++++++
 lib/libc/gen/commaize_number.c |  101 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 189 insertions(+), 3 deletions(-)

diffs (220 lines):

diff -r ea26b53fad5b -r c57c0e20fd0a lib/libc/gen/Makefile.inc
--- a/lib/libc/gen/Makefile.inc Tue Mar 15 00:48:04 2011 +0000
+++ b/lib/libc/gen/Makefile.inc Tue Mar 15 03:47:04 2011 +0000
@@ -1,11 +1,12 @@
-#      $NetBSD: Makefile.inc,v 1.174 2011/03/12 19:52:48 christos Exp $
+#      $NetBSD: Makefile.inc,v 1.175 2011/03/15 03:47:04 erh Exp $
 #      from: @(#)Makefile.inc  8.6 (Berkeley) 5/4/95
 
 # gen sources
 .PATH: ${ARCHDIR}/gen ${.CURDIR}/gen
 
 SRCS+=         _errno.c alarm.c alphasort.c arc4random.c assert.c basename.c clock.c \
-       closedir.c closefrom.c confstr.c ctermid.c ctype_.c daemon.c \
+       closedir.c closefrom.c commaize_number.c \
+       confstr.c ctermid.c ctype_.c daemon.c \
        dehumanize_number.c devname.c dirname.c disklabel.c err.c errx.c \
        errlist.c errno.c execl.c execle.c execlp.c execv.c execvp.c \
        extattr.c fmtcheck.c fmtmsg.c fnmatch.c fstab.c ftok.c \
@@ -50,7 +51,8 @@
 
 .include "${ARCHDIR}/gen/Makefile.inc"
 
-MAN+=  alarm.3 arc4random.3 basename.3 bswap.3 clock.3 closefrom.3 confstr.3 \
+MAN+=  alarm.3 arc4random.3 basename.3 bswap.3 clock.3 closefrom.3 \
+       commaize_number.3 confstr.3 \
        cpuset.3 ctermid.3 ctype.3 daemon.3 devname.3 directory.3 dirname.3 \
        endutxent.3 err.3 exec.3 extattr.3 \
        fmtcheck.3 fmtmsg.3 fnmatch.3 fpclassify.3 fpgetmask.3 \
diff -r ea26b53fad5b -r c57c0e20fd0a lib/libc/gen/commaize_number.3
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libc/gen/commaize_number.3    Tue Mar 15 03:47:04 2011 +0000
@@ -0,0 +1,83 @@
+.\"    $NetBSD: commaize_number.3,v 1.1 2011/03/15 03:47:04 erh Exp $
+.\"
+.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Eric Haszlakiewicz.
+.\"
+.\" 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.
+.\"
+.Dd March 12, 2011
+.Dt COMMAIZE_NUMBER 3
+.Os
+.Sh NAME
+.Nm commaize_number
+.Nd format a number into a human readable form by adding commas (actually, the locale specific thousands separator)
+.Sh SYNOPSIS
+.In stdlib.h
+.Ft int
+.Fn commaize_number "char *buffer" "size_t len" "int64_t number"
+.Sh DESCRIPTION
+The
+.Fn commaize_number
+function formats the signed 64 bit quantity given in
+.Fa number
+into
+.Fa buffer ,
+which 
+must be at least
+.Fa len
+bytes long.
+.Pp
+If the formatted number would be too long to fit into
+.Fa buffer ,
+then an error is returned.
+.Sh RETURN VALUES
+.Fn commaize_number
+returns the number of characters stored in
+.Fa buffer
+(excluding the terminating NUL) upon success, or \-1 upon failure with 
+.Va errno
+set to indicate the error.
+.Sh ERRORS
+.Fn commaize_number
+will fail and nothing will be written to
+.Fa buffer
+if:
+.Bl -tag -width Er
+.It Bq Er ENOMEM
+The formatted number, including commas and terminating NUL, is too long to fit in
+.Fa len
+bytes.
+.El
+.Sh SEE ALSO
+.Xr humanize_number 9 ,
+.Xr setlocale 3 ,
+.Xr ls 1 .
+.Sh HISTORY
+.Fn humanize_number
+first appeared in
+.Nx 6.0 .
+.Pp
+.Sh AUTHORS
+.An Eric Haszlakiewicz Aq erh%netbsd.org@localhost
diff -r ea26b53fad5b -r c57c0e20fd0a lib/libc/gen/commaize_number.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libc/gen/commaize_number.c    Tue Mar 15 03:47:04 2011 +0000
@@ -0,0 +1,101 @@
+/*     $NetBSD: commaize_number.c,v 1.1 2011/03/15 03:47:04 erh Exp $ */
+
+/*-
+ * Copyright (c) 2011 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Eric Haszlakiewicz.
+ *
+ * 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 <errno.h>
+#include <inttypes.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+/**
+ * Format a number with commas (or another locale specific separator) between
+ * every three digits.
+ *
+ * Uses localeconv to figure out which separator to use, but defaults
+ * to a comma if the locale specific thousands separator isn't set.
+ */
+int commaize_number(char *buf, size_t len, int64_t number)
+{
+    char commabuf[22];  /* 64 bits == 20 digits, +1 for sign, +1 for NUL */
+       const char *thousands_sep = ",";
+       unsigned int separator_len = 1;
+       struct lconv *localeinfo;
+
+       int nchars, ndigits;
+       int chars_needed;
+
+       int dest_offset;
+       int ii;
+
+       if ((nchars = snprintf(commabuf, sizeof(commabuf), "%" PRId64, number)) 
+           >= (int)sizeof(commabuf))
+       {
+               errno = ENOMEM;
+               return -1;
+       }
+
+       localeinfo = localeconv();
+       if (localeinfo && localeinfo->thousands_sep &&
+           localeinfo->thousands_sep[0])
+       {
+               thousands_sep = localeinfo->thousands_sep;
+               separator_len = strlen(localeinfo->thousands_sep);
+       }
+
+       ndigits = nchars;
+       if (commabuf[0] == '-')
+               ndigits--;
+       chars_needed = nchars + separator_len * ((ndigits - 1) / 3);
+       if (chars_needed + 1 > (int)len)
+       {
+               errno = ENOMEM;
+               return -1;
+       }
+
+       buf[chars_needed] = '\0';
+
+       dest_offset = chars_needed - 1;
+       for (ii = 1 ; ii <= nchars ; ii++)
+       {
+               buf[dest_offset] = commabuf[nchars - ii];
+
+               if ((ii % 3) == 0 && ii < (int)nchars && commabuf[nchars - ii - 1] != '-')
+               {
+                       memcpy(&buf[dest_offset - separator_len], thousands_sep, separator_len);
+                       dest_offset -= separator_len;
+               }
+
+               dest_offset--;
+       }
+       return chars_needed;
+}
+