Change license, rewrite in C, remove info manual, remove dist2.0

Signed-off-by: Mattias Andrée <maandree@kth.se>

16 files changed, 443 insertions, 1676 deletions

diff --git a/.gitignore b/.gitignore
index 99e7d15..62d48ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,19 +1,4 @@
-_/
-/bin/
-/obj/
-__pycache__/
-\#*\#
-.*
-!.git*
+*\#*
 *~
-*.new
-*.bak
-*.swo
-*.swp
-*.pyc
-*.pyo
-*.info
-*.pdf
-*.dvi
-*.ps
-
+*.o
+/median
diff --git a/COPYING b/COPYING
deleted file mode 100644
index 959b0d7..0000000
--- a/COPYING
+++ /dev/null
@@ -1,15 +0,0 @@
-median — Calculate the median values for a set of groups
-Copyright © 2014, 2015  Mattias Andrée (maandree@member.fsf.org)
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
diff --git a/LICENSE b/LICENSE
index 94a9ed0..d501217 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,674 +1,15 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 3, 29 June 2007
+ISC License
 
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
+© 2014, 2015, 2021 Mattias Andrée <maandree@kth.se>
 
-                            Preamble
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
 
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-
-  14. Revised Versions of this License.
-
-  The Free Software Foundation may publish revised and/or new versions of
-the GNU General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
-
-  Each version is given a distinguishing version number.  If the
-Program specifies that a certain numbered version of the GNU General
-Public License "or any later version" applies to it, you have the
-option of following the terms and conditions either of that numbered
-version or of any later version published by the Free Software
-Foundation.  If the Program does not specify a version number of the
-GNU General Public License, you may choose any version ever published
-by the Free Software Foundation.
-
-  If the Program specifies that a proxy can decide which future
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-to choose that version for the Program.
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-  Later license versions may give you additional or different
-permissions.  However, no additional obligations are imposed on any
-author or copyright holder as a result of your choosing to follow a
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-  15. Disclaimer of Warranty.
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-  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
-APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
-HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
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-ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
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-  16. Limitation of Liability.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
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-GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
-USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
-DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
-PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
-EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
-SUCH DAMAGES.
-
-  17. Interpretation of Sections 15 and 16.
-
-  If the disclaimer of warranty and limitation of liability provided
-above cannot be given local legal effect according to their terms,
-reviewing courts shall apply local law that most closely approximates
-an absolute waiver of all civil liability in connection with the
-Program, unless a warranty or assumption of liability accompanies a
-copy of the Program in return for a fee.
-
-                     END OF TERMS AND CONDITIONS
-
-            How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-state the exclusion of warranty; and each file should have at least
-the "copyright" line and a pointer to where the full notice is found.
-
-    <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) <year>  <name of author>
-
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-Also add information on how to contact you by electronic and paper mail.
-
-  If the program does terminal interaction, make it output a short
-notice like this when it starts in an interactive mode:
-
-    <program>  Copyright (C) <year>  <name of author>
-    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
-
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, your program's commands
-might be different; for a GUI interface, you would use an "about box".
-
-  You should also get your employer (if you work as a programmer) or school,
-if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU GPL, see
-<http://www.gnu.org/licenses/>.
-
-  The GNU General Public License does not permit incorporating your program
-into proprietary programs.  If your program is a subroutine library, you
-may consider it more useful to permit linking proprietary applications with
-the library.  If this is what you want to do, use the GNU Lesser General
-Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/Makefile b/Makefile
index c3d97ff..ce35988 100644
--- a/Makefile
+++ b/Makefile
@@ -1,136 +1,44 @@
-# Copying and distribution of this file, with or without modification,
-# are permitted in any medium without royalty provided the copyright
-# notice and this notice are preserved.  This file is offered as-is,
-# without any warranty.
+.PHONY:
+
+CONFIGFILE = config.mk
+include $(CONFIGFILE)
+
+all: median
+
+median: median.o
+	$(CC) -o $@ median.o $(LDFLAGS)
+
+median.o: median.c
+	$(CC) -c -o $@ median.c $(CFLAGS) $(CPPFLAGS)
+
+check: median
+	test "$$(printf '%s\n' 1 5 2 | ./median)" = 2
+	test "$$(printf '%s\n' 1 2 | ./median)" = 1.5
+	test "$$(printf '%s\n' '1 a' '2 a' | ./median)" = '1.5 a'
+	test "$$(printf '%s\n' '1 a' '2 b' | ./median)" = "$$(printf '%s\n' '1 a' '2 b')"
+	test "$$(printf '%s\n' '1 a' '2 b' '3 a' | ./median)" = "$$(printf '%s\n' '2 a' '2 b')"
+	test "$$(printf '%s\n' '1 a' '2 b' '3 a' '10 a' | ./median)" = "$$(printf '%s\n' '3 a' '2 b')"
+	test "$$(printf '%s\n' '1' '2 ' | ./median)" = "$$(printf '%s\n' '1' '2 ')"
+	test "$$(printf '1\ta\n3 a\n' | ./median)" = "$$(printf '1\ta\n3 a\n')"
+	test "$$(printf '%s\n' a c d | ./median)" = c
+	test "$$(printf '%s\n' a d c | ./median)" = c
+	test "$$(printf '%s\n' a b | ./median)" = a
+	test "$$(printf '%s\n' a b b | ./median)" = b
+
+install:
+	mkdir -p -- "$(DESTDIR)$(PREFIX)/bin"
+	mkdir -p -- "$(DESTDIR)$(MANPREFIX)/man1"
+	cp -- median "$(DESTDIR)$(PREFIX)/bin/"
+	cp -- median.1 "$(DESTDIR)$(MANPREFIX)/man1/"
 
-
-PREFIX = /usr
-BIN = /bin
-DATA = /share
-BINDIR = $(PREFIX)$(BIN)
-DATADIR = $(PREFIX)$(DATA)
-DOCDIR = $(DATADIR)/doc
-INFODIR = $(DATADIR)/info
-MANDIR = $(DATADIR)/man
-MAN1DIR = $(MANDIR)/man1
-LICENSEDIR = $(DATADIR)/licenses
-
-COMMAND = median
-PKGNAME = median
-
-
-
-.PHONY: default
-default: info
-
-.PHONY: all
-all: doc
-
-.PHONY: doc
-doc: info pdf dvi ps
-
-.PHONY: info
-info: bin/median.info
-bin/%.info: doc/info/%.texinfo doc/info/fdl.texinfo
-	@mkdir -p bin
-	makeinfo $<
-	mv $*.info $@
-
-.PHONY: pdf
-pdf: bin/median.pdf
-bin/%.pdf: doc/info/%.texinfo doc/info/fdl.texinfo
-	@mkdir -p obj/pdf bin
-	cd obj/pdf ; texi2pdf ../../$< < /dev/null
-	mv obj/pdf/$*.pdf $@
-
-.PHONY: dvi
-dvi: bin/median.dvi
-bin/%.dvi: doc/info/%.texinfo doc/info/fdl.texinfo
-	@mkdir -p obj/dvi bin
-	cd obj/dvi ; $(TEXI2DVI) ../../$< < /dev/null
-	mv obj/dvi/$*.dvi $@
-
-.PHONY: ps
-ps: bin/median.ps
-bin/%.ps: doc/info/%.texinfo doc/info/fdl.texinfo
-	@mkdir -p obj/ps bin
-	cd obj/ps ; texi2pdf --ps ../../$< < /dev/null
-	mv obj/ps/$*.ps $@
-
-
-
-.PHONY: install
-install: install-base install-info install-man
-
-.PHONY: install
-install-all: install-base install-doc
-
-.PHONY: install-base
-install-base: install-command install-copyright
-
-.PHONY: install-command
-install-command:
-	install -dm755 -- "$(DESTDIR)$(BINDIR)"
-	install -m755 src/median -- "$(DESTDIR)$(BINDIR)/$(COMMAND)"
-
-.PHONY: install-copyright
-install-copyright: install-copying install-license
-
-.PHONY: install-copying
-install-copying:
-	install -dm755 -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)"
-	install -m644 COPYING -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)"
-
-.PHONY: install-license
-install-license:
-	install -dm755 -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)"
-	install -m644 LICENSE -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)"
-
-.PHONY: install-doc
-install-doc: install-info install-pdf install-ps install-dvi install-man
-
-.PHONY: install-info
-install-info: bin/median.info
-	install -dm755 -- "$(DESTDIR)$(INFODIR)"
-	install -m644 $< -- "$(DESTDIR)$(INFODIR)/$(PKGNAME).info"
-
-.PHONY: install-pdf
-install-pdf: bin/median.pdf
-	install -dm755 -- "$(DESTDIR)$(DOCDIR)"
-	install -m644 $< -- "$(DESTDIR)$(DOCDIR)/$(PKGNAME).pdf"
-
-.PHONY: install-ps
-install-ps: bin/median.ps
-	install -dm755 -- "$(DESTDIR)$(DOCDIR)"
-	install -m644 $< -- "$(DESTDIR)$(DOCDIR)/$(PKGNAME).ps"
-
-.PHONY: install-dvi
-install-dvi: bin/median.dvi
-	install -dm755 -- "$(DESTDIR)$(DOCDIR)"
-	install -m644 $< -- "$(DESTDIR)$(DOCDIR)/$(PKGNAME).dvi"
-
-.PHONY: install-man
-install-man: doc/man/median.1
-	install -dm755 -- "$(DESTDIR)$(MAN1DIR)"
-	install -m644 $< -- "$(DESTDIR)$(MAN1DIR)/$(COMMAND).1"
-
-
-
-.PHONY: uninstall
 uninstall:
-	-rm -- "$(DESTDIR)$(BINDIR)/$(COMMAND)"
-	-rm -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)/COPYING"
-	-rm -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)/LICENSE"
-	-rmdir -- "$(DESTDIR)$(LICENSEDIR)/$(PKGNAME)"
-	-rm -- "$(DESTDIR)$(INFODIR)/$(PKGNAME).info"
-	-rm -- "$(DESTDIR)$(DOCDIR)/$(PKGNAME).pdf"
-	-rm -- "$(DESTDIR)$(DOCDIR)/$(PKGNAME).ps"
-	-rm -- "$(DESTDIR)$(DOCDIR)/$(PKGNAME).dvi"
-	-rm -- "$(DESTDIR)$(MAN1DIR)/$(COMMAND).1"
-
+	-rm -f -- "$(DESTDIR)$(PREFIX)/bin/median"
+	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man1/median.1"
 
-
-.PHONY: clean
 clean:
-	-rm -r obj bin
+	-rm -f -- median *.o
+
+.SUFFIXES:
+.SUFFIXES: .c .o
 
+.PHONY: all check install uninstall clean
diff --git a/README b/README
index c7a8649..eea8c25 100644
--- a/README
+++ b/README
@@ -2,13 +2,25 @@ NAME
 	median - Calculate the median values for a set of groups
 
 SYNOPSIS
-	median < INPUT
+	median
 
 DESCRIPTION
 	median takes the first blank space-separated column values
 	and the remainder as keys. It will then print the median for
-	each key. As a side effect median will print the result
-	sorted by the keys.
+	each key. Lines with the same key form a group.
+
+	median outputs the median value for each key, no order of
+	the output lines are prescribed. No order is prescribed for
+	the input lines.
+
+	Lines without a blank space are parsed as having the empty
+	string as the key, for lines with a blank space, the first
+	blank space is parsed as part of the key.
+
+	For groups with an even number of elements, if the mean of
+	the middle two values are used as the median if all values
+	in the group are numerical, otherwise the lower value is
+	used as the median.
 
 EXAMPLES
 	$ cat <<EOF | median
@@ -38,6 +50,3 @@ RATIONALE
 
 SEE ALSO
 	sort(1), expr(1), sets(1)
-
-	Full documentation available locally via: info '(median)'
-
diff --git a/config.mk b/config.mk
new file mode 100644
index 0000000..2e90419
--- /dev/null
+++ b/config.mk
@@ -0,0 +1,6 @@
+PREFIX    = /usr
+MANPREFIX = $(PREFIX)/share/man
+
+CPPFLAGS  = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700
+CFLAGS    = -std=c99 -Wall -O2
+LDFLAGS   = -s
diff --git a/dist/archlinux/stable/.gitignore b/dist/archlinux/stable/.gitignore
deleted file mode 100644
index dcaac12..0000000
--- a/dist/archlinux/stable/.gitignore
+++ /dev/null
@@ -1,6 +0,0 @@
-*
-!/.git*
-*~
-!/PKGBUILD
-!/median.install
-
diff --git a/dist/archlinux/stable/PKGBUILD b/dist/archlinux/stable/PKGBUILD
deleted file mode 100644
index 959abf6..0000000
--- a/dist/archlinux/stable/PKGBUILD
+++ /dev/null
@@ -1,27 +0,0 @@
-# Maintainer: Mattias Andrée <`base64 -d`(bWFhbmRyZWUK)@member.fsf.org>
-
-pkgname=median
-pkgver=1.2
-pkgrel=1
-pkgdesc="Calculate the median values for a set of groups"
-arch=(any)
-url="https://github.com/maandree/median"
-license=(GPL3)
-depends=(python3)
-makedepends=(make coreutils texinfo)
-install=$pkgname.install
-source=($url/archive/$pkgver.tar.gz)
-sha256sums=(e988111e206ecfb7fae08218997f919179d25be6a88d9c8cbbc1388bb6e665d9)
-
-
-build() {
-  cd "$srcdir/$pkgname-$pkgver"
-  make PREFIX=/usr
-}
-
-
-package() {
-  cd "$srcdir/$pkgname-$pkgver"
-  make PREFIX=/usr install DESTDIR="$pkgdir"
-}
-
diff --git a/dist/archlinux/stable/median.install b/dist/archlinux/stable/median.install
deleted file mode 100644
index e5eade9..0000000
--- a/dist/archlinux/stable/median.install
+++ /dev/null
@@ -1,20 +0,0 @@
-_file="median"
-
-infodir="usr/share/info"
-file="${_file}.info"
-
-
-post_install() {
-  [[ -x "usr/bin/install-info" ]] || return 0
-  install-info -- "${infodir}/${file}" "${infodir}/dir" 2> /dev/null
-}
-
-post_upgrade() {
-  post_install "$1"
-}
-
-pre_remove() {
-  [[ -x "usr/bin/install-info" ]] || return 0
-  install-info --delete -- "${infodir}/${file}" "${infodir}/dir" 2> /dev/null
-}
-
diff --git a/doc/info/fdl.texinfo b/doc/info/fdl.texinfo
deleted file mode 100644
index cb71f05..0000000
--- a/doc/info/fdl.texinfo
+++ /dev/null
@@ -1,505 +0,0 @@
-@c The GNU Free Documentation License.
-@center Version 1.3, 3 November 2008
-
-@c This file is intended to be included within another document,
-@c hence no sectioning command or @node.
-
-@display
-Copyright @copyright{} 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
-@uref{http://fsf.org/}
-
-Everyone is permitted to copy and distribute verbatim copies
-of this license document, but changing it is not allowed.
-@end display
-
-@enumerate 0
-@item
-PREAMBLE
-
-The purpose of this License is to make a manual, textbook, or other
-functional and useful document @dfn{free} in the sense of freedom: to
-assure everyone the effective freedom to copy and redistribute it,
-with or without modifying it, either commercially or noncommercially.
-Secondarily, this License preserves for the author and publisher a way
-to get credit for their work, while not being considered responsible
-for modifications made by others.
-
-This License is a kind of ``copyleft'', which means that derivative
-works of the document must themselves be free in the same sense.  It
-complements the GNU General Public License, which is a copyleft
-license designed for free software.
-
-We have designed this License in order to use it for manuals for free
-software, because free software needs free documentation: a free
-program should come with manuals providing the same freedoms that the
-software does.  But this License is not limited to software manuals;
-it can be used for any textual work, regardless of subject matter or
-whether it is published as a printed book.  We recommend this License
-principally for works whose purpose is instruction or reference.
-
-@item
-APPLICABILITY AND DEFINITIONS
-
-This License applies to any manual or other work, in any medium, that
-contains a notice placed by the copyright holder saying it can be
-distributed under the terms of this License.  Such a notice grants a
-world-wide, royalty-free license, unlimited in duration, to use that
-work under the conditions stated herein.  The ``Document'', below,
-refers to any such manual or work.  Any member of the public is a
-licensee, and is addressed as ``you''.  You accept the license if you
-copy, modify or distribute the work in a way requiring permission
-under copyright law.
-
-A ``Modified Version'' of the Document means any work containing the
-Document or a portion of it, either copied verbatim, or with
-modifications and/or translated into another language.
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-A ``Secondary Section'' is a named appendix or a front-matter section
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-The ``Invariant Sections'' are certain Secondary Sections whose titles
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-allowed to be designated as Invariant.  The Document may contain zero
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-Sections then there are none.
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-The ``Cover Texts'' are certain short passages of text that are listed,
-as Front-Cover Texts or Back-Cover Texts, in the notice that says that
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-  or any later version published by the Free Software Foundation;
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diff --git a/doc/info/median.texinfo b/doc/info/median.texinfo
deleted file mode 100644
index 1255902..0000000
--- a/doc/info/median.texinfo
+++ /dev/null
@@ -1,128 +0,0 @@
-\input texinfo   @c -*-texinfo-*-
-
-@c %**start of header
-@setfilename median.info
-@settitle median
-@afourpaper
-@documentencoding UTF-8
-@documentlanguage en
-@finalout
-@c %**end of header
-
-
-@dircategory Utilities
-@direntry
-* median: (median).            Calculate the median values for a set of groups
-@end direntry
-
-
-@copying
-Copyright @copyright{} 2014 Mattias Andrée
-
-@quotation
-Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.3 or
-any later version published by the Free Software Foundation; with no
-Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
-Texts. A copy of the license is included in the section entitled
-``GNU Free Documentation License''.
-@end quotation
-@end copying
-
-@ifnottex
-@node Top
-@top median -- Calculate the median values for a set of groups
-@insertcopying
-@end ifnottex
-
-@titlepage
-@title median
-@subtitle Calculate the median values for a set of groups
-@author by Mattias Andrée (maandree)
-
-@page
-@c @center `'
-@vskip 0pt plus 1filll
-@insertcopying
-@end titlepage
-
-@contents
-
-
-
-@menu
-* Overview::                        Brief overview of @command{median}.
-* Invoking::                        Invocation of @command{median}.
-* GNU Free Documentation License::  Copying and sharing this manual.
-@end menu
-
-
-
-@node Overview
-@chapter Overview
-
-@command{median} is command line tool for getting the median
-values of groups. For each input line it parses the first
-column, separated by a blank space, as a value and the remainder
-of the line as a key. If the line does not contain a blank
-space and entire line is parsed as a value and the key is an
-empty string. If the line however contains a blank space it is
-included in the key, thus a line contain only a value and a line
-contain a value followed by a blank space is not interpreted has
-having the same key. @command{median} outputs the median value
-for each key. In @command{median}'s current implementation the
-keys will be sorted in the output. Keys do not have to be sorted
-or groups. @command{median} will do its best to print the median
-of in the same format as the input values. The input for a group
-is of even number and is numerical the mean value of the two
-middle values is used, otherwise the lower of the two middle
-values is is used. Of course, if the number of values is odd,
-the middle value is always used and it does not matter whether
-the input is numerical or not.
-
-
-
-@node Invoking
-@chapter Invoking
-
-@command{median} is command line filter that does not take any
-arguments. See @ref{Overview} for detail about the input and
-output format.
-
-Simple example:
-@example
-$ cat <<EOF | median
-> -10
-> 2
-> 4
-> 3
-> 50
-> EOF
-3
-@end example
-
-Example with 3 groups, one non-numerical:
-@example
-$ cat <<EOF | median
-> 10 group 1
-> 20 group 1
-> 01 group 2
-> 02 group 2
-> a group 3
-> b group 3
-> c group 3
-> d group 3
-> EOF
-15 group 1
-01.5 group 2
-b group 3
-@end example
-
-
-
-@node GNU Free Documentation License
-@appendix GNU Free Documentation License
-@include fdl.texinfo
-
-@bye
-
diff --git a/doc/man/median.1 b/doc/man/median.1
deleted file mode 100644
index b684304..0000000
--- a/doc/man/median.1
+++ /dev/null
@@ -1,64 +0,0 @@
-.TH MEDIAN 1 MEDIAN
-.SH NAME
-median - Calculate the median values for a set of groups
-.SH SYNOPSIS
-.B median
-<
-.I INPUT
-.SH DESCRIPTION
-.B median
-takes the first blank space-separated column values and the remainder
-as keys. It will then print the median for each key. As a side effect
-median will print the result sorted by the keys.
-.SH EXAMPLES
-.nf
-$ cat <<EOF | median
-\-10
-2
-4
-3
-50
-EOF
-3
-.fi
-.PP
-.nf
-$ cat <<EOF | median
-\+003  c
-\&.001  a
-\-002  b
-\+001  c
-\-001  b
-\+002  c
-EOF
-\&.001  a
-\-001.5  b
-\+002  c
-.fi
-.SH RATIONALE
-Combining
-.BR sort (1),
-.BR sed (1),
-.BR wc (1),
-.BR expr (1)
-to do this is too much work to do on a regular basis.
-.SH "SEE ALSO"
-.BR sort (1),
-.BR expr (1),
-.BR sets (1)
-.PP
-Full documentation available locally via: info \(aq(median)\(aq
-.SH AUTHORS
-Principal author, Mattias Andrée.  See the COPYING file for the full
-list of authors.
-.SH LICENSE
-Copyright \(co 2014, 2015  Mattias Andrée
-.br
-License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
-.br
-This is free software: you are free to change and redistribute it.
-.br
-There is NO WARRANTY, to the extent permitted by law.
-.SH BUGS
-Please report bugs to https://github.com/maandree/median/issues or to
-maandree@member.fsf.org
diff --git a/median b/median
new file mode 100755
index 0000000..a6abdb6
--- /dev/null
+++ b/median
diff --git a/median.1 b/median.1
new file mode 100644
index 0000000..f4756af
--- /dev/null
+++ b/median.1
@@ -0,0 +1,60 @@
+.TH MEDIAN 1 MEDIAN
+.SH NAME
+median - Calculate the median values for a set of groups
+.SH SYNOPSIS
+.B median
+.SH DESCRIPTION
+.B median
+takes the first blank space-separated column values and
+the remainder as keys. It will then print the median
+for each key. Lines with the same key form a group.
+.PP
+.B median
+outputs the median value for each key, no order of the
+output lines are prescribed. No order is prescribed for
+the input lines.
+.PP
+Lines without a blank space are parsed as having the empty
+string as the key, for lines with a blank space, the first
+blank space is parsed as part of the key.
+.PP
+For groups with an even number of elements, if the mean of
+the middle two values are used as the median if all values
+in the group are numerical, otherwise the lower value is
+used as the median.
+.SH EXAMPLES
+.nf
+$ cat <<EOF | median
+\-10
+2
+4
+3
+50
+EOF
+3
+.fi
+.PP
+.nf
+$ cat <<EOF | median
+\+003  c
+\&.001  a
+\-002  b
+\+001  c
+\-001  b
+\+002  c
+EOF
+\&.001  a
+\-001.5  b
+\+002  c
+.fi
+.SH RATIONALE
+Combining
+.BR sort (1),
+.BR sed (1),
+.BR wc (1),
+.BR expr (1)
+to do this is too much work to do on a regular basis.
+.SH "SEE ALSO"
+.BR sort (1),
+.BR expr (1),
+.BR sets (1)
diff --git a/median.c b/median.c
new file mode 100644
index 0000000..d282426
--- /dev/null
+++ b/median.c
@@ -0,0 +1,308 @@
+/* See LICENSE file for copyright and license details. */
+#include <ctype.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+struct group {
+	char *key;
+	struct group *next;
+	struct group *prev;
+	char **elems;
+	size_t nelems;
+	size_t elems_size;
+	int numerical;
+};
+
+
+static const char *argv0 = "median";
+
+static struct group groups_head;
+static struct group groups_tail;
+
+
+static int
+isnumerical(const char *s)
+{
+	if (*s == '+' || *s == '-')
+		s++;
+	if (s[0] == '.' && !s[1])
+		return 0;
+	while (isdigit(*s))
+		s++;
+	if (*s == '.') {
+		s++;
+		while (isdigit(*s))
+			s++;
+	}
+	return *s ? 0 : 1;
+}
+
+
+static int
+cmp_num(const void *apv, const void *bpv)
+{
+	const char *a = *(const char **)apv;
+	const char *b = *(const char **)bpv;
+	int mul = 1;
+	size_t an = 0, bn = 0, i;
+
+	if (*a == '-' || *b == '-') {
+		mul = -1;
+		a = &a[1];
+		b = &b[1];
+	} else if (*a == '-') {
+		return -1;
+	} else if (*b == '-') {
+		return +1;
+	} else {
+		a = &a[*a == '+'];
+		b = &b[*b == '+'];
+	}
+
+	while (*a == '0') a++;
+	while (*b == '0') b++;
+
+	while (a[an] && a[an] != '.') an++;
+	while (b[bn] && b[bn] != '.') bn++;
+
+	if (an != bn)
+		return an < bn ? -mul : mul;
+
+	for (i = 0; a[i] && a[i] == b[i]; i++);
+	a = &a[i];
+	b = &b[i];
+
+	if (i > an) {
+		if (!*a)
+			while (*b == '0') b++;
+		if (!*b)
+			while (*a == '0') a++;
+	}
+
+	if (!*a && !*b) {
+		return 0;
+	} else if (!*a) {
+		return -mul;
+	} else if (!*b) {
+		return mul;
+	} else if (*a < *b) {
+		return -mul;
+	} else {
+		return mul;
+	}
+}
+
+
+static int
+cmp_str(const void *apv, const void *bpv)
+{
+	const char *a = *(const char **)apv;
+	const char *b = *(const char **)bpv;
+	return strcmp(a, b);
+}
+
+
+static int
+avg(char *a, const char *b)
+{
+	size_t i;
+	int carry = 0, val;
+	for (i = 0; a[i]; i++) {
+		val = (a[i] & 15) + (b[i] & 15);
+		carry = val & 1;
+		a[i] = (val >> 1) | '0';
+	}
+	return carry;
+}
+
+
+static int
+subavg(char *a, const char *b)
+{
+	size_t i;
+	int carry = 0, val;
+	for (i = 0; a[i]; i++) {
+		val = (a[i] & 15) - (b[i] & 15);
+		carry = val & 1;
+		a[i] = (val >> 1) | '0';
+	}
+	return carry;
+}
+
+
+static void
+median2(const char *low, const char *high, const char *key)
+{
+	int low_plus  = *low  == '+', low_minus  = *low  == '-', low_dot;
+	int high_plus = *high == '+', high_minus = *high == '-', high_dot;
+	size_t low_int, low_frac = 0, high_int, high_frac = 0;
+	size_t max_int, max_frac, i;
+	char *low2, *high2, *tmp;
+	const char *prefix;
+	int carry;
+
+	for (low_int  = 0; low[low_int]   && low[low_int]   != '.'; low_int++);
+	for (high_int = 0; high[high_int] && high[high_int] != '.'; high_int++);
+	low_dot  = low[low_int]   == '.';
+	high_dot = high[high_int] == '.';
+
+	low  = &low[low_plus | low_minus];
+	high = &high[high_plus | high_minus];
+
+	if (low_dot)
+		low_frac = strlen(&low[low_int + 1]);
+	if (high_dot)
+		high_frac = strlen(&high[high_int + 1]);
+
+	max_int  = low_int  > high_int  ? low_int  : high_int;
+	max_frac = low_frac > high_frac ? low_frac : high_frac;
+
+	low2 = malloc(max_int + max_frac + 1);
+	high2 = malloc(max_int + max_frac + 1);
+	if (!low2 || !high2) {
+		perror(argv0);
+		exit(1);
+	}
+	low2[max_int + max_frac] = '\0';
+	high2[max_int + max_frac] = '\0';
+
+	memset(low2, '0', max_int - low_int);
+	memcpy(&low2[max_int - low_int], low, low_int);
+	memcpy(&low2[max_int], &low[low_int + 1], low_frac);
+	memset(&low2[max_int + low_frac], '0', max_frac - low_frac);
+
+	memset(high2, '0', max_int - high_int);
+	memcpy(&high2[max_int - high_int], high, high_int);
+	memcpy(&high2[max_int], &high[high_int + 1], high_frac);
+	memset(&high2[max_int + high_frac], '0', max_frac - high_frac);
+
+	if (low_minus && high_minus) {
+		prefix = "-";
+		carry = avg(high2, low2);
+	} else if (low_minus) {
+		for (i = 0; low2[i] && low2[i] == high2[i]; i++);
+		if (low2[i] <= high2[i]) {
+			prefix = "+";
+			carry = subavg(high2, low2);
+		} else {
+			prefix = "-";
+			carry = subavg(low2, high2);
+			tmp = low2, low2 = high2, high2 = tmp;
+		}
+	} else {
+		prefix = (low_plus || high_plus) ? "+" : "";
+		carry = avg(high2, low2);
+	}
+
+	printf("%s%.*s%s""%s%s%s\n",
+	       prefix, (int)max_int, high2,
+	       (carry || max_frac) ? "." : "", &high2[max_int], carry ? "5" : "", key);
+
+	free(low2);
+	free(high2);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+	char *line = NULL, *key;
+	struct group *group = NULL;
+	size_t size = 0;
+	ssize_t len;
+
+	groups_head.next = &groups_tail;
+	groups_tail.prev = &groups_head;
+
+	if (argc) {
+		argv0 = *argv++, argc--;
+		if (argc && argv[0][0] == '-' && argv[0][1] == '-' && !argv[0][2])
+			argv++, argc--;
+		if (argc) {
+			fprintf(stderr, "usage: %s\n", argv0);
+			return 1;
+		}
+	}
+
+	while ((len = getdelim(&line, &size, '\n', stdin)) > 0) {
+		if (len && line[--len] == '\n')
+			line[len] = '\0';
+
+		for (key = line; *key && !isspace(*key); key++);
+		if (group && !strcmp(group->key, key))
+			goto found_group;
+		for (group = groups_head.next; group->key; group = group->next)
+			if (!strcmp(group->key, key))
+				goto found_group;
+		group = calloc(1, sizeof(*group));
+		if (!group) {
+			perror(argv0);
+			return 1;
+		}
+		group->key = strdup(key);
+		if (!group->key) {
+			perror(argv0);
+			return 1;
+		}
+		group->numerical = 1;
+		group->prev = groups_tail.prev;
+		group->next = &groups_tail;
+		groups_tail.prev->next = group;
+		groups_tail.prev = group;
+
+	found_group:
+		if (group->nelems == group->elems_size) {
+			if (group->elems_size > SIZE_MAX / 2 / sizeof(*group->elems)) {
+				errno = ENOMEM;
+				perror(argv0);
+				return 1;
+			}
+			group->elems_size = group->elems_size ? group->elems_size * 2 : 16;
+			group->elems = realloc(group->elems, group->elems_size * sizeof(*group->elems));
+			if (!group->elems) {
+				perror(argv0);
+				return 1;
+			}
+		}
+		*key = '\0';
+		group->elems[group->nelems] = strdup(line);
+		if (!group->elems[group->nelems]) {
+			perror(argv0);
+			return 1;
+		}
+		if (group->numerical)
+			if (!isnumerical(line))
+				group->numerical = 0;
+		group->nelems++;
+	}
+
+	if (ferror(stdin)) {
+		perror(argv0);
+		return 1;
+	}
+
+	free(line);
+	while ((group = groups_head.next)->key) {
+		qsort(group->elems, group->nelems, sizeof(*group->elems), group->numerical ? cmp_num : cmp_str);
+		if (group->nelems % 2 || !group->numerical)
+			printf("%s%s\n", group->elems[(group->nelems - 1) / 2], group->key);
+		else if (group->nelems)
+			median2(group->elems[group->nelems / 2 - 1], group->elems[group->nelems / 2 - 0], group->key);
+		groups_head.next = group->next;
+		while (group->nelems--)
+			free(group->elems[group->nelems]);
+		free(group->elems);
+		free(group->key);
+		free(group);
+	}
+
+	if (fflush(stdout) || ferror(stdout) || fclose(stdout)) {
+		perror(argv0);
+		return 1;
+	}
+	return 0;
+}
diff --git a/src/median b/src/median
deleted file mode 100755
index 8684cef..0000000
--- a/src/median
+++ /dev/null
@@ -1,85 +0,0 @@
-#!/usr/bin/env python3
-# -*- python -*-
-'''
-median — Calculate the median values for a set of groups
-Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-'''
-
-lines = []
-try:
-    while True:
-        lines.append(input())
-except:
-    pass
-
-get_key   = lambda x : x[x.index(' '):] if ' ' in x else ''
-get_value = lambda x : x[:x.index(' ')] if ' ' in x else x
-lines     = [(get_value(line), get_key(line)) for line in lines if not line == '']
-
-lines.sort(key = lambda x : x[1]);
-
-last, values = None, None
-lines.append((..., ...))
-for value, key in lines:
-    if last != key:
-        if last is not None:
-            try:
-                values.sort(key = lambda x : float(x))
-            except:
-                values.sort()
-            if len(values) % 2 == 1:
-                median = values[len(values) // 2]
-            else:
-                low  = values[len(values) // 2 - 1]
-                high = values[len(values) // 2 - 0]
-                try:
-                    low_plus,  low_minus,  low_dot  =  (low[0] == '+'),  (low[0] == '-'), ('.' in  low)
-                    high_plus, high_minus, high_dot = (high[0] == '+'), (high[0] == '-'), ('.' in high)
-                    if  low_plus or  low_minus:   low =  low[1:]
-                    if high_plus or high_minus:  high = high[1:]
-                    if not  low_dot:  low += '.'
-                    if not high_dot: high += '.'
-                    lowi , lowd  = [len(x) for x in  low.split('.')]
-                    highi, highd = [len(x) for x in high.split('.')]
-                    if lowd < highd:   low += '0'
-                    if lowd > highd:  high += '0'
-                    mediani = max(lowi, highi)
-                    mediand = max(lowd, highd)
-                    median  = float(low)  * (-1 if  low_minus else 1)
-                    median += float(high) * (-1 if high_minus else 1)
-                    negative, median = median < 0, abs(median) / 2
-                    if (int(low.replace('.', '')[-1]) + int(high.replace('.', '')[-1])) % 2 == 1:
-                        mediand += 1
-                    if mediand == 0:
-                        median = '%%0%ii' % mediani % median
-                        if low_dot or high_dot:
-                            median += '.'
-                    else:
-                        median = '%%0%i.%if' % (max(1, mediani) + mediand + 1, mediand) % median
-                        if mediani == 0:
-                            median = median[1:]
-                    if   low_minus and high_minus:  prefix = '-'
-                    elif negative:                  prefix = '-'
-                    elif low_plus  or high_plus:    prefix = '+'
-                    elif low_minus or high_minus:   prefix = '0'
-                    else:                           prefix = ''
-                    median = prefix + median
-                except:
-                    median = values[len(values) // 2 - 1]
-            print(median + last)
-        last, values = key, []
-    values.append(value)
-