kmx.io/null_shell

diff --git a/.gitignore b/.gitignore
index 7bafa14..56a03d3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,13 +1 @@
-*.in
-/.deps
-/aclocal.m4
-/autom4te.cache
-/compile
-/config.log
-/config.status
-/configure
-/depcomp
-/install-sh
-/Makefile
-/missing
-/null-shell
+/null_shell
diff --git a/AUTHORS b/AUTHORS
deleted file mode 100644
index 4952d07..0000000
--- a/AUTHORS
+++ /dev/null
@@ -1 +0,0 @@
-Thomas de Grivel <thoxdg@gmail.com>
diff --git a/COPYING b/COPYING
deleted file mode 100644
index f288702..0000000
--- a/COPYING
+++ /dev/null
@@ -1,674 +0,0 @@
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-
-  15. Disclaimer of Warranty.
-
-  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
-OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
-THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
-IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
-ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  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
-THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
-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 <https://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
-<https://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
-<https://www.gnu.org/licenses/why-not-lgpl.html>.
diff --git a/ChangeLog b/ChangeLog
deleted file mode 100644
index e69de29..0000000
--- a/ChangeLog
+++ /dev/null
diff --git a/INSTALL b/INSTALL
deleted file mode 100644
index 8865734..0000000
--- a/INSTALL
+++ /dev/null
@@ -1,368 +0,0 @@
-Installation Instructions
-*************************
-
-   Copyright (C) 1994-1996, 1999-2002, 2004-2016 Free Software
-Foundation, Inc.
-
-   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 warranty of any kind.
-
-Basic Installation
-==================
-
-   Briefly, the shell command './configure && make && make install'
-should configure, build, and install this package.  The following
-more-detailed instructions are generic; see the 'README' file for
-instructions specific to this package.  Some packages provide this
-'INSTALL' file but do not implement all of the features documented
-below.  The lack of an optional feature in a given package is not
-necessarily a bug.  More recommendations for GNU packages can be found
-in *note Makefile Conventions: (standards)Makefile Conventions.
-
-   The 'configure' shell script attempts to guess correct values for
-various system-dependent variables used during compilation.  It uses
-those values to create a 'Makefile' in each directory of the package.
-It may also create one or more '.h' files containing system-dependent
-definitions.  Finally, it creates a shell script 'config.status' that
-you can run in the future to recreate the current configuration, and a
-file 'config.log' containing compiler output (useful mainly for
-debugging 'configure').
-
-   It can also use an optional file (typically called 'config.cache' and
-enabled with '--cache-file=config.cache' or simply '-C') that saves the
-results of its tests to speed up reconfiguring.  Caching is disabled by
-default to prevent problems with accidental use of stale cache files.
-
-   If you need to do unusual things to compile the package, please try
-to figure out how 'configure' could check whether to do them, and mail
-diffs or instructions to the address given in the 'README' so they can
-be considered for the next release.  If you are using the cache, and at
-some point 'config.cache' contains results you don't want to keep, you
-may remove or edit it.
-
-   The file 'configure.ac' (or 'configure.in') is used to create
-'configure' by a program called 'autoconf'.  You need 'configure.ac' if
-you want to change it or regenerate 'configure' using a newer version of
-'autoconf'.
-
-   The simplest way to compile this package is:
-
-  1. 'cd' to the directory containing the package's source code and type
-     './configure' to configure the package for your system.
-
-     Running 'configure' might take a while.  While running, it prints
-     some messages telling which features it is checking for.
-
-  2. Type 'make' to compile the package.
-
-  3. Optionally, type 'make check' to run any self-tests that come with
-     the package, generally using the just-built uninstalled binaries.
-
-  4. Type 'make install' to install the programs and any data files and
-     documentation.  When installing into a prefix owned by root, it is
-     recommended that the package be configured and built as a regular
-     user, and only the 'make install' phase executed with root
-     privileges.
-
-  5. Optionally, type 'make installcheck' to repeat any self-tests, but
-     this time using the binaries in their final installed location.
-     This target does not install anything.  Running this target as a
-     regular user, particularly if the prior 'make install' required
-     root privileges, verifies that the installation completed
-     correctly.
-
-  6. You can remove the program binaries and object files from the
-     source code directory by typing 'make clean'.  To also remove the
-     files that 'configure' created (so you can compile the package for
-     a different kind of computer), type 'make distclean'.  There is
-     also a 'make maintainer-clean' target, but that is intended mainly
-     for the package's developers.  If you use it, you may have to get
-     all sorts of other programs in order to regenerate files that came
-     with the distribution.
-
-  7. Often, you can also type 'make uninstall' to remove the installed
-     files again.  In practice, not all packages have tested that
-     uninstallation works correctly, even though it is required by the
-     GNU Coding Standards.
-
-  8. Some packages, particularly those that use Automake, provide 'make
-     distcheck', which can by used by developers to test that all other
-     targets like 'make install' and 'make uninstall' work correctly.
-     This target is generally not run by end users.
-
-Compilers and Options
-=====================
-
-   Some systems require unusual options for compilation or linking that
-the 'configure' script does not know about.  Run './configure --help'
-for details on some of the pertinent environment variables.
-
-   You can give 'configure' initial values for configuration parameters
-by setting variables in the command line or in the environment.  Here is
-an example:
-
-     ./configure CC=c99 CFLAGS=-g LIBS=-lposix
-
-   *Note Defining Variables::, for more details.
-
-Compiling For Multiple Architectures
-====================================
-
-   You can compile the package for more than one kind of computer at the
-same time, by placing the object files for each architecture in their
-own directory.  To do this, you can use GNU 'make'.  'cd' to the
-directory where you want the object files and executables to go and run
-the 'configure' script.  'configure' automatically checks for the source
-code in the directory that 'configure' is in and in '..'.  This is known
-as a "VPATH" build.
-
-   With a non-GNU 'make', it is safer to compile the package for one
-architecture at a time in the source code directory.  After you have
-installed the package for one architecture, use 'make distclean' before
-reconfiguring for another architecture.
-
-   On MacOS X 10.5 and later systems, you can create libraries and
-executables that work on multiple system types--known as "fat" or
-"universal" binaries--by specifying multiple '-arch' options to the
-compiler but only a single '-arch' option to the preprocessor.  Like
-this:
-
-     ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
-                 CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
-                 CPP="gcc -E" CXXCPP="g++ -E"
-
-   This is not guaranteed to produce working output in all cases, you
-may have to build one architecture at a time and combine the results
-using the 'lipo' tool if you have problems.
-
-Installation Names
-==================
-
-   By default, 'make install' installs the package's commands under
-'/usr/local/bin', include files under '/usr/local/include', etc.  You
-can specify an installation prefix other than '/usr/local' by giving
-'configure' the option '--prefix=PREFIX', where PREFIX must be an
-absolute file name.
-
-   You can specify separate installation prefixes for
-architecture-specific files and architecture-independent files.  If you
-pass the option '--exec-prefix=PREFIX' to 'configure', the package uses
-PREFIX as the prefix for installing programs and libraries.
-Documentation and other data files still use the regular prefix.
-
-   In addition, if you use an unusual directory layout you can give
-options like '--bindir=DIR' to specify different values for particular
-kinds of files.  Run 'configure --help' for a list of the directories
-you can set and what kinds of files go in them.  In general, the default
-for these options is expressed in terms of '${prefix}', so that
-specifying just '--prefix' will affect all of the other directory
-specifications that were not explicitly provided.
-
-   The most portable way to affect installation locations is to pass the
-correct locations to 'configure'; however, many packages provide one or
-both of the following shortcuts of passing variable assignments to the
-'make install' command line to change installation locations without
-having to reconfigure or recompile.
-
-   The first method involves providing an override variable for each
-affected directory.  For example, 'make install
-prefix=/alternate/directory' will choose an alternate location for all
-directory configuration variables that were expressed in terms of
-'${prefix}'.  Any directories that were specified during 'configure',
-but not in terms of '${prefix}', must each be overridden at install time
-for the entire installation to be relocated.  The approach of makefile
-variable overrides for each directory variable is required by the GNU
-Coding Standards, and ideally causes no recompilation.  However, some
-platforms have known limitations with the semantics of shared libraries
-that end up requiring recompilation when using this method, particularly
-noticeable in packages that use GNU Libtool.
-
-   The second method involves providing the 'DESTDIR' variable.  For
-example, 'make install DESTDIR=/alternate/directory' will prepend
-'/alternate/directory' before all installation names.  The approach of
-'DESTDIR' overrides is not required by the GNU Coding Standards, and
-does not work on platforms that have drive letters.  On the other hand,
-it does better at avoiding recompilation issues, and works well even
-when some directory options were not specified in terms of '${prefix}'
-at 'configure' time.
-
-Optional Features
-=================
-
-   If the package supports it, you can cause programs to be installed
-with an extra prefix or suffix on their names by giving 'configure' the
-option '--program-prefix=PREFIX' or '--program-suffix=SUFFIX'.
-
-   Some packages pay attention to '--enable-FEATURE' options to
-'configure', where FEATURE indicates an optional part of the package.
-They may also pay attention to '--with-PACKAGE' options, where PACKAGE
-is something like 'gnu-as' or 'x' (for the X Window System).  The
-'README' should mention any '--enable-' and '--with-' options that the
-package recognizes.
-
-   For packages that use the X Window System, 'configure' can usually
-find the X include and library files automatically, but if it doesn't,
-you can use the 'configure' options '--x-includes=DIR' and
-'--x-libraries=DIR' to specify their locations.
-
-   Some packages offer the ability to configure how verbose the
-execution of 'make' will be.  For these packages, running './configure
---enable-silent-rules' sets the default to minimal output, which can be
-overridden with 'make V=1'; while running './configure
---disable-silent-rules' sets the default to verbose, which can be
-overridden with 'make V=0'.
-
-Particular systems
-==================
-
-   On HP-UX, the default C compiler is not ANSI C compatible.  If GNU CC
-is not installed, it is recommended to use the following options in
-order to use an ANSI C compiler:
-
-     ./configure CC="cc -Ae -D_XOPEN_SOURCE=500"
-
-and if that doesn't work, install pre-built binaries of GCC for HP-UX.
-
-   HP-UX 'make' updates targets which have the same time stamps as their
-prerequisites, which makes it generally unusable when shipped generated
-files such as 'configure' are involved.  Use GNU 'make' instead.
-
-   On OSF/1 a.k.a. Tru64, some versions of the default C compiler cannot
-parse its '<wchar.h>' header file.  The option '-nodtk' can be used as a
-workaround.  If GNU CC is not installed, it is therefore recommended to
-try
-
-     ./configure CC="cc"
-
-and if that doesn't work, try
-
-     ./configure CC="cc -nodtk"
-
-   On Solaris, don't put '/usr/ucb' early in your 'PATH'.  This
-directory contains several dysfunctional programs; working variants of
-these programs are available in '/usr/bin'.  So, if you need '/usr/ucb'
-in your 'PATH', put it _after_ '/usr/bin'.
-
-   On Haiku, software installed for all users goes in '/boot/common',
-not '/usr/local'.  It is recommended to use the following options:
-
-     ./configure --prefix=/boot/common
-
-Specifying the System Type
-==========================
-
-   There may be some features 'configure' cannot figure out
-automatically, but needs to determine by the type of machine the package
-will run on.  Usually, assuming the package is built to be run on the
-_same_ architectures, 'configure' can figure that out, but if it prints
-a message saying it cannot guess the machine type, give it the
-'--build=TYPE' option.  TYPE can either be a short name for the system
-type, such as 'sun4', or a canonical name which has the form:
-
-     CPU-COMPANY-SYSTEM
-
-where SYSTEM can have one of these forms:
-
-     OS
-     KERNEL-OS
-
-   See the file 'config.sub' for the possible values of each field.  If
-'config.sub' isn't included in this package, then this package doesn't
-need to know the machine type.
-
-   If you are _building_ compiler tools for cross-compiling, you should
-use the option '--target=TYPE' to select the type of system they will
-produce code for.
-
-   If you want to _use_ a cross compiler, that generates code for a
-platform different from the build platform, you should specify the
-"host" platform (i.e., that on which the generated programs will
-eventually be run) with '--host=TYPE'.
-
-Sharing Defaults
-================
-
-   If you want to set default values for 'configure' scripts to share,
-you can create a site shell script called 'config.site' that gives
-default values for variables like 'CC', 'cache_file', and 'prefix'.
-'configure' looks for 'PREFIX/share/config.site' if it exists, then
-'PREFIX/etc/config.site' if it exists.  Or, you can set the
-'CONFIG_SITE' environment variable to the location of the site script.
-A warning: not all 'configure' scripts look for a site script.
-
-Defining Variables
-==================
-
-   Variables not defined in a site shell script can be set in the
-environment passed to 'configure'.  However, some packages may run
-configure again during the build, and the customized values of these
-variables may be lost.  In order to avoid this problem, you should set
-them in the 'configure' command line, using 'VAR=value'.  For example:
-
-     ./configure CC=/usr/local2/bin/gcc
-
-causes the specified 'gcc' to be used as the C compiler (unless it is
-overridden in the site shell script).
-
-Unfortunately, this technique does not work for 'CONFIG_SHELL' due to an
-Autoconf limitation.  Until the limitation is lifted, you can use this
-workaround:
-
-     CONFIG_SHELL=/bin/bash ./configure CONFIG_SHELL=/bin/bash
-
-'configure' Invocation
-======================
-
-   'configure' recognizes the following options to control how it
-operates.
-
-'--help'
-'-h'
-     Print a summary of all of the options to 'configure', and exit.
-
-'--help=short'
-'--help=recursive'
-     Print a summary of the options unique to this package's
-     'configure', and exit.  The 'short' variant lists options used only
-     in the top level, while the 'recursive' variant lists options also
-     present in any nested packages.
-
-'--version'
-'-V'
-     Print the version of Autoconf used to generate the 'configure'
-     script, and exit.
-
-'--cache-file=FILE'
-     Enable the cache: use and save the results of the tests in FILE,
-     traditionally 'config.cache'.  FILE defaults to '/dev/null' to
-     disable caching.
-
-'--config-cache'
-'-C'
-     Alias for '--cache-file=config.cache'.
-
-'--quiet'
-'--silent'
-'-q'
-     Do not print messages saying which checks are being made.  To
-     suppress all normal output, redirect it to '/dev/null' (any error
-     messages will still be shown).
-
-'--srcdir=DIR'
-     Look for the package's source code in directory DIR.  Usually
-     'configure' can determine that directory automatically.
-
-'--prefix=DIR'
-     Use DIR as the installation prefix.  *note Installation Names:: for
-     more details, including other options available for fine-tuning the
-     installation locations.
-
-'--no-create'
-'-n'
-     Run the configure checks, but stop before creating any output
-     files.
-
-'configure' also accepts some other, not widely useful, options.  Run
-'configure --help' for more details.
diff --git a/LICENSE.md b/LICENSE.md
deleted file mode 100644
index 3039fae..0000000
--- a/LICENSE.md
+++ /dev/null
@@ -1,13 +0,0 @@
-Copyright (c) 2020 Thomas de Grivel <thoxdg@gmail.com>
-
-Permission to use, copy, modify, and 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.
-
-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
new file mode 100644
index 0000000..7de8a04
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,30 @@
+# Copyright (c) 2020,2024 Thomas de Grivel <thodg@kmx.io>
+#
+# Permission to use 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.
+#
+# 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.
+
+PROG = null_shell
+SRC = null_shell.c
+
+CFLAGS = -W -Wall -Werror -std=c89 -pedantic -O2 -pipe
+LDFLAGS = -static
+
+${PROG}: ${SRC}
+	${CC} ${CPPFLAGS} ${CFLAGS} ${LDFLAGS} ${SRC} -o ${PROG}
+
+clean:
+	rm -f ${PROG}
+
+install:
+	install -m 0755 ${PROG} /bin/${PROG}
+
+.PHONY: clean install
diff --git a/Makefile.am b/Makefile.am
deleted file mode 100644
index 7ddd8b9..0000000
--- a/Makefile.am
+++ /dev/null
@@ -1,8 +0,0 @@
-bin_PROGRAMS = null-shell
-bin_PATH = /bin
-
-null_shell_SOURCES = \
-	null_shell.c
-
-null_shell_CFLAGS = -std=c89 -W -Wall -Werror
-null_shell_LDFLAGS = -static
diff --git a/NEWS b/NEWS
deleted file mode 100644
index e69de29..0000000
--- a/NEWS
+++ /dev/null
diff --git a/README b/README
deleted file mode 100644
index e69de29..0000000
--- a/README
+++ /dev/null
diff --git a/README.md b/README.md
index 55272ad..b1cb6a6 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-Null shell 0.1
+Null shell 0.2
 ==============
 
 The null shell is a UNIX shell that behaves like /dev/null.
diff --git a/autogen.sh b/autogen.sh
deleted file mode 100755
index ef8902a..0000000
--- a/autogen.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/sh
-
-set -e
-srcdir="$(dirname $0)"
-cd "$srcdir"
-if [ -z ${LIBTOOLIZE} ] && GLIBTOOLIZE="`which glibtoolize 2>/dev/null`"; then
-  LIBTOOLIZE="${GLIBTOOLIZE}"
-  export LIBTOOLIZE
-fi
-which autoreconf >/dev/null || \
-  (echo "configuration failed, please install autoconf first" && exit 1)
-autoreconf --install --force --warnings=all
diff --git a/configure.ac b/configure.ac
deleted file mode 100644
index 37eeae8..0000000
--- a/configure.ac
+++ /dev/null
@@ -1,12 +0,0 @@
-AC_PREREQ([2.59])
-AC_INIT([null-shell], [0.1], [kmx.io], [null-shell], [http://kmx.io/])
-AC_CONFIG_SRCDIR([null_shell.c])
-
-AM_INIT_AUTOMAKE
-
-AC_PROG_CC
-
-AC_PREFIX_DEFAULT([])
-
-AC_CONFIG_FILES([Makefile])
-AC_OUTPUT
diff --git a/null_shell.c b/null_shell.c
index 5ada6e0..b082af1 100644
--- a/null_shell.c
+++ b/null_shell.c
@@ -1,9 +1,9 @@
 /*
- * Copyright (c) 2020 Thomas de Grivel <thoxdg@gmail.com>
+ * Copyright (c) 2020,2024 Thomas de Grivel <thodg@kmx.io>
  *
- * Permission to use, copy, modify, and 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.
+ * Permission to use 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.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
@@ -18,7 +18,7 @@
 
 #define BUFSIZ 8192
 
-int main ()
+int main (void)
 {
   char buf[BUFSIZ];
   while (read(STDIN_FILENO, buf, BUFSIZ) > 0)