README

                            rra-c-util 11.0.0
                 (Russ Allbery's utility libraries for C)
               Maintained by Russ Allbery <eagle@eyrie.org>

  Copyright 2000, 2009-2010, 2013-2024 Russ Allbery <eagle@eyrie.org>.
  Copyright 2009-2014 The Board of Trustees of the Leland Stanford Junior
  University.  This software is distributed under a BSD-style license.
  Please see the section LICENSE below for more information.

BLURB

  rra-c-util is my collection of portability functions, utility functions,
  Autoconf macros, and related shared C infrastructure, akin to gnulib but
  without any GPL-covered code and additional support for Kerberos and PAM
  development.  It serves as a common repository of code and
  infrastructure used across multiple projects so that files have a
  canonical latest version.  It's not intended for installation as a
  regular package; instead, other packages are expected to copy files from
  here as needed.

DESCRIPTION

  The origins of this package are in the libinn utility library in INN.
  Some of the utility and portability functions here are directly inspired
  by or based on versions in older versions of INN, and I wrote and
  rewrote considerable additional portability code and utility libraries
  when I took over INN maintenance.  When I started maintaining other C
  packages, I started copying pieces of libinn into those packages and
  merging it with other portability and utility code.  Over time, each
  package gained a slightly different version of various utility
  functions, replacements for missing functions, and Autoconf macros.

  The goal of this package is to merge all the various versions of any
  portability or utility code that's used in more than one of my packages
  in one place.  Then, each package can update to the latest rra-c-util
  version before each release and gain from the improvements made for all
  other packages.  You can think of it as my version of Gnulib [1], with
  everything released under a permissive license (no GPL).

  [1] https://www.gnu.org/software/gnulib/

  The facilities in this package try to ensure portability and backward
  compatibility whenever reasonable, but I will drop support for systems
  that are older than fifteen years if supporting them becomes a burden.

  As well as C portability frameworks, Autoconf macros, and a general C
  utility library, this package has also accumulated a collection of
  standard tests (for C and Perl packages) and a small library of test
  utilities and support functions.  It also includes extensive support for
  writing and testing PAM modules, and a portable implementation of AFS
  PAGs.

  This package uses the infrastructure of C TAP Harness for testing, but
  is not the canonical version of tests/runtests.c, tests/tap/basic.[ch],
  tests/tap/macros.h, or tests/tap/libtap.sh.  Those files should be
  pulled from C TAP Harness [2] instead.

  [2] https://www.eyrie.org/~eagle/software/c-tap-harness/

REQUIREMENTS

  Everything requires a C compiler to build and expects an ISO C89 or
  later C compiler and libraries.  Presence of strdup is also assumed,
  which is guaranteed by POSIX 2008 but common in many earlier C libraries
  as well.  Otherwise, the files are meant to be copied into packages and
  the requirements depend on which files one copies.

  A Kerberos library, either MIT Kerberos or Heimdal, is required to build
  this package as-is, since the Kerberos portability layer is built and
  tested by default.  The other code will run fine without this
  requirement when copied into other packages.

  PAM libraries and headers are required to build the package as-is, since
  the PAM supporting library is built and tested by default.  Other code
  can be copied from this package without introducing a PAM dependency.

  The libevent.m4, sqlite3.m4, and systemd.m4 Autoconf macro files require
  the pkg-config [1] Autoconf macros when running autoreconf or the
  equivalent.

  [1] https://www.freedesktop.org/wiki/Software/pkg-config/

  To build the the kafs portability layer, one of Linux, Mac OS X, Solaris
  11, the kafs library that comes with either Heimdal or KTH Kerberos, the
  kopenafs library that comes with newer OpenAFS, AFS header files (on any
  other platform besides AIX or IRIX), or AFS libraries (on AIX and IRIX)
  is required.  AIX binaries with AFS PAG support may not run on AIX
  systems that do not have an AFS client installed due to how AIX handles
  system calls.

  A dummy Perl module is built and tested as part of the rra-c-util build
  in order to exercise the included Perl test support libraries.  This
  requires Perl 5.12 or later and Module::Build (available from CPAN).
  The included components of rra-c-util are usable without Perl (by
  copying them to another package), even though the build will fail.

  To bootstrap from a Git checkout, or if you change the Automake files
  and need to regenerate Makefile.in, you will need Automake 1.11 or
  later.  For bootstrap or if you change configure.ac or any of the m4
  files it includes and need to regenerate configure or config.h.in, you
  will need Autoconf 2.64 or later.  Perl is also required to generate
  manual pages from a fresh Git checkout.

BUILDING

  You can build rra-c-util with the standard commands:

      ./configure
      make

  If you are building from a Git clone, first run ./bootstrap in the
  source directory to generate the build files.  Building outside of the
  source directory is also supported, if you wish, by creating an empty
  directory and then running configure with the correct relative path.

  Pass --enable-kafs to configure to attempt to build kafs support, which
  will use either an existing libkafs or libkopenafs library or build the
  kafs replacement included in this package.  You can also add
  --without-libkafs to force the use of the internal kafs replacement.

  Normally, configure will use krb5-config to determine the flags to use
  to compile with your Kerberos libraries.  To specify a particular
  krb5-config script to use, either set the PATH_KRB5_CONFIG environment
  variable or pass it to configure like:

      ./configure PATH_KRB5_CONFIG=/path/to/krb5-config

  If krb5-config isn't found, configure will look for the standard
  Kerberos libraries in locations already searched by your compiler.  If
  the the krb5-config script first in your path is not the one
  corresponding to the Kerberos libraries you want to use, or if your
  Kerberos libraries and includes aren't in a location searched by default
  by your compiler, you need to specify a different Kerberos installation
  root via --with-krb5=PATH.  For example:

      ./configure --with-krb5=/usr/pubsw

  You can also individually set the paths to the include directory and the
  library directory with --with-krb5-include and --with-krb5-lib.  You may
  need to do this if Autoconf can't figure out whether to use lib, lib32,
  or lib64 on your platform.

  To not use krb5-config and force library probing even if there is a
  krb5-config script on your path, set PATH_KRB5_CONFIG to a nonexistent
  path:

      ./configure PATH_KRB5_CONFIG=/nonexistent

  krb5-config is not used and library probing is always done if either
  --with-krb5-include or --with-krb5-lib are given.

  GSS-API libraries are found the same way: with krb5-config by default if
  it is found, and a --with-gssapi=PATH flag to specify the installation
  root.  PATH_KRB5_CONFIG is similarly used to find krb5-config for the
  GSS-API libraries, and --with-gssapi-include and --with-gssapi-lib can
  be used to specify the exact paths, overriding any krb5-config results.

  Pass --enable-silent-rules to configure for a quieter build (similar to
  the Linux kernel).  Use make warnings instead of make to build with full
  compiler warnings (requires either GCC or Clang and may require a
  relatively current version of the compiler).

  Installing rra-c-util is not normally done.  Instead, see the section on
  using this code below.

TESTING

  rra-c-util comes with a test suite, which you can run after building
  with:

      make check

  If a test fails, you can run a single test with verbose output via:

      tests/runtests -o <name-of-test>

  Do this instead of running the test program directly since it will
  ensure that necessary environment variables are set up.

  To run the full test suite, and to use the Perl test support libraries,
  Perl 5.12 or later is required.  The following additional Perl modules
  will be used if present:

  * Devel::Cover
  * IPC::System::Simple
  * Perl::Critic::Community
  * Test::CPAN::Changes (part of CPAN-Changes)
  * Test::Kwalitee
  * Test::MinimumVersion
  * Test::Perl::Critic
  * Test::Pod
  * Test::Pod::Coverage
  * Test::Spelling
  * Test::Strict
  * Test::Synopsis

  All are available on CPAN.  Those tests will be skipped if the modules
  are not available.

  To enable tests that don't detect functionality problems but are used to
  sanity-check the release, set the environment variable RELEASE_TESTING
  to a true value.  To enable tests that may be sensitive to the local
  environment or that produce a lot of false positives without uncovering
  many problems, set the environment variable AUTHOR_TESTING to a true
  value.

USING THIS CODE

  While there is an install target, it's present only because Automake
  provides it automatically.  Its use is not recommended.  Instead, the
  code in this package is intended to be copied into your package and
  refreshed from the latest release of rra-c-util for each release.

  You can obviously copy the code and integrate it however works best for
  your package and your build system.  Here's how I do it for my packages
  as an example:

  * Create a portable directory and copy macros.h, system.h, stdbool.h,
    and dummy.c along with whatever additional functions that your package
    uses that may not be present on all systems.  If you use much of the
    util directory (see below), you'll need asprintf.c and reallocarray.c
    at least.  If you use util/network.c, you'll also need getaddrinfo.c,
    getaddrinfo.h, getnameinfo.c, getnameinfo.h, inet_*.c, and socket.h.
    You'll need winsock.c for networking portability to Windows.

  * Copy the necessary portions of configure.ac from this package into
    your package.  configure.ac is commented to try to give you a guide
    for what you need to copy over.  You will also need to make an m4
    subdirectory, add the code to configure.ac to load Autoconf macros
    from m4, and possibly copy over m4/socket.m4 and m4/inet-ntoa.m4.

  * Copy the code from Makefile.am for building libportable.a into your
    package and be sure to link your package binaries with libportable.a.
    If you include this code in a shared library, you'll need to build
    libportable.la instead; see the Automake manual for the differences.
    You'll need to change LIBRARIES to LTLIBRARIES and LIBOBJS to
    LTLIBOBJS in addition to renaming the targets.

  * Create a util directory and copy over the portions of the utility
    library that you want.  You will probably need messages.[ch] and
    xmalloc.[ch] if you copy anything over at all, since most of the rest
    of the library uses those.  You will also need m4/vamacros.m4 if you
    use messages.[ch].

  * Copy the code from Makefile.am for building libutil.a into your
    package and be sure to link your package binaries with libutil.a.  As
    with libportable.a, if you want to use the utility functions in a
    shared library, you'll need to instead build libutil.la and change
    some of the Automake variables.

  * If your package uses a TAP-based test suite written in C, consider
    using the additional TAP utility functions in tests/tap (specifically
    messages.*, process.*, and string.*).

  * If you're using the Kerberos portability code, copy over
    portable/krb5.h, portable/krb5-extra.c, m4/krb5.m4, m4/lib-depends.m4,
    m4/lib-pathname.m4, and optionally util/messages-krb5.[ch].  You'll
    also need the relevant fragments of configure.ac.  You may want to
    remove some things from krb5.h and krb5-extra.c the corresponding
    configure checks if your code doesn't need all of those functions.  If
    you need krb5_get_renewed_creds, also copy over krb5-renew.c.  Don't
    forget to add $(KRB5_CPPFLAGS) to CPPFLAGS for libportable and
    possibly libutil, and if you're building a shared library, also add
    $(KRB5_LDFLAGS) to LDFLAGS and $(KRB5_LIBS) to LIBADD for those
    libraries.

    For a Kerberos-enabled test suite, also consider copying the
    kerberos.* libraries in tests/tap for a Kerberos-enabled test suite.
    If you want to use kerberos_generate_conf from tests/tap/kerberos.c,
    also copy over tests/data/generate-krb5-conf.

  * For testing that requires making Kerberos administrative changes,
    consider copying over the kadmin.* libraries in tests/tap.

  * For testing packages that use remctl, see the tests/tap/remctl.c and
    tests/tap/remctl.h files for C tests and tests/tap/remctl.sh for shell
    scripts.

  * If you're using the kafs portability code, copy over the kafs
    directory, m4/kafs.m4, m4/lib-pathname.m4, portable/k_haspag.c, the
    code to build kafs from Makefile.am, and the relevant fragments of
    configure.ac.

  * If you're using the PAM portability code, copy over pam-util/*,
    portable/pam*, m4/pam-const.m4, and the relevant fragments of
    configure.ac.

  * Copy over any other Autoconf macros that you want to use in your
    package from the m4 directory.

  * Copy over any generic tests from tests/docs and tests/perl that are
    appropriate for your package.  If you use any of these, also copy over
    the tests/tap/perl directory and tests/data/perl.conf (and customize
    the latter for your package).

  * If the package embeds a Perl module, copy over any tests from the
    perl/t directory that are applicable.  This can provide generic
    testing of the embedded Perl module using Perl's own test
    infrastructure.  If you use any of these, also copy over the
    perl/t/data/perl.conf file and customize it for your package.  You
    will need to arrange for perl/t/data to contain copies of the
    perlcriticrc and perltidyrc files, either by making copies of the
    files from tests/data or by using make to copy them.

  I also copy over all the relevant tests from the tests directory and the
  build machinery for them from Makefile.am so that the portability and
  utility layer are tested along with the rest of the package.  The test
  driver should come from C TAP Harness.

SUPPORT

  The rra-c-util web page at:

      https://www.eyrie.org/~eagle/software/rra-c-util/

  will always have the current version of this package, the current
  documentation, and pointers to any additional resources.

  For bug tracking, use the issue tracker on GitHub:

      https://github.com/rra/rra-c-util/issues

  Please be aware that I tend to be extremely busy and work projects often
  take priority.  I'll save your report and get to it as soon as I can,
  but it may take me a couple of months.

SOURCE REPOSITORY

  rra-c-util is maintained using Git.  You can access the current source
  on GitHub at:

      https://github.com/rra/rra-c-util

  or by cloning the repository at:

      https://git.eyrie.org/git/devel/rra-c-util.git

  or view the repository via the web at:

      https://git.eyrie.org/?p=devel/rra-c-util.git

  The eyrie.org repository is the canonical one, maintained by the author,
  but using GitHub is probably more convenient for most purposes.  Pull
  requests are gratefully reviewed and normally accepted.

LICENSE

  The rra-c-util package as a whole is covered by the following copyright
  statement and license:

    Copyright 2000, 2009-2010, 2013-2024 Russ Allbery <eagle@eyrie.org>
    Copyright 2009-2014
        The Board of Trustees of the Leland Stanford Junior University

    Permission is hereby granted, free of charge, to any person obtaining
    a copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including
    without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to
    permit persons to whom the Software is furnished to do so, subject to
    the following conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

  Some files in this distribution are individually released under
  different licenses, all of which are compatible with the above general
  package license but which may require preservation of additional
  notices.  All required notices, and detailed information about the
  licensing of each file, are recorded in the LICENSE file.

  Files covered by a license with an assigned SPDX License Identifier
  include SPDX-License-Identifier tags to enable automated processing of
  license information.  See https://spdx.org/licenses/ for more
  information.

  For any copyright range specified by files in this package as YYYY-ZZZZ,
  the range specifies every single year in that closed interval.