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# Check how to create a tarball. -*- Autoconf -*-
# Copyright (C) 2004-2018 Free Software Foundation, Inc.
#
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
# _AM_PROG_TAR(FORMAT)
# --------------------
# Check how to create a tarball in format FORMAT.
# FORMAT should be one of 'v7', 'ustar', or 'pax'.
#
# Substitute a variable $(am__tar) that is a command
# writing to stdout a FORMAT-tarball containing the directory
# $tardir.
# tardir=directory && $(am__tar) > result.tar
#
# Substitute a variable $(am__untar) that extract such
# a tarball read from stdin.
# $(am__untar) < result.tar
#
AC_DEFUN([_AM_PROG_TAR],
[# Always define AMTAR for backward compatibility. Yes, it's still used
# in the wild :-( We should find a proper way to deprecate it ...
AC_SUBST([AMTAR], ['$${TAR-tar}'])
# We'll loop over all known methods to create a tar archive until one works.
_am_tools='gnutar m4_if([$1], [ustar], [plaintar]) pax cpio none'
m4_if([$1], [v7],
[am__tar='$${TAR-tar} chof - "$$tardir"' am__untar='$${TAR-tar} xf -'],
[m4_case([$1],
[ustar],
[# The POSIX 1988 'ustar' format is defined with fixed-size fields.
# There is notably a 21 bits limit for the UID and the GID. In fact,
# the 'pax' utility can hang on bigger UID/GID (see automake bug#8343
# and bug#13588).
am_max_uid=2097151 # 2^21 - 1
am_max_gid=$am_max_uid
# The $UID and $GID variables are not portable, so we need to resort
# to the POSIX-mandated id(1) utility. Errors in the 'id' calls
# below are definitely unexpected, so allow the users to see them
# (that is, avoid stderr redirection).
am_uid=`id -u || echo unknown`
am_gid=`id -g || echo unknown`
AC_MSG_CHECKING([whether UID '$am_uid' is supported by ustar format])
if test $am_uid -le $am_max_uid; then
AC_MSG_RESULT([yes])
else
AC_MSG_RESULT([no])
_am_tools=none
fi
AC_MSG_CHECKING([whether GID '$am_gid' is supported by ustar format])
if test $am_gid -le $am_max_gid; then
AC_MSG_RESULT([yes])
else
AC_MSG_RESULT([no])
_am_tools=none
fi],
[pax],
[],
[m4_fatal([Unknown tar format])])
AC_MSG_CHECKING([how to create a $1 tar archive])
# Go ahead even if we have the value already cached. We do so because we
# need to set the values for the 'am__tar' and 'am__untar' variables.
_am_tools=${am_cv_prog_tar_$1-$_am_tools}
for _am_tool in $_am_tools; do
case $_am_tool in
gnutar)
for _am_tar in tar gnutar gtar; do
AM_RUN_LOG([$_am_tar --version]) && break
done
am__tar="$_am_tar --hard-dereference --format=m4_if([$1], [pax], [posix], [$1]) -chf - "'"$$tardir"'
am__tar_="$_am_tar --hard-dereference --format=m4_if([$1], [pax], [posix], [$1]) -chf - "'"$tardir"'
am__untar="$_am_tar -xf -"
;;
plaintar)
# Must skip GNU tar: if it does not support --format= it doesn't create
# ustar tarball either.
(tar --version) >/dev/null 2>&1 && continue
am__tar='tar chf --hard-dereference - "$$tardir"'
am__tar_='tar chf --hard-dereference - "$tardir"'
am__untar='tar xf -'
;;
pax)
am__tar='pax -L -x $1 -w "$$tardir"'
am__tar_='pax -L -x $1 -w "$tardir"'
am__untar='pax -r'
;;
cpio)
am__tar='find "$$tardir" -print | cpio -o -H $1 -L'
am__tar_='find "$tardir" -print | cpio -o -H $1 -L'
am__untar='cpio -i -H $1 -d'
;;
none)
am__tar=false
am__tar_=false
am__untar=false
;;
esac
# If the value was cached, stop now. We just wanted to have am__tar
# and am__untar set.
test -n "${am_cv_prog_tar_$1}" && break
# tar/untar a dummy directory, and stop if the command works.
rm -rf conftest.dir
mkdir conftest.dir
echo GrepMe > conftest.dir/file
AM_RUN_LOG([tardir=conftest.dir && eval $am__tar_ >conftest.tar])
rm -rf conftest.dir
if test -s conftest.tar; then
AM_RUN_LOG([$am__untar <conftest.tar])
AM_RUN_LOG([cat conftest.dir/file])
grep GrepMe conftest.dir/file >/dev/null 2>&1 && break
fi
done
rm -rf conftest.dir
AC_CACHE_VAL([am_cv_prog_tar_$1], [am_cv_prog_tar_$1=$_am_tool])
AC_MSG_RESULT([$am_cv_prog_tar_$1])])
AC_SUBST([am__tar])
AC_SUBST([am__untar])
]) # _AM_PROG_TAR