1# Check how to create a tarball.                            -*- Autoconf -*-
2
3# Copyright (C) 2004-2018 Free Software Foundation, Inc.
4#
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9# _AM_PROG_TAR(FORMAT)
10# --------------------
11# Check how to create a tarball in format FORMAT.
12# FORMAT should be one of 'v7', 'ustar', or 'pax'.
13#
14# Substitute a variable $(am__tar) that is a command
15# writing to stdout a FORMAT-tarball containing the directory
16# $tardir.
17#     tardir=directory && $(am__tar) > result.tar
18#
19# Substitute a variable $(am__untar) that extract such
20# a tarball read from stdin.
21#     $(am__untar) < result.tar
22#
23AC_DEFUN([_AM_PROG_TAR],
24[# Always define AMTAR for backward compatibility.  Yes, it's still used
25# in the wild :-(  We should find a proper way to deprecate it ...
26AC_SUBST([AMTAR], ['$${TAR-tar}'])
27
28# We'll loop over all known methods to create a tar archive until one works.
29_am_tools='gnutar m4_if([$1], [ustar], [plaintar]) pax cpio none'
30
31m4_if([$1], [v7],
32  [am__tar='$${TAR-tar} chof - "$$tardir"' am__untar='$${TAR-tar} xf -'],
33
34  [m4_case([$1],
35    [ustar],
36     [# The POSIX 1988 'ustar' format is defined with fixed-size fields.
37      # There is notably a 21 bits limit for the UID and the GID.  In fact,
38      # the 'pax' utility can hang on bigger UID/GID (see automake bug#8343
39      # and bug#13588).
40      am_max_uid=2097151 # 2^21 - 1
41      am_max_gid=$am_max_uid
42      # The $UID and $GID variables are not portable, so we need to resort
43      # to the POSIX-mandated id(1) utility.  Errors in the 'id' calls
44      # below are definitely unexpected, so allow the users to see them
45      # (that is, avoid stderr redirection).
46      am_uid=`id -u || echo unknown`
47      am_gid=`id -g || echo unknown`
48      AC_MSG_CHECKING([whether UID '$am_uid' is supported by ustar format])
49      if test $am_uid -le $am_max_uid; then
50         AC_MSG_RESULT([yes])
51      else
52         AC_MSG_RESULT([no])
53         _am_tools=none
54      fi
55      AC_MSG_CHECKING([whether GID '$am_gid' is supported by ustar format])
56      if test $am_gid -le $am_max_gid; then
57         AC_MSG_RESULT([yes])
58      else
59        AC_MSG_RESULT([no])
60        _am_tools=none
61      fi],
62
63  [pax],
64    [],
65
66  [m4_fatal([Unknown tar format])])
67
68  AC_MSG_CHECKING([how to create a $1 tar archive])
69
70  # Go ahead even if we have the value already cached.  We do so because we
71  # need to set the values for the 'am__tar' and 'am__untar' variables.
72  _am_tools=${am_cv_prog_tar_$1-$_am_tools}
73
74  for _am_tool in $_am_tools; do
75    case $_am_tool in
76    gnutar)
77      for _am_tar in tar gnutar gtar; do
78        AM_RUN_LOG([$_am_tar --version]) && break
79      done
80      am__tar="$_am_tar --hard-dereference --format=m4_if([$1], [pax], [posix], [$1]) -chf - "'"$$tardir"'
81      am__tar_="$_am_tar --hard-dereference --format=m4_if([$1], [pax], [posix], [$1]) -chf - "'"$tardir"'
82      am__untar="$_am_tar -xf -"
83      ;;
84    plaintar)
85      # Must skip GNU tar: if it does not support --format= it doesn't create
86      # ustar tarball either.
87      (tar --version) >/dev/null 2>&1 && continue
88      am__tar='tar chf --hard-dereference - "$$tardir"'
89      am__tar_='tar chf --hard-dereference - "$tardir"'
90      am__untar='tar xf -'
91      ;;
92    pax)
93      am__tar='pax -L -x $1 -w "$$tardir"'
94      am__tar_='pax -L -x $1 -w "$tardir"'
95      am__untar='pax -r'
96      ;;
97    cpio)
98      am__tar='find "$$tardir" -print | cpio -o -H $1 -L'
99      am__tar_='find "$tardir" -print | cpio -o -H $1 -L'
100      am__untar='cpio -i -H $1 -d'
101      ;;
102    none)
103      am__tar=false
104      am__tar_=false
105      am__untar=false
106      ;;
107    esac
108
109    # If the value was cached, stop now.  We just wanted to have am__tar
110    # and am__untar set.
111    test -n "${am_cv_prog_tar_$1}" && break
112
113    # tar/untar a dummy directory, and stop if the command works.
114    rm -rf conftest.dir
115    mkdir conftest.dir
116    echo GrepMe > conftest.dir/file
117    AM_RUN_LOG([tardir=conftest.dir && eval $am__tar_ >conftest.tar])
118    rm -rf conftest.dir
119    if test -s conftest.tar; then
120      AM_RUN_LOG([$am__untar <conftest.tar])
121      AM_RUN_LOG([cat conftest.dir/file])
122      grep GrepMe conftest.dir/file >/dev/null 2>&1 && break
123    fi
124  done
125  rm -rf conftest.dir
126
127  AC_CACHE_VAL([am_cv_prog_tar_$1], [am_cv_prog_tar_$1=$_am_tool])
128  AC_MSG_RESULT([$am_cv_prog_tar_$1])])
129
130AC_SUBST([am__tar])
131AC_SUBST([am__untar])
132]) # _AM_PROG_TAR
133