1#!/bin/sh
2# -*- perl -*-
3# Ensure that pwd works even when run from a very deep directory.
4
5# Copyright (C) 2006-2023 Free Software Foundation, Inc.
6
7# This program is free software: you can redistribute it and/or modify
8# it under the terms of the GNU General Public License as published by
9# the Free Software Foundation, either version 3 of the License, or
10# (at your option) any later version.
11
12# This program is distributed in the hope that it will be useful,
13# but WITHOUT ANY WARRANTY; without even the implied warranty of
14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15# GNU General Public License for more details.
16
17# You should have received a copy of the GNU General Public License
18# along with this program.  If not, see <https://www.gnu.org/licenses/>.
19
20. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
21print_ver_ pwd
22
23require_readable_root_
24require_perl_
25
26ARGV_0=$0
27export ARGV_0
28
29# Don't use CuTmpdir here, since File::Temp's use of rmtree can't
30# remove the deep tree we create.
31$PERL -Tw -I"$abs_srcdir/tests" -MCuSkip -- - <<\EOF
32
33# Show that pwd works even when the length of the resulting
34# directory name is longer than PATH_MAX.
35use strict;
36
37(my $ME = $ENV{ARGV_0}) =~ s|.*/||;
38
39sub normalize_to_cwd_relative ($$$)
40{
41  my ($dir, $dev, $ino) = @_;
42  my $slash = -1;
43  my $next_slash;
44  while (1)
45    {
46      $slash = index $dir, '/', $slash + 1;
47      $slash <= -1
48        and die "$ME: $dir does not contain old CWD\n";
49      my $dir_prefix = $slash ? substr ($dir, 0, $slash) : '/';
50      my ($d, $i) = (stat $dir_prefix)[0, 1];
51      defined $d && defined $i
52        or die "$ME: $dir_prefix: stat failed: $!\n";
53      $d eq $dev && $i eq $ino
54        and return substr $dir, $slash + 1;
55    }
56}
57
58# Set up a safe, well-known environment
59$ENV{IFS}  = '';
60
61# Taint checking requires a sanitized $PATH.  This script performs no $PATH
62# search, so on most Unix-based systems, it is fine simply to clear $ENV{PATH}.
63# However, on Cygwin, it's used to find cygwin1.dll, so set it.
64$ENV{PATH} = '/bin:/usr/bin';
65
66# Save CWD's device and inode numbers.
67my ($dev, $ino) = (stat '.')[0, 1];
68
69# Construct the expected "."-relative part of pwd's output.
70my $z = 'z' x 31;
71my $n = 256;
72my $expected = "/$z" x $n;
73# Remove the leading "/".
74substr ($expected, 0, 1) = '';
75
76my $i = 0;
77do
78  {
79    mkdir $z, 0700
80      or CuSkip::skip "$ME: skipping this test; cannot create long "
81        . "directory name at depth $i: $!\n";
82    chdir $z
83  }
84until (++$i == $n);
85
86my $abs_top_builddir = $ENV{abs_top_builddir};
87$abs_top_builddir
88  or die "$ME: envvar abs_top_builddir not defined\n";
89my $build_src_dir = "$abs_top_builddir/src";
90$build_src_dir =~ m!^([-+.:/\w]+)$!
91  or CuSkip::skip "$ME: skipping this test; odd build source directory name:\n"
92    . "$build_src_dir\n";
93$build_src_dir = $1;
94
95my $pwd_binary = "$build_src_dir/pwd";
96
97-x $pwd_binary
98  or die "$ME: $pwd_binary is not an executable file\n";
99chomp (my $actual = qx!$pwd_binary!);
100
101# Convert the absolute name from pwd into a $CWD-relative name.
102# This is necessary in order to avoid a spurious failure when run
103# from a directory in a bind-mounted partition.  What happens is
104# pwd reads a ".." that contains two or more entries with identical
105# dev,ino that match the ones we're looking for, and it chooses a
106# name that does not correspond to the one already recorded in $CWD.
107$actual = normalize_to_cwd_relative $actual, $dev, $ino;
108
109if ($expected ne $actual)
110  {
111    my $e_len = length $expected;
112    my $a_len = length $actual;
113    warn "expected len: $e_len\n";
114    warn "actual len:   $a_len\n";
115    warn "expected: $expected\n";
116    warn "actual: $actual\n";
117    exit 1;
118  }
119EOF
120
121fail=$?
122
123Exit $fail
124