tests: attempt compatibility w/ busybox lsof

BusyBox lsof(1) ignores the `-p PID' argument and shows
the open files for every process it knows about.  BusyBox
lsof also lacks the `NODE' column of the non-BusyBox
implementation, so we'll rely on /proc/PID/fd/ in those
cases since the deleted file checks are Linux-only and
it's common to have procfs is mounted on /proc on Linux.

1 files changed, 11 insertions, 20 deletions

diff --git a/t/httpd-corner.t b/t/httpd-corner.t
index da1c24b9..35c88600 100644
--- a/t/httpd-corner.t
+++ b/t/httpd-corner.t
@@ -639,30 +639,21 @@ SKIP: {
 };
 
 SKIP: {
-        skip 'only testing lsof(8) output on Linux', 1 if $^O ne 'linux';
-        my $lsof = require_cmd('lsof', 1) or skip 'no lsof in PATH', 1;
-        my $null_in = '';
-        my $rdr = { 2 => \(my $null_err), 0 => \$null_in };
-        my @lsof = xqx([$lsof, '-p', $td->{pid}], undef, $rdr);
-        my $d = [ grep(/\(deleted\)/, @lsof) ];
-        is_deeply($d, [], 'no lingering deleted inputs') or diag explain($d);
+        skip 'only testing /proc/PID/fd on Linux', 1 if $^O ne 'linux';
+        my $fd_dir = "/proc/$td->{pid}/fd";
+        -d $fd_dir or skip '/proc/$PID/fd missing', 1;
+        my @child = grep defined, map readlink, glob "$fd_dir/*";
+        my @d = grep /\(deleted\)/, @child;
+        is_deeply(\@d, [], 'no lingering deleted inputs') or diag explain(\@d);
 
         # filter out pipes inherited from the parent
-        my @this = xqx([$lsof, '-p', $$], undef, $rdr);
-        my $bad;
-        my $extract_inodes = sub {
-                map {;
-                        my @f = split(' ', $_);
-                        my $inode = $f[-2];
-                        $bad = $_ if $inode !~ /\A[0-9]+\z/;
-                        $inode => 1;
-                } grep (/\bpipe\b/, @_);
-        };
-        my %child = $extract_inodes->(@lsof);
+        my @this = grep defined, map readlink, glob "/proc/$$/fd/*";
+        my $extract_inodes = sub { map { $_ => 1 } grep /\bpipe\b/, @_ };
+        my %child = $extract_inodes->(@child);
         my %parent = $extract_inodes->(@this);
-        skip("inode not in expected format: $bad", 1) if defined($bad);
         delete @child{(keys %parent)};
-        is_deeply([], [keys %child], 'no extra pipes with -W0');
+        is_deeply([], [keys %child], 'no extra pipes with -W0') or
+                diag explain([child => \%child, parent => \%parent]);
 };
 
 # ensure compatibility with other PSGI servers