1 files changed, 110 insertions, 0 deletions
diff --git a/tests/misc/head-elide-tail.pl b/tests/misc/head-elide-tail.pl
new file mode 100755
index 0000000..260a94b
--- /dev/null
+++ b/tests/misc/head-elide-tail.pl
@@ -0,0 +1,110 @@
+#!/usr/bin/perl
+# Exercise head's --bytes=-N option.
+
+# Copyright (C) 2003-2020 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+use strict;
+
+(my $program_name = $0) =~ s|.*/||;
+
+$ENV{PROG} = 'head';
+
+# Turn off localization of executable's output.
+@ENV{qw(LANGUAGE LANG LC_ALL)} = ('C') x 3;
+
+# This should match the definition in head.c.
+my $READ_BUFSIZE = 8192;
+
+my @Tests =
+  (
+   # Elide the exact size of the file.
+   ['elide-b1', "--bytes=-2", {IN=>"a\n"}, {OUT=>''}],
+   # Elide more than the size of the file.
+   ['elide-b2', "--bytes=-2", {IN=>"a"},   {OUT=>''}],
+   # Leave just one byte.
+   ['elide-b3', "--bytes=-2", {IN=>"abc"}, {OUT=>'a'}],
+   # Make it so the elided bytes straddle the end of the first
+   # $READ_BUFSIZE block.
+   ['elide-b4', "--bytes=-2",
+    {IN=> 'a' x ($READ_BUFSIZE-3) . "\nbcd"},
+    {OUT=>'a' x ($READ_BUFSIZE-3) . "\nb"}],
+   # Make it so the elided bytes straddle the end of the 2nd
+   # $READ_BUFSIZE block.
+   ['elide-b5', "--bytes=-2",
+    {IN=> 'a' x (2 * $READ_BUFSIZE - 2) . 'bcd'},
+    {OUT=>'a' x (2 * $READ_BUFSIZE - 2) . 'b'}],
+
+   ['elide-l0', "--lines=-1", {IN=>''}, {OUT=>''}],
+   ['elide-l1', "--lines=-1", {IN=>"a\n"}, {OUT=>''}],
+   ['elide-l2', "--lines=-1", {IN=>"a"}, {OUT=>''}],
+   ['elide-l3', "--lines=-1", {IN=>"a\nb"}, {OUT=>"a\n"}],
+   ['elide-l4', "--lines=-1", {IN=>"a\nb\n"}, {OUT=>"a\n"}],
+   ['elide-l5', "--lines=-0", {IN=>"a\nb\n"}, {OUT=>"a\nb\n"}],
+   ['elide-l6', "--lines=-0", {IN=>"a\nb"}, {OUT=>"a\nb"}],
+  );
+
+if ($ENV{RUN_EXPENSIVE_TESTS})
+  {
+    # Brute force: use all combinations of file sizes [0..20] and
+    # number of bytes to elide [0..20].  For better coverage, recompile
+    # head with -DHEAD_TAIL_PIPE_READ_BUFSIZE=4 and
+    # -DHEAD_TAIL_PIPE_BYTECOUNT_THRESHOLD=8
+    my $s = "abcdefghijklmnopqrst";
+    for my $file_size (0..20)
+      {
+        for my $n_elide (0..20)
+          {
+            my $input = substr $s, 0, $file_size;
+            my $out_len = $n_elide < $file_size ? $file_size - $n_elide : 0;
+            my $output = substr $input, 0, $out_len;
+            my $t = ["elideb$file_size-$n_elide", "--bytes=-$n_elide",
+                     {IN=>$input}, {OUT=>$output}];
+            push @Tests, $t;
+            my @u = @$t;
+            # Insert the ---presume-input-pipe option.
+            $u[0] .= 'p';
+            $u[1] .= ' ---presume-input-pipe';
+            push @Tests, \@u;
+          }
+      }
+
+    $s =~ s/(.)/$1\n/g;
+    $s .= 'u'; # test without trailing '\n'
+    for my $file_size (0..21)
+      {
+        for my $n_elide (0..21)
+          {
+            my $input = substr $s, 0, 2 * $file_size;
+            my $out_len = $n_elide < $file_size ? $file_size - $n_elide : 0;
+            my $output = substr $input, 0, 2 * $out_len;
+            my $t = ["elidel$file_size-$n_elide", "--lines=-$n_elide",
+                     {IN=>$input}, {OUT=>$output}];
+            push @Tests, $t;
+            my @u = @$t;
+            # Insert the ---presume-input-pipe option.
+            $u[0] .= 'p';
+            $u[1] .= ' ---presume-input-pipe';
+            push @Tests, \@u;
+          }
+      }
+  }
+
+my $save_temps = $ENV{DEBUG};
+my $verbose = $ENV{VERBOSE};
+
+my $prog = $ENV{PROG} || die "$0: \$PROG not specified in environment\n";
+my $fail = run_tests ($program_name, $prog, \@Tests, $save_temps, $verbose);
+exit $fail;