tests/head/head-elide-tail.pl

   1 #!/usr/bin/perl
   2 # Exercise head's --bytes=-N option.
   3
   4 # Copyright (C) 2003-2024 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18
  19 use strict;
  20
  21 (my $program_name = $0) =~ s|.*/||;
  22
  23 $ENV{PROG} = 'head';
  24
  25 # Turn off localization of executable's output.
  26 @ENV{qw(LANGUAGE LANG LC_ALL)} = ('C') x 3;
  27
  28 # This should match the definition in head.c.
  29 my $READ_BUFSIZE = 8192;
  30
  31 my @Tests =
  32   (
  33    # Elide the exact size of the file.
  34    ['elide-b1', "--bytes=-2", {IN=>"a\n"}, {OUT=>''}],
  35    # Elide more than the size of the file.
  36    ['elide-b2', "--bytes=-2", {IN=>"a"},   {OUT=>''}],
  37    # Leave just one byte.
  38    ['elide-b3', "--bytes=-2", {IN=>"abc"}, {OUT=>'a'}],
  39    # Make it so the elided bytes straddle the end of the first
  40    # $READ_BUFSIZE block.
  41    ['elide-b4', "--bytes=-2",
  42     {IN=> 'a' x ($READ_BUFSIZE-3) . "\nbcd"},
  43     {OUT=>'a' x ($READ_BUFSIZE-3) . "\nb"}],
  44    # Make it so the elided bytes straddle the end of the 2nd
  45    # $READ_BUFSIZE block.
  46    ['elide-b5', "--bytes=-2",
  47     {IN=> 'a' x (2 * $READ_BUFSIZE - 2) . 'bcd'},
  48     {OUT=>'a' x (2 * $READ_BUFSIZE - 2) . 'b'}],
  49
  50    ['elide-l0', "--lines=-1", {IN=>''}, {OUT=>''}],
  51    ['elide-l1', "--lines=-1", {IN=>"a\n"}, {OUT=>''}],
  52    ['elide-l2', "--lines=-1", {IN=>"a"}, {OUT=>''}],
  53    ['elide-l3', "--lines=-1", {IN=>"a\nb"}, {OUT=>"a\n"}],
  54    ['elide-l4', "--lines=-1", {IN=>"a\nb\n"}, {OUT=>"a\n"}],
  55    ['elide-l5', "--lines=-0", {IN=>"a\nb\n"}, {OUT=>"a\nb\n"}],
  56    ['elide-l6', "--lines=-0", {IN=>"a\nb"}, {OUT=>"a\nb"}],
  57   );
  58
  59 if ($ENV{RUN_EXPENSIVE_TESTS})
  60   {
  61     # Brute force: use all combinations of file sizes [0..20] and
  62     # number of bytes to elide [0..20].  For better coverage, recompile
  63     # head with -DHEAD_TAIL_PIPE_READ_BUFSIZE=4 and
  64     # -DHEAD_TAIL_PIPE_BYTECOUNT_THRESHOLD=8
  65     my $s = "abcdefghijklmnopqrst";
  66     for my $file_size (0..20)
  67       {
  68         for my $n_elide (0..20)
  69           {
  70             my $input = substr $s, 0, $file_size;
  71             my $out_len = $n_elide < $file_size ? $file_size - $n_elide : 0;
  72             my $output = substr $input, 0, $out_len;
  73             my $t = ["elideb$file_size-$n_elide", "--bytes=-$n_elide",
  74                      {IN=>$input}, {OUT=>$output}];
  75             push @Tests, $t;
  76             my @u = @$t;
  77             # Insert the ---presume-input-pipe option.
  78             $u[0] .= 'p';
  79             $u[1] .= ' ---presume-input-pipe';
  80             push @Tests, \@u;
  81           }
  82       }
  83
  84     $s =~ s/(.)/$1\n/g;
  85     $s .= 'u'; # test without trailing '\n'
  86     for my $file_size (0..21)
  87       {
  88         for my $n_elide (0..21)
  89           {
  90             my $input = substr $s, 0, 2 * $file_size;
  91             my $out_len = $n_elide < $file_size ? $file_size - $n_elide : 0;
  92             my $output = substr $input, 0, 2 * $out_len;
  93             my $t = ["elidel$file_size-$n_elide", "--lines=-$n_elide",
  94                      {IN=>$input}, {OUT=>$output}];
  95             push @Tests, $t;
  96             my @u = @$t;
  97             # Insert the ---presume-input-pipe option.
  98             $u[0] .= 'p';
  99             $u[1] .= ' ---presume-input-pipe';
 100             push @Tests, \@u;
 101           }
 102       }
 103   }
 104
 105 my $save_temps = $ENV{DEBUG};
 106 my $verbose = $ENV{VERBOSE};
 107
 108 my $prog = $ENV{PROG} || die "$0: \$PROG not specified in environment\n";
 109 my $fail = run_tests ($program_name, $prog, \@Tests, $save_temps, $verbose);
 110 exit $fail;