1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385
|
#!/usr/bin/perl -w
#
# `Diff' program in Perl
# Copyright 1998 M-J. Dominus. (mjd-perl-diff@plover.com)
#
# This program is free software; you can redistribute it and/or modify it
# under the same terms as Perl itself.
#
# Altered to output in `context diff' format (but without context)
# September 1998 Christian Murphy (cpm@muc.de)
#
# Command-line arguments and context lines feature added
# September 1998 Amir D. Karger (karger@bead.aecom.yu.edu)
#
# In this file, "item" usually means "line of text", and "item number" usually
# means "line number". But theoretically the code could be used more generally
use strict;
use Algorithm::Diff qw(diff);
use File::stat;
use vars qw ($opt_C $opt_c $opt_u $opt_U);
use Getopt::Std;
my $usage = << "ENDUSAGE";
Usage: $0 [{-c | -u}] [{-C | -U} lines] oldfile newfile
-c will do a context diff with 3 lines of context
-C will do a context diff with 'lines' lines of context
-u will do a unified diff with 3 lines of context
-U will do a unified diff with 'lines' lines of context
ENDUSAGE
getopts('U:C:cu') or bag("$usage");
bag("$usage") unless @ARGV == 2;
my ($file1, $file2) = @ARGV;
if (defined $opt_C || defined $opt_c) {
$opt_c = ""; # -c on if -C given on command line
$opt_u = undef;
} elsif (defined $opt_U || defined $opt_u) {
$opt_u = ""; # -u on if -U given on command line
$opt_c = undef;
} else {
$opt_c = ""; # by default, do context diff, not old diff
}
my ($char1, $char2); # string to print before file names
my $Context_Lines; # lines of context to print
if (defined $opt_c) {
$Context_Lines = defined $opt_C ? $opt_C : 3;
$char1 = '*' x 3; $char2 = '-' x 3;
} elsif (defined $opt_u) {
$Context_Lines = defined $opt_U ? $opt_U : 3;
$char1 = '-' x 3; $char2 = '+' x 3;
}
# After we've read up to a certain point in each file, the number of items
# we've read from each file will differ by $FLD (could be 0)
my $File_Length_Difference = 0;
open (F1, $file1) or bag("Couldn't open $file1: $!");
open (F2, $file2) or bag("Couldn't open $file2: $!");
my (@f1, @f2);
chomp(@f1 = <F1>);
close F1;
chomp(@f2 = <F2>);
close F2;
# diff yields lots of pieces, each of which is basically a Block object
my $diffs = diff(\@f1, \@f2);
exit 0 unless @$diffs;
my $st = stat($file1);
print "$char1 $file1\t", scalar localtime($st->mtime), "\n";
$st = stat($file2);
print "$char2 $file2\t", scalar localtime($st->mtime), "\n";
my ($hunk,$oldhunk);
# Loop over hunks. If a hunk overlaps with the last hunk, join them.
# Otherwise, print out the old one.
foreach my $piece (@$diffs) {
$hunk = new Hunk ($piece, $Context_Lines);
next unless $oldhunk;
if ($hunk->does_overlap($oldhunk)) {
$hunk->prepend_hunk($oldhunk);
} else {
$oldhunk->output_diff(\@f1, \@f2);
}
} continue {
$oldhunk = $hunk;
}
# print the last hunk
$oldhunk->output_diff(\@f1, \@f2);
exit 1;
# END MAIN PROGRAM
sub bag {
my $msg = shift;
$msg .= "\n";
warn $msg;
exit 2;
}
# Package Hunk. A Hunk is a group of Blocks which overlap because of the
# context surrounding each block. (So if we're not using context, every
# hunk will contain one block.)
{
package Hunk;
sub new {
# Arg1 is output from &LCS::diff (which corresponds to one Block)
# Arg2 is the number of items (lines, e.g.,) of context around each block
#
# This subroutine changes $File_Length_Difference
#
# Fields in a Hunk:
# blocks - a list of Block objects
# start - index in file 1 where first block of the hunk starts
# end - index in file 1 where last block of the hunk ends
#
# Variables:
# before_diff - how much longer file 2 is than file 1 due to all hunks
# until but NOT including this one
# after_diff - difference due to all hunks including this one
my ($class, $piece, $context_items) = @_;
my $block = new Block ($piece); # this modifies $FLD!
my $before_diff = $File_Length_Difference; # BEFORE this hunk
my $after_diff = $before_diff + $block->{"length_diff"};
$File_Length_Difference += $block->{"length_diff"};
# @remove_array and @insert_array hold the items to insert and remove
# Save the start & beginning of each array. If the array doesn't exist
# though (e.g., we're only adding items in this block), then figure
# out the line number based on the line number of the other file and
# the current difference in file lengths
my @remove_array = $block->remove;
my @insert_array = $block->insert;
my ($a1, $a2, $b1, $b2, $start1, $start2, $end1, $end2);
$a1 = @remove_array ? $remove_array[0 ]->{"item_no"} : -1;
$a2 = @remove_array ? $remove_array[-1]->{"item_no"} : -1;
$b1 = @insert_array ? $insert_array[0 ]->{"item_no"} : -1;
$b2 = @insert_array ? $insert_array[-1]->{"item_no"} : -1;
$start1 = $a1 == -1 ? $b1 - $before_diff : $a1;
$end1 = $a2 == -1 ? $b2 - $after_diff : $a2;
$start2 = $b1 == -1 ? $a1 + $before_diff : $b1;
$end2 = $b2 == -1 ? $a2 + $after_diff : $b2;
# At first, a hunk will have just one Block in it
my $hunk = {
"start1" => $start1,
"start2" => $start2,
"end1" => $end1,
"end2" => $end2,
"blocks" => [$block],
};
bless $hunk, $class;
$hunk->flag_context($context_items);
return $hunk;
}
# Change the "start" and "end" fields to note that context should be added
# to this hunk
sub flag_context {
my ($hunk, $context_items) = @_;
return unless $context_items; # no context
# add context before
my $start1 = $hunk->{"start1"};
my $num_added = $context_items > $start1 ? $start1 : $context_items;
$hunk->{"start1"} -= $num_added;
$hunk->{"start2"} -= $num_added;
# context after
my $end1 = $hunk->{"end1"};
$num_added = ($end1+$context_items > $#f1) ?
$#f1 - $end1 :
$context_items;
$hunk->{"end1"} += $num_added;
$hunk->{"end2"} += $num_added;
}
# Is there an overlap between hunk arg0 and old hunk arg1?
# Note: if end of old hunk is one less than beginning of second, they overlap
sub does_overlap {
my ($hunk, $oldhunk) = @_;
return "" unless $oldhunk; # first time through, $oldhunk is empty
# Do I actually need to test both?
return ($hunk->{"start1"} - $oldhunk->{"end1"} <= 1 ||
$hunk->{"start2"} - $oldhunk->{"end2"} <= 1);
}
# Prepend hunk arg1 to hunk arg0
# Note that arg1 isn't updated! Only arg0 is.
sub prepend_hunk {
my ($hunk, $oldhunk) = @_;
$hunk->{"start1"} = $oldhunk->{"start1"};
$hunk->{"start2"} = $oldhunk->{"start2"};
unshift (@{$hunk->{"blocks"}}, @{$oldhunk->{"blocks"}});
}
# DIFF OUTPUT ROUTINES. THESE ROUTINES CONTAIN DIFF FORMATTING INFO...
sub output_diff {
if (defined $main::opt_u) {&output_unified_diff(@_)}
elsif (defined $main::opt_c) {&output_context_diff(@_)}
else {die "unknown diff"}
}
sub output_unified_diff {
my ($hunk, $fileref1, $fileref2) = @_;
my @blocklist;
# Calculate item number range.
my $range1 = $hunk->unified_range(1);
my $range2 = $hunk->unified_range(2);
print "@@ -$range1 +$range2 @@\n";
# Outlist starts containing the hunk of file 1.
# Removing an item just means putting a '-' in front of it.
# Inserting an item requires getting it from file2 and splicing it in.
# We splice in $num_added items. Remove blocks use $num_added because
# splicing changed the length of outlist.
# We remove $num_removed items. Insert blocks use $num_removed because
# their item numbers---corresponding to positions in file *2*--- don't take
# removed items into account.
my $low = $hunk->{"start1"};
my $hi = $hunk->{"end1"};
my ($num_added, $num_removed) = (0,0);
my @outlist = @$fileref1[$low..$hi];
map {s/^/ /} @outlist; # assume it's just context
foreach my $block (@{$hunk->{"blocks"}}) {
foreach my $item ($block->remove) {
my $op = $item->{"sign"}; # -
my $offset = $item->{"item_no"} - $low + $num_added;
$outlist[$offset] =~ s/^ /$op/;
$num_removed++;
}
foreach my $item ($block->insert) {
my $op = $item->{"sign"}; # +
my $i = $item->{"item_no"};
my $offset = $i - $hunk->{"start2"} + $num_removed;
splice(@outlist,$offset,0,"$op$$fileref2[$i]");
$num_added++;
}
}
map {s/$/\n/} @outlist; # add \n's
print @outlist;
}
sub output_context_diff {
my ($hunk, $fileref1, $fileref2) = @_;
my @blocklist;
print "***************\n";
# Calculate item number range.
my $range1 = $hunk->context_range(1);
my $range2 = $hunk->context_range(2);
# Print out file 1 part for each block in context diff format if there are
# any blocks that remove items
print "*** $range1 ****\n";
my $low = $hunk->{"start1"};
my $hi = $hunk->{"end1"};
if (@blocklist = grep {$_->remove} @{$hunk->{"blocks"}}) {
my @outlist = @$fileref1[$low..$hi];
map {s/^/ /} @outlist; # assume it's just context
foreach my $block (@blocklist) {
my $op = $block->op; # - or !
foreach my $item ($block->remove) {
$outlist[$item->{"item_no"} - $low] =~ s/^ /$op/;
}
}
map {s/$/\n/} @outlist; # add \n's
print @outlist;
}
print "--- $range2 ----\n";
$low = $hunk->{"start2"};
$hi = $hunk->{"end2"};
if (@blocklist = grep {$_->insert} @{$hunk->{"blocks"}}) {
my @outlist = @$fileref2[$low..$hi];
map {s/^/ /} @outlist; # assume it's just context
foreach my $block (@blocklist) {
my $op = $block->op; # + or !
foreach my $item ($block->insert) {
$outlist[$item->{"item_no"} - $low] =~ s/^ /$op/;
}
}
map {s/$/\n/} @outlist; # add \n's
print @outlist;
}
}
sub context_range {
# Generate a range of item numbers to print. Only print 1 number if the range
# has only one item in it. Otherwise, it's 'start,end'
my ($hunk, $flag) = @_;
my ($start, $end) = ($hunk->{"start$flag"},$hunk->{"end$flag"});
$start++; $end++; # index from 1, not zero
my $range = ($start < $end) ? "$start,$end" : $end;
return $range;
}
sub unified_range {
# Generate a range of item numbers to print for unified diff
# Print number where block starts, followed by number of lines in the block
# (don't print number of lines if it's 1)
my ($hunk, $flag) = @_;
my ($start, $end) = ($hunk->{"start$flag"},$hunk->{"end$flag"});
$start++; $end++; # index from 1, not zero
my $length = $end - $start + 1;
my $first = $length < 2 ? $end : $start; # strange, but correct...
my $range = $length== 1 ? $first : "$first,$length";
return $range;
}
} # end Package Hunk
# Package Block. A block is an operation removing, adding, or changing
# a group of items. Basically, this is just a list of changes, where each
# change adds or deletes a single item.
# (Change could be a separate class, but it didn't seem worth it)
{
package Block;
sub new {
# Input is a chunk from &Algorithm::LCS::diff
# Fields in a block:
# length_diff - how much longer file 2 is than file 1 due to this block
# Each change has:
# sign - '+' for insert, '-' for remove
# item_no - number of the item in the file (e.g., line number)
# We don't bother storing the text of the item
#
my ($class,$chunk) = @_;
my @changes = ();
# This just turns each change into a hash.
foreach my $item (@$chunk) {
my ($sign, $item_no, $text) = @$item;
my $hashref = {"sign" => $sign, "item_no" => $item_no};
push @changes, $hashref;
}
my $block = { "changes" => \@changes };
bless $block, $class;
$block->{"length_diff"} = $block->insert - $block->remove;
return $block;
}
# LOW LEVEL FUNCTIONS
sub op {
# what kind of block is this?
my $block = shift;
my $insert = $block->insert;
my $remove = $block->remove;
$remove && $insert and return '!';
$remove and return '-';
$insert and return '+';
warn "unknown block type";
return '^'; # context block
}
# Returns a list of the changes in this block that remove items
# (or the number of removals if called in scalar context)
sub remove { return grep {$_->{"sign"} eq '-'} @{shift->{"changes"}}; }
# Returns a list of the changes in this block that insert items
sub insert { return grep {$_->{"sign"} eq '+'} @{shift->{"changes"}}; }
} # end of package Block
|