NAME

File::Compare - Compare files to check for equality/difference

SYNOPSIS

use File::Compare;

if files_are_equal("file1.txt", "file2.txt")
		{ say "These are identical files"; }
	files_are_different("foo", "bar") ?? say "diff" !! say "same";

say "we match" if files_are_equal("x.png", "y.png", chunk_size=> 4*1024*1024);
	say "OH NOES" if files_are_different("i/dont/exist", "me/neither") ~~ Failure;

DESCRIPTION

File::Compare checks to see if files have the same contents, by comparing them as byte-buffers if they are of the same size.

files_are_equal(), files_are_different() The function files_are_equal returns Bool::True if the files have the same contents, Bool::False if any bytes are different, and a Failure object if an error occurs. The other function, files_are_different, returns the opposite boolean values, and is mostly provided for code readability sugar. Note that Failure Boolifies to False, so the behavior is slightly different between the two functions.

compare_multiple_files Another function, compare_multiple_files, will compare the contents of an array of files (passed in as any mixture of Str and IO::Path objects). It will return an array of arrays of IO::Path objects, with matching files grouped together.

chunk_size parameter All three functions can take an optional named parameter, chunk_size, which accepts any positive integer. This parameter tells File::Compare what size of chunks should be read from the disk at once, since the read operation is often the slowest. The default reads 8 MiB of each file at a time. A smaller value may be more useful in a memory-limited environment, or when files are most likely different. A larger value could improve performance when files are most likely the same.

DIFFERENCES FROM PERL 5 VERSION

This code returns boolean values and Failure objects instead of 1, 0, -1 for difference, equality, and failure respectively. The read chunk size is also increased four-fold because you're not really trying to run Rakudo on a 80486 processor, are you?

Comparing Text

This Perl 6 version drops the compare_text function that was included in Perl 5. Since most text files are of managable size, consider this code, which uses Perl's native newline handling: "file1".IO.open.lines eq "file2".IO.open.lines Functions can be evaluated on this as well: foo( "old/script.p6".IO.open.lines ) eq foo( "new/script.p6".IO.open.lines ) Though, you may be better off looking at a module like Text::Diff instead.

TODO

Support IO objects as parameters.

SEE ALSO

* File::Find::Duplicates - Searches directories and lists of files to find duplicate items. * Text::Diff - Perform diffs on files and record sets.

AUTHOR

Brent "Labster" Laabs, 2013.

Released under the same terms as Perl 6; see the LICENSE file for details.