compare-dir

Compare two directories and show the differences, or find duplicated files within a single directory.

• For two directories, it compares the file contents if the file sizes are the same. Useful to verify backup copies.
• For a single directory, it cryptographically hashes matching file sizes to discover exact duplicates.

Installation

cargo install compare-dir

See Releases for the change history.

Usage

Compare two directories:

compare-dir <dir1> <dir2>

Find duplicated files in a single directory:

compare-dir <dir>

Please use the -h option to see all options.

Symbols

When comparing two directories, the output is human-readable by default. The --symbol (or -s) option changes the output format to be symbolized, which is easier for programs to read.

For example:

=>= dir/path

means that dir/path in dir1 is newer than the file in dir2, but they have the same file sizes and contents.

The following bash example creates a list of paths of the same contents.

compare-dir -s <dir1> <dir2> | grep '^..=' | cut -c 5-

If you prefer sed over cut:

compare-dir -s <dir1> <dir2> | grep '^..=' | sed 's/^....//'

To do this in PowerShell:

compare-dir -s <dir1> <dir2> | sls '^..=' | %{$_ -replace '^....', ''}

Hash Cache

The file hashes are cached in a file named .hash_cache.

If you think file contents may be changed without their last modified time changed, please remove the cache file. The tool will then recompute the hashes.

If one of ancestor directories has the cache file, the nearest one is used instead. For example:

touch ~/data/.hash_cache
compare-dir ~/data/subdir

Then ~/data/.hash_cache is used as the cache file, instead of ~/data/subdir/.hash_cache.