bridge

Bridge

A small CLI utility used to find duplicate files.

Table of Contents

• Project home
• Overview
  • Generate report
  • Prune duplicate files
• Features
• Changelog
• Requirements
  • Building source code
  • Running
• Installation
  • From source
  • Using release binaries
• Configuration Options
  • Command-line Arguments
    • report subcommand
    • prune subcommand
• Examples
  • Generating a report
    • Single path, recursive
    • Multiple paths, non-recursive
    • Invalid flag
  • Pruning duplicate files
    • Dry-run (minimal)
    • Dry-run (verbose)
    • Backup files before removing them
• License
  • Core project files
  • ByteCountSI, ByteCountIEC functions
• References

Project home

See our GitHub repo for the latest code, to file an issue or submit improvements for review and potential inclusion into the project.

Overview

1. Generate report
   • Find duplicate files and report them via console-only output or an output CSV file
2. Remove flagged files
   • Process CSV file report generated earlier: if flag is set, (optionally) backup and then remove marked files

Generate report

Generating a report is the first step towards indicating which files from a duplicate file set that you wish to remove (specified explicitly) and which you wish to keep (default behavior).

Prune duplicate files

Pruning duplicate files is an optional second step following the generation of a duplicate files report (via the report subcommand).

You first open the CSV file using an application like Microsoft Excel or LibreOffice Calc and then mark each file (remove_file column) that you wish to remove with either true or false; the default is false, so marking an entry with false is not strictly necessary.

Once marked, you are then able to remove those files by specifying the full path to the CSV file (via the prune subcommand). See the Examples section for details.

Features

• Efficient evaluation of potential duplicates by limiting checksum generation to two or more identically sized files
• Support for creating CSV report of all duplicate file matches
• Support for generating (rough) console equivalent of CSV file for (potential) quick review
• Support for creating Microsoft Excel workbook of all duplicate file matches
• Support for evaluating one or many paths
• Recursive or shallow directory evaluation
• Optional removal of (user-flagged) duplicate files from a previously generated CSV report
• Go modules (vs classic GOPATH setup)

Changelog

See the CHANGELOG.md file for the changes associated with each release of this application. Changes that have been merged to master, but not yet an official release may also be noted in the file under the Unreleased section. A helpful link to the Git commit history since the last official release is also provided for further review.

Requirements

The following is a loose guideline. Other combinations of Go and operating systems for building and running tools from this repo may work, but have not been tested.

Building source code

• Go
  • see this project's go.mod file for preferred version
  • this project tests against officially supported Go releases
    • the most recent stable release (aka, "stable")
    • the prior, but still supported release (aka, "oldstable")
• GCC
  • if building with custom options (as the provided Makefile does)
• make
  • if using the provided Makefile

Running

• Windows 10
• Ubuntu Linux 18.04+

Installation

From source

1. Download Go
2. Install Go
3. Clone the repo
   1. cd /tmp
   2. git clone https://github.com/atc0005/bridge
   3. cd bridge
4. Install dependencies (optional)
   • for Ubuntu Linux
     • sudo apt-get install make gcc
   • for CentOS Linux
     1. sudo yum install make gcc
5. Build
   • for current operating system
     • go build -mod=vendor ./cmd/bridge/
       • forces build to use bundled dependencies in top-level vendor folder
   • for all supported platforms (where make is installed)
     • make all
   • for Windows
     • make windows
   • for Linux
     • make linux
6. Copy the applicable binary to whatever systems needs to run it
   • if using Makefile: look in /tmp/release_assets/bridge/
   • if using go build: look in /tmp/bridge/

NOTE: Depending on which Makefile recipe you use the generated binary may be compressed and have an xz extension. If so, you should decompress the binary first before deploying it (e.g., xz -d bridge-linux-amd64.xz).

Using release binaries

1. Download the latest release binaries
2. Decompress binaries
   • e.g., xz -d bridge-linux-amd64.xz
3. Deploy
   • Place bridge in a location of your choice
     • e.g., /usr/local/bin/bridge

NOTE:

DEB and RPM packages are provided as an alternative to manually deploying binaries.

Configuration Options

Command-line Arguments

report subcommand

prune subcommand

Examples

Generating a report

Single path, recursive

This example illustrates using the application to process a single path, recursively.

./bridge.exe report -recurse -path "/tmp/path1" -csvfile "path1-report.csv"

Multiple paths, non-recursive

This example illustrates using the application to process multiple paths, without recursively evaluating any subdirectories.

./bridge.exe report -path "/tmp/path1" -path "/tmp/path2"  -csvfile "report.csv"

Invalid flag

Accidentally typing the wrong flag results in a message like this one:

$ ./bridge.exe report -fake-flag
DEBUG: subcommand 'report'
flag provided but not defined: -fake-flag

bridge x.y.z
https://github.com/atc0005/bridge

Usage of "bridge report":
  -console
        Dump (approximate) CSV file equivalent to console.
  -csvfile string
        The (required) fully-qualified path to a CSV file that this application should generate.
  -duplicates int
        Number of files of the same file size needed before duplicate validation logic is applied. (default 2)
  -excelfile string
        The (optional) fully-qualified path to an Excel file that this application should generate.
  -ignore-errors
        Ignore minor errors whenever possible. This option does not affect handling of fatal errors such as failure to generate output report files.
  -path value
        Path to process. This flag may be repeated for each additional path to evaluate.
  -recurse
        Perform recursive search into subdirectories per provided path.
  -size int
        File size limit (in bytes) for evaluation. Files smaller than this will be skipped. (default 1)
DEBUG: err returned from reportCmd.Parse(): flag provided but not defined: -fake-flag

ERROR: flag provided but not defined: -fake-flag

Pruning duplicate files

Dry-run (minimal)

./bridge.exe prune -input-csvfile "report.csv" -dry-run -ignore-errors

Here we specify:

• Don't actually remove files, just simulate the process
• input CSV file (file previously generated by the report subcommand)
• ignore (minor) errors

Because the console flag wasn't specified, the output is minimal.

Dry-run (verbose)

./bridge.exe prune -input-csvfile "report.csv" -dry-run -ignore-errors -console

Here we specify:

• Don't actually remove files, just simulate the process
• input CSV file (file previously generated by the report subcommand)
• ignore (minor) errors
• console flag
  • enables printing table of parsed CSV contents
  • enables printing table of file removal candidates

Because the console flag was specified, the output is more verbose.

Backup files before removing them

./bridge.exe prune -input-csvfile "report.csv" -backup-dir /tmp/tacos -dry-run -ignore-errors -console

Here we specify:

• the input CSV file (file previously generated by the report subcommand)
• the backup directory that should be used to copy files to (just before a file removal operation is attempted)
• ignore (minor) errors
• console flag
  • enables printing table of parsed CSV contents
  • enables printing table of file removal candidates

Because the console flag was specified, the output is more verbose. This can make the removal process easier to troubleshoot due to the explicit listing of what would be removed and what actually occurred.

License

Core project files

From the LICENSE file:

MIT License

Copyright (c) 2020 Adam Chalkley

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

ByteCountSI, ByteCountIEC functions

These utility functions are provided by Stefan Nilsson under the Attribution 3.0 Unported (CC BY 3.0) license. See the References section of this document for links to additional information.

References

• https://yourbasic.org/golang/formatting-byte-size-to-human-readable-format/

  • https://yourbasic.org/golang/byte-count.go
  • https://creativecommons.org/licenses/by/3.0/

• https://stackoverflow.com/questions/28322997/how-to-get-a-list-of-values-into-a-flag-in-golang

• https://golang.org/pkg/flag/#Value

• https://gobyexample.com/command-line-subcommands

• https://stackoverflow.com/questions/50324612/merge-maps-in-golang/50325337#50325337

• https://yourbasic.org/golang/gotcha-change-value-range/

• https://www.digitalocean.com/community/tutorials/understanding-defer-in-go

• https://golangcode.com/writing-to-file/

• https://www.joeshaw.org/dont-defer-close-on-writable-files/

• https://golang.org/pkg/os/#File.Sync

• https://www.linode.com/docs/development/go/creating-reading-and-writing-files-in-go-a-tutorial/

• https://medium.com/@sebassegros/golang-dealing-with-maligned-structs-9b77bacf4b97

• https://goenning.net/2017/01/25/adding-custom-data-go-binaries-compile-time/

  • covers updating variables at build time, particularly sub-packages (GH-55)

• https://github.com/360EntSecGroup-Skylar/excelize