14 unstable releases (3 breaking)

new 0.4.5 May 20, 2024
0.4.4 May 20, 2024
0.4.1 Apr 25, 2024
0.3.7 Apr 17, 2024
0.1.3 Mar 13, 2024

#3 in #cat

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MIT license


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ricat: A Rust-Based cat Command Implementation

This project is a Rust-based reimagining of the classic Unix cat command, drawing inspiration from its original implementation in GNU Core Utilities. It demonstrates the power and flexibility of Rust for system utilities development.

About ricat

ricat is designed with flexibility in mind, making it a valuable tool in the command line toolkit. One of its powerful features is the ability to seamlessly integrate with the pipe | operator, allowing users to pipe the output of any command directly into ricat for further processing. This means you can easily use ricat to view, modify, or extend the output of other commands in real-time. Whether it's adding line numbers, appending symbols to each line, or leveraging any of ricat's other features, integrating ricat into your command line workflows can significantly enhance your productivity and command line capabilities.


Ensure you have Rust and Cargo installed on your system. If you don't have Rust installed, you can install it from the official site.

You can install ricat directly from crates.io by running:

cargo install ricat

This command installs the ricat binary, making it available for use in your terminal

Update existing installation

If you have ricat already installed, you can update it by force installing the newer version over the older version:

cargo install ricat --force


  • Line Numbering: Add line numbers to the output with the -n flag.
  • Dollar Sign Appending: Append a $ sign at the end of each line using the -d flag.
  • Tab Space Replacement: Replace tab spaces with ^I using the -t flag.
  • Empty Line Compression: Compress multiple consecutive empty lines into a single empty line with the -s flag.
  • Text Search: Search for lines containing a specific text or regular expression pattern using the --search and --text flags.
    • Case-insensitive search is supported with the --ignore-case or -i flag.
    • For Regular Expression search, append the regex with reg:. For example, ricat --search --text "reg:\\d+" my_file.txt
  • Base64 Encoding: Encode the input text using Base64 with the --encode-base64 flag.
  • Base64 Decoding: Decode Base64 encoded text using the --decode-base64 flag.
  • Multiple File Support: Concatenate and process multiple files specified as command-line arguments.
  • Standard Input Processing: Read from standard input when no file arguments are provided, allowing ricat to be used in command pipelines.
  • Pagination: Display the output in a paginated manner based on the terminal window size using the --pages flag.
  • Presets: Now Ricat uses ricat_cfg.toml file to store the presets for the features. You can change the presets according to your needs. It is stores in $HOME/.config/ricat/ricat_cfg.toml

These features make ricat a versatile tool for text processing and manipulation, providing a range of functionalities to enhance your command-line workflows.


Read a File Without Line Numbering

ricat my_file.txt

Read a File With Line Numbering Enabled

ricat my_file.txt -n

Read a File with $ sign at the end of each Line

ricat -d my_file.txt

Read Multiple Files

To read and concatenate the contents of multiple files, specify each file path separated by a space:

ricat file1.txt file2.txt file3.txt

Search Text within a File

For searching text within a file, use the --search flag, along with the --text flag to specify the text to search for.

To search for and return lines containing a specific pattern or word within a single file:

ricat --search --text "string_to_search" my_file.txt

For regular expression searches, ensure the pattern is a valid regex. For example, to find lines containing digits:

ricat --search --text "reg:\\d+" my_file.txt

For ignoring case sensitivity, use the --ignore-case or -i flag:

ricat --search --text "string_to_search" --ignore-case my_file.txt

Read from the Standard Input by User

  • This behavior allows ricat to be used in a pipeline of commands, where it can receive input from a previous command and pass its output to the next command. Without any arguments, ricat effectively acts as a simple text editor that displays what you type in real-time, making it useful for creating short text files directly from the command line by redirecting the output to a file using the > operator.

Piping output from another command to ricat

df | ricat --search --text "/dev/nvme0"

This command will show the disk space usage for all the partitions of drive nvme0

Base64 Encoding-Decoding

ricat --encode-base64 message.txt

This will convert all the contents of message.txt via base-64 encoding

ricat --decode-base64 encoded_message.txt

This command will convert the contents of encoded_message.txt via base-64 decoding

echo -n "And" | base64 | ricat --decode-base64

Example of encoding and then decoding the string "And"

Show all features currently implemented for ricat

ricat --help

Configuration Presets

Config file for ricat is stored in $HOME/.config/ricat/ricat_cfg.toml. You can change the presets for the features in this file. The file is created when you run the ricat command for the first time.


number_feature = false
dollar_sign_feature = false
tabs_feature = false
compress_empty_line_feature = false


ricat provides benchmark scripts to compare its performance with the standard cat and a previous version of ricat already installed.

  • benchmark.sh: Compares the execution time of current:ricat, cat and prev:ricat for a single run with a specified memory size (default: 1GB).
  • benchmark_plot.sh: Averages the execution time over multiple iterations (default: 10) and plots a comparision graph.
./benchmark_plot.sh <memory_size_in_MB>

Eg. ./benchmark_plot.sh 4096

These benchmarks scripts utilise memory-mapped I/O for improved performance when reading large files without applying any features.

Testing ricat

To test the ricat features, you can run the following command:


Run this command in the root of the project

Extending ricat

Adding new features to ricat is straightforward. Implement the LineTextFeature trait for any struct to create a new feature. For example, to add a feature that highlights TODO comments in your text files, define a struct implementing LineTextFeature that scans each line for the pattern and applies the desired formatting.


[x] Remove the need of -f flag for reading the filename input

[x] Return all the lines with a given pattern/word.

[x] Feature: Adding Encoding and Decoding ability (base64)

[ ] Non-UTF8 Support: To be Done. See Issue #18

[ ] Stand-in replacement for cat.


Contributions are most welcome! If you have ideas for new features or improvements, please feel free to submit a pull request or open an issue.

Bug Reporting

To report bugs, you can go to the GitHub Discussions

Release Notes


  • Bug Fix: Configuration file was not getting read properly.


  • Added support for configuration presets for the features in the ricat_cfg.toml file.
  • Added ability to quit pagination mode by pressing q key.
  • fixes & improvements.
  • Updated Documentation for the project.


  • Added support for Memory Mapped IO, improves performance times by almost 150% for reading files directly without any features applied.
  • Added benchmarks for memory mapped IO addition.


  • Added custom testing file for testing the ricat features.

  • Fixed Bug with ricat not working with the standard input mode: #21

    -- To run the test cases, run ./test-ricat.sh in the root directory of the project.


  • Updated searching using Regex, now you can search for a regular expression pattern in the file via using reg: prefix.
  • Optimized Performance for features, using Buffered Writer for output, makes less System Calls for writing to the output.
  • Optimized Regex Searching via Caching the Compiled Regex, earlier was compiling for each search.
  • Code Refactored for easier understanding and maintainability.
  • Bug Fixes: Fixed issue with regex search.

0.3.3 to 0.3.6

  • Added Ability to search text/regular expression in the file with --ignore-case flag.
  • Added Ability to encode and decode in base64 format [ --encode-base64 & --decode-base64 flags]
  • Bug Fixes: ricat without any file input was not applying feature on standard input mode.


  • Added ability to do pagination according to your current terminal window size [--pages flag]


  • Added ability to combine multiple files in output.
  • Added ability to search text/regular expression in the file.

0.1.2 to 0.2.0

  • Added dollar sign appending at the end of each line feature.
  • Implemented tab space replacement with ^I.
  • Compresses multiple consecutive empty lines into a single empty line.
  • Initial support for standard input processing without file input.


  • Added features to number the lines.


  • Released with printing from standard input to standard output functionality.


~289K SLoC