Overview
`lesspipe` is a utility that helps `less` handle various file formats beyond plain text files. When `less` opens a file, it executes the `lesspipe` script to convert the file's content to standard output, which `less` then receives and displays.
Key Features
- View contents of compressed files (gzip, bzip2, xz, etc.) directly
- View the list and contents of files within archive files (tar, zip, rar, etc.)
- Extract and view text from non-text files like PDFs and images (requires relevant tools)
- Maintain
less's powerful search and navigation capabilities
Installation and Setup
`lesspipe` is often provided as part of the `less` package on most Linux distributions or as a separate `lesspipe` package. The key is to set the `LESSOPEN` environment variable to make `less` use `lesspipe`.
Check Installation
It is pre-installed on most systems, but you can check for its existence with the following command.
which lesspipeInstall Package (if needed)
If lesspipe is not installed, you can install it with the following commands.
Debian/Ubuntu
sudo apt update && sudo apt install lessFedora/RHEL
sudo dnf install lessSet LESSOPEN Environment Variable
To enable lesspipe, you need to add the LESSOPEN environment variable to your shell configuration file (e.g., ~/.bashrc, ~/.zshrc). The exact path to lesspipe may vary by system, so confirm it with which lesspipe.
Example LESSOPEN Configuration
export LESSOPEN="|/usr/bin/lesspipe %s"
export LESS_ADVANCED_PREPROCESSOR=1
source ~/.bashrcA typical configuration is as follows. Apply changes immediately using the `source` command.
LESSOPEN Variable Explanation
|: Indicates that the output oflesspipewill be piped toless.%s: A placeholder representing the path to the filelessis trying to open.LESS_ADVANCED_PREPROCESSOR=1: Used in somelesspipeversions to enable advanced preprocessor features.
Usage Examples
Once `lesspipe` is correctly configured, using the `less` command as usual will automatically handle various file formats.
View Contents of a gzip Compressed File
less my_log.gzView the contents of a `.gz` file directly with `less` without decompressing it.
View List of Files in a tar Archive
less my_archive.tar.gzCheck the list of files inside a `.tar.gz` file with `less` without decompressing it.
View List of Files in a zip Archive
less my_documents.zipCheck the list of files inside a `.zip` file with `less` without decompressing it.
View Text Content of a PDF File
less document.pdfIf tools like `pdftotext` are installed, you can view the text content of a PDF file with `less`.
View Strings in a Binary File
less /bin/lsFor binary files, you can view extracted strings with `less` using the `strings` command.
Tips & Considerations
Tips and considerations for effectively using `lesspipe`.
Custom lesspipe Scripts
The default lesspipe script is a shell script, which means you can modify it as needed or create your own lesspipe script and specify it in the LESSOPEN variable. For example, you can add additional processing logic for specific file types.
- Copy and modify the existing
lesspipescript - Add logic for new file types
- Specify the path to your custom script in the
LESSOPENvariable
Performance Considerations
When opening very large compressed files or archives with lesspipe, it may take time to extract and convert the file contents. This can result in a slight delay before less starts.
Security Precautions
lesspipe executes external commands to process files. Therefore, using an untrusted lesspipe script or having malicious files processed through lesspipe can lead to security issues. Always use lesspipe from a trusted source and be cautious when configuring the LESSOPEN variable.
Check Supported File Formats
By examining the lesspipe script installed on your system, you can determine which file formats it supports and which external tools it uses. You can typically view the script's content with a command like cat /usr/bin/lesspipe (or the appropriate path).