LFTP Exclude File Extensions

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Introduction

LFTP is a powerful command-line file transfer program that allows users to mirror directories, upload and download files, and manage remote file systems. However, when mirroring directories, users may encounter issues with large file types that they do not want to download. In this article, we will explore how to exclude file extensions using LFTP and regular expressions.

Understanding LFTP and Regular Expressions

Before we dive into the solution, it's essential to understand the basics of LFTP and regular expressions. LFTP is a command-line tool that uses a syntax similar to FTP, but with additional features and options. Regular expressions, on the other hand, are a powerful tool for matching patterns in strings.

Regular Expression Basics

Regular expressions are a way to describe patterns in strings using a set of special characters and syntax. In LFTP, regular expressions are used to match file names and extensions. Here are some basic regular expression concepts:

  • .: Matches any single character (except newline)
  • ****: Escapes special characters (e.g., . matches a literal period)
  • []: Matches any character inside the brackets (e.g., [a-zA-Z] matches any letter)
  • ^: Matches the start of a string
  • $: Matches the end of a string
  • |: Matches either the expression on the left or the right

Excluding File Extensions with LFTP

To exclude file extensions using LFTP, you can use the --exclude option followed by a regular expression that matches the file extensions you want to exclude. For example, to exclude .mp4 and .swf files, you can use the following command:

lftp -c "mirror --exclude='\.mp4$|\.swf{{content}}#39; /remote/directory /local/directory"

In this example, the regular expression \.mp4$|\.swf$ matches any file name that ends with .mp4 or .swf.

Using Regular Expressions with LFTP

LFTP supports a wide range of regular expression features, including character classes, anchors, and quantifiers. Here are some examples of regular expressions you can use with LFTP:

  • Exclude all files with a .mp4 extension: --exclude='\.mp4
  • Exclude all files with a .swf extension: --exclude='\.swf

    © 2025 InfoSphere

  • Exclude all files with a .mp4 or .swf extension: --exclude='\.mp4$|\.swf

    © 2025 InfoSphere

  • Exclude all files with a .mp4 or .swf extension, but only if they are larger than 100MB: --exclude='\.mp4$|\.swf

    © 2025 InfoSphere

    --size-limit 100M

    • Tips and Tricks

    Here are some additional tips and tricks for using regular expressions with LFTP:

    Conclusion

    In this article, we explored how to exclude file extensions using LFTP and regular expressions. By using the --exclude option followed by a regular expression, you can easily exclude file types that you do not want to download. We also covered some additional tips and tricks for using regular expressions with LFTP.

    Common Issues and Solutions

    Here are some common issues and solutions you may encounter when using LFTP and regular expressions:

    CentOS Specific Configuration

    If you are using CentOS, you may need to configure the lftp package to use the correct regular expression engine. Here are the steps to follow:

    1. Install the lftp package: sudo yum install lftp
    2. Configure the lftp package: sudo nano /etc/lftp.conf
    3. Add the following line to the file: regular_expression_engine = perl
    4. Save and close the file: sudo service lftp restart

    Regular Expression Engine Options

    LFTP supports several regular expression engines, including:

    You can specify the regular expression engine to use by adding the following option to the lftp command:

    lftp -c "mirror --exclude='\.mp4$|\.swf{{content}}#39; --regular_expression_engine=perl /remote/directory /local/directory"

    Conclusion

    Q: What is LFTP and how does it work?

    A: LFTP is a powerful command-line file transfer program that allows users to mirror directories, upload and download files, and manage remote file systems. It uses a syntax similar to FTP, but with additional features and options.

    Q: How do I exclude file extensions using LFTP?

    A: To exclude file extensions using LFTP, you can use the --exclude option followed by a regular expression that matches the file extensions you want to exclude. For example, to exclude .mp4 and .swf files, you can use the following command:

    lftp -c "mirror --exclude='\.mp4$|\.swf{{content}}#39; /remote/directory /local/directory"

    Q: What is a regular expression and how does it work?

    A: A regular expression is a way to describe patterns in strings using a set of special characters and syntax. In LFTP, regular expressions are used to match file names and extensions. Here are some basic regular expression concepts:

    Q: How do I use regular expressions with LFTP?

    A: To use regular expressions with LFTP, you can add the --exclude option followed by a regular expression that matches the file extensions you want to exclude. For example, to exclude all files with a .mp4 extension, you can use the following command:

    lftp -c "mirror --exclude='\.mp4{{content}}#39; /remote/directory /local/directory"

    Q: What are some common regular expression patterns used with LFTP?

    A: Here are some common regular expression patterns used with LFTP:

    Q: How do I troubleshoot regular expression issues with LFTP?

    A: To troubleshoot regular expression issues with LFTP, you can use the --debug option to see the regular expression being used. For example:

    lftp -c "mirror --debug --exclude='\.mp4$|\.swf{{content}}#39; /remote/directory /local/directory"

    This will show you the regular expression being used and help you identify any issues.

    Q: What are some common issues and solutions when using LFTP and regular expressions?

    A: Here are some common issues and solutions when using LFTP and regular expressions:

    Q: How do I configure LFTP to use a specific regular expression engine?

    A: To configure LFTP to use a specific regular expression engine, you can add the following option to the lftp command:

    lftp -c "mirror --exclude='\.mp4$|\.swf{{content}}#39; --regular_expression_engine=perl /remote/directory /local/directory"

    This will use the Perl regular expression engine.

    Q: What are some additional tips and tricks for using LFTP and regular expressions?

    A: Here are some additional tips and tricks for using LFTP and regular expressions:

    Conclusion

    In this Q&A article, we covered some common questions and answers about using LFTP and regular expressions to exclude file extensions. We also covered some additional tips and tricks for using LFTP and regular expressions.