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Decompress

Decompresses a single compressed file to the target path. Automatically detects whether the file is a tar-wrapped archive or pure compression format.

Common Properties​

  • Name - The custom name of the node.
  • Color - The custom color of the node.
  • Delay Before (sec) - Waits in seconds before executing the node.
  • Delay After (sec) - Waits in seconds after executing node.
  • Continue On Error - Automation will continue regardless of any error. The default value is false.
info

If the ContinueOnError property is true, no error is caught when the project is executed, even if a Catch node is used.

Inputs​

  • Source Path - Path to the compressed file to decompress. Supports various compression formats.

  • Target Path - Destination path for the decompressed file or directory. The content will be extracted to this location.

How It Works​

The Decompress node intelligently handles different types of compressed files:

  1. Detects the compression format from the file extension
  2. Analyzes the file content to determine if it's tar-wrapped (created by Compress node) or pure compression (created by external tools)
  3. For tar-wrapped files: Extracts the tar archive and decompresses in one step, preserving the original filename and directory structure
  4. For pure compression: Decompresses the file directly
  5. Saves the decompressed content to the target path

Smart Detection​

The node performs magic byte checking to determine the file type:

  • Checks for tar header signature ("ustar" at byte offset 257)
  • Handles files created by the Compress node (tar-wrapped)
  • Handles files created by external compression tools (pure compression)

Supported Compression Formats​

Compression Formats with Tar Detection​

  • .gz, .gzip - Gzip compressed files
  • .bz2, .bzip2 - Bzip2 compressed files
  • .zst, .zstd - Zstandard compressed files
  • .xz - XZ compressed files
  • .lz4 - LZ4 compressed files
  • .br - Brotli compressed files

Other Formats​

  • .zip - Zip archives
  • Any other format supported by the archiver library

Examples​

Example 1: Decompress a Gzip File​

Decompress a Gzip compressed file:

// Set source and target paths
msg.compressedFile = "/home/user/archives/application.log.gz";
msg.outputPath = "/home/user/logs/";

Configure the Decompress node:

  • Source Path: {{msg.compressedFile}}
  • Target Path: {{msg.outputPath}}

Example 2: Decompress a Zstandard Archive​

Decompress a folder that was compressed with Zstandard:

// Decompress a Zstandard archive
msg.zstFile = "/home/user/backups/project.zst";
msg.extractPath = "/home/user/restore/";

Configure the Decompress node:

  • Source Path: {{msg.zstFile}}
  • Target Path: {{msg.extractPath}}

Example 3: Decompress XZ Compressed File​

Decompress a file with maximum compression (XZ):

// Decompress XZ compressed file
msg.xzFile = "/home/user/archives/database.sql.xz";
msg.outputPath = "/home/user/restore/";

Configure the Decompress node:

  • Source Path: {{msg.xzFile}}
  • Target Path: {{msg.outputPath}}

Example 4: Batch Decompression​

Decompress multiple files in a loop:

// Define array of compressed files
msg.compressedFiles = [
    "/home/user/archives/file1.gz",
    "/home/user/archives/file2.zst",
    "/home/user/archives/file3.xz"
];

// Set output directory
msg.outputDir = "/home/user/extracted/";

// Set current index
msg.currentIndex = 0;

Configure the Decompress node:

  • Source Path: {{msg.compressedFiles[msg.currentIndex]}}
  • Target Path: {{msg.outputDir}}

Use a Loop or Iterator to process all files.

Example 5: Conditional Decompression​

Check file size before decompressing:

const fs = require('fs');
const path = require('path');

msg.compressedFile = "/home/user/archives/large-file.gz";

// Get file size
const stats = fs.statSync(msg.compressedFile);
const fileSizeInMB = stats.size / (1024 * 1024);

// Set output path
msg.outputPath = "/home/user/temp/";

// Store file info for logging
msg.fileInfo = {
    name: path.basename(msg.compressedFile),
    sizeInMB: fileSizeInMB.toFixed(2),
    format: path.extname(msg.compressedFile)
};

Configure the Decompress node:

  • Source Path: {{msg.compressedFile}}
  • Target Path: {{msg.outputPath}}

Example 6: Decompress with Error Handling​

Decompress with proper error handling in workflow:

// Set paths
msg.archiveFile = "/home/user/downloads/data.gz";
msg.extractPath = "/home/user/data/extracted/";

// Initialize error tracking
msg.decompressErrors = [];
msg.decompressSuccess = false;

Configure the Decompress node:

  • Source Path: {{msg.archiveFile}}
  • Target Path: {{msg.extractPath}}
  • Continue On Error: Enabled

Add a Function node after Decompress to check results:

// Check if decompression was successful
const fs = require('fs');

if (fs.existsSync(msg.extractPath)) {
    msg.decompressSuccess = true;
    msg.message = "Decompression completed successfully";
} else {
    msg.decompressSuccess = false;
    msg.message = "Decompression failed";
}

Usage Tips​

  1. Target Path Considerations:

    • For tar-wrapped files (created by Compress node), files are extracted to the target directory
    • For pure compressed single files, specify the complete output file path
    • Create the target directory beforehand if it doesn't exist

  2. Format Compatibility:

    • The node automatically handles files created by both Robomotion's Compress node and external tools
    • No need to specify the compression format - it's detected automatically

  3. Performance:

    • Decompression speed varies by format:
      • LZ4: Fastest decompression
      • Gzip/Zstandard: Fast decompression
      • Bzip2/XZ: Slower decompression
    • Large files may take significant time, especially with XZ compression

  4. Disk Space:

    • Ensure sufficient disk space for the decompressed content
    • Compressed files can expand significantly (5-10x or more)
    • Monitor available disk space before decompressing large files

  5. File Integrity:

    • Corrupted compressed files will cause decompression to fail
    • Always verify compressed files before decompressing if downloaded from external sources

Common Errors and Solutions​

Error: "Source path cannot be empty"​

Cause: The Source Path input is not provided or is empty.

Solution: Ensure you provide a valid path to the compressed file.

Error: "Source path does not exist"​

Cause: The specified compressed file does not exist at the given path.

Solution:

  • Verify the source path is correct
  • Check that the file exists and hasn't been moved or deleted
  • Ensure proper path formatting

Error: "Target path cannot be empty"​

Cause: The Target Path input is not provided or is empty.

Solution: Provide a valid destination path for the decompressed content.

Error: Invalid or corrupted archive​

Cause: The compressed file is corrupted or in an invalid format.

Solution:

  • Verify the file was downloaded or created completely
  • Check the file isn't corrupted (re-download if necessary)
  • Ensure the file extension matches the actual compression format
  • Try opening the file with a standard decompression tool to verify integrity

Error: Unsupported compression format​

Cause: The file format is not recognized or supported.

Solution:

  • Check that the file extension is one of the supported formats
  • Verify the file is actually compressed (not just renamed)
  • Use the appropriate node for the file type (e.g., Unarchive for multi-file archives)

Error: Permission denied​

Cause: Insufficient permissions to read the source file or write to the target location.

Solution:

  • Ensure read permissions for the compressed file
  • Verify write permissions for the target directory
  • Check file ownership and permissions

Error: Disk space insufficient​

Cause: Not enough disk space to extract the decompressed content.

Solution:

  • Free up disk space on the target drive
  • Choose a different target location with more available space
  • Check the expected decompressed size before proceeding

Error: Target file already exists​

Cause: A file already exists at the target path.

Solution:

  • Remove or rename the existing file
  • Choose a different target path
  • Implement file cleanup in your workflow before decompression
    • Compress files and folders
  • Unarchive - Extract all files from multi-file archives
  • Extract File - Extract a specific file from an archive
  • Archive - Create archives with multiple files