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Extract File

Extracts a specific file from an archive to the target path without extracting the entire archive.

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 archive file containing the file to extract. Supports Zip, Tar, TarGz, and other archive formats.

  • File - Name of the file to extract from the archive, including its extension. This should be the exact filename as it appears in the archive (case-sensitive on some systems).

  • Target Path - Destination path where the extracted file will be saved. This should be the complete path including the filename.

How It Works​

The Extract File node performs selective extraction:

  1. Opens the archive file specified in Source Path
  2. Searches for the exact filename specified in the File input
  3. Extracts only that specific file
  4. Saves it to the Target Path location
  5. Leaves the archive file unchanged

This is much more efficient than extracting the entire archive when you only need one or a few specific files.

Examples​

Example 1: Extract a Configuration File from Zip​

Extract a specific configuration file from a Zip archive:

// Define paths
msg.archiveFile = "/home/user/backups/project-backup.zip";
msg.configFile = "config/settings.json";
msg.outputPath = "/home/user/restore/settings.json";

Configure the Extract File node:

  • Source Path: {{msg.archiveFile}}
  • File: {{msg.configFile}}
  • Target Path: {{msg.outputPath}}

Example 2: Extract from TarGz Archive​

Extract a specific document from a compressed tar archive:

// Extract a document from tar.gz
msg.backupArchive = "/home/user/backups/documents.tar.gz";
msg.fileName = "reports/monthly-report.pdf";
msg.extractedFile = "/home/user/reports/current-report.pdf";

Configure the Extract File node:

  • Source Path: {{msg.backupArchive}}
  • File: {{msg.fileName}}
  • Target Path: {{msg.extractedFile}}

Example 3: Extract Log File from Archive​

Extract a specific log file for analysis:

// Extract a specific log file
msg.logArchive = "/home/user/archives/logs-2024-01.zip";
msg.logFileName = "application.log";
msg.extractPath = "/home/user/analysis/application.log";

Configure the Extract File node:

  • Source Path: {{msg.logArchive}}
  • File: {{msg.logFileName}}
  • Target Path: {{msg.extractPath}}

Example 4: Extract with Dynamic Filename​

Extract files based on date or pattern:

// Get today's date for filename
const today = new Date();
const dateStr = today.toISOString().split('T')[0]; // YYYY-MM-DD

msg.archivePath = "/home/user/backups/daily-reports.zip";
msg.targetFile = `report-${dateStr}.xlsx`;
msg.outputPath = `/home/user/reports/today-report.xlsx`;

Configure the Extract File node:

  • Source Path: {{msg.archivePath}}
  • File: {{msg.targetFile}}
  • Target Path: {{msg.outputPath}}

Example 5: Extract Multiple Specific Files​

Extract several specific files from the same archive:

// Define archive and files to extract
msg.archive = "/home/user/backups/project.zip";
msg.filesToExtract = [
    { file: "src/config.js", output: "/home/user/project/config.js" },
    { file: "src/database.js", output: "/home/user/project/database.js" },
    { file: "package.json", output: "/home/user/project/package.json" }
];

// Start with first file
msg.currentIndex = 0;
msg.currentFile = msg.filesToExtract[msg.currentIndex];

Configure the Extract File node:

  • Source Path: {{msg.archive}}
  • File: {{msg.currentFile.file}}
  • Target Path: {{msg.currentFile.output}}

Use a Loop to iterate through all files in the array.

Example 6: Extract File from Nested Path​

Extract a file from a nested directory structure within the archive:

// Extract from nested path
msg.archiveFile = "/home/user/releases/app-v2.0.zip";
msg.nestedFile = "app/resources/images/logo.png";
msg.outputFile = "/home/user/assets/logo.png";

Configure the Extract File node:

  • Source Path: {{msg.archiveFile}}
  • File: {{msg.nestedFile}}
  • Target Path: {{msg.outputFile}}

Example 7: Extract with Validation​

Extract a file and validate it exists before using:

// Set extraction parameters
msg.archivePath = "/home/user/data/archive.zip";
msg.dataFile = "data/export.csv";
msg.extractedPath = "/home/user/processing/export.csv";

Configure the Extract File node:

  • Source Path: {{msg.archivePath}}
  • File: {{msg.dataFile}}
  • Target Path: {{msg.extractedPath}}

Add a Function node after extraction:

const fs = require('fs');

// Verify file was extracted
if (fs.existsSync(msg.extractedPath)) {
    const stats = fs.statSync(msg.extractedPath);
    msg.extractSuccess = true;
    msg.extractedSize = stats.size;
    msg.message = `Successfully extracted ${msg.dataFile} (${stats.size} bytes)`;
} else {
    msg.extractSuccess = false;
    msg.message = `Failed to extract ${msg.dataFile}`;
}

Usage Tips​

  1. File Path Format:

    • Use the exact path as it appears in the archive
    • Include directory separators (/) for files in subdirectories
    • Path is case-sensitive on Unix/Linux systems
    • Use forward slashes (/) even on Windows

  2. Finding File Names:

    • Use the Inspect Archive File node first to see all available files
    • This ensures you use the correct filename and path

  3. Target Path:

    • Specify the complete path including the filename
    • The directory must exist or be created beforehand
    • You can rename the file during extraction by using a different filename in the target path

  4. Performance Benefits:

    • Much faster than extracting the entire archive
    • Saves disk space by only extracting needed files
    • Useful for large archives when you only need specific files

  5. Multiple Extractions:

    • You can extract multiple files from the same archive
    • Each extraction requires a separate node or loop iteration
    • The archive remains intact and can be read multiple times

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 archive file.

Error: "Source path does not exist"​

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

Solution:

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

Error: "File name cannot be empty"​

Cause: The File input is not provided or is empty.

Solution: Provide the name of the file to extract from the archive.

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 extracted file.

Error: File not found in archive​

Cause: The specified file does not exist in the archive.

Solution:

  • Use the Inspect Archive File node to list all files in the archive
  • Verify the filename is correct (including case sensitivity)
  • Check if the file includes a directory path (e.g., "folder/file.txt")
  • Ensure there are no extra spaces or special characters in the filename

Error: Permission denied​

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

Solution:

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

Error: Target directory does not exist​

Cause: The directory portion of the target path doesn't exist.

Solution:

  • Create the target directory before extraction
  • Use a File System node to create the directory structure
  • Or ensure the parent directories exist

Error: Corrupted archive​

Cause: The archive file is corrupted or invalid.

Solution:

  • Verify the archive file is valid by opening it with a standard tool
  • Re-download or re-create the archive if it's corrupted
  • Check if the archive was completely downloaded