fstat64 - Linux

Overview

fstat64 retrieves information about the open file descriptor provided. This command is commonly used to obtain metadata about files, directories, and other file system objects.

Syntax

fstat64 <file descriptor>

Options/Flags

None

Examples

Retrieve file metadata:

fstat64 3

Obtain file size:

fstat64 /proc/self/fd/1 | awk '{print $7}'

Check file type (regular file, directory, etc.):

fstat64 3 | grep "File type:"

Common Issues

• Invalid file descriptor: Ensure the provided file descriptor is valid and refers to an open file.
• Permission errors: The user may not have sufficient permissions to access the file.
• Stale file descriptor: If the file has been closed or moved since the file descriptor was obtained, the command may return an error.

Integration

Combine with other commands:

• lsof: Identify the process associated with a file descriptor.
• du: Calculate disk usage based on file size information obtained from fstat64.

Related Commands

• stat: Similar to fstat64, but operates on file paths.
• ls: List file metadata, including file descriptor numbers.