free_handle - Linux

Overview

free_handle is a command-line utility commonly used to help troubleshoot memory issues, identify memory leaks, and analyze memory allocation and deallocation patterns in Linux operating systems.

Syntax

free_handle [options]

Options/Flags

  • -e, –exec-suffix
    Determines a specific user in whose memory space the reports are generated for. The default suffix is "user" if there is no exec suffix, or a "process name" if a suffix is available.

  • -f, –file
    Reads data from a specified file location instead of the default /proc/self/fd directory.

  • -h, –help
    Displays help information about the command.

  • -m, –mode
    Sets the reporting mode. Available modes are:

    • c: Closure report
    • p: Processes report
    • u: User report

  • -s, –sort
    Defines the order of sorting for the output. Available options are:

    • bytes: Sorts by bytes
    • count: Sorts by count

Examples

Example 1: Displaying file descriptor information

$ free_handle

Output:

USER          SIZE      COUNT       OPENED
user           1.41 KiB      75           fd:3

Example 2: Generating a closure report

$ free_handle -m c

This command generates a report showing the memory allocated by the current process.

Example 3: Sorting output by count

$ free_handle -s count

This command displays files ordered by the number of file descriptors associated with them.

Common Issues

  • Permission denied error: Ensure you have sufficient permissions to access the /proc/self/fd directory or the specified file.

Integration

free_handle can be integrated into scripts or combined with other commands for advanced analysis. For instance, the output of free_handle can be piped into other commands like grep or sort to filter or organize the results further.

Related Commands

  • fuser
  • lsof
  • pmap
  • procstat