listres

listres [options] pid | core-file

-a
    Display all resources, including those considered less important.

-d
    Display a detailed listing of each resource.

-f
    Dump resources related to open files.

-l
    Dump shared libraries used by the process.

-s
    Dump signal handling information.

pid
    The process ID of the running process to inspect.

core-file
    The path to a core dump file to analyze.

The listres command is a utility used to display a list of resources currently used by a specified process or a core file. This can include information like files opened, shared libraries mapped into memory, signal handlers, and other resources utilized by the process. listres proves particularly useful for debugging, troubleshooting, and understanding the runtime behavior of programs. By inspecting the resources a process is holding, developers can identify issues such as file descriptor leaks, library dependencies, or unexpected signal handling configurations. It can be used with a running process using its PID or examine resources in a core dump for post-mortem debugging.
The output provides a detailed snapshot of the process's resource landscape, enabling a comprehensive analysis of its operational characteristics. Note that to inspect another process you will need the appropriate privileges.

Root privileges or membership in appropriate groups may be required to inspect the resources of processes owned by other users. The information provided depends on the system and glibc version, and its accuracy and completeness cannot be guaranteed.

The output of listres can vary based on the options used and the target process or core file. It generally lists resource types with corresponding details.
For example, when listing files with -f, each open file's descriptor number, file path, and access mode (read, write, etc.) are shown. Shared libraries listed with -l show the library name and its memory mapping addresses. Understanding these details helps in diagnosing issues like file leaks or incorrect library loading.

Due to the sensitive nature of process resource information, access to listres and its output should be carefully controlled. Unauthorized access could reveal confidential data or expose system vulnerabilities. Always exercise caution when inspecting processes owned by other users or running with elevated privileges. Limit access with appropriate permissions if possible.
Be aware that the output may contain sensitive data like file paths or parts of memory mappings.

The listres command is a part of the glibc (GNU C Library) development tools. It has been available for many years. It is designed to provide insights into the resources used by a process at a specific point in time, or recorded in a core dump after a program crash. It became popular as a lightweight alternative for resource inspection compared to more heavyweight tools.

lsof(8), strace(1), pmap(1)