getdtablesize - Linux

Overview

getdtablesize retrieves the maximum number of file descriptors that a process can open simultaneously. It is commonly used to determine system resource limits and monitor system performance.

Syntax

getdtablesize [-a]

Options/Flags

| Flag | Description | Default |
|—|—|—|
| -a | Display system-wide limit, not per-process limit | false |

Examples

Example 1: Get per-process file descriptor limit:

getdtablesize

Example 2: Get system-wide file descriptor limit:

getdtablesize -a

Common Issues

• Negative value: If the command returns a negative value, it indicates an error occurred. Check the system logs for details.
• Unexpected value: If the returned value seems unreasonably low, it may indicate a resource exhaustion situation. Investigate system resource usage to identify the cause.

Integration

• Use with ulimit to modify or view user-specific file descriptor limits.
• Combine with sysctl to configure system-wide file descriptor limits.

Related Commands

• ulimit
• sysctl