Articles/Linux

SIGHUP Signal Explained (Signal 1)

What the Linux SIGHUP signal does and when it's used.

Published October 23, 2026

SIGHUP (signal number 1) originally signaled that a terminal was disconnected ("hung up"); now commonly used to tell a daemon to reload its configuration.

Key points

  • Many long-running services (like Nginx) treat SIGHUP as a "reload config without restarting" signal
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