From fb5c1fbf6a2639d8fbe7428240429674f7db6bbf Mon Sep 17 00:00:00 2001
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 =?UTF-8?q?=D0=B8=D0=BD?= <i@atroshin.ru>
Date: Tue, 11 Aug 2026 00:37:41 +0300
Subject: [PATCH] =?UTF-8?q?Ignore=20SIGHUP=20=E2=80=94=20survive=20termina?=
 =?UTF-8?q?l=20closure=20in=20background?=
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__main__.py: add signal.SIGHUP → SIG_IGN before setting up
SIGINT/SIGTERM handlers. Sniffer no longer dies when the terminal
closes or the shell session ends.

README: add Background / Daemon section with nohup examples.
---
 README.md                     | 11 +++++++++++
 simtrace2_pysniff/__main__.py |  1 +
 2 files changed, 12 insertions(+)

diff --git a/README.md b/README.md
index 15c08f4..f437635 100644
--- a/README.md
+++ b/README.md
@@ -129,6 +129,17 @@ Non-TPDU messages (ATR, PPS, card state changes, Fi/Di) print identically in all
 - **GSMTAP**: ATR (subtype 1) and TPDU (subtype 2) over UDP to Wireshark
 - **PCAP**: all messages as GSMTAP-encapsulated packets (LINKTYPE 155), openable in Wireshark
 
+## Background / Daemon
+
+SIGHUP is ignored by default — terminal closure won't kill the sniffer.
+To run persistently in the background with output to files:
+
+```sh
+nohup ./sniff-start.sh --output /tmp/sniff.log &> /tmp/sniff-err.log &
+# or
+FORMAT=timestamp nohup python -m simtrace2_pysniff --output /tmp/sniff.log &> /tmp/sniff-err.log &
+```
+
 ## Library Usage
 
 ```python
diff --git a/simtrace2_pysniff/__main__.py b/simtrace2_pysniff/__main__.py
index 5235774..4b49d82 100644
--- a/simtrace2_pysniff/__main__.py
+++ b/simtrace2_pysniff/__main__.py
@@ -131,6 +131,7 @@ def main():
             file_dumper.close()
         sys.exit(0)
 
+    signal.signal(signal.SIGHUP, signal.SIG_IGN)
     signal.signal(signal.SIGINT, on_signal)
     signal.signal(signal.SIGTERM, on_signal)