Package: tcpdump Version: 4.99.0-2+deb11u1 Severity: minor Tags: upstream X-Debbugs-Cc: debbug.tcpd...@sideload.33mail.com
Normally by convention useful environmental variables are documented in an ENVIRONMENT section of the man page. There is no coverage of any env vars in the man page. I was trying to work out how to make timestamps print in terms of the UTC timezone. It’s undocumented. As a guess, I tried: $ env TZ=UTC tcpdump -r session.pcap It worked as expected. Is that because tcpdump reads the TZ variable? Or does tcpdump make a system call to obtain the time and the system uses the TZ variable? If it’s the former, then TZ should be documented in the man page. If it’s the latter, then it’s unclear to me how to document that but nonetheless users should be informed somehow. Along these lines, it’s worth noting that the man page says this: “A packet trace that crosses a daylight savings time change will give skewed time stamps (the time change is ignored).” Perhaps a TZ that’s shifted by 12 hours or set to a timezone that does not honor daylight savings will work around that problem? If so, the man page could suggest that. -- System Information: Debian Release: 11.5 APT prefers oldstable-updates APT policy: (990, 'oldstable-updates'), (990, 'oldstable-security'), (990, 'testing'), (990, 'oldstable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 5.10.0-19-amd64 (SMP w/2 CPU threads) Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages tcpdump depends on: ii adduser 3.118 ii libc6 2.31-13+deb11u5 ii libpcap0.8 1.10.0-2 ii libssl1.1 1.1.1n-0+deb11u3 tcpdump recommends no packages. Versions of packages tcpdump suggests: ii apparmor 2.13.6-10 -- no debconf information
