From owner-freebsd-questions@freebsd.org Mon Feb 24 01:25:09 2020 Return-Path: Delivered-To: freebsd-questions@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 20A2E24EBDE for ; Mon, 24 Feb 2020 01:25:09 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from kicp.uchicago.edu (kicp.uchicago.edu [128.135.20.70]) by mx1.freebsd.org (Postfix) with ESMTP id 48Qkrg6qxxz4Qpf for ; Mon, 24 Feb 2020 01:25:07 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from [IPv6:2607:fb90:a23c:e2b:6c2d:78df:5510:1acd] (unknown [172.58.139.27]) (Authenticated sender: galtsev) by kicp.uchicago.edu (Postfix) with ESMTPSA id 340574E674; Sun, 23 Feb 2020 19:25:07 -0600 (CST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3608.60.0.2.5\)) Subject: Re: rm | Cleaning up recycle bin From: Valeri Galtsev In-Reply-To: <20200224020823.2462aad4.freebsd@edvax.de> Date: Sun, 23 Feb 2020 19:25:05 -0600 Cc: Steve O'Hara-Smith , freebsd-questions@freebsd.org Content-Transfer-Encoding: quoted-printable Message-Id: <9FAFBB4E-04E8-4965-A8F9-3F32086F293E@kicp.uchicago.edu> References: <20200223184908.b35d656a.freebsd@edvax.de> <20200223182411.81a22ce74509b8778a39d8d3@sohara.org> <20200224020823.2462aad4.freebsd@edvax.de> To: Polytropon X-Mailer: Apple Mail (2.3608.60.0.2.5) X-Rspamd-Queue-Id: 48Qkrg6qxxz4Qpf X-Spamd-Bar: +++++++ Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=uchicago.edu (policy=none); spf=none (mx1.freebsd.org: domain of galtsev@kicp.uchicago.edu has no SPF policy when checking 128.135.20.70) smtp.mailfrom=galtsev@kicp.uchicago.edu X-Spamd-Result: default: False [7.71 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; DMARC_POLICY_SOFTFAIL(0.10)[uchicago.edu : No valid SPF, No valid DKIM,none]; RECEIVED_SPAMHAUS_PBL(0.00)[27.139.58.172.khpj7ygk5idzvmvt5x4ziurxhy.zen.dq.spamhaus.net : 127.0.0.10]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; MIME_GOOD(-0.10)[text/plain]; IP_SCORE(0.12)[ip: (0.33), ipnet: 128.135.0.0/16(0.16), asn: 160(0.13), country: US(-0.05)]; RECEIVED_SPAMHAUS_XBL(5.00)[27.139.58.172.khpj7ygk5idzvmvt5x4ziurxhy.zen.dq.spamhaus.net : 127.0.0.4]; NEURAL_SPAM_MEDIUM(1.00)[0.999,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_SPAM_LONG(1.00)[1.000,0]; RCVD_IN_DNSWL_NONE(0.00)[70.20.135.128.list.dnswl.org : 127.0.10.0]; R_SPF_NA(0.00)[]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:160, ipnet:128.135.0.0/16, country:US]; MID_RHS_MATCH_FROM(0.00)[]; GREYLIST(0.00)[pass,meta]; RCVD_COUNT_TWO(0.00)[2] X-Spam: Yes X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Feb 2020 01:25:09 -0000 > On Feb 23, 2020, at 7:08 PM, Polytropon wrote: >=20 > On Sun, 23 Feb 2020 18:24:11 +0000, Steve O'Hara-Smith wrote: >> Multiple entries for the same file are quite common for = binaries, >> for example /bin/csh and /bin/tcsh are links to the same file, or for = that >> matter nearly everything in /rescue is a link to the same file. When = there >> are multiple links to a file none of them are special, they're all = just >> links. >=20 > Technically, they serve a very specific purpose: When a program > is invoked, it can query argv[0] for the name it was called with. > In case of "csh" vs. "tcsh", this can affect the shell's behaviour. > It's even more obvious for all the programs in /rescue, where > for example "cp" and "ps" point to the same binary, but make that > binary do totally different things when invoked. >=20 > While a symbolic link (symlink) is, as their name suggests, > just a symbolic name for a different file or directory, a > hardlink is actually just an additional name for a file, > and there is no precedence in hard links (like with symlinks, > "_this_ is a reference, but _that_ is the original); they're > all originals. That's why a hardlink can never cross the > border of a filesystem, while a symlink can. >=20 >=20 >=20 > On Sun, 23 Feb 2020 18:58:18 -0600, Valeri Galtsev wrote: >> Thank you, Steve! Very educational. We (I at least) sometimes >> forget fundamentals. >=20 > That's why my little addition for educational completeness. ;-) >=20 Thank you, Polytropon! I can say pretty much about everything you post = on the list: very educational, and detailed! Valeri >=20 >=20 > --=20 > Polytropon > Magdeburg, Germany > Happy FreeBSD user since 4.0 > Andra moi ennepe, Mousa, ... > _______________________________________________ > freebsd-questions@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to = "freebsd-questions-unsubscribe@freebsd.org" ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++