From owner-svn-src-all@freebsd.org Sun Aug 30 17:37:56 2020 Return-Path: Delivered-To: svn-src-all@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 C10443C25F5; Sun, 30 Aug 2020 17:37:56 +0000 (UTC) (envelope-from fernape@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BfgXN4jQ8z4FW3; Sun, 30 Aug 2020 17:37:56 +0000 (UTC) (envelope-from fernape@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 85DC51A3E9; Sun, 30 Aug 2020 17:37:56 +0000 (UTC) (envelope-from fernape@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 07UHbuw9093295; Sun, 30 Aug 2020 17:37:56 GMT (envelope-from fernape@FreeBSD.org) Received: (from fernape@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 07UHbu8A093294; Sun, 30 Aug 2020 17:37:56 GMT (envelope-from fernape@FreeBSD.org) Message-Id: <202008301737.07UHbu8A093294@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: fernape set sender to fernape@FreeBSD.org using -f From: =?UTF-8?Q?Fernando_Apestegu=c3=ada?= Date: Sun, 30 Aug 2020 17:37:56 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r364976 - head/usr.bin/tsort X-SVN-Group: head X-SVN-Commit-Author: fernape X-SVN-Commit-Paths: head/usr.bin/tsort X-SVN-Commit-Revision: 364976 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Aug 2020 17:37:56 -0000 Author: fernape (ports committer) Date: Sun Aug 30 17:37:56 2020 New Revision: 364976 URL: https://svnweb.freebsd.org/changeset/base/364976 Log: tsort(1): Add EXAMPLES section Add a couple of simple examples to the man page Approved by: manpages (gbe@) Differential Revision: https://reviews.freebsd.org/D25883 Modified: head/usr.bin/tsort/tsort.1 Modified: head/usr.bin/tsort/tsort.1 ============================================================================== --- head/usr.bin/tsort/tsort.1 Sun Aug 30 17:13:04 2020 (r364975) +++ head/usr.bin/tsort/tsort.1 Sun Aug 30 17:37:56 2020 (r364976) @@ -31,7 +31,7 @@ .\" @(#)tsort.1 8.3 (Berkeley) 4/1/94 .\" $FreeBSD$ .\" -.Dd December 27, 2006 +.Dd August 30, 2020 .Dt TSORT 1 .Os .Sh NAME @@ -75,6 +75,71 @@ This is primarily intended for building libraries, where optimal ordering is not critical, and cycles occur often. .El +.Sh EXAMPLES +Assuming a file named +.Pa dag +with the following contents representing a directed acyclic graph: +.Bd -literal -offset indent +A B +A F +B C +B D +D E +.Ed +.Pp +Sort the nodes of the graph: +.Bd -literal -offset indent +$ tsort dag +A +F +B +D +C +E +.Ed +.Pp +White spaces and new line characters are considered equal. +This file for example is considered equal to the one we defined before: +.Bd -literal -offset indent +$ cat dga +A B A F B C B D D E +.Ed +.Pp +Assume we add a new directed arc from D to A creating a cycle: +.Bd -literal -offset indent +A B +A F +B C +B D +D E +D A +.Ed +.Pp +Ordering the graph detects the cycle: +.Bd -literal -offset indent +$ tsort dag +tsort: cycle in data +tsort: A +tsort: B +tsort: D +D +E +A +F +B +C +.Ed +.Pp +Same as above but silencing the warning about the cycle: +.Bd -literal -offset indent +$ tsort -q dag +D +E +A +F +B +C +.Ed .Sh SEE ALSO .Xr ar 1 .Sh HISTORY