using cat and <<
in [Shell]
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From: Chris F.A. Johnson on 11 Jun 2010 20:56 On 2010-06-12, Seebs wrote: > On 2010-06-11, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote: >> On 2010-06-11, Thomas 'PointedEars' Lahn wrote: >>> The problem appears to be that you don't know about `--'. > >> Nor does echo. > > In his defense, I suspect that at least one person has created at least > one version of "echo" which did. Trying to predict the possible ways > in which someone somewhere has broken echo is hopeless. > > I am reasonably sure there has been at least one version of false which > could be persuaded to print a version message and exit successfully, > just because people really are that stupid. I'm quite sure that I've > seen an implementation where "true --version" produced output on > stdout or stderr... I believe it's since been fixed. $ /bin/true --version true (GNU coreutils) 7.1 Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. -- Chris F.A. Johnson, author <http://shell.cfajohnson.com/> =================================================================== Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress) Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)
From: Tim Harig on 11 Jun 2010 21:11 On 2010-06-12, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote: > On 2010-06-12, Seebs wrote: >> On 2010-06-11, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote: >>> On 2010-06-11, Thomas 'PointedEars' Lahn wrote: >>>> The problem appears to be that you don't know about `--'. >> >>> Nor does echo. >> >> In his defense, I suspect that at least one person has created at least >> one version of "echo" which did. Trying to predict the possible ways >> in which someone somewhere has broken echo is hopeless. >> >> I am reasonably sure there has been at least one version of false which >> could be persuaded to print a version message and exit successfully, >> just because people really are that stupid. I'm quite sure that I've >> seen an implementation where "true --version" produced output on >> stdout or stderr... I believe it's since been fixed. > > $ /bin/true --version > true (GNU coreutils) 7.1 > Copyright (C) 2009 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. You coreutils is a year old: 20:03,501$ /bin/true --version true (GNU coreutils) 8.5 Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by Jim Meyering.
From: Seebs on 11 Jun 2010 23:03 On 2010-06-12, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote: > $ /bin/true --version > true (GNU coreutils) 7.1 > Copyright (C) 2009 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Ahh, but does "/bin/false --version" exit successfully, because it successfully printed the version? :) -s -- Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nospam(a)seebs.net http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated!
From: Tim Harig on 11 Jun 2010 23:28 On 2010-06-12, Seebs <usenet-nospam(a)seebs.net> wrote: > On 2010-06-12, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote: >> $ /bin/true --version >> true (GNU coreutils) 7.1 >> Copyright (C) 2009 Free Software Foundation, Inc. >> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. >> This is free software: you are free to change and redistribute it. >> There is NO WARRANTY, to the extent permitted by law. > > Ahh, but does "/bin/false --version" exit successfully, because it > successfully printed the version? :) 22:25,501$ /bin/false --version false (GNU coreutils) 8.5 Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by Jim Meyering. 22:25,502,(1)$ Nope, returns 1.
From: News123 on 12 Jun 2010 11:34
Seebs wrote: > On 2010-06-12, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote: >> $ /bin/true --version >> true (GNU coreutils) 7.1 >> Copyright (C) 2009 Free Software Foundation, Inc. >> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. >> This is free software: you are free to change and redistribute it. >> There is NO WARRANTY, to the extent permitted by law. > > Ahh, but does "/bin/false --version" exit successfully, because it > successfully printed the version? :) > > -s Why would you care???? i don't use --version in my scripts and when I type false --version, then I don't care for it's exit status. You can always construct failing scenario, but I cannot imagine whenever an exit code of 0 would have killed me or my scripts. |