Path: csiph.com!xmission!news.snarked.org!news.linkpendium.com!news.linkpendium.com!panix!usenet.stanford.edu!not-for-mail From: Eli Schwartz Newsgroups: gnu.bash.bug Subject: =?UTF-8?B?UmU6IOKAmGNvbW1hbmQg4oCmICbigJkgY3JlYXRlcyBzdWJzaGVsbA==?= Date: Tue, 30 Jun 2020 17:29:04 -0400 Lines: 116 Approved: bug-bash@gnu.org Message-ID: References: <7dvoi92p.dag@gnui.org> <09ea84b2-4fb1-6b05-7c0b-fe6b2ab00c6f@archlinux.org> NNTP-Posting-Host: lists.gnu.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="23p2O7VoEnMBKOEvvC1FHeiN5RHRmId8O" X-Trace: usenet.stanford.edu 1593552564 29043 209.51.188.17 (30 Jun 2020 21:29:24 GMT) X-Complaints-To: action@cs.stanford.edu To: bug-bash@gnu.org Envelope-to: bug-bash@gnu.org X-Spam-BL-Results: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=archlinux.org; s=orion; t=1593552549; bh=OVf75lgtq1rCwYQ+SjOItksw3ah9xhX6fXC9rxH6HJQ=; h=Subject:To:References:From:Date:In-Reply-To; b=odi2BWW+wuk6NxqhdFqTkmksvaI62cVtmE2+nK2jPnWomKHy+TBpVjb+RU/mw8sv5 OmVNBeiHG+UQpeqVRmWSwfXNMztVSBKGDiDn/QK7aLm3X7mGbc4NWKjCXxGVuKw4fX B9YqQBJmVThiuTOHzg0TlT11ReyD0zVgSFBSt6PnayQErmj4R68z7AO3+IDhV3n3LK iHmON2LvcHwpvAQkW2A6b2+g9WyKOK9IffJXk7RgQz+PrakNkGASESJ80ojxBl1enQ PpUqWTGCAbEmvtJd0DngvRFTIo5HEqcQO4uh4lslCrMF/hB8Tv3LRTF19JDxQ8OoBD 8dFge33d1RgPXO9We8au1oUWhN7gsKIGgaQgnoJglNNmE1IN38TQ8fC6y0b+rJOwqs OUyP+Y53PhCrdOROBVThjNuTHC5UzlS5Kx8Q8XDXzWJC5/BZPBL9gAHBhN8P/NwEA1 5/Z6U7xjoGxNkHodTo3LHxvG/JMFHMFAq7Z0dT7ADpEbIBC5WjXKqBPzNJAe8Cnhes VLqWcp2u5Kv0oHZfASD4Gii3JLAZ8nYnG806StcA068DETvx7QU47KqOBOqb6HUwAO RQVWwDiqXn6XzshCy5FN0UVimFFnUFX8Csk7yCxtdslFXX++nImeJENlrnyK+qbyLV 8wqGOhkGU/bCBtV+hwYvk6D4= X-Clacks-Overhead: GNU Terry Pratchett User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 In-Reply-To: <7dvoi92p.dag@gnui.org> Received-SPF: pass client-ip=88.198.91.70; envelope-from=eschwartz@archlinux.org; helo=orion.archlinux.org X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/30 17:29:15 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -53 X-Spam_score: -5.4 X-Spam_bar: ----- X-Spam_report: (-5.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: bug-bash@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports for the GNU Bourne Again SHell List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Mailman-Original-Message-ID: <09ea84b2-4fb1-6b05-7c0b-fe6b2ab00c6f@archlinux.org> X-Mailman-Original-References: <7dvoi92p.dag@gnui.org> Xref: csiph.com gnu.bash.bug:16503 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --23p2O7VoEnMBKOEvvC1FHeiN5RHRmId8O Content-Type: multipart/mixed; boundary="ZeXSzd7PohwcDSMxeFtfJM8DUXxoJuapA" --ZeXSzd7PohwcDSMxeFtfJM8DUXxoJuapA Content-Type: text/plain; charset=utf-8 Content-Language: en-US-large Content-Transfer-Encoding: quoted-printable On 6/30/20 4:37 PM, Dmitry Alexandrov wrote: > Chet Ramey wrote: >> On 6/29/20 4:33 PM, Dmitry Alexandrov wrote: >>> 1) unexpected, as (a) it does not seem to be documented, (b) it=CA=BC= s counter-intuitive and (c) other bourne-like shells (busybox ash, dash, = ksh93, mksh, zsh) does not do that; >> >> It's an opportunity for optimization, not a bug >=20 > I am not saying that this is a bug, only that it is inconsistent with a= lmost any other bourne-like shell. And I understood Chet's point to be that you shouldn't have "expected" something which isn't guaranteed. Just because it works out that way, doesn't mean it has to; it's not like other shells document this behavior= =2E Relying on undocumented behavior isn't the greatest. :p >>> 2) inconvenient, as in some cases PID of the parent shell is not an a= ppropriate substitute for the PID of the real process. >=20 >> since the results are correct. >=20 > The results are _different_ across shell and, unfortunately, results pr= ovided by Bash are the least useful. Consider: >=20 > $ command =E2=80=A6 & > [1] 30737 > $ strace -p $! > strace: Process 30737 attached > wait4(-1, >=20 > :-/ Useful replacements: You could decline to use "command", and it doesn't involve a shell proces= s. $ cat & [1] 2092238 $ ps --pid $! --ppid $! PID TTY TIME CMD 2092238 pts/42 00:00:00 cat [1]+ Stopped cat If you need to ensure a disk executable is used, $ "$(type -P cat)" & [1] 2092352 $ ps --pid $! --ppid $! PID TTY TIME CMD 2092352 pts/42 00:00:00 cat [1]+ Stopped "$(type -P cat)" Anyway, Chet didn't say it won't be changed to do what you expected; after all, it's acknowledged as an opportunity for optimization, and optimization is good.. --=20 Eli Schwartz Arch Linux Bug Wrangler and Trusted User --ZeXSzd7PohwcDSMxeFtfJM8DUXxoJuapA-- --23p2O7VoEnMBKOEvvC1FHeiN5RHRmId8O Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEvSewel70XCra9w4EhIGKaBmvSpsFAl77rqAACgkQhIGKaBmv SpsARg/+MhNQa7HtLmKN6pydnsleTywHvQ1tqqtEB7SRlodAvvVwhwEM+NK8oMyC tLtcKSLSH8F79QFjh17eHuLwm90NyGYcuJ/02gjOgxa09UVUPhqTNTMMTV3jIMd4 lpMyEd8P9S6XDdnhJLSbIUGM5kpJ8fFoHKOMlCWlo8fEKzmHdfPXI3Xy5nlDDKsp 49RcpKNkctCgBWYgunV0/8RWvVM1nd+jCO9b/f95FQLHVUibrrP332A/pj+aBvea 0juPOpGwFv1tCrzhOaCpfQSuGBcTraoqMH/MoKeANMQxUw0IUcp65kRHuTnw8gyc /otV0NzM0VPmrI/2vwb6VyCnxryXQiyOaR8zOF0hXjQupfxICr37k1+18KnHEhBX 0cHg/m01LBxxeetCzYkneuI6rBJDS3o5A+S109MTr7SxBY2w2HPytLCfOxagZ4t2 Kkd5m6iONHTcaQQRLzDemJNrSR5hi4ob5DNYPMemMwicVyNpja21KH9m6cdUPgZ0 iiyeSl0ZO1jvVSIJ1FET+vMA2fsfL5oC7gUlg0UCjRSPqESNi3TfMoMXICk4beiS wkK6AtCtBWPe+2fixTg1hcyxxV02zIkkEgxKP8qCENG8YDbX0fVj2kQ2QB927tEO 2NTOsU4QFHsQ5N5ZOhaehcxFacIzSuUUOWFMutbOlTgsdxi5aliJAjMEAQEKAB0W IQRgQRMEwJ02YoNA7v/OsWfvtXIr1gUCXvuuoAAKCRDOsWfvtXIr1tpkEACFITem 1W14vhLWYYbBH9M/IlCsEJdXresn5VoI75jG80az59hzwyc+Lhgqt7+1vJxUoawg A0AjvI7HoJjoj0bGF7wkH7AIQWhiSu573i/ORuYovOBPv/fEwVeDBHE3hGnSALWg 27b9EoyUFAYakGBbNfZ63LQZw81cfYg77kop2KzEQPsaWF742AzZrwI9l52oXtcF L4tiEYSfkEJSBakYR/brCExGewJCa5m5iHzvuCuMr+fnIdxUThuNQkTdi522FS5P IzIvtHH/cWg1FLtzkG98ozxRRUSn7DRWRBjMnEkKi4tsHUE2bpSR3tJbrgszsI2R znCEddPTvl7lCP3hczj/2KT0kJ3Dzn3bgPdbc1NFZO8aeNEO2jLtmoyH9BuI6KRD u/sNc15cH7Rxljt7lLTrc+5vLOV5Yk7Wime+LAgX1dO1GohTI9yMk1sM0c0JGX9V 5TwaBFmNirV46DnTL1TkPhI8Yw8MvinIwx7YrAwePKWWRYVTLx0d769Yc5yl2R8w mguGIDA65zjRyJxbtd5FPKK+xXvlETKu22D3bGpWg64jsYQ0cgHZAYMgy1/HFrAE Gn6+LPimF6e0ubBP/cZcQ+T27FQno352PvFSAIzOu1bpyLzEvYnXdqf5ZcJIu6aM 8bnuwd2/pZoY43bDqYHtprOd06MD+U7rPEs9MQ== =Wh2c -----END PGP SIGNATURE----- --23p2O7VoEnMBKOEvvC1FHeiN5RHRmId8O--