Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > gnu.bash.bug > #14660

Re: bash sockets: printf \x0a does TCP fragmentation

Path csiph.com!xmission!news.snarked.org!news.linkpendium.com!news.linkpendium.com!panix!usenet.stanford.edu!not-for-mail
From Chet Ramey <chet.ramey@case.edu>
Newsgroups gnu.bash.bug
Subject Re: bash sockets: printf \x0a does TCP fragmentation
Date Tue, 25 Sep 2018 09:46:55 -0400
Lines 21
Approved bug-bash@gnu.org
Message-ID <mailman.1296.1537883232.1284.bug-bash@gnu.org> (permalink)
References <c6de6616-dda0-570d-de56-419e7676be8a@cbii-hh.de> <20180921231101307758654@bob.proulx.com> <714e1ba0-0052-2f2b-676d-778f2b7129c1@testssl.sh> <20180922111950901701520@bob.proulx.com> <948d4864-8808-9ce4-cc1e-2cce68256897@case.edu> <bd1b9a9c-a515-3900-a7b3-17548694d4df@testssl.sh>
Reply-To chet.ramey@case.edu
NNTP-Posting-Host lists.gnu.org
Mime-Version 1.0
Content-Type text/plain; charset=utf-8
Content-Transfer-Encoding 7bit
X-Trace usenet.stanford.edu 1537883233 6389 208.118.235.17 (25 Sep 2018 13:47:13 GMT)
X-Complaints-To action@cs.stanford.edu
Cc chet.ramey@case.edu, bug-bash@gnu.org
To dirk+bash@testssl.sh
Envelope-to bug-bash@gnu.org
Openpgp preference=signencrypt
Autocrypt addr=chet.ramey@case.edu; prefer-encrypt=mutual; keydata= xsDiBEEOsGwRBACFa0A1oa71HSZLWxAx0svXzhOZNQZOzqHmSuGOG92jIpQpr8DpvgRh40Yp AwdcXb8QG1J5yGAKeevNE1zCFaA725vGSdHUyypHouV0xoWwukYO6qlyyX+2BZU+okBUqoWQ koWxiYaCSfzB2Ln7pmdys1fJhcgBKf3VjWCjd2XJTwCgoFJOwyBFJdugjfwjSoRSwDOIMf0D /iQKqlWhIO1LGpMrGX0il0/x4zj0NAcSwAk7LaPZbN4UPjn5pqGEHBlf1+xDDQCkAoZ/VqES GZragl4VqJfxBr29Ag0UDvNbUbXoxQsARdero1M8GiAIRc50hj7HXFoERwenbNDJL86GPLAQ OTGOCa4W2o29nFfFjQrsrrYHzVtyA/9oyKvTeEMJ7NA3VJdWcmn7gOu0FxEmSNhSoV1T4vP2 1Wf7f5niCCRKQLNyUy0wEApQi4tSysdz+AbgAc0b/bHYVzIf2uO2lIEZQNNt+3g2bmXgloWm W5fsm/di50Gm1l1Na63d3RZ00SeFQos6WEwLUHEB0yp6KXluXLLIZitEJM0gQ2hldCBSYW1l eSA8Y2hldC5yYW1leUBjYXNlLmVkdT7CYQQTEQIAIQIbAwYLCQgHAwIDFQIDAxYCAQIeAQIX gAUCRX3FIgIZAQAKCRC7WGnwZOp0q069AKCNDRn+zzN/AHbaynls/Lvq1kH/RQCgkLvF8bDs maUHSxSIPqzlGuKWDxbOwE0EQQ6wbxAEAJCukwDigRDPhAuI+lf+6P64lWanIFOXIndqhvU1 3cDbQ/Wt5LwPzm2QTvd7F+fcHOgZ8KOFScbDpjJaRqwIybMTcIN0B2pBLX/C10W1aY+cUrXZ gXUGVISEMmpaP9v02auToo7XXVEHC+XLO9IU7/xaU98FL69l6/K4xeNSBRM/AAMHA/wNAmRB pcyK0+VggZ5esQaIP/LyolAm2qwcmrd3dZi+g24s7yjV0EUwvRP7xHRDQFgkAo6++QbuecU/ J90lxrVnQwucZmfz9zgWDkT/MpfB/CNRSKLFjhYq2yHmHWT6vEjw9Ry/hF6Pc0oh1a62USdf aKAiim0nVxxQmPmiRvtCmcJJBBgRAgAJBQJBDrBvAhsMAAoJELtYafBk6nSr43AAn2ZZFQg8 Gs/zUzvXMt7evaFqVTzcAJ0cHtKpP1i/4H4R9+OsYeQdxxWxTQ==
User-Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.9.1
In-Reply-To <bd1b9a9c-a515-3900-a7b3-17548694d4df@testssl.sh>
Content-Language en-US
X-Junkmail-Status score=8/90, host=mpv2-2015.case.edu
X-Junkmail-PrAS-Raw score=8/90, refid=2.7.2:2018.9.25.125716:17:8.317, ip=, rules=__HAS_REPLYTO, __HAS_CC_HDR, __MULTIPLE_RCPTS_CC_X2, __SUBJ_REPLY, __BOUNCE_CHALLENGE_SUBJ, __BOUNCE_NDR_SUBJ_EXEMPT, __TO_MALFORMED_2, __TO_NO_NAME, __REFERENCES, __HAS_FROM, FROM_EDU_TLD, __HAS_MSGID, __SANE_MSGID, DATE_TZ_NA, __USER_AGENT, __MOZILLA_USER_AGENT, __MIME_VERSION, __IN_REP_TO, __CT, __CT_TEXT_PLAIN, __CTE, __REPLYTO_SAMEAS_FROM_ADDY, __REPLYTO_SAMEAS_FROM_ACC, __FROM_DOMAIN_IN_ANY_CC2, __REPLYTO_SAMEAS_FROM_DOMAIN, __ANY_URI, __URI_WITH_PATH, __URI_NO_WWW, __CP_URI_IN_BODY, __SUBJ_ALPHA_NEGATE, __URI_IN_BODY, __URI_NOT_IMG, __FORWARDED_MSG, __NO_HTML_TAG_RAW, BODYTEXTP_SIZE_3000_LESS, BODY_SIZE_900_999, __MIME_TEXT_P1, __MIME_TEXT_ONLY, __URI_NS, HTML_00_01, HTML_00_10, BODY_SIZE_5000_LESS, IN_REP_TO, MSG_THREAD, __FROM_DOMAIN_IN_RCPT, MULTIPLE_REAL_RCPTS, LEGITIMATE_SIGNS, __SINGLE_URI_TEXT, __MIME_TEXT_P, SINGLE_URI_IN_BODY, [TRUNCATED], so=2010-03-03 19:42:08, dmn=2016-08-03-0138
X-detected-operating-system by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic]
X-Received-From 129.22.103.227
X-BeenThere bug-bash@gnu.org
X-Mailman-Version 2.1.21
Precedence list
List-Id Bug reports for the GNU Bourne Again SHell <bug-bash.gnu.org>
List-Unsubscribe <https://lists.gnu.org/mailman/options/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=unsubscribe>
List-Archive <http://lists.gnu.org/archive/html/bug-bash/>
List-Post <mailto:bug-bash@gnu.org>
List-Help <mailto:bug-bash-request@gnu.org?subject=help>
List-Subscribe <https://lists.gnu.org/mailman/listinfo/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=subscribe>
Xref csiph.com gnu.bash.bug:14660

Show key headers only | View raw


On 9/25/18 9:04 AM, dirk+bash@testssl.sh wrote:

> FYI: I ended up checking with type before whether an external printf
> exists and set a variable for this and then just call this variable.
> 
> env or exec: never thought about it (thanks!) but as both are external
> commands, that would mean upon every call one additional external program.
> (yes, I know that there is such thing as a fs buffer). Subshells also costs
> resources. As this is a core function I am happy for every homeopathic dose
> of time I safe here :-)

`exec' is a shell builtin. It will `cost' in terms of a fork, but you're
going to fork and exec a different program anyway -- /usr/bin/printf --
so it's basically a wash. In either case, there's one fork and one
execve.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
		 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/

Back to gnu.bash.bug | Previous | Next | Find similar | Unroll thread


Thread

Re: bash sockets: printf \x0a does TCP fragmentation Chet Ramey <chet.ramey@case.edu> - 2018-09-25 09:46 -0400

csiph-web