Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #72218
| Path | csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.albasani.net!rt.uk.eu.org!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!news.tele.dk!news.tele.dk!small.news.tele.dk!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail |
|---|---|
| Return-Path | <cameron@cskk.homeip.net> |
| X-Original-To | python-list@python.org |
| Delivered-To | python-list@mail.python.org |
| X-Spam-Status | OK 0.000 |
| X-Spam-Evidence | '*H*': 1.00; '*S*': 0.00; 'syntax': 0.04; 'subject:Python': 0.06; 'assignment': 0.07; 'string': 0.09; 'arguments': 0.09; 'etc).': 0.09; 'sanity': 0.09; 'tmp': 0.09; '"%s"': 0.16; '"f"': 0.16; '>the': 0.16; 'above)': 0.16; 'argument.': 0.16; 'check.': 0.16; 'code?': 0.16; 'doing:': 0.16; 'emit': 0.16; 'from:addr:cs': 0.16; 'from:addr:zip.com.au': 0.16; 'from:name:cameron simpson': 0.16; 'invalid.': 0.16; 'message- id:@cskk.homeip.net': 0.16; 'received:cskk.homeip.net': 0.16; 'received:homeip.net': 0.16; 'simpson': 0.16; 'skip:> 20': 0.16; 'syntax,': 0.16; 'wrote:': 0.18; 'skip:f 30': 0.19; 'seems': 0.21; 'command': 0.22; 'shell': 0.22; 'header:User-Agent:1': 0.23; 'error': 0.23; 'string,': 0.24; 'cheers,': 0.24; '(or': 0.24; 'pass': 0.26; 'values': 0.27; 'header:In-Reply-To:1': 0.27; 'leave': 0.29; 'went': 0.31; 'dropped': 0.31; 'probably': 0.32; 'run': 0.32; 'open': 0.33; 'running': 0.33; 'really': 0.36; 'method': 0.36; 'useful': 0.36; 'charset:us-ascii': 0.36; 'skip:- 20': 0.37; 'to:addr:python-list': 0.38; 'does': 0.39; 'to:addr:python.org': 0.39; 'middle': 0.60; 'number,': 0.60; 'first': 0.61; 'content-disposition:inline': 0.62; 'yourself': 0.78; 'received:192.168.15': 0.84 |
| Date | Thu, 29 May 2014 15:10:24 +1000 |
| From | Cameron Simpson <cs@zip.com.au> |
| To | python-list@python.org |
| Subject | Re: passing Python assignment value to shell |
| MIME-Version | 1.0 |
| Content-Type | text/plain; charset=us-ascii; format=flowed |
| Content-Disposition | inline |
| In-Reply-To | <92C18466-C23B-4AB9-9863-540A8FB6E3E3@gmail.com> |
| User-Agent | Mutt/1.5.21 (2010-09-15) |
| References | <92C18466-C23B-4AB9-9863-540A8FB6E3E3@gmail.com> |
| X-BeenThere | python-list@python.org |
| X-Mailman-Version | 2.1.15 |
| Precedence | list |
| List-Id | General discussion list for the Python programming language <python-list.python.org> |
| List-Unsubscribe | <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe> |
| List-Archive | <http://mail.python.org/pipermail/python-list/> |
| List-Post | <mailto:python-list@python.org> |
| List-Help | <mailto:python-list-request@python.org?subject=help> |
| List-Subscribe | <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.10438.1401340238.18130.python-list@python.org> (permalink) |
| Lines | 45 |
| NNTP-Posting-Host | 2001:888:2000:d::a6 |
| X-Trace | 1401340238 news.xs4all.nl 2856 [2001:888:2000:d::a6]:56811 |
| X-Complaints-To | abuse@xs4all.nl |
| Xref | csiph.com comp.lang.python:72218 |
Show key headers only | View raw
On 28May2014 21:48, Satish Muthali <satish.muthali@gmail.com> wrote:
>This is what I went about doing:
>
> reecalc = [s.split() for s in os.Popen("free -ht").read().splitlines()]
I think you dropped an "f" in your cut/paste. Try to be precise.
> freecalc_total = freecalc[4]
> freecalc_total = freecalc_total[3]
> freecalc_total = freecalc_total.translate(None, 'M )
This is syntacticly invalid. Did this really come from working code?
Also, .translate does not accept None as its first argument.
> tmp = "%s" % freecalc_total
If freecalc_total is a string (as it seems from the above) then this line does
nothing.
If freecalc_total were a number, it would probably be better to use "%d"
instead of "%s"; %d will emit an error if freecalc_total is not a number, a
useful sanity check.
> command = "stressapptest -M %s -s 20" % tmp
> p = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=
>subprocess.PIPE).communicate()[0]
>
>Please let me know if this is the optimal method to achieve in order to pass
>the assignment value to shell. I am open to suggestions or a better way of
>implementation/logic.
It is better to avoid shell=True unless you really need to run a shell command
(shell syntax or control structures, etc). This is because by plonking "%s" in
the middle of your shell string, you leave yourself open to "injection"
accidents (or attacks, of you can be tricked in the values you substitute).
Since you are running a command with known arguments and no shell syntax, you
do not need the shell. So just construct the arguments directly:
[ "stressapptest", "-M", str(freecalc_total), "-s", "20" ]
and set shell=False.
Cheers,
Cameron Simpson <cs@zip.com.au>
Back to comp.lang.python | Previous | Next | Find similar | Unroll thread
Re: passing Python assignment value to shell Cameron Simpson <cs@zip.com.au> - 2014-05-29 15:10 +1000
csiph-web