Forcing reading _only_ from standard input

On Tue, Aug 21, 2018 at 3:12 AM Richard Walker <richard.walker at ardc.edu.au> wrote: > > Hi. I have a script in which I process data from > standard input like this: > > VOCAB_WITH_NEW_VOCAB_NOTE="$(echo "$VOCAB" | "${BASEX}" -i - -q $" > copy \$c := . modify ... > > etc. etc. > > The script has been working fine. > > However, due to a defect in an earlier line in the script, > during one test run, the value of $VOCAB was (incorrectly) > an empty string. > > But in this case, I got a quite unexpected result from > the above invocation of BaseX. > > I can easily repeat the same phenomenon out of the script's context > thus: > > $ echo '' | basex -i - -q '.' > <vocabulary xmlns="http://vocabs.ands.org.au/registry/schema/2017/01/vocabulary" ... > etc. etc. > > In this case, rather than processing the empty string > provided as standard input, BaseX fetched data from one of my databases. > > Can I/how do I force the option "-i -" to mean > "read data from standard input, and _only_ from standard input, > even if that is empty"? > > -- > Richard Walker > Australian Research Data Commons (ARDC) > (formerly, Australian National Data Service, ANDS) > 101 Liversidge Street > The Australian National University > Acton ACT 2601, Australia > E: Richard.Walker at ardc.edu.au > T: +61 2 6125 0584 > W: ardc.edu.au > W: www.ands.org.au >

On 22 Aug 2018, at 3:44 am, Christian Grün <christian.gruen at gmail.com> wrote: > I didn’t manage to reproduce this behavior. Do you work with the > latest version of BaseX?

> If yes, could you possibly download a fresh > version (e.g. the zip distribution) and tell us step by step how I can > simulate the behavior?

> Further clarification/correction to what I reported: > > * When I said "empty string", in fact the "problem" arises > when standard input is _not_ empty, but includes just a > blank line. > * When standard input is empty, I get an exception > NoSuchElementException. That is probably acceptable: > at least, it is better than getting output that has > nothing to do with the input data. > * When I said "one of my databases", I think that _may_ have > been wrong. It may be content from an XML file in the > current directory (or, as you'll see below, from some > part of the distribution) ... I can't easily tell. > > What follows was done on a Mac; > "$" is a placeholder for the shell prompt. > > Three tests: > * The first test shows what I expected to be the > behaviour for data read from standard input. > * The second test shows when standard input is > empty (echo -n ''): an exception. > * The third test shows when standard input contains > just a blank line (echo ''): it seems to read from the > factbook.xml data (from basex/etc/factbook.xml?) > > > $ mkdir basex-report > $ cd basex-report > $ wget http://files.basex.org/releases/9.0.2/BaseX902.zip > ... output omitted ... > $ unzip BaseX902.zip > Archive: BaseX902.zip > extracting: basex/.basexhome > inflating: basex/BaseX.jar > creating: basex/bin/ > inflating: basex/bin/basex > inflating: basex/bin/basex.bat > ... etc. > $ echo '<x />' | basex/bin/basex -i- -q '.' > /Users/rwalker/basex-report/basex/.basex: writing new configuration file. > <x/>$ <-- shell prompt printed immediately after output > $ echo -n '' | basex/bin/basex -i- -q '.' > Exception in thread "main" java.util.NoSuchElementException > at java.util.Scanner.throwFor(Scanner.java:862) > at java.util.Scanner.next(Scanner.java:1371) > at org.basex.util.MainParser.string(MainParser.java:110) > at org.basex.BaseX.parseArgs(BaseX.java:235) > at org.basex.core.CLI.<init>(CLI.java:50) > at org.basex.BaseX.<init>(BaseX.java:55) > at org.basex.BaseX.main(BaseX.java:42) > $ echo '' | basex/bin/basex -i- -q '.' > <mondial> > <continent id="f0_119" name="Europe"/> > <continent id="f0_123" name="Asia"/> > <continent id="f0_126" name="America"/> > <continent id="f0_129" name="Australia/Oceania"/> > <continent id="f0_132" name="Africa"/> > <country id="f0_136" name="Albania" capital="f0_1461" population="3249136" datacode="AL" total_area="28750" population_growth="1.34" infant_mortality="49.2" gdp_agri="55" gdp_total="4100" inflation="16" indep_date="28 11 1912" government="emerging democracy" car_code="AL"> > <name>Albania</name> > <city id="f0_1461" country="f0_136" longitude="10.7" latitude="46.2"> > <name>Tirane</name> > ... etc. >

On 23 Aug 2018, at 1:06 am, Christian Grün <christian.gruen at gmail.com> wrote: > Feel free to check out the latest stable snapshot [1]. > > [1] http://files.basex.org/releases/latest/