the processes are started but they are "lazy" and concurrent. Isn't that nice?
Working in a (unix) shell is like working in a functional language... cheers Dierk > Am 19.08.2015 um 23:02 schrieb KARR, DAVID <dk0...@att.com>: > >> -----Original Message----- >> From: Dierk König [mailto:dierk.koe...@canoo.com] >> Sent: Wednesday, August 19, 2015 1:42 PM >> To: users@groovy.incubator.apache.org >> Subject: Re: Questions about example of piping process output >> >> Hi, >> >> thanks for reading the book! >> >> I was just about to answer when I recognized that I was about to >> restate the >> text that follows the example: >> >> We’re using the pipeTo method of Process, which is invoked by using >> the overridden >> or (|) operator. Then we wait for the process to finish with a safe >> time to wait, and >> print the result. >> The observant reader (yes, that’s all of you!) will have recognized >> that although >> the code is a slick solution, there’s also a pure Groovy solution >> that’s platform independent >> >> >> In other words, this solution _is_ platform dependent and cygwin is >> a bit of a "unusual" platform to run commands at... > > What I'm confused about is that running "execute()" seems to say that it > starts the process, but those three seem to be started independently, and > then we later attempt to connect them with a pipe. Does "execute()" not > actually start the process? The second two processes need input that isn't > provided yet. > >>> Am 19.08.2015 um 21:56 schrieb KARR, DAVID <dk0...@att.com>: >>> >>> While reading REGINA, I saw the following script: >>> -------------- >>> def listFiles = 'ls'.execute() >>> def ignoreCase = "tr '[A-Z]' '[a-z]'".execute() >>> def reverseSort = 'sort -r'.execute() >>> >>> listFiles | ignoreCase | reverseSort >>> >>> reverseSort.waitForOrKill(1000) >>> if(reverseSort.exitValue()) { >>> print reverseSort.err.text >>> } else { >>> print reverseSort.text >>> } >>> ------------------- >>> >>> I find this curious. It doesn't even seem to me that this could >> work as they intended, although when I run it on Linux, it does >> apparently print reasonable output. On Win7/Cygwin however, it >> prints "-rThe system cannot find the file specified.". Any idea >> what's going on here? >>> >>> Also, the javadoc for "execute()" says that it starts the process >> and returns the process object. Ignoring for a moment why it >> completely fails on Cygwin, what exactly is the "pipe" line >> actually doing? >
