How to use OSProcess with stdin and stdout

> Hi!
>
> I'm trying to do some OCR from squeak using tesseract. I installed OSProcess.
> So far so good. But I don't know what classes to use for stdIn and stdOut. My
> code would look something like this:
>
> | proc stdIn stdOut d |
> stdIn := ???
> stdOut := ???
> proc := ExternalUnixOSProcess forkAndExec: '/usr/bin/tesseract' arguments:
> #('-' '-' '--dpi' '100') environment: nil descriptors: (Array with: stdIn
> with: stdOut with: nil).
> proc ifNil: [self class noAccessorAvailable].
> d := Delay forMilliseconds: 50.
> [proc runState == #complete] whileFalse: [d wait].
> " and now read the text from stdOut..."
>
> Can someone fill in the blanks or point me to code that does similar things?
> Thanks very much.

>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
>
>
> If one ignores the message when selecting "head" , then that's a risk no ?
>
> "The package you are about to install is not listed as being compatible
> with your image version (Squeak5.3), so the package may not work properly.
> Do you still want to proceed with the install Yes/No"
>
> If you downloaded via "Squeak Map Catalog" (Package Loader) the "head"
>
>   - OSProcess
>   - CommandShell
>
> Selecting "head" works but gives a warning that it is "potentially"
> not compatible with the VM (or Image?).
>
> In my case when I install (succesfully I think) I get:
>
>  OSProcess versionString  prints : '4.6.19'
>  CommandShell versionString prints: '4.7.10'
>
> What I worry about is that I may be installing with "head",
> is more recent than the one supported by the image or VM.
>
> How can I check that they are compatible ?
>
> Thanks,
> David Stes
>

> On Thu, May 14, 2020 at 09:37:26PM +0200, Martin Kuball wrote:
> > Hi!
> >
> > I'm trying to do some OCR from squeak using tesseract. I installed
> > OSProcess. So far so good. But I don't know what classes to use for stdIn
> > and stdOut. My>
> > code would look something like this:
> > | proc stdIn stdOut d |
> >
> > stdIn := ???
> > stdOut := ???
> > proc := ExternalUnixOSProcess forkAndExec: '/usr/bin/tesseract' arguments:
> > #('-' '-' '--dpi' '100') environment: nil descriptors: (Array with: stdIn
> > with: stdOut with: nil).
> > proc ifNil: [self class noAccessorAvailable].
> > d := Delay forMilliseconds: 50.
> > [proc runState == #complete] whileFalse: [d wait].
> > " and now read the text from stdOut..."
> >
> > Can someone fill in the blanks or point me to code that does similar
> > things? Thanks very much.
>
> Hi Martin,
>
> First, please also install CommandShell in addition to OSProcess. Get the
> latest versions of both OSProcess and CommandShell, regardless of the
> version of Squeak you are using. If you are using SqueakMap to load them,
> then please select the versions labelled "(head)".
>
> Start out by trying something like this:
>
>     OSProcess outputOf: 'tesseract - - --dpi 100'
>
> I'm not sure if this will do what you want but please give it a try,
> and if it does not work I'll try to give a better answer.
>
> This uses a couple of new methods that I added to OSPrecess recently,
> but have not mentioned until now. If it proves to be useful you, you
> will be the first :-)
>
> Assuming that it works, here is what will have happened:
>
> - The argument string is parsed into a unix-style command pipeline
>
> - The pipeline is all objects, with OS process proxies doing the work
>
> - When evaluated, and stderr result will show up in an error notifier
>   in your image (proceed though the notifier)
>
> - Command stdout is collected and answered as the result of #outputOf:
>
> I would recommend running this in a debugger so you can step through
> it and see what is going on.
>
> Dave

> On Fri, 15 May 2020 at 03:37, Martin Kuball <[hidden email]> wrote:
> > Hi!
> >
> > I'm trying to do some OCR from squeak using tesseract. I installed
> > OSProcess.
>
> Another option would be calling the library functions directly using FFI.
> I notice...
> https://github.com/ottopedi/Squeak_Tesseract
>
> cheers -ben

> Am Donnerstag, 14. Mai 2020, 23:27:59 CEST schrieb David T. Lewis:
> > On Thu, May 14, 2020 at 09:37:26PM +0200, Martin Kuball wrote:
> > > Hi!
> > >
> > > I'm trying to do some OCR from squeak using tesseract. I installed
> > > OSProcess. So far so good. But I don't know what classes to use for stdIn
> > > and stdOut. My>
> > > code would look something like this:
> > > | proc stdIn stdOut d |
> > >
> > > stdIn := ???
> > > stdOut := ???
> > > proc := ExternalUnixOSProcess forkAndExec: '/usr/bin/tesseract' arguments:
> > > #('-' '-' '--dpi' '100') environment: nil descriptors: (Array with: stdIn
> > > with: stdOut with: nil).
> > > proc ifNil: [self class noAccessorAvailable].
> > > d := Delay forMilliseconds: 50.
> > > [proc runState == #complete] whileFalse: [d wait].
> > > " and now read the text from stdOut..."
> > >

> > > things? Thanks very much.
> >
> > Hi Martin,
> >
> > First, please also install CommandShell in addition to OSProcess. Get the
> > latest versions of both OSProcess and CommandShell, regardless of the
> > version of Squeak you are using. If you are using SqueakMap to load them,
> > then please select the versions labelled "(head)".
> >
> > Start out by trying something like this:
> >
> >     OSProcess outputOf: 'tesseract - - --dpi 100'
> >
> > I'm not sure if this will do what you want but please give it a try,
> > and if it does not work I'll try to give a better answer.
> >
> > This uses a couple of new methods that I added to OSPrecess recently,
> > but have not mentioned until now. If it proves to be useful you, you
> > will be the first :-)
> >
> > Assuming that it works, here is what will have happened:
> >
> > - The argument string is parsed into a unix-style command pipeline
> >
> > - The pipeline is all objects, with OS process proxies doing the work
> >
> > - When evaluated, and stderr result will show up in an error notifier
> >   in your image (proceed though the notifier)
> >
> > - Command stdout is collected and answered as the result of #outputOf:
> >
> > I would recommend running this in a debugger so you can step through
> > it and see what is going on.
> >
> > Dave
>
> Hi Dave,
>
> thanks for your answer. Acutally I did install CommandShell because I thougth
> it might help me understand the usage of OSProcess. And maybe it will if I
> give it more time.
>
> So here is what I did: I configure the following repository:
>
> MCHttpRepository
> location: 'http://www.squeaksource.com/OSProcess'
> user: ''
> password: ''
>
> and installed OSProcess-Base dtl.71, OSProcess-AIO dlt.9 and OSProcess-Unix
> dtl.35. But I do not see any mention of a head label. So where did I go wrong?
>

> Hi Martin,
>
> On Fri, May 15, 2020 at 09:20:17PM +0200, Martin Kuball wrote:
> > Am Donnerstag, 14. Mai 2020, 23:27:59 CEST schrieb David T. Lewis:
> > > On Thu, May 14, 2020 at 09:37:26PM +0200, Martin Kuball wrote:
> > > > Hi!
> > > >
> > > > I'm trying to do some OCR from squeak using tesseract. I installed
> > > > OSProcess. So far so good. But I don't know what classes to use for
> > > > stdIn
> > > > and stdOut. My>
> > > >
> > > > code would look something like this:
> > > > | proc stdIn stdOut d |
> > > >
> > > > stdIn := ???
> > > > stdOut := ???
> > > > proc := ExternalUnixOSProcess forkAndExec: '/usr/bin/tesseract'
> > > > arguments:
> > > > #('-' '-' '--dpi' '100') environment: nil descriptors: (Array with:
> > > > stdIn
> > > > with: stdOut with: nil).
> > > > proc ifNil: [self class noAccessorAvailable].
> > > > d := Delay forMilliseconds: 50.
> > > > [proc runState == #complete] whileFalse: [d wait].
> > > > " and now read the text from stdOut..."
> > > >
>  > > > Can someone fill in the blanks or point me to code that does similar
> > > >
> > > > things? Thanks very much.
> > >
> > > Hi Martin,
> > >
> > > First, please also install CommandShell in addition to OSProcess. Get
> > > the
> > > latest versions of both OSProcess and CommandShell, regardless of the
> > > version of Squeak you are using. If you are using SqueakMap to load
> > > them,
> > > then please select the versions labelled "(head)".
> > >
> > > Start out by trying something like this:
> > >     OSProcess outputOf: 'tesseract - - --dpi 100'
> > >
> > > I'm not sure if this will do what you want but please give it a try,
> > > and if it does not work I'll try to give a better answer.
> > >
> > > This uses a couple of new methods that I added to OSPrecess recently,
> > > but have not mentioned until now. If it proves to be useful you, you
> > > will be the first :-)
> > >
> > > Assuming that it works, here is what will have happened:
> > >
> > > - The argument string is parsed into a unix-style command pipeline
> > >
> > > - The pipeline is all objects, with OS process proxies doing the work
> > >
> > > - When evaluated, and stderr result will show up in an error notifier
> > >
> > >   in your image (proceed though the notifier)
> > >
> > > - Command stdout is collected and answered as the result of #outputOf:
> > >
> > > I would recommend running this in a debugger so you can step through
> > > it and see what is going on.
> > >
> > > Dave
> >
> > Hi Dave,
> >
> > thanks for your answer. Acutally I did install CommandShell because I
> > thougth it might help me understand the usage of OSProcess. And maybe it
> > will if I give it more time.
> >
> > So here is what I did: I configure the following repository:
> >
> > MCHttpRepository
> >
> > location: 'http://www.squeaksource.com/OSProcess'
> > user: ''
> > password: ''
> >
> > and installed OSProcess-Base dtl.71, OSProcess-AIO dlt.9 and
> > OSProcess-Unix
> > dtl.35. But I do not see any mention of a head label. So where did I go
> > wrong?
> From the OSProcess repository, load OSProcess-dtl.118. From the CommandShell
> repository, load CommandShell-dtl.109. These are currently the most recent
> versions. Ignore the sub-packages such as "OSProcess-Unix", that is
> something I did to support Pharo (something of a fools errand if I may say
> so). All of the sub-packages are included in the full OSProcess and
> CommandShell packages.
>
> A shortcut to do this is:
>
> Installer ss project: 'OSProcess'; install: 'OSProcess'.
> Installer ss project: 'CommandShell'; install: 'CommandShell'.
>
> The "(head)" version labels in the SqueakMap package loader do the same
> thing, except for the alarming warning messages which you can safely ignore.
> > The command you suggested worked. At least if I provide the image to
> > tesseract as a file. I will go on with the debugger and try to find out
> > how to feed the image data to stdIn.
>
> The basic Unix shell redirector operators #> and #< should work. For
> example, try evaluating this:
>
>    OSProcess outputOf: 'cat < /etc/services | edit'
>
> I am not familiar with tesseract, but you can probably use the same
> approach.
>
> Dave

> Hi David,
>
> I finally found a solution to my problem. Successfully converted 1300 images in
> a couple of minutes. The code I come up with is roughly the following (using
> the wc program here as a proof of concept before switching to tesseract and
> image data for the input):
>
> | input output stdErr proc accessProtect res err |
> input := ExternalPipe nonBlockingPipe.
> output := ExternalPipe blockingPipe.
> stdErr := ExternalPipe nonBlockingPipe.
> proc := ExternalOSProcess concreteClass
> programName: '/usr/bin/wc'
> arguments: #('-w')
> initialEnvironment: nil.
> proc initialStdIn: input reader.
> proc initialStdOut: output writer.
> proc initialStdErr: stdErr writer.
> accessProtect := Semaphore forMutualExclusion.
> accessProtect critical: [
> proc value.
> input nextPutAll: 'this is a test'.
> input closeWriter.
> res := output upToEndOfFile.
> err := stdErr upToEndOfFile
> ].
> proc waitForTermination.
> output close.
> stdErr close.
> proc exitStatus ~= 0
> ifTrue: [^ 'error ' , proc exitStatus , ': ' , err].
> ifFalse: [^res]
>

>
> Thanks again for your help and the great code.
>
> Martin
>
>
>
> Am Samstag, 16. Mai 2020, 00:13:19 CEST schrieb David T. Lewis:
> > Hi Martin,
> >
> > On Fri, May 15, 2020 at 09:20:17PM +0200, Martin Kuball wrote:
> > > Am Donnerstag, 14. Mai 2020, 23:27:59 CEST schrieb David T. Lewis:
> > > > On Thu, May 14, 2020 at 09:37:26PM +0200, Martin Kuball wrote:
> > > > > Hi!
> > > > >
> > > > > I'm trying to do some OCR from squeak using tesseract. I installed
> > > > > OSProcess. So far so good. But I don't know what classes to use for
> > > > > stdIn
> > > > > and stdOut. My>
> > > > >
> > > > > code would look something like this:
> > > > > | proc stdIn stdOut d |
> > > > >
> > > > > stdIn := ???
> > > > > stdOut := ???
> > > > > proc := ExternalUnixOSProcess forkAndExec: '/usr/bin/tesseract'
> > > > > arguments:
> > > > > #('-' '-' '--dpi' '100') environment: nil descriptors: (Array with:
> > > > > stdIn
> > > > > with: stdOut with: nil).
> > > > > proc ifNil: [self class noAccessorAvailable].
> > > > > d := Delay forMilliseconds: 50.
> > > > > [proc runState == #complete] whileFalse: [d wait].
> > > > > " and now read the text from stdOut..."
> > > > >
> >  > > > Can someone fill in the blanks or point me to code that does similar
> > > > >
> > > > > things? Thanks very much.
> > > >
> > > > Hi Martin,
> > > >
> > > > First, please also install CommandShell in addition to OSProcess. Get
> > > > the
> > > > latest versions of both OSProcess and CommandShell, regardless of the
> > > > version of Squeak you are using. If you are using SqueakMap to load
> > > > them,
> > > > then please select the versions labelled "(head)".
> > > >
> > > > Start out by trying something like this:
> > > >     OSProcess outputOf: 'tesseract - - --dpi 100'
> > > >
> > > > I'm not sure if this will do what you want but please give it a try,
> > > > and if it does not work I'll try to give a better answer.
> > > >
> > > > This uses a couple of new methods that I added to OSPrecess recently,
> > > > but have not mentioned until now. If it proves to be useful you, you
> > > > will be the first :-)
> > > >
> > > > Assuming that it works, here is what will have happened:
> > > >
> > > > - The argument string is parsed into a unix-style command pipeline
> > > >
> > > > - The pipeline is all objects, with OS process proxies doing the work
> > > >
> > > > - When evaluated, and stderr result will show up in an error notifier
> > > >
> > > >   in your image (proceed though the notifier)
> > > >
> > > > - Command stdout is collected and answered as the result of #outputOf:
> > > >
> > > > I would recommend running this in a debugger so you can step through
> > > > it and see what is going on.
> > > >
> > > > Dave
> > >
> > > Hi Dave,
> > >
> > > thanks for your answer. Acutally I did install CommandShell because I
> > > thougth it might help me understand the usage of OSProcess. And maybe it
> > > will if I give it more time.
> > >
> > > So here is what I did: I configure the following repository:
> > >
> > > MCHttpRepository
> > >
> > > location: 'http://www.squeaksource.com/OSProcess'
> > > user: ''
> > > password: ''
> > >
> > > and installed OSProcess-Base dtl.71, OSProcess-AIO dlt.9 and
> > > OSProcess-Unix
> > > dtl.35. But I do not see any mention of a head label. So where did I go
> > > wrong?
> > From the OSProcess repository, load OSProcess-dtl.118. From the CommandShell
> > repository, load CommandShell-dtl.109. These are currently the most recent
> > versions. Ignore the sub-packages such as "OSProcess-Unix", that is
> > something I did to support Pharo (something of a fools errand if I may say
> > so). All of the sub-packages are included in the full OSProcess and
> > CommandShell packages.
> >
> > A shortcut to do this is:
> >
> > Installer ss project: 'OSProcess'; install: 'OSProcess'.
> > Installer ss project: 'CommandShell'; install: 'CommandShell'.
> >
> > The "(head)" version labels in the SqueakMap package loader do the same
> > thing, except for the alarming warning messages which you can safely ignore.
> > > The command you suggested worked. At least if I provide the image to
> > > tesseract as a file. I will go on with the debugger and try to find out
> > > how to feed the image data to stdIn.
> >
> > The basic Unix shell redirector operators #> and #< should work. For
> > example, try evaluating this:
> >
> >    OSProcess outputOf: 'cat < /etc/services | edit'
> >
> > I am not familiar with tesseract, but you can probably use the same
> > approach.
> >
> > Dave
>
>
>
>
>

> Hi Martin,
>
> On Fri, May 22, 2020 at 10:35:08PM +0200, Martin Kuball wrote:
> > Hi David,
> >
> > I finally found a solution to my problem. Successfully converted 1300
> > images in a couple of minutes. The code I come up with is roughly the
> > following (using the wc program here as a proof of concept before
> > switching to tesseract and>
> > image data for the input):
> > | input output stdErr proc accessProtect res err |
> >
> > input := ExternalPipe nonBlockingPipe.
> > output := ExternalPipe blockingPipe.
> > stdErr := ExternalPipe nonBlockingPipe.
> > proc := ExternalOSProcess concreteClass
> >
> > programName: '/usr/bin/wc'
> > arguments: #('-w')
> > initialEnvironment: nil.
> >
> > proc initialStdIn: input reader.
> > proc initialStdOut: output writer.
> > proc initialStdErr: stdErr writer.
> > accessProtect := Semaphore forMutualExclusion.
> > accessProtect critical: [
> >
> > proc value.
> > input nextPutAll: 'this is a test'.
> > input closeWriter.
> > res := output upToEndOfFile.
> > err := stdErr upToEndOfFile
> >
> > ].
> > proc waitForTermination.
> > output close.
> > stdErr close.
> > proc exitStatus ~= 0
> >
> > ifTrue: [^ 'error ' , proc exitStatus , ': ' , err].
> > ifFalse: [^res]
>
> I'm glad it worked out for you!
>
> > Mybe it is possible to reuse more of your high-level code. But I wanted
> > low
> > overhead and complete control over the input and output streams.
>
> Indeed, it can be interesting to work with this at a lower level so you
> can see exactly what is going on.
>
> > By the way uninstalling an older version of OSProcess and installing the
> > new one left a OSProcess watcher with an ObsoleteUnixOSProcessAccessor
> > running.
> This does not surprise me. That would just be the child process watcher that
> was left running after removing all the OSProcess classes, so I guess you
> would have to terminate the old process in that case.

>
> > And a final question: If you want to get a deeper understanding of process
> > handling in squeak, what would you recomend to read? Is the blue book
> > still a good reference?
>
> I think we are talking about two different things here. In Smalltalk, a
> process is very lightweight, more like what you would call a thread in most
> operating systems today. The blue book descriptions are still very relevant.
> There have been some changes and improvements in Squeak over the years, but
> the basics would still be the same.

>
> The "processes" in OSProcess are a different thing entirely. These refer to
> the processes of the underlying operating system. For an operating system
> like Unix (Linux) or Windows, these processes are heavier-weight, and they
> carry quite a lot of execution context in addition to the basic schedulable
> unit of execution.
>
> If you were to make a comparison, a Process in Squeak is like a "green
> thread" in typical operating system lingo.
>
> But to your question - yes I would start with the blue book, and then others
> on this list (notably Eliot Miranda) can give explanations of the finer
> points and the more recent chnages.
>
> Dave
>
> > Thanks again for your help and the great code.
> >
> > Martin
> >
> > Am Samstag, 16. Mai 2020, 00:13:19 CEST schrieb David T. Lewis:
> > > Hi Martin,
> > >
> > > On Fri, May 15, 2020 at 09:20:17PM +0200, Martin Kuball wrote:
> > > > Am Donnerstag, 14. Mai 2020, 23:27:59 CEST schrieb David T. Lewis:
> > > > > On Thu, May 14, 2020 at 09:37:26PM +0200, Martin Kuball wrote:
> > > > > > Hi!
> > > > > >
> > > > > > I'm trying to do some OCR from squeak using tesseract. I installed
> > > > > > OSProcess. So far so good. But I don't know what classes to use
> > > > > > for
> > > > > > stdIn
> > > > > > and stdOut. My>
> > > > > >
> > > > > > code would look something like this:
> > > > > > | proc stdIn stdOut d |
> > > > > >
> > > > > > stdIn := ???
> > > > > > stdOut := ???
> > > > > > proc := ExternalUnixOSProcess forkAndExec: '/usr/bin/tesseract'
> > > > > > arguments:
> > > > > > #('-' '-' '--dpi' '100') environment: nil descriptors: (Array
> > > > > > with:
> > > > > > stdIn
> > > > > > with: stdOut with: nil).
> > > > > > proc ifNil: [self class noAccessorAvailable].
> > > > > > d := Delay forMilliseconds: 50.
> > > > > > [proc runState == #complete] whileFalse: [d wait].
> > > > > > " and now read the text from stdOut..."
> > > > > >
> > >  > > > Can someone fill in the blanks or point me to code that does
> > >  > > > similar
> > > > > >
> > > > > > things? Thanks very much.
> > > > >
> > > > > Hi Martin,
> > > > >
> > > > > First, please also install CommandShell in addition to OSProcess.
> > > > > Get
> > > > > the
> > > > > latest versions of both OSProcess and CommandShell, regardless of
> > > > > the
> > > > > version of Squeak you are using. If you are using SqueakMap to load
> > > > > them,
> > > > > then please select the versions labelled "(head)".
> > > > >
> > > > > Start out by trying something like this:
> > > > >     OSProcess outputOf: 'tesseract - - --dpi 100'
> > > > >
> > > > > I'm not sure if this will do what you want but please give it a try,
> > > > > and if it does not work I'll try to give a better answer.
> > > > >
> > > > > This uses a couple of new methods that I added to OSPrecess
> > > > > recently,
> > > > > but have not mentioned until now. If it proves to be useful you, you
> > > > > will be the first :-)
> > > > >
> > > > > Assuming that it works, here is what will have happened:
> > > > >
> > > > > - The argument string is parsed into a unix-style command pipeline
> > > > >
> > > > > - The pipeline is all objects, with OS process proxies doing the
> > > > > work
> > > > >
> > > > > - When evaluated, and stderr result will show up in an error
> > > > > notifier
> > > > >
> > > > >   in your image (proceed though the notifier)
> > > > >
> > > > > - Command stdout is collected and answered as the result of
> > > > > #outputOf:
> > > > >
> > > > > I would recommend running this in a debugger so you can step through
> > > > > it and see what is going on.
> > > > >
> > > > > Dave
> > > >
> > > > Hi Dave,
> > > >
> > > > thanks for your answer. Acutally I did install CommandShell because I
> > > > thougth it might help me understand the usage of OSProcess. And maybe
> > > > it
> > > > will if I give it more time.
> > > >
> > > > So here is what I did: I configure the following repository:
> > > >
> > > > MCHttpRepository
> > > >
> > > > location: 'http://www.squeaksource.com/OSProcess'
> > > > user: ''
> > > > password: ''
> > > >
> > > > and installed OSProcess-Base dtl.71, OSProcess-AIO dlt.9 and
> > > > OSProcess-Unix
> > > > dtl.35. But I do not see any mention of a head label. So where did I
> > > > go
> > > > wrong?
> > >
> > > From the OSProcess repository, load OSProcess-dtl.118. From the
> > > CommandShell repository, load CommandShell-dtl.109. These are currently
> > > the most recent versions. Ignore the sub-packages such as
> > > "OSProcess-Unix", that is something I did to support Pharo (something
> > > of a fools errand if I may say so). All of the sub-packages are
> > > included in the full OSProcess and CommandShell packages.
> > >
> > > A shortcut to do this is:
> > > Installer ss project: 'OSProcess'; install: 'OSProcess'.
> > > Installer ss project: 'CommandShell'; install: 'CommandShell'.
> > >
> > > The "(head)" version labels in the SqueakMap package loader do the same
> > > thing, except for the alarming warning messages which you can safely
> > > ignore.> >
> > > > The command you suggested worked. At least if I provide the image to
> > > > tesseract as a file. I will go on with the debugger and try to find
> > > > out
> > > > how to feed the image data to stdIn.
> > >
> > > The basic Unix shell redirector operators #> and #< should work. For
> > >
> > > example, try evaluating this:
> > >    OSProcess outputOf: 'cat < /etc/services | edit'
> > >
> > > I am not familiar with tesseract, but you can probably use the same
> > > approach.
> > >
> > > Dave

> Sorry, I just saw this thread. For the future, I did a small wrapper like
> this that might help [1]. It looks like I didn't convert the repo to Tonel
> yet and IIRC there are few dependencies other than OSP, so it may load in
> Squeak (or could be used for inspiration). I would also be happy to accept
> PRs to make it so. I probably will convert to Tonel at some point - although
> it looks like Tonel support in Squeak may be imminent, so hopefully no
> problem there :)
>
>
> Martin Kuball wrote
>
> > Mybe it is possible to reuse more of your high-level code.
>
> This is what I ended up with [2]:
> | p result |
>
> p := PipeableOSProcess waitForCommand: commandString.
> p succeeded ifFalse: [ ^ self error: 'tesseract failed with: ', p
> errorUpToEnd ].
> result := self tempFile readStreamDo: [ :str | str contents ].
> self tempFile delete.
> ^ result.
>
> If I had to do it again, I'd probably try via FFI. I've had a longstanding
> belief that wrapping command line stuff is an easy way to "get it to work"
> and then I can later "get it right" with FFI, but after doing a lot of this
> sort of thing, there are so many quirks that I think it might usually be
> easier to just start with FFI (although maybe the grass is always
> greener...).
>
> [1]. https://github.com/seandenigris/Tesseract-St
> [2].
> https://github.com/seandenigris/Tesseract-St/blob/master/src/Tesseract.packa
> ge/Tesseract.class/instance/evaluate..st
>
>
>
> -----
> Cheers,
> Sean
> --
> Sent from: http://forum.world.st/Squeak-Dev-f45488.html