Mail Archives: cygwin/2012/04/10/18:57:07
Hello All,
some oh, ten years ago or so I ran into this problem and thought I had it
licked wherein I'm launching Cygwin's bash utility (and from it another
program compiled under Cygwin) from Java. However, while the same code
works on every other version of Windows I can remember trying, it seems to
have returned for Windows 7. Either that, or I've forgotten some small
configuration fix!
I've searched the archives and found nothing pertinent so I entered a
question about this on Stackoverflow - could save some writing here to
just reference that:
http://stackoverflow.com/questions/10092730/launching-cygwin-built-executable-from-java-on-windows-7-fails-with-error-while
In short, a Gnu C program compiled under Cygwin wakes up, checks security
and configuration information, then calls Java. Later, under certain
conditions, the Java program wants to instantiate a program similar to
itself, so it calls the OS-level tools to launch the same C program from
Java, and the new instance of the C program then calls the same or
modestly different Java program. The error occurs when the first (oldest)
Java program attempts to launch the (second) C program. The call is
something like this:
cmd.exe /C C:/cygwin/bin/bash -c '/cygdrive/c/opt/ST/v3.3/bin/ST.exe'
The reason for calling cmd.exe (on some versions 'command.exe') is due to
inconsistencies in behavior if one just calls bash or other executable
programs as this is a general purpose interface. (This was developed more
than a decade ago and needs to run everywhere - if there's a better way,
I'm open to it, but this has worked well for a long time.)
It's worth mentioning that there is a test program that confirms the
Java call to the OS is working correctly by launching some basic level
Cygwin program. It reports success at calling programs to be run under
bash. (It could be the test is insufficient / flawed!)
Both the Windows PATH and every place I can find to set the "linux" PATH
have C:\cygwin\bin or equivalent. I recall that a LONG time ago, I'd copy
the cygwin1.dll to various places to cure this type of problem, but I
don't think I've done that in a long time (or don't recall doing it!) -
doing so now (making a copy in C:/Windows/system32/ for example) didn't
help.
I'm sure it is no surprise to anyone that everything works fine when it's
NOT being launched from Java... But it seems odd to me that I have an old
version of XP running with this same setup and the calls from Java work
fine!
I doubt very much this has anything to do with the Cygwin version, but
I'll provide whatever data anyone asks for. However, some things cygcheck
reports that caught my eye are to be found below. One notable thing is
apparent "orphaned Cygwin installations" - but I don't recall ever making
true installations in the locations claimed! (Maybe cygwin1.dll makes
these from wherever it's used?)
Thank you for any and all help.
Regards,
Richard
______________________________________________________________________
Excerpts from cygcheck:
Windows 7 Professional N Ver 6.1 Build 7600
Running under WOW64 on AMD64
Cygwin installations found in the registry:
System: Key: c5e39b7a9d22bafb Path: C:\cygwin
System: Key: 715c149bf086df04 Path: C:\opt\ScienceTools\v3.3 (ORPHANED)
System: Key: a8fb4064ab2b92ac Path: C:\windows (ORPHANED)
Cygwin DLL version info:
DLL version: 1.7.6
DLL epoch: 19
DLL old termios: 5
DLL malloc env: 28
Cygwin conv: 181
API major: 0
API minor: 230
Shared data: 5
DLL identifier: cygwin1
Mount registry: 3
Cygwin registry name: Cygwin
Program options name: Program Options
Installations name: Installations
Cygdrive default prefix:
Build date:
Shared id: cygwin1S5
Warning: There are multiple cygwin1.dlls on your path
(YES, I did that trying to cure this problem!)
--
Richard
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