Re: force write in Gfortran

[Paulo Ziemer <ziemer at lncc dot br>]

Hi,

This happens only when I use Gfortran. I will try to be more accurate in 
describing my problem:

If I have several strings to write to a file, my program just writes

the first Write command, and nothing happens for the following write
commands.

For example:
***********************
!   part of file test.for
    OPEN (6, FILE= 'OUT.txt')
     Write(6,*)'test_1'
     Write(6,*)'test_2'
     Write(6,*)'test_3'
*************************
by this code my OUT.txt will have only as content the "string" "test_1"

It seems the pointer to the file is lost after the first acess.

This happens only when several files are linked to forme one
executable. If the executable is created just from my "test.for"
everthing goes ok and all the string are correctely written.


Because my program is very large and takes a lot of time to execute, I 
was in doubt if the program was "waiting" to write or if it was not 
writing at all.
I tried to use the Flush statament but also didn't work. It seems he 
cannot  flush because to pointer to the file is somehow lost.


below is the output of gfortran-v
***********************************************************************************
ziemer@hemo06:/home/ziemer$ gfortran -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v 
--enable-languages=c,c++,java,f95,objc,ada,treelang --prefix=/usr 
--with-gxx-include-dir=/usr/include/c++/4.0.2 --enable-shared 
--with-system-zlib --libexecdir=/usr/lib --enable-nls 
--without-included-gettext --enable-threads=posix --program-suffix=-4.0 
--enable-__cxa_atexit --enable-libstdcxx-allocator=mt 
--enable-clocale=gnu --enable-libstdcxx-debug --enable-java-gc=boehm 
--enable-java-awt=gtk --enable-gtk-cairo 
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-4.0-1.4.2.0/jre 
--enable-mpfr --disable-werror --enable-checking=release i486-linux-gnu
Thread model: posix
gcc version 4.0.2 20050808 (prerelease) (Ubuntu 4.0.1-4ubuntu9)


***************

thank you very much


Janne Blomqvist wrote:

> On Fri, Mar 24, 2006 at 11:44:45AM -0300, Paulo Ziemer wrote:
>  
>
> > Hi,
> >
> > Is there any way to force Gfortran not buffer and write immediately  to 
> > a file?  I have tried to use the environment GFORTRAN_UNBUFFRED_ALL but 
> > it didn't work. 
> >
> > Using ifort compiler the results are written much more faster than using 
> > Gfortran. Anyone knows a good strategy to debug the file acess / write 
> > process?  Sometime files are not created or only the first write command 
> > is correctly written (in the case we have several write commands in 
> > sequence).
> >    
>
> You can try the FLUSH statement, which flushes the io buffers for the
> unit in question (or all open units, if a unit number is not
> specified IIRC).
>
> If you want more specific help, I suggest you post a code snippet that
> demonstrates your problem, along with the output of 'gfortran -v'.
>
>