Problems reading binary file in FORTRAN

[marcelosousa1]

I am having problems reading a binary file in FORTRAN. I know that the file was generated by the code below:

open(7,file='hctd1_kxx.dat',form='unformatted')
...
write(7) iscl
write(7) inode,npoints
write(7) (kxm(i)*(10**(prop(i))),i=1,npoints)
close(7)

iscl, inode, npoints are integer*4 and kxm(), prop() are real*4

I am trying to read the file using the code below (variables have consistent data types and sizes):

open(11,file='hctd1_kxx.dat',status='old', form='unformatted', ACTION='READ')
...
read(7) iscl
read(7) inode,npoints
read(7) (single(i),i=1,npoints)

The program reads OK until it reaches the line above, where it always crashes after performing 256 iterations (it should go to npoints=406924).

I tried different input files and opening the file using different options for the CONVERT specifier and it keeps crashing after the first 256 entries.

The error message I get is the following: "forrtl: severe (67): input statement requires too much data".

Does anyone have any suggestions?

Thanks a lot for your attention!

Marcelo
P.S.: my compiler is Compaq Visual Fortran 6.5

 

[zeitghost]

Have you checked that it creates a file of the correct size before you try to read the data back?

 

[quicknote]

I understand the frustration of encountering errors while trying to read a binary file in FORTRAN. It is important to carefully check the data types and sizes of the variables used in both the writing and reading processes to ensure compatibility. In this case, it seems that the issue may lie in the way the file was written. The code provided for writing the file uses the "unformatted" form, which means that the data is written without any additional formatting information. This can sometimes cause issues when trying to read the file, as the program may not know how to properly interpret the data.

I would suggest trying to write the file using the "formatted" form, which includes additional formatting information that can help with reading the file. Additionally, it may be helpful to check the documentation for your compiler to see if there are any specific options or settings that need to be used when reading unformatted files.

If the issue persists, it may also be helpful to reach out to your compiler's support team for further assistance. They may have more specific insights or suggestions on how to resolve this issue.

In general, when encountering errors while reading binary files in FORTRAN, it is important to carefully check the code for any potential issues with data types, sizes, and formatting. It may also be helpful to use debugging tools to track the flow of the program and identify where the error is occurring. I hope this information helps and good luck with your research.