What's the best way to check whether a given netCDF file exists in Fortran90? I have a Fortran program which simulates several systems and stores the data in a NETCDF file, and I'd like to be able to set it up so that I can run the code with already-existing netCDF files and just append the extra data.
It seems to work with the following:
status = nf90_open(filePath, NF90_WRITE, netcdfID)
if (status /= nf90_noerr) then
new_status = nf90_create(filePath, NF90_NETCDF4, netcdfID)
! setup
else
! check file has correct dimensions etc
end if
But I'd like to be able to be specific about the error, but the documentation isn't very specific about what the error code is when the file already exists.
I've also considered checking the status of the nf90_create(...) call, but I don't know how to specify cmode=NF90_NETCDF4 and cmode=NF90_NOCLOBBER at the same time.
To be honest, when I use NetCDF with Fortran and need to look at the documentation, I look at the C-documentation at https://www.unidata.ucar.edu/software/netcdf/docs/modules.html and 'translate' it to the Fortran API (for example replacing the nc_ with nf90_) because the C documentation is far more current than the Fortran one.
There seem to be these possible status results:
NF90_NOERR No error.
NF90_EPERM Attempting to create a netCDF file in a directory where you do not have permission to open files.
NF90_ENFILE Too many files open
NF90_ENOMEM Out of memory.
NF90_EHDFERR HDF5 error. (NetCDF-4 files only.)
NF90_EDIMMETA Error in netCDF-4 dimension metadata. (NetCDF-4 files only.)
None of these suggest that you were opening a file that doesn't exist. Maybe try it out?
But if you only want to know whether the file already exists, why not use Fortran's INQUIRE statement?
logical :: fileExists
...
inquire(file=filePath, exist=fileExists)
if (fileExists) then
call nf90_open(
else
call nf90_create(
end if
Related
I need to create a file in fortran and then read the data in the file.
call execute_command_line('pwd > workdir.dat')
open(unit=10, file='workdir.dat', status='replace', IOSTAT=open_stat)
if (open_stat /= 0) stop "Reading workdir.dat file Error"
read(10,"(A)") workdir
close(10)
However, workdir.dat is empty when I try to open it, giving me serious open error. It seems that the system only flush the content of workdir.dat to the file at the end of the program. How do I make sure workdir.dat is ready to use before open ?
The open statement includes the clause status=replace which, in effect, tells the run time system that to discard the file's contents and write them anew. To be precise, the language standard states wrt to the status specifier on an open statement:
If REPLACE is specified and the file does exist, the file is deleted,
a new file is created with the same name, and the status is changed to
OLD.
Change the clause to status=old which is the correct specification for this case.
I just want to know that how to retrieve all the record from universe database table using universe basic subroutine.I am new in universe.
Perhaps something like this in the unibasic
OPEN "filename" to FIL ELSE STOP 201,"cannot open filename"
EXECUTE "SELECT filename"
LOOP WHILE READNEXT ID
READ REC FROM FIL,ID ELSE REC = ""
* you now have the entire row in REC
REPEAT
Can you provide more information on what you are trying to do?
Having a subroutine call return the entire contents of a UniVerse file could return a large amount of data. I would expect you would be better off only returning a subset of the items so the calling routine can process a bit at a time.
New content based on comment:
Ok, since you mentioned a type 19 file, I assume you want to read one file from the directory/folder the file points to.
In your subroutine, you can use OPEN on the type 19 file, and use the READ command to read the file. ( Note that you can also use READU, READL, MATREAD, MATREADU, or MATREADL to get the entire file in the directory/folder, depending on if/how you want to lock the item and if you want the data in a dynamic or dimensioned array. If you only need a specific attribute you can then use READV, READVL or READVU commands.
Or, since this is a type 19 file, you can use sequential reads. Open the file with OPENSEQ and read with the READSEQ or READBLK command.
There is an article and sample code on GitHub on how to execute U2 UniVerse Subroutine.
Execute Rocket MV U2 Subroutine Asynchronously using C# (async\await) and U2 Toolkit for .NET. Convert Subroutine Multi-Value Output to Json/Objects/DataTable
These sample code are based on C# (async\await), but you can use for synchronous programming as well with little code tweak.
For article:
Go to this link :
https://github.com/RocketSoftware/multivalue-lab/tree/master/U2/Demos/U2-Toolkit/AsyncAwait/Execute_Subroutine_Async
Read ‘Subroutine-Async.docx’ file.
Sample Code for this article on GitHub
Go to this link :
https://github.com/RocketSoftware/multivalue-lab/tree/master/U2/Demos/U2-Toolkit/AsyncAwait/Execute_Subroutine_Async
OPEN '',FILENAME TO F.FILE ELSE STOP
SELECT F.FILE
LOOP
READNEXT K.FILE ELSE EXIT
READ R.FILE FROM F.FILE, K.FILE ELSE NULL
PRINT R.FILE
REPEAT
PRINT "All over Red Rover"
Filename should be in quotes, i.e "MYFILE" or 'MYFILE'
The loop will repeat till all records have been read and will then exit.
So I have a software program that for reasons that are beyond this post, I will not include but to put it simply, I'd like to "MOD" the original software. The program is launched from a Windows Application named ViaNet.exe with accompanying DLL files such as ViaNetDll.dll. The Application is given an argument such as ./Statup.cat. There is also a WatchDog process that uses the argument ./App.cat instead of the former.
I was able to locate a log file buried in my Windows/Temp folder for the ViaNet.exe Application. Looking at the log it identifies files such as:
./Utility/base32.atc:_Encode32 line 67
./Utilities.atc:MemFun_:Invoke line 347
./Utilities.atc:_ForEachProperty line 380
./Cluster/ClusterManager.atc:ClusterManager:GetClusterUpdates line 1286
./Cluster/ClusterManager.atc:ClusterManager:StopSync line 505
./Cluster/ClusterManager.atc:ConfigSynchronizer:Update line 1824
Going to those file locations reveal files by those names, but not ending with .atc but instead .cat. The log also indicates some sort of Class, Method and Line # but .cat files are in binary form.
Searching the program folder for any files with the extension .atc reveals three -- What I can assume are uncompiled .cat files -- files. Low and behold, once opened it's obviously some sort of source code -- with copyright headers, lol.
global ConfigFolder, WriteConfigFile, App, ReadConfigFile, CreateAssocArray;
local mgrs = null;
local email = CreateAssocArray( null);
local publicConfig = ReadConfigFile( App.configPath + "\\publicConfig.dat" );
if ( publicConfig != null )
{
mgrs = publicConfig.cluster.shared.clusterGroup[1].managers[1];
local emailInfo = publicConfig.cluster.shared.emailServer;
if (emailInfo != null)
{
if (emailInfo.serverName != "")
{
email.serverName = emailInfo.serverName;
}
if (emailInfo.serverEmailAddress != "")
{
email.serverEmailAddress = emailInfo.serverEmailAddress;
}
if (emailInfo.adminEmailAddress != null)
{
email.adminEmailAddress = emailInfo.adminEmailAddress;
}
}
}
if (mgrs != null)
{
WriteConfigFile( ConfigFolder + "ZoneInfo.dat", mgrs);
}
WriteConfigFile( ConfigFolder + "EmailInfo.dat", email);
So to end this as simply as possible, I'm trying to find out two things. #1 What Programming Language is this? and #2 Can the .cat be decompiled back to .atc. files? -- and vice versa. Looking at the log it would appear that the Application is decoding/decompiling the .cat files already to interpret them verses running them as bytecode/natively. Searching for .atc on Google results in AutoCAD. But looking at the results, shows it to be some sort of palette files, nothing source code related.
It would seem to me that if I can program in this unknown language, let alone, decompile the existing stuff, I might get lucky with modding the software. Thanks in advance for any help and I really really hope someone has an answer for me.
EDIT
So huge news people, I've made quite an interesting discovery. I downloaded a patch from the vendor, it contained a batch file that was executing ViaNet.exe Execute [Patch Script].atc. I quickly discovered that you can use Execute to run both .atc and .cat files equally, same as with no argument. Once knowing this I assumed that there must be various arguments you can try, well after a random stroke of luck, there is one. That being Compile [Script].atc. This argument will compile also any .atc file to .cat. I've compiled the above script for comparison: http://pastebin.com/rg2YM8Q9
So I guess the goal now is to determine if it's possible to decompile said script. So I took a step further and was successful at obtaining C++ pseudo code from the ViaNet.exe and ViaNetDll.dll binaries, this has shed tons of understanding on the proprietary language and it's API they use. From what I can tell each execution is decompiled first then ran thru the interpreter. They also have nicknamed their language ATCL, still no idea what it stands for. While searching the API, I found several debug methods with names like ExecuteFile, ExecuteString, CompileFile, CompileString, InspectFunction and finally DumpObjCode. With the DumpObjCode method I'm able to perform some sort of dump of script files. Dump file for above script: http://pastebin.com/PuCCVMPf
I hope someone can help me find a pattern with the progress I made. I'm trying my best to go over the pseudo code but I don't know C++, so I'm having a really hard time understanding the code. I've tried to seperate what I can identify as being the compile script subroutines but I'm not certain: http://pastebin.com/pwfFCDQa
If someone can give me an idea of what this code snippet is doing and if it looks like I'm on the right path, I'd appreciate it. Thank you in advanced.
I would like to know if in Fortran it is possible to use just a single command (with options/specifiers) to do the following:
open a file if it exists and append some data
(this can be done with: open(unit=40,file='data.data',Access = 'append',Status='old') but if the file does not exist a runtime error is issued)
create the file if it does not exist and write some data.
I am currently using inquire to check whether the file exist or not but then I still have to use the open statement to append or write data.
As far as I am aware of, the only safe solution is to do the way you're already doing it, using different open statements for the different cases:
program proba
implicit none
logical :: exist
inquire(file="test.txt", exist=exist)
if (exist) then
open(12, file="test.txt", status="old", position="append", action="write")
else
open(12, file="test.txt", status="new", action="write")
end if
write(12, *) "SOME TEXT"
close(12)
end program proba
You may be interested in my Fortran interface library to libc file system calls (modFileSys), which could at least spare you the logical variable and the inquire statement by querying the file status directly:
if (file_exists("test.txt")) then
...
else
...
end if
but of course you can program a similar function easily yourself, and especially it won't save you from the two open statements...
open(61,file='data.txt',action='write',position='append')
write(61,*) 'hey'
close(61)
This will append to an existing file, otherwise create and write. Adding status='unknown' would be equivalent.
if you replace the status from 'old' to 'unknown' then you will not get the run time error if the file exists or now.
Thanks
In open statement add the attribute access as follows;
Open(unit=031,file='filename.dat',form='formatted',status='unknown',access='append')
The above statement will open the file without destroying old data and write command will append the new lines in the file.
The simplest solution for fortran 90.
I would like to open 10,000 files with file names starting from abc25000 until abc35000 and copy some information into each file. The code I have written is as below:
PROGRAM puppy
IMPLICIT NONE
integer :: i
CHARACTER(len=3) :: n1
CHARACTER(len=5) :: cnum
CHARACTER(len=8) :: n2
loop1: do i = 25000 ,35000 !in one frame
n1='abc'
write(cnum,'(i5)') i
n2=n1//cnum
print*, n2
open(unit=i ,file=n2)
enddo loop1
end
This code is supposed to generate files starting from abc24000 until abc35000 but it stops about half way saying that
At line 17 of file test-openFile.f90 (unit = 26021, file = '')
Fortran runtime error: Too many open files
What do I need to do to fix the above code?
This limit is set by your OS. If you're using a Unix/Linux variant, you can check the limit using from the command line using ulimit -n, and raise it using ulimit -n 16384. You'll need to set a limit greater than 10000 to allow for all the other files that the shell will have open. You may also need admin privileges to do this.
I regularly bump the limit up to 2048 to run Fortran programs, but never as high as 10000. However, I echo the other answers that, if possible, it's better to restructure your program to close each file before opening the next.
You need to work on the files one at a time (or in small groups that do not exceed the limitation imposed by the operating system).
for each file:
open file
write
close file
Operating systems tend to have limits on resources. Typically on, for instance, Linux, there is by default a limit of 1024 file descriptors per process. The error message you're getting is just the Fortran runtime library passing information upwards that it was unable to open yet another file due to an OS error.