No output after compiling and executing the code - fortran

I'm new to fortran and i'm trying to execute this as an output.
program write2file
implicit none
! open file
open (10, file='output_file.txt', status='unknown')
! write to file
write(10, *) 'Hello World!'
! close file
close(10)
end program write2file
I'm running it on Linux and I have tried to use this statement to compile and execute the output, but unfortunately, I wasn't able to get the 'output_file.txt'
Does anyone know what's wrong?

This is a comment rather than an answer but I feel in need of better formatting. After you execute the command
ifort -o output hi.f90
you should have an executable called output in your current working directory. To execute that executable execute the command
./output
which will, if you are successful, write the output you want to wherever the current version of the program directs it.
Reading your comments makes me suspect that you think the command
ifort -o output hi.f90
ought to execute your program and cause the creation of the output requested. But that command just compiles your sources (in the file hi.f90) into the executable called ouptut. Is this the first time you've used a compiler ?

Related

Unable to execute Fortran77 program after successful compilation

I have a Fortran program and have command to compile it. It compiles but after that even I am unable to execute it. Any help or detailed explanation would be highly appreciated. A part of the program which I am facing problem with is mentioned below.
READ 20, ITEXT
OPEN(14, STATUS='UNKNOWN')
OPEN(3, STATUS='UNKNOWN') ! DIPAK
OPEN(9, STATUS='UNKNOWN',FILE=ITEXT) ! EFG 1
OPEN(10,STATUS='UNKNOWN',FILE='/usr/local/bin/EBTABLE.DAT',FORM='UNFORMATTED') ! DIPAK
OPEN(11,STATUS='UNKNOWN',FILE='/usr/local/bin/TL03_99.DAT', FORM='UNFORMATTED') ! DIPAK
OPEN(12,STATUS='UNKNOWN', FORM='UNFORMATTED',
1ACCESS='DIRECT',RECL=8192)
OPEN(13,STATUS='UNKNOWN', FORM='UNFORMATTED',
1ACCESS='DIRECT',RECL=8192)
The files EBTABLE.DAT and TL03_99.DAT are copied at the mentioned locations.
The command used for compiling it is given as:
fort77 -a -f -g -h -w8 ../cascade.f -o cascade
After this how should I execute, suppose my input file is named cascade.inp

Xcode 8.3: Run target with input from file

I wrote a simple C++ program that requires some input to run. In the terminal I simply run in ./myProgram < fileWithData.txt. However I could not figure out how to specify and input file for the target executed in Xcode. I used the command line project. Of course I could use a different target, for example run Terminal.app and then pass it the executable with the input file but then I can no longer debug it.
This question: Cannot get lldb to read file input explains how to set the input path in lldb, but I could not find a way to specify lldb commands that are executed before the process is started.
I don't think there's a way to do this entirely from within Xcode. However if you set the Run Scheme in Xcode to the launch mode "Wait for executable to be launched," hit run, and then run your program from Terminal.app with the appropriate piping, the Xcode-embedded lldb will connect to it.

GDB list shows nothing

A program compiled with arm-linux-gnueabi-gcc -g3 main.c .
$ gdb a.out
$ l
$ main.c: No such file or directory.
It is unable to display program lines with line number. let me know If i am missing something ?
However I am able to run program , with run command even backtrace I am able to get.
My issue is same as gdb can not load source file?
but , GDB version 7.8.
GDB needs source code to be present on same machine as in where binary been run.
mine was cross compilation , I was running program on different host . That's why I had that issue.

Changing the status of a temporary file with the open statement in gfortran

I am using an old Fortran code and I have running it using g77-3.3 in an old OS. Since this version of the compiler no longer comes with most Linux distributions I tried using gfortran (4.9.2), and I am facing this small problem.
This codes uses temporary files. It writes to this file and then at a certain point it changes the status of the file to scratch, like in the following example:
PROGRAM testopenfile
IMPLICIT NONE
WRITE(8,*)'fdsasfd'
OPEN(8,STATUS='SCRATCH')
CLOSE(8)
END PROGRAM
This piece of code works with the g77 compiler, but when I run it with gfortran I get the message:
At line 4 of file testopenfile.f (unit = 8, file = 'fort.8')
Fortran runtime error: Cannot change STATUS paramter in OPEN statement.
Has this way of setting temporary files changed in gfortran? Am I doing something wrong? Could this be a bug in this version of gfortran?
If you write to unit 8 before opening the file, you are in fact writing to a file called fort.8, see here. Apparently, this file is still open at unit 8 when you try to attach the scratch file to it.
You can solve this by opening the scratch file before writing to the unit:
PROGRAM testopenfile
IMPLICIT NONE
OPEN(8,STATUS='SCRATCH')
WRITE(8,*)'fdsasfd'
CLOSE(8)
END PROGRAM
or by using a different unit.
Chapter C.6.3 ("OPEN statement (9.5.6)") in the Fortran 2008 Standard treats this case and has an example which looks just like your code. It states that this "example is invalid because it attempts to change the value of the STATUS= specifier."
If you want to delete the file on closing, you can also do
PROGRAM testopenfile
IMPLICIT NONE
WRITE(8,*)'fdsasfd'
CLOSE(8,status='DELETE')
END PROGRAM

How can I solve Fortran runtime error: End of file?

I am using Codeblock 13.12. My file is not readable. and getting the runtime error
program asd
implicit none
integer :: x
open(unit = 2, file = "text.txt")
read(2,*)x
write(*,*)x
end program
and my text.txt file is :
1
I've seen many answers, but none of them worked for my code
Your program is just fine. As a matter of fact, even if the first line is not properly terminated, gfortran will take the EOF as the EOL and still work.
Your problem is you are working in the IDE CodeBlock. The IDE does not run the program in your working directory so the file text.txt is not where the program is running, hence the end of file error.
Check out this post Codeblock working directory which will guide you to solving your problem.