I have a question that will help me understand how stuff works and investigate feasibility of a bigger plan I have in mind.
Simply given - lets assume that all things run locally - I am wondering if it is possible to:
create an html page with a form that will prompt the user to enter
the local path of an input file inputFile.dat
this input file will be fed to a c++ exe program that expects it for input
the c++ exe file will run (this exe file depends on libraries etc but lets assume all are local here)
... and will output the result on screen
It sounds simple, but is it?
Many thanks folks!
Yes, this is definitely possible, if you want to use PHP or some other scripting language.
Create a form on your web page
Add the directory of the program
Add the directory of the data
When submitted, use the PHP (or other language) exec function (docs) to execute the program, with the supplied data as argument
The exec function returns output from the program.
Display the output as wished on your page.
Good luck!
Related
In short: I am trying to load a csv file but the program always overwrites the existing file as an empty new file.
Longer: I am pretty new to Fortran, so bear with me. I am trying to read data from a csv file into a fortran program. Now I didn't write the program and it is pretty big, so I can't post the whole thing here. The program consists of a whole bunch of .f90 files and everything is compiled using a makefile. Now since I am loading the gcc module before compiling, I am assuming that it is compiled using GNU Fortran, because it is part of gcc. (idk how to find out if that is correct)
The compiler returns an executable in a different directory. When I execute the program in that directory it apparently overwrites the existing .csv file with a new blank one, so the program only reads "End of File". I don't know why it always creates a new file, how do I stop it from doing so?
As a side note, the csv file I am trying to read simply consists of a single column of floats, e.g.
"0.01, 0.13, 0.041,..." etc.
The code that I inserted into a subroutine of one of the .f90 files is the following:
real*8, dimension(nz) :: Nsq
integer :: i
open(10, file='Nsq.csv')
do i=1,20
read(10, *) Nsq(i)
enddo
close(10)
I have also tried to write a small test program, essentially running the same code as above. That one works just fine and outputs the contents of the csv file without any issues. For that one I use gfortran to compile it.
I have no experience in Fortran at all, so I am completely stumped, why this happens. I know the chances are slim that you guys can help me with this, since I can't provide the whole source code. But maybe someone has an idea why this occurs. Maybe you know an alternate way of reading csv files?
Thanks for your time.
The open-statement in Fortran OPEN(connect-spec-list), has a lot of connection specifications which define how an external file should be managed (see. Fortran 2018 Standard sec 12.5.6).
When you open a file using the simplest form of the open-statement:
OPEN(unit=unitid,file="filename")
A lot of default assumptions are made such as: ACCESS="SEQUENTIAL", ASYNCHRONOUS="NO", BLANK="NULL", .... The most important ones, however, are ACTION and STATUS which define the purpose of the file. The action specification states if you want to use the file for reading, writing or both, while the status essentially defines if we work on an existing file or not, and what we should do with it (replace it, keep it, ...)
Both these specifications have a default compiler dependent state.
In the Intel compiler suit, the default is action="readwrite", status="unknown" (see here and here)
Intel defines the status="unknown" as :Indicates the file may or may not exist. If the file does not exist, a new file is created and its status changes to 'OLD'.
The Gnu compiler suit has a different take on this. The default action is defined by a set of rules which depend on its accessibility if the file exists (+rw,+r-w,-r+w) (see here). The behaviour for the default action="unknown" is not documented but seems to be REWRITE (see Default Status of "Unknown" in Open)
It is advised to use a proper method if you know what you want to do with the file:
OPEN(newunit=unitid, file="filename", action="read", status="old")
I have a workflow Knime, in the middle I must execute an external program to create an Excel file.
Exists some node that allows me to achieve this? I don't need to put any input or output, only execute the program and wait to generate the Excel file (I require to use this Excel for the next nodes).
There are (at least) two “External Tool” nodes which allow running executables on the command line:
External Tool
External Tool (Labs)
In case that should not be enough, you can always go for a Java Snippet node. The java.lang.Runtime class should be your entry point.
It's could be used the External tool node. The node requires inputs and outputs... but, you can use a table creator node for input:
This create an empty table.
In the external tool node, you must include an Input file and Output file, depending on your request, this config could be meaningless but require to the Node works.
In this case, the external app creates a text with the result of the execution, so, in the initial table (Table creator node), will be read the file and get the information into Knime.
I've never worked with web pages before and I'd like to know how best to automate the following through programming/scripting:
go to http://financials.morningstar.com/ratios/r.html?t=GMCR®ion=USA&culture=en_US
invoke the 'Export to CSV' button near the top right
save this file into local directory
parse file
Part 4 doesn't need to use the same language as for 1-3 but ideally I would like to do everything in one shot using one language.
I noticed that if I hover my mouse over the button it says: javascript:exportKeyStat2CSV(); Is this a java function I could call somehow?
Any suggestions are appreciated.
It's a JavaScript function, which is not Java!
At first glance, this may seem like you need to execute Javascript to get it done, but if you look at the source of the document, you can see the function is simply implemented like this:
function exportKeyStat2CSV(){
var orderby = SRT_keyStuts.getOrderFromCookie("order");
var urlstr = "//financials.morningstar.com/ajax/exportKR2CSV.html?&callback=?&t=XNAS:GMCR®ion=usa&culture=en-US&cur=&order="+orderby;
document.location = urlstr;
}
So, it builds a url, which is completely fixed, except the order by part, which is taken from a cookie. Then it simply navigates to that url by setting document.location. A small test shows you even get a csv file if you leave the order by part empty, so probably, you can just download the CSV from the base url that is in the code.
Downloading can be done using various tools, for instance WGet for Windows. See SuperUser for more possibilities. Anyway, 'step 1 to 3' is actually just a single command.
After that, you just need to parse the file. Parsing CSV files can be done using batch, and there are several examples available. I won't get into details, since you didn't provide any in your question.
PS. I'd check their terms of use before you actually implement this.
The button directs me to this link:
http://financials.morningstar.com/ajax/exportKR2CSV.html?&callback=?&t=XNAS:GMCR®ion=usa&culture=en-US&cur=&order=asc
You could use the Python 3 module urllib and fetch the file, save it using the os or shutil modules, then parse it using one of the many CSV parsing modules, or by making your own.
i am pretty new to html and as part of project we have to create a game where the player has to select different tags and then gets rewarded according to a value which is stored in a .csv file.
I created the layout so far with diffrent buttons, now i want to know how can i search inside the csv file and return the corresponding value? I am using html and javascript so far.
There are about 6000 entries in this file. Is it wise to load them all into an array?
And how can i share variables between functions without calling them one after the other?
For example to find out how often a button was pressed i obviously could not use a var in a script since it would be lost after the script was executed so i had to create a html input text field to store the variable constantly.
Your help is appreciated :)
Regards,
Marcurion
It would be wise to use a DBMS, however if the project requirement is to use CSV you could use a server side programming language like PHP to read and write the CSV file.
I wouldnt recommend to load all entries in the array, instead you could only load what you need but this can be achieved by using a DBMS.
To share variables between functions on javascript you will need to declare them as global variables, you could google: "javascript variables scope" or "javascript global variables" and read a little more of scopes.
If you want to know how often the button was pressed you can make AJAX requests to a server side script that can handle what you need if the script needs to be submited or executed.
You could check out JQuery framework to use events, ajax and infinite other things.
My advice is for you to read a little more about javascript, a framework for javascript like JQuery and a little of server side languages like PHP, with these tools you can easily develop what you need.
I'm currently looking for a way to add data to an already compiled ELF executable, i.e. embedding a file into the executable without recompiling it.
I could easily do that by using cat myexe mydata > myexe_with_mydata, but I couldn't access the data from the executable because I don't know the size of the original executable.
Does anyone have an idea of how I could implement this ? I thought of adding a section to the executable or using a special marker (0xBADBEEFC0FFEE for example) to detect the beginning of the data in the executable, but I do not know if there is a more beautiful way to do it.
Thanks in advance.
You could add the file to the elf file as a special section with objcopy(1):
objcopy --add-section sname=file oldelf newelf
will add the file to oldelf and write the results to newelf (oldelf won't be modified)
You can then use libbfd to read the elf file and extract the section by name, or just roll your own code that reads the section table and finds you section. Make sure to use a section name that doesn't collide with anything the system is expecting -- as long as your name doesn't start with a ., you should be fine.
I've created a small library called elfdataembed which provides a simple interface for extracting/referencing sections embedded using objcopy. This allows you to pass the offset/size to another tool, or reference it directly from the runtime using file descriptors. Hopefully this will help someone in the future.
It's worth mentioning this approach is more efficient than compiling to a symbol, as it allows external tools to reference the data without needing to be extracted, and it also doesn't require the entire binary to be loaded into memory in order to extract/reference it.