I make a call just like this:
value = ./simulated_annealing
Which is a C Object file, but Rails tells me it cannot find that file. I
put it in the same dir that the rest of the models files (since it's
called by one of those models), but I guess it should be in any other
place.
I've tried that outside Ruby and it works great.
What do I have to do?
The thing is, when you say:
./simulated_annealing
you're explicitly saying: run file named simulated_annealing which is found in the current directory. That's what the ./ means. If the file's located elsewhere you need to provide the path to it, or add that path to the environment variable $PATH. So, you should replace that line with:
/path/to/simulated_annealing
where /path/to represents the actual path.
The best option is to use an absolute path for running the program. For ex.,
you can create a directory "bin" under your rails application top level
directory. Place your program under "bin" directory. Then you can
execute the program something like:
cmd = "#{RAILS_ROOT}/bin/cbin arg1 arg2"
value = `#{cmd}`
Related
I am currenly working on an erlang project and stuck in reading the file. I want to read a text file which is in the /src folder where all the erlang and a text file are in the same structure. Then too, I am not being able to read the file despite of specifying file paths. Any help would be appreciated.
start() ->
{ok,DataList} = file:consult("Calls.txt"),
io:format("** Calls to be made **"),
io:fwrite("~w~n",[DataList]).
The data file stores contents like : {john, [jill,joe,bob]}.
Try add folder name to the path or try set full patch to the file:
1> {ok,DataList} = file:consult("src/Calls.txt").
Notes: the error {error,enoent} mean that the file does not exist or you don't have a rights to read/write current file, for this case need set 777 rights or similar.
If you need to use src/call.txt, then this simply means that your IDE (or you) has created a src folder in which the calls.txt file has been placed. At the same time, the IDE is using a path that only includes the top level folder (i.e., the root folder for the IDE project). So src/call.txt must be used in that case. This isn’t a problem with Erlang, or even the IDE. It’s just the way your project is set up.
You can do either of two things. Move the calls.txt file up one level in the IDE file manager, so that it can be referenced as calls.txt, not src/call.txt. You can also just change the path to “calls.txt” before you run it from the command line.
enoent means "Error: No Entry/Entity". It means the file couldn't be found. When I try your code, it works correctly and outputs
[{john,[jill,joe,bob]}]
In terminal i could have used something like:
mv *.ext /some/output/dir/
I want to so the same in ruby. I can use system command for that under backticks (`) or using the system(), but how to achieve the same in ruby way?
I tried:
FileUtils.mv '*.sql', '/some/output/dir/'
This is not working as it looks specifically for a file name '*.sql'
You can do:
FileUtils.mv Dir.glob('*.sql'), '/some/output/dir/'
You need to use a Glob, as in:
Dir.glob('*.sql').each do|f|
# ... your logic here
end
or more succinct:
Dir.glob('*.sql').each {|f| FileUtils.mv(f, 'your/path/here')}
Check the official documentation on FileUtils#mv which has even an example with Glob.
Update: If you want to be sure you don't iterate (although I wouldn't worry about it that much) you can always execute what you consider to be optimized in shell, directly from ruby, e.g.:
`mv *.ext /some/output/dir/`
I will do using FileUtils::cp, as it copies a file content src to dest. If dest is a directory, copies src to dest/src. If src is a list of files, then dest must be a directory.
FileUtils.cp Dir['*.sql'], '/some/output/dir/'
I wouldn't use ::mv, as if file and dest exist on the different disk partition, the file is copied then the original file is removed.
But if you don't bother with the deletion of the original files, then go with ::mv.
I need to add a new path (sumatraPDF) on my PATH variable.
I don't know why it does not work...
I think everything is right but when I try to execute sumatrapdf.exe from CMD it cannot find the program.
This is what I did:
The path is correct, I checked it 1000 times.
The idea is use LaTeX with sublimetext and when I save a .text file sumatra has to open and show to me the result. If I want that I have to add the path of SumatraPDF... but it does not work.
I think you are editing something in the windows registry but that has no effect on the path.
Try this:
How to Add, Remove or Edit Environment variables in Windows 7
the variable of interest is the PATH
also you can type on the command line:
Set PATH=%PATH%;(your new path);
Another method that worked for me on Windows 7 that did not require administrative privileges:
Click on the Start menu, search for "environment," click "Edit environment variables for your account."
In the window that opens, select "PATH" under "User variables for username" and click the "Edit..." button. Add your new path to the end of the existing Path, separated by a semi-colon (%PATH%;C:\Python27;...;C:\NewPath). Click OK on all the windows, open a new CMD window, and test the new variable.
I founded the problem:
Just insert the folder without the executable file.
so Instead of:
C:\Program Files (x86)\SumatraPDF\SumatraPDF.exe
you have to write this:
C:\Program Files (x86)\SumatraPDF\
In answer to the OP:
The PATH environment variable specifies which folders Windows will search in, in order to find such files as executable programs or DLLs. To make your Windows installation find your program, you specify the folder that the program resides in, NOT the program file itself!
So, if you want Windows to look for executables (or other desired files) in the folder:
C:\PHP
because, for example, you want to install PHP manually, and choose that folder into which to install PHP, then you add the entry:
C:\PHP
to your PATH environment variable, NOT an entry such as "C:\PHP\php.exe".
Once you've added the folder entry to your PATH environment variable, Windows will search that folder, and will execute ANY named executable file you specify, if that file happens to reside in that folder, just the same as with all the other existing PATH entries.
Before editing your PATH variable, though, protect yourself against foul ups in advance. Copy the existing value of the PATH variable to a Notepad file, and save it as a backup. If you make a mistake editing PATH, you can simply revert to the previous version with ease if you take this step.
Once you've done that, append your desired path entries to the text (again, I suggest you do this in Notepad so you can see what you're doing - the Windows 7 text box is a pain to read if you have even slight vision impairment), then paste that text into the Windows text box, and click OK.
Your PATH environment variable is a text string, consisting of a list of folder paths, each entry separated by semicolons. An example has already been given by someone else above, such as:
C:\Program Files; C:\Winnt; C:\Winnt\System32
Your exact version may vary depending upon your system.
So, to add "C:\PHP" to the above, you change it to read as follows:
C:\Program Files; C:\Winnt; C:\Winnt\System32; C:\PHP
Then you copy & paste that text into the windows dialogue box, click OK, and you should now have a new PATH variable, ready to roll. If your changes don't take effect immediately, you can always restart the computer.
The path is a list of directories where the command prompt will look for executable files, if it can't find it in the current directory. The OP seems to be trying to add the actual executable, when it just needs to specify the path where the executable is.
Try this in cmd:
cd address_of_sumatrapdf.exe_file && sumatrapdf.exe
Where you should put the address of your .exe file instead of adress_of_sumatrapdf.exe_file.
What is the difference between:
include("./somepath/class.php");
and
include("somepath/class.php");
There shouldn't be any difference, directory wise, since the former assumes relative directory structure. The only potential pitfall could be if "somepath" were actually a command to be run - some users expect to type a command for a local script file and assume it should run, when you actually have to run "./somepath" to invoke it. This, of course, only pertains to commands not on your $PATH.
I don't see any difference. "." means current directory.
. refers to the current working directory.
Sometimes you want to specify explicitly that what you want is in the current working directory, and that it is not from something in your path variable for example.
For example in PHP "somepath/somefile" is appended after paths specified in include_dir (for example: /home/var/; /home/bin/ ....) directive.
The second variant is more specific it says: search in current directory!
In my controller, a function runs a shell command. I'm having a hard time to locate the script in the commad. For example, in my controller I have this:
def find_usage
command = 'ruby usage.rb'
#{command}
end
My question is where to put that usage.rb file and how to reference it without hard code the entire path. It works when I hard code the path as /home/user/xyz/usage.rb, but I don't think it's right to do.
You could stuff it into /script and then reference RAILS_ROOT/script/usage.rb in your code. RAILS_ROOT is a constant that contains the absolute path to your application.