Calling shell command to run C++ code from Ruby - ruby-on-rails

I have a compiled c++ file that I would like to run from within a temporary directory in ruby:
folder = Dir.mktmpdir
begin
puts folder
File.open("#{folder}/input.xml", 'w') { |file| file.write(builder.to_xml) }
ensure
system '.././program'
FileUtils.remove_entry folder
end
The above code properly creates all the desired file/folder, but does not run the system call, and does not produce an error. I have tried the all of the varieties listed here: Calling shell commands from Ruby but cannot seem to get it to function. If I comment out the file deletion line and manually go and execute the command listed above, the program functions properly. Also, if I instead save the file to the same location as the ./program, the ./program works. What is preventing me from running the command from a sub-folder?

maybe system finding a program has name .././program
try the backtick operator or %x function
puts `.././program`
puts %x{.././program}

Related

trying to run an .exe file in lua

recently i have been trying to run a script in lua that through os.execute() will execute a script in C# compiled into an executablethat is in the same directory as my script.
In my first attempt adding the entire directory until the executable worked:
os.execute("C:\\ServerTest\\test\\tex\\testcode.exe")
however I need this script to work on other computers, which means I can't add the entirely path to the file.I tried countless methods to execute the .exe file inside the same directory without using the entire path and none of the methods worked
os.execute("./testcode")
os.execute [[".\testcode.exe"]]
os.execute(".\\testcode.exe")
os.execute "testcode.exe"
I even tried to create an environment variable and run the entire directory from it xD
os.execute("set wTest=%cd%")
os.execute("%wTest%\\testcode.exe")
but nothing worked. I also tried to use io.popen() but didn't get results either (because the executable will close a computer process, it does not give any output :V)
does anyone know how I can do this?????

sql*plus # vs ## to run a file

We have some migration scripts that use ##filename and #filename in SQL*Plus scripts to call another file. (e.g. to call thesql.sql its ##thesql)
I want to understand the difference between the # and the ##.
I have found many answers explaining #filename will call a file from the current directory but nothing about the double #.
FYI: ##filename and ##filename.sql both seem to work because it assumes the extension
I ended up finding the answer on https://www.orafaq.com/wiki/SQL*Plus_FAQ#What_is_the_difference_between_.40_and_.40.40.3F
What is the difference between # and ##?
The # (at symbol) is equivalent to the START command and is used to run SQL*Plus command scripts.
SQL> #myscript.sql
A single # symbol runs a script in the current directory (or one specified with a full or relative path, or one that is found in your SQLPATH or ORACLE_PATH).
## will start a sqlplus script that is in the same directory as the script that called it (relative to the directory of the current script). This is normally used for nested command files. This technique is commonly used by scripts that call subscripts in the ?/rdbms/admin directory. The ## reference does not support relative directory references such as ##dir/file.sql or ##./file.sql.
I just found that START command, like most other SQLPlus commands, can be continued on the next line after you put a dash "-" at the end of the previous line (useful when a script takes many or long arguments). However, this does not work for # or ## - in SQLPlus version 19.3 anyway.
Command line continuation works for both START and # in SQLcl (command line tool from SQL Developer).

Ruby change directory in code

So, I've came across an issue where I delete the current folder where my ruby script is executing ex:
/home/user/scriptfolder
Now i have my ruby gem running and I do this:
mycommand --deletefull
now mycommand is an GLI command, which should delete the content of the folder and the folder itself. I do that by using my custom class:
ClientModuleDir.rm_f(path)
now after deleting it I want to just do cd ..
however I've tried several methods:
system('cd ..')
Dir.chdir(dir) #dir is abs path without the scripfolder name, i've tried every combination with this command, nothing works so far.
However these methods are not working.
I still am in the
/home/user/scriptfolder
after executing these commands, but the folder DOES NOT EXIST. When I manually do cd .. and i do ls the folder is not there.
How do I change "physically" the folder in ruby code ?
The current working directory is always kept for the current program only. Changing the working directory in a program won't affect any other running programs, including its parent.
Thus, when you delete the directory in your Ruby script and change the working directory of the Ruby process one level down, this won't affect the shell process which has started your Ruby script.

Notepad++ sets incorrect path when running script

I have a simple script that I want to import into another with require, but when I run it from Notepad++ I get the usual error that require produces.
The funny thing is that it worked an hour ago and I did not restart the computer since then.
The files are in the same directory, so the simple file name (without .lua) worked and should still work. (relative path)
Lua runs the script just fine.
this is what I entered in Notepad:
cmd /k lua "$(FULL_CURRENT_PATH)"
Earlier I also had a problem with Penlight, maybe there is some connection, so here it is:
I tried to require"pl" but it failed to find the module. (ran from SciTE, worked prevously)
I tried it in the Lua command line and it worked like a charm.
Tried again in SciTE and voila it worked again.
I have no idea what causes any of them.
ps.: using the lfs module and os.execute("cd /d ...path...") did not work
Lua is searching for your required module in the folders of LUA_PATH. In the script you run via F5, put this statement:
print('current path is:')
os.execute('cd')
require 'someModuleThatDoesntExist'
After printing the "working" forlder (Program Files/Notepad++), it tries to find the required module and fails. The traceback shows that Lua looks through many different folders, none of them being the one containing FULL_CURRENT_PATH, so it can't find the module.
You have several choices:
put your scripts in one of the listed paths
set LUA_PATH in your environment to contain the folder name where your scripts are located
change package.path from your script so it knows where to look for other modules. You could do this by either:
including an extra parameter to your F5, namely CURRENT_DIRECTORY, and make your script take its first command line param (CURRENT_DIRECTORY) to add it to package.path
parse arg[0] when your script starts, to get the folder containing script, and extend package.path
For example with #3, first option, you would use
cmd /k lua "$(FULL_CURRENT_PATH)" "$(CURRENT_DIRECTORY)"
in notepad++ and in your Lua module you would use
thisModuleDir = arg[1]
package.path = thisModuleDir .. ";" .. package.path
require 'yourmodule'

How do I save a ruby file? (error)

I am receiving the error No such file or directory in my command line and I think it's because I am not saving the ruby files somewhere specific. All I did was create a random folder where I would save my ruby files.
Do I need to save my scripts in the original ruby folder? Thanks!
** This is Windows 7.
More info -
All I did was make a simple file named "Matz.rb" because I'm currently reading the O'reilly Ruby book. In my code all I wrote was puts "Hello Matz". I saved this on my desktop. When I go to the command line it and I write ruby matz.rb it says "ruby: No such file or directory -- matz.rb " Please help :(
If this has something to do with PATH or shells, I honestly have no idea what those really are because I just started coding last night.
You are most likely not in the right folder. You somehow need to tell the ruby interpreter where it is looking for the file.
Either make sure you're in the right folder - the cd command allows you to change location:
cd C:\Users\Username\Desktop
ruby Matz.rb
or specify the path explicitly:
ruby C:\Users\Username\Desktop\Matz.rb
By default, the ruby interpreter will look in your current directory (the location shown in your prompt) for whatever filename you give it.
Edit: I'll attempt to explain what I mean step-by-step.
When you initially open the command prompt, it will indicate what folder you are in (your "current working directory") in the prompt:
C:\Users\YourUsername >
In the above example, you are working in the C:\Users\YourUsername folder.
You can move directories using the cd command. For example, typing cd Desktop moves you into the folder called Desktop, assuming such a folder exists in your current location
You can move to another folder outside your current folder by specifying explicitly where you want to be: cd C:\Another\Place
When you run a ruby command such as ruby Matz.rb, the system knows how to find the ruby program because the installer placed its location into the PATH environment variable. Don't worry about this too much, this just explains the "magic" by which it knows what ruby means, no matter where you are.
Ruby finds the file you specify (in the above example, Matz.rb) by looking in the current directory. To re-iterate, it is looking in whatever folder is written right there in your prompt.
You can tell ruby to look outside the current folder by specifying the full path (as shown in the answer above).
To go from a new command window that you've just opened, to typing ruby Matz.rb and having it work, you need to do the following:
Move to the correct directory
Run the command
If we assume your username is alex and you have a folder on your desktop called "rubycode", which contains Matz.rb, you could do this:
Open a command prompt, which will most likely start in C:\Users\Alex
Move to the rubycode folder on your desktop: cd Desktop\rubycode. All subsequent commands will be working from within this folder.
Run the ruby command, specifying the file: ruby Matz.rb
Continue to run ruby commands as you learn ruby.
I hope that makes sense.

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