I can't understand why this error occurs. I have a file named hello.rb, it is in "C/Ruby192/bin/hello.rb".
irb(main):005:0>load("hello.rb")
Load Error: no such file to load -- hello.rb
from(irb):5:in`load'
from(irb):5
from C:/Ruby192/bin/irb:12:in`<main>'
I would be very appreciative if you could solve this problem.
From the fine manual:
load(filename, wrap=false) → true
Loads and executes the Ruby program in the file filename. If the filename does not resolve to an absolute path, the file is searched for in the library directories listed in $:.
Your "hello.rb" is not an absolute path so load looks through $: to find it in the library directories. Presumably, 'C/Ruby192/bin' isn't in $: (or '.' isn't in $: if you're in C/Ruby192/bin/ already). Try specifying the full path:
> load('C/Ruby192/bin/hello.rb')
> load('./hello.rb') # If you're in C/Ruby192/bin/ already
Related
I'm trying to use Atom to run a Lua script. However, when I try to load files via the require() command, it always says it's unable to locate them. The files are all in the same folder. For example, to load utils.lua I have tried
require 'utils'
require 'utils.lua'
require 'D:\Users\Mike\Dropbox\Lua Modeling\utils.lua'
require 'D:\\Users\\Mike\\Dropbox\\Lua Modeling\\utils.lua'
require 'D:/Users/Mike/Dropbox/Lua Modeling/utils.lua'
I get errors like
Lua: D:\Users\Mike\Dropbox\Lua Modeling\main.lua:12: module 'D:\Users\Mike\Dropbox\Lua Modeling\utils.lua' not found:
no field package.preload['D:\Users\Mike\Dropbox\Lua Modeling\utils.lua']
no file '.\D:\Users\Mike\Dropbox\Lua Modeling\utils\lua.lua'
no file 'D:\Program Files (x86)\Lua\5.1\lua\D:\Users\Mike\Dropbox\Lua Modeling\utils\lua.lua'
no file 'D:\Program Files (x86)\Lua\5.1\lua\D:\Users\Mike\Dropbox\Lua Modeling\utils\lua\init.lua'
no file 'D:\Program Files (x86)\Lua\5.1\D:\Users\Mike\Dropbox\Lua Modeling\utils\lua.lua'
The messages says on the first line that 'D:\Users\Mike\Dropbox\Lua Modeling\utils.lua' was not found, even though that is the full path of the file. What am I doing wrong?
Thanks.
The short answer
You should be able to load utils.lua by using the following code:
require("utils")
And by starting your program from the directory that utils.lua is in:
cd "D:\Users\Mike\Dropbox\Lua Modeling"
lua main.lua
The long answer
To understand what is going wrong here, it is helpful to know a little bit about how require works. The first thing that require does is to search for the module in the module path. From Programming in Lua chapter 8.1:
The path used by require is a little different from typical paths. Most programs use paths as a list of directories wherein to search for a given file. However, ANSI C (the abstract platform where Lua runs) does not have the concept of directories. Therefore, the path used by require is a list of patterns, each of them specifying an alternative way to transform a virtual file name (the argument to require) into a real file name. More specifically, each component in the path is a file name containing optional interrogation marks. For each component, require replaces each ? by the virtual file name and checks whether there is a file with that name; if not, it goes to the next component. The components in a path are separated by semicolons (a character seldom used for file names in most operating systems). For instance, if the path is
?;?.lua;c:\windows\?;/usr/local/lua/?/?.lua
then the call require"lili" will try to open the following files:
lili
lili.lua
c:\windows\lili
/usr/local/lua/lili/lili.lua
Judging from your error message, your Lua path seems to be the following:
.\?.lua;D:\Program Files (x86)\Lua\5.1\lua\?.lua;D:\Program Files (x86)\Lua\5.1\lua\?\init.lua;D:\Program Files (x86)\Lua\5.1\?.lua
To make that easier to read, here are each the patterns separated by line breaks:
.\?.lua
D:\Program Files (x86)\Lua\5.1\lua\?.lua
D:\Program Files (x86)\Lua\5.1\lua\?\init.lua
D:\Program Files (x86)\Lua\5.1\?.lua
From this list you can see that when calling require
Lua fills in the .lua extension for you
Lua fills in the rest of the file path for you
In other words, you should just specify the module name, like this:
require("utils")
Now, Lua also needs to know where the utils.lua file is. The easiest way is to run your program from the D:\Users\Mike\Dropbox\Lua Modeling folder. This means that when you run require("utils"), Lua will expand the first pattern .\?.lua into .\utils.lua, and when it checks that path it will find the utils.lua file in the current directory.
In other words, running your program like this should work:
cd "D:\Users\Mike\Dropbox\Lua Modeling"
lua main.lua
An alternative
If you can't (or don't want to) change your working directory to run the program, you can use the LUA_PATH environment variable to add new patterns to the path that require uses to search for modules.
set LUA_PATH=D:\Users\Mike\Dropbox\Lua Modeling\?.lua;%LUA_PATH%;
lua "D:\Users\Mike\Dropbox\Lua Modeling\main.lua"
There is a slight trick to this. If the LUA_PATH environment variable already exists, then this will add your project's folder to the start of it. If LUA_PATH doesn't exist, this will add ;; to the end, which Lua fills in with the default path.
I am trying to write some data in one Ruby file to a file in another folder but I am having trouble identifying the path to get to the file I want to write to.
My current code is:
File.write('../csv_fixtures/loans.csv', 'test worked!')
And my folder structure is as follows:
Where I am trying to run my code in 'run_spec.rb' and write to 'loans.csv'.
Additionally, this is the error I am getting:
Give the path relative to the working directory, not the file that you call File.write from. The working directory is the place you've navigated to through cd before calling the ruby code. If you ran rspec from the root of your project, then the working directory will also be the root. So, in this case, it looks like it would be ./spec/csv_fixtures/loans.csv. You can run puts Dir.pwd to see the working directory that all paths should be relative to.
If you wanted to something more like require_relative, you have to use some sort of workaround to turn it into an absolute path, such as File.dirname(__FILE__) which gives the absolute path of the folder containing the current file:
path = File.join(File.dirname(__FILE__, "../csv_fixtures/loans.csv"))
I have a command line program that asks the user a set of questions and stores them in a file. The only problem is, I need it to create a new file and it won't.
Here is what I have tried:
File.open("path/to/file", "w")and File.open("path/to/file", "w+")
Both times I get this error
in 'initialize': No such file or directory # rb_sysopen - path/to/file (Errno::ENOENT)
Here is my current code:
File.open("path/to/file", "w") { |f| f.write(array.join("\n")) }
When someone writes path/to/file in a blog post or documentation, they don't intend for you to literally write path/to/file in your code. The point is that you need to edit that string to actually have the real path to your file, either as a relative path or an absolute path.
You said you are getting this error from the Ruby interpreter:
No such file or directory # rb_sysopen - path/to/file (Errno::ENOENT)
This means that in the current working directory, there is no directory named "path", or if there is a directory named "path", then it doesn't have a child directory named "to".
You could solve the immediate problem by running mkdir -p path/to, but that would be weird. It is better to just write an appropriate path in your code, pointing to a directory that already exists. Try changing the path to simply be output.txt (without any slashes) and see how that works.
Ensure you are using an absolute path, and if so, make sure the directory you want to store the file in is missing. Try creating it first:
require 'fileutils'
FileUtils.mkdir_p '/path/to'
File.open('/path/to/file', 'w') { ... }
I'm building a webcrawler and I want it to output to a new file that is timestamped. I've completed what I thought would be the more difficult part but I cannot seem to get it to save to the desktop.
Dir.chdir "~/Desktop"
dirname = "scraper_out"
filename = "#{time}"
Dir.mkdir(dirname) unless File.exists?(dirname)
Dir.chdir(dirname)
File.new(filename, "w")
It errors out on the first line
`chdir': No such file or directory # dir_chdir - ~/Desktop
I've read the documentation on FileUtils, File and cannot seem to find where people change into nested directories from the root.
Edit: I don't think FileUtils understands the ~.
~/ is not recognized by Ruby in this context.
Try:
Dir.chdir ENV['HOME']+"/Desktop"
This might help you
Create a file in a specified directory
I have created a project in /Projects/test that have the following files:
/Projects/test/first.rb
/Projects/test/second.rb
In first.rb, I do:
load 'second.rb'
And it gets loaded correctly. However, if I open the console and I type $:, I don't see the current directory "." in the load path. How does Ruby know where to load that 'second.rb' from?
See the documentation of Kernel#load clearly :
Loads and executes the Ruby program in the file filename. If the filename does not resolve to an absolute path, the file is searched for in the library directories listed in $:. If the optional wrap parameter is true, the loaded script will be executed under an anonymous module, protecting the calling program’s global namespace. In no circumstance will any local variables in the loaded file be propagated to the loading environment.
In case load 'second.rb' - second.rb has been internally resolved to the absolute path /Projects/test/second.rb,as your requiring file in the directory is same as required file directory. Nothing has been searched to the directories listed in$: for your case.
Just remember another way always
- The load method looks first in the current directory for files
Contrary to the currently accepted answer, the argument 'second.rb' does not resolve to an absolute path. If that were what was meant, you would also be able to require 'second.rb', since require has exactly the same wording about absolute paths.
I think what's happening here is just that the phrasing in the documentation for load is not clear at all about what the actual steps are. When it says "Loads and executes the Ruby program in the file filename," it means that literally — it treats the argument as a file name and attempts to load it as a Ruby program. If isn't an absolute path†, then Ruby goes through $LOAD_PATH and looks for it in those places. If that doesn't turn anything up, then it just goes ahead and tries to open it just as you passed it in. That's the logic that MRI actually follows.
† The actual check that Ruby does is essentially "Does the path start with '/', '~' or './'?".