I came across the following line of code
#base_dir = File.expand_path(".")
Can anyone tell what the use is of expand_path and the "." as a parameter?
File.expand_path() receives a directory (like "." that denotes the current directory) and returns the absolute path of that same directory.
So in this case it will return the absolute path of the current working directory.
Look here the documentation of this method:
http://ruby-doc.org/core-1.9.3/File.html
Related
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 an image with the filename media_httpfarm3static_mAyIi.jpg.
I would like to search the parent folder and all subfolders of that parent folder for a file that contains that name - it doesn't have to be the EXACT name, but must contain that string.
E.g. this file should be returned: 11605730-media_httpfarm3static_mAyIi.jpg
So this is a 2-part question:
How do I achieve the above?
Once I have the file, how do I return the path for that file?
Use Dir::[] and File::absolute_path:
partial_name = "media_httpfarm3static_mAyIi.jpg"
Dir["../**/*#{partial_name}"].each do |filename|
puts File.absolute_path(filename)
end
This uses the glob "../**/*media_httpfarm3static_mAyIi.jpg" (go up one directory, then search all sub directories (recursively), for any file ending in the partial string "media_httpfarm3static_mAyIi.jpg". The relative paths are then returned in an Array.
You can use Array#each, Array#map, etc. to convert this into what you need. To convert a relative path, into an absolute path, just pass it to File::absolute_path.
Once you have the absolute path, you can use it to open the file, read the file, etc.
On File Paths
The glob "../**/*media_httpfarm3static_mAyIi.jpg" is relative to the current working directory. Normally, this is the directory from which the program was run. Not the directory of the source file. This can change using various utilities to change it.
To always use a glob relative to the source code file, try:
Dir[File.expand_path('../**/*#{partial_name}', __FILE__)]
You can also use:
Dir[File.join(__dir__, "..", "**", "*#{partial_name}")]
Note: __dir__ was added in Ruby 2.0. For older versions of ruby use File.dirname(__FILE__)
In the first code sample File::absolute_path was used. In the last sample File::expand_path is used. In most situations these can be used interchangeably. There is a minor difference, per the documentations:
File::absolute_path
Converts a pathname to an absolute pathname. Relative paths are
referenced from the current working directory of the process unless
dir_string is given, in which case it will be used as the starting
point. If the given pathname starts with a “~” it is NOT expanded, it
is treated as a normal directory name.
File::expand_path
Converts a pathname to an absolute pathname. Relative paths are
referenced from the current working directory of the process unless
dir_string is given, in which case it will be used as the starting
point. The given pathname may start with a “~”, which expands to the
process owner’s home directory (the environment variable HOME must be
set correctly). “~user” expands to the named user’s home directory.
Ok so with siriproxy it my lib folder along with the rb file for the plugin I have created a myconfig.yml file so I can change certain settings by writing to that file.
I have been able to write to the file but only if I include the full path all the way from the home directory down.
But is there not a way to open the file from the same directory i am in? I have tried every path combination I can think of.
There has to be one i am missing
If you use the following in your ruby file, you should get the absolute path where it is
File.expand_path(__FILE__)
From doc __FILE__
The name of the file currently being executed, including path relative to the directory where the application was started up (or the current directory, if it has been changed)
From doc File.expand_path
Converts a pathname to an absolute pathname.
As you probably want the directory, you should use File.dirname(__FILE__), so the path of your file myconfig.yml should be obtained with
File.join(File.expand_path(File.dirname(__FILE__)), 'myconfig.yml')
In more recent Ruby (>=2.0.0), you can use __dir__ (from Archonic's comment):
Returns the canonicalized absolute path of the directory of the file from which this method is called. It means symlinks in the path is resolved. If FILE is nil, it returns nil. The return value equals to File.dirname(File.realpath(FILE)).
I was trying to get path current path in PHP. I tried looking though phpinfo();, but I haven't found any interesting values which could be used to get path to my script. There is no nice values which I used on Linux, like $_SERVER["PWD"].
Now I'm wondering how I'm supposed to find current path. Maybe some function will work... I really have no idea. Because I don't want to hardcode path to script.
getcwd() is what you are looking for.
It's not entirely clear whether you mean the current working directory, or the path to the current script. For the working directory, see #Taze's answer.
For the current script, the __FILE__ magic constant will give you the full filesystem path to the current file.
Note that these constants take "current file" literally: If you include a file and call __FILE__ there, it will show the included file's path.
The getcwd() method will return the current working directory on success.
<?php
echo getcwd() . "\n";
?>
How would I, say, determine if the file ~/.my_proj_config exists on any OS in Ruby?
A call to Dir.home is a OS independent way to get to the home directory for the user. You can then use it like
File.exists?(File.join(Dir.home, ".my_proj_config"))
This works in Ruby 1.9, but note that the call to expand_path is required on some systems (e.g. Windows):
File.exists?( File.expand_path "~/.my_proj_config" )
Use the class File and its method exist?.
Take a look at the Pathname class, specifically the realpath function - This will get you the full (expanded) path to your file.
http://www.ruby-doc.org/stdlib/libdoc/pathname/rdoc/classes/Pathname.html#M001991
You then use the File class along with exists? method to find out if that exists. You shouldn't need to use realpath if you use this method, however.
http://www.ruby-doc.org/core/classes/File.html#M000045