I am trying to create a registry key called foo if it doesn't exist, if it does exist I am trying to read its value. If value >0 I am trying to decrement it by one as a way to track trial uses of a piece of software, but I am getting this error:
$ ruby _RUNME.rb
no key exists
c:/Ruby200-x64/lib/ruby/2.0.0/win32/registry.rb:261:in `call': no implicit conversion of String into Integer (TypeError)
from c:/Ruby200-x64/lib/ruby/2.0.0/win32/registry.rb:261:in `CreateKey'
from c:/Ruby200-x64/lib/ruby/2.0.0/win32/registry.rb:412:in `create'
from c:/Ruby200-x64/lib/ruby/2.0.0/win32/registry.rb:503:in `create'
from _RUNME.rb:18:in `rescue in <main>'
from _RUNME.rb:5:in `<main>'
My code is:
begin
Win32::Registry::HKEY_CURRENT_USER.open('SOFTWARE\foo') do |reg|
value = reg['foo']
if(value.to_i>0)
reg['foo'] = value.to_i-1
else
puts "no trial uses left"
sleep(10)
Kernel.exit(false)
end
end
rescue
puts "no key exists"
Win32::Registry::HKEY_CURRENT_USER.create("software\\foo","Win32::Registry::KEY_ALL_ACCESS")
Win32::Registry::HKEY_CURRENT_USER.open('SOFTWARE\foo') do |reg|
reg['foo']="55"
puts "wrote new key foo with value 55"
end
end
using Ruby version 2.0.0
Related
I am making a tool in ruby which can interact with databases.
I am using amalgalite as an adapter for sqlite3.
Code:
require 'amalgalite'
# this is class RQuery
class RQuery
def db_open(db_name)
#db = Amalgalite::Database.new "#{db_name}.db"
make_class
end
def exec_this(query)
#db.execute(query)
end
def make_class
tables_list = exec_this("select name from sqlite_master where type='table'")
tables_list.each do |table|
#class_created = Object.const_set(table[0].capitalize, Class.new)
#class_created.class_eval do
define_singleton_method :first do
RQuery.new.exec_this("select * from #{table[0]} order by #{table[0]}.id ASC limit 1")
end
end
end
end
def eval_this(input)
instance_eval(input)
end
def code
print '>>'
input = gets
exit if input =~ /^q$/
puts eval_this(input)
code
end
end
Now when I am running the code everything works fine until I call table_name.first
It gives output
vbhv#fsociety ~/git/R-Query/bin $ ruby main.rb
Enter the code or q for quit
>>db_open('vbhv')
users
persons
people
programmers
>>Users.first
/home/vbhv/git/R-Query/lib/r-query.rb:36:in `instance_eval': undefined method `execute' for nil:NilClass (NoMethodError)
Did you mean? exec
from /home/vbhv/git/R-Query/lib/r-query.rb:29:in `block (3 levels) in make_class'
from (eval):1:in `eval_this'
from /home/vbhv/git/R-Query/lib/r-query.rb:36:in `instance_eval'
from /home/vbhv/git/R-Query/lib/r-query.rb:36:in `eval_this'
from /home/vbhv/git/R-Query/lib/r-query.rb:43:in `code'
from /home/vbhv/git/R-Query/lib/r-query.rb:44:in `code'
from /home/vbhv/git/R-Query/lib/r-query.rb:44:in `code'
from main.rb:4:in `<main>'
Now the 'execute' function it is talking about is inside amalgalite. What am I doing wrong here?? Thanks in Advance!
The problem in this was that the new class formed dynamically doesn't know about the connection variable '#db'. Hence the code solves the problem.
#class_created.instance_variable_set(:#database, #db)
A big thanks to Jagdeep Singh.
I would like to expect that YAML.load_file(foo) of ruby YAML module returns null if foo is not a YAML file. But I get exception:
did not find expected alphabetic or numeric character while scanning an alias at line 3 column 3 (Psych::SyntaxError)
from /usr/lib/ruby/2.4.0/psych.rb:377:in `parse_stream'
from /usr/lib/ruby/2.4.0/psych.rb:325:in `parse'
from /usr/lib/ruby/2.4.0/psych.rb:252:in `load'
from /usr/lib/ruby/2.4.0/psych.rb:473:in `block in load_file'
from /usr/lib/ruby/2.4.0/psych.rb:472:in `open'
from /usr/lib/ruby/2.4.0/psych.rb:472:in `load_file'
from ./select.rb:27:in `block in selecting'
from ./select.rb:26:in `each'
from ./select.rb:26:in `selecting'
from ./select.rb:47:in `block (2 levels) in <main>'
from ./select.rb:46:in `each'
from ./select.rb:46:in `block in <main>'
from ./select.rb:44:in `each'
from ./select.rb:44:in `<main>'
How can I triage if a file is a YAML file or not without a exception? In my case, I navigate to a directory and process markdown files: I add to a list markdown files with a key output: word and I return that list
mylist = Array.new
mylist = []
for d in (directory - excludinglist)
begin
info = YAML.load_file(d)
if info
if info.has_key?('output')
if info['output'].has_key?(word)
mylist.push(d)
end
end
end
rescue Psych::SyntaxError => error
return []
end
end
return mylist
When I catch exceptions, the bucle does not continue to push elements on my list.
The short answer: you can't.
Because YAML is just a text file, the only way to know whether a given text file is YAML or not is to parse it. The parser will try to parse the file, and if it is not valid YAML, it will raise an error.
Errors and exceptions are a common part of Ruby, especially in the world of IO. There's no reason to be afraid of them. You can easily rescue from them and continue on your way:
begin
yaml = YAML.load_file(foo)
rescue Psych::SyntaxError => e
# handle the bad YAML here
end
You mentioned that the following code will not work because you need to handle multiple files in a directory:
def foo
mylist = []
for d in (directory - excludinglist)
begin
info = YAML.load_file(d)
if info
if info.has_key?('output')
if info['output'].has_key?(word)
mylist.push(d)
end
end
end
rescue Psych::SyntaxError => error
return []
end
return mylist
end
The only issue here is that when you hit an error, you respond by returning from the function early. If you don't return, the for-loop will continue and you will get your desired functionality:
def foo
mylist = []
for d in (directory - excludinglist)
begin
info = YAML.load_file(d)
if info
if info.has_key?('output')
if info['output'].has_key?(word)
mylist.push(d)
end
end
end
rescue Psych::SyntaxError => error
# do nothing!
# puts "or your could display an error message!"
end
end
return mylist
end
Psych::SyntaxError gets raised by Psych::Parser#parse, the source for which is written in C. So unless you want to work with C, you can't write a patch for the method in Ruby to prevent the exception from getting raised.
Still, you could certainly rescue the exception, like so:
begin
foo = YAML.load_file("not_yaml.txt")
rescue Psych::SyntaxError => error
puts "bad yaml"
end
Is there any good example of handling mongodb related exceptions in ruby?
In this case I have:
/home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/networking.rb:89:in `send_message_with_gle': 11000: E11000 duplicate key error index: somedb.somecoll.$_id_ dup key: { : "some_id" } (Mongo::OperationFailure)
from /home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/collection.rb:1108:in `block in insert_documents'
from /home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/util/logging.rb:33:in `block in instrument'
from /home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/util/logging.rb:65:in `instrument'
from /home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/util/logging.rb:32:in `instrument'
from /home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/collection.rb:1106:in `insert_documents'
from /home/askar/.rvm/gems/ruby-1.9.3-p429/gems/mongo-1.8.6/lib/mongo/collection.rb:375:in `insert'
from lib/tasks/getorders.rb:47:in `block in <main>'
from lib/tasks/getorders.rb:25:in `each'
from lib/tasks/getorders.rb:25:in `<main>'
I'm having this error because I'm trying to insert a document with the id that already exists in mongodb database, I just want to know how to handle mongodb related exceptions in ruby.
For example, if an exception occurs, then I would change the id of the hash and then re-try to insert it.
How rescue block would look like?
The ruby block would look something like :
begin
# your operation
rescue Mongo::OperationFailure => e
if e.message =~ /^11000/
puts "Duplicate key error #{$!}"
# do something to recover from duplicate
else
raise e
end
end
# the rest of the exceptions follow ..
# if you just care about the dup error
# then ignore them
#rescue Mongo::MongoRubyError
# #Mongo::ConnectionError, Mongo::ConnectionTimeoutError, Mongo::GridError, Mongo::InvalidSortValueError, Mongo::MongoArgumentError, Mongo::NodeWithTagsNotFound
# puts "Ruby Error : #{$!}"
#rescue Mongo::MongoDBError
# # Mongo::AuthenticationError, Mongo::ConnectionFailure, Mongo::InvalidOperation, Mongo::OperationFailure
# puts "DB Error : #{$!}"
#rescue Mongo::OperationTimeout
# puts "Socket operation timeout Error : #{$!}"
#rescue Mongo::InvalidNSName
# puts "invalid collection or database Error : #{$!}"
#end
But, if you are updating a record that already exists, why not you use an upsert.
If you are creating a new record then why not let the mongod create the _id ?
Can also use write concerns.
#mongo_client.save({:doc => 'foo'}, {:w => 0}) # writes are not acknowledged
This is not as good as the rescue though.
If your ruby driver is >= 2.0.0, you should use Mongo::Error class for most of mongodb related exceptions. Here is how your rescue block should look like:
begin
# Document insert code
rescue Mongo::Error => e
if e.message.include? 'E11000'
# Change the id of the hash & re-try to insert it
end
end
I'm using mongomapper to store pages in a db, and I index them first. In the index method, I loop through each word, and check to see if it is already in the words hashmap. If not, I add an empty array to the hash, then push its location to the array.
def index_words
#words = self.body.split(" ")
#words.each_with_index do |word,i|
if self.words[word.stem].nil?
self.words[word.stem] = []
end
puts "Called from #{caller[0]}"
self.words[word.stem].push(i)
end
end
When I run this, I get an undefined method error, saying that self.words[word.stem] is nil. Furthermore, this method is actually being called from the loop, when it's only called once in the constructor:
def initialize(*args)
super
index_words
end
The error message is:
p = Page.new({author: 'Michael',url: 'michaelfine.me',title: 'Michael Fine',body: 'Body Text'})
called fromPage.rb:19:in `each'
NoMethodError: undefined method `push' for nil:NilClass
from Page.rb:24:in `block in index_words'
from Page.rb:19:in `each'
from Page.rb:19:in `each_with_index'
from Page.rb:19:in `index_words'
from Page.rb:14:in `initialize'
from (irb):103:in `new'
from (irb):103
from /Users/Michael/.rvm/rubies/ruby-1.9.3-p286/bin/irb:16:in `<main>'
I have some script on Ruby 1.9.3:
require "net/imap"
imap = Net::IMAP.new(mail_imap_server)
imap.login(mail_login, mail_password)
imap.select("INBOX")
puts imap.search(["FROM", "homer#simpson.com"])
imap.logout
imap.disconnect
If the desired message is present, then all is well.
If the desired message is missing, an error:
/opt/local/lib/ruby1.9/1.9.1/net/imap.rb:1332:in `block in search_internal': undefined method `[]' for nil:NilClass (NoMethodError)
from /opt/local/lib/ruby1.9/1.9.1/monitor.rb:211:in `mon_synchronize'
from /opt/local/lib/ruby1.9/1.9.1/net/imap.rb:1326:in `search_internal'
from /opt/local/lib/ruby1.9/1.9.1/net/imap.rb:752:in `search'
from ./mail.rb:12:in `mail'
from ./mail.rb:26:in `<main>'
How can I solve this problem?
first check if there are messages in the result, use a rescue just in case
require "net/imap"
imap = Net::IMAP.new(mail_imap_server)
imap.login(mail_login, mail_password)
imap.select("INBOX")
begin
messages = imap.search(["FROM", "homer#simpson.com"])
puts messages if messages.length > 0
rescue
puts "Error while retrieving the message"
end
imap.logout
imap.disconnect