I'm having problem with this case statement, the scenario is the follow
subDomainBlock are multi-line strings coming from other function and they are like
"fo-ds-ats.member.g02.yahoodns.net has address 98.139.21.169
fo-ds-ats.member.g02.yahoodns.net has IPv6 address 2001:4998:58:2201::50
Host wiki.yahoo.com not found: 3(NXDOMAIN)"
The complete function involve is
def data_filter(subDomainBlock)
line = subDomainBlock.split("\n")
#puts " yo soy #{line.class}"
line.each do | choise |
puts "-------------------"# puts "#{choise}#{choise.class}"
case choise
when choise.include?('not found')
nil
when choise.include?('has address')
puts "tiene una di"
when choise.include?('is an alias')
puts "es un alias"
when choise.include?('IPv6')
else
puts choise
end
end
end
I also tried to do the #{choise.include?('XXXXXXX')} but doesn't work.
Don't pass a variable to the case condition
case
when choise.include?('not found')
nil
when choise.include?('has address')
puts "tiene una di"
when choise.include?('is an alias')
puts "es un alias"
when choise.include?('IPv6')
else
puts choise
end
You can use regex matchers for when statements.
def data_filter(subDomainBlock)
line = subDomainBlock.split("\n")
line.each do |choise|
case choise
when /not found/
nil
when /has address/
puts "tiene una di"
when /is an alias/
puts "es un alias"
when /IPv6/
else
puts choise
end
end
end
You can not use choise variable in when condition.
don't use case-when, use if-elsif
Related
I am writing a short ruby script that takes a file as an argument and then parses that file.
I have put together a few conditions in the initialize method to ensure that a file path exists and it is readable and if it nots it prints an error message to the user.
However when I run the file with out a file attached along side the message "please add log file path". I also receive the following error messages.
please add log file path
Traceback (most recent call last):
3: from webserver_log_parser.rb:41:in `<main>'
2: from webserver_log_parser.rb:41:in `new'
1: from webserver_log_parser.rb:6:in `initialize'
webserver_log_parser.rb:6:in `exist?': no implicit conversion of nil into String (TypeError)
I would be really grateful if someone could explain why this happens and a way to fix this issue.
def initialize(log_file_path = nil)
puts 'please add log file path' unless log_file_path
puts 'Could not find the file path' unless File.exist?(log_file_path)
puts '${log_file_path} is unreadable' unless File.readable?(log_file_path)
extract_log_file(log_file_path)
end
def extract_log_file(log_file_path)
webpages = Hash.new { |url, ip_address| url[ip_address] = [] }
File.readlines(log_file_path).each do |line|
url, ip_address = line.split
webpages[url] << ip_address
end
sort_results(webpages)
end
def sort_results(results)
total_views = {}
unique_views = {}
results.each do |url, ip_address|
total_views[url] = ip_address.length
unique_views[url] = ip_address.uniq.length
end
display_results(total_views, unique_views)
end
def display_results(views, unique_views)
puts 'The most viewed pages are as follows:'
total_views_sorted = views.sort_by { |_k, count| -count }
total_views_sorted.each { |key, count| puts "#{key} #{count}" }
puts 'The pages with the most unique views are as follows:'
unique_sort = unique_views.sort_by { |_k, count| -count }
unique_sort.each { |key, count| puts "#{key} #{count}" }
end
end
if $PROGRAM_NAME == __FILE__
LogParser.new(ARGV[0])
end```
If you want to directly terminate the script with a message, you can use abort.
def initialize(log_file_path = nil)
abort("please add log file path") unless log_file_path
abort("Could not find the file path") unless File.exist?(log_file_path)
abort("${log_file_path} is unreadable") unless File.readable?(log_file_path)
extract_log_file(log_file_path)
end
When your guard conditions are triggered, you need to stop further processing (no need to check for readability of a file at file_path if you already established that file_path is nil). It could look like this, for example:
def initialize(log_file_path = nil)
unless log_file_path
puts 'please add log file path'
return
end
unless File.exist?(log_file_path)
puts 'Could not find the file path'
return
end
unless File.readable?(log_file_path)
puts '${log_file_path} is unreadable'
return
end
extract_log_file(log_file_path)
end
I've seen similar answers to this question but I think I need something more specific to my code. Basically I've called the row from the CSV file but now I need to delete the called row. Sounds simple as I write this yet here I am asking you all for help. I know there is a lot of code here but I figured the more there is the more easier you will be able to understand the context. Apologies if there is too much noise in the code.
def delete_user_menu
puts "============================================"
delete_users_active_list
puts " "
puts "Please type in the name of the user you wish to eradicate: "
print "> "
eradicate(gets.chomp)
end
def eradicate(delete_input)
delete_row = delete_authentication(delete_input)
if delete_row
puts "Are you sure you want to delete #{delete_input} from the database?"
puts "[y]es or [n]o"
print "> "
delete_answer = gets.chomp
if delete_answer == "y"
delete_user
after_deletion_menu
elsif delete_answer == "n"
puts "Close call! Taking you back to main menu."
sleep 2
admin_main_menu
else
puts "Input not recognised. Please try again."
eradicate(delete_input)
end
else
puts "User not recognized. Please try again."
sleep 1
delete_user_menu
end
end
def delete_user
# this is where the delete user function needs to go
after_deletion_menu
end
def after_deletion_menu
puts " "
puts "User deleted! What would you like to do now?"
puts "1. Delete another user"
puts "2. Back to main menu"
print "> "
after_deletion_choice = gets.chomp
if after_deletion_choice == "1"
delete_user_menu
elsif after_deletion_choice == "2"
admin_main_menu
else
puts "Input not recognized. Please try again."
after_deletion_menu
end
end
def delete_users_active_list
CSV.foreach("./users.csv", headers: true) do |row|
username = row['username']
puts "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
puts "Username: #{username}"
end
end
def delete_authentication(username)
CSV.open('users.csv', headers: true).find { |row| row['username'] == username }
end
I've had a look at this question How to remove a row from a CSV with Ruby
but I don't fully understand the answers, hence why I'm here. Any help is much appreciated.
I looked at the link. First, they are reading the entire csv file into table:
table = CSV.table(#csvfile)
then deleting the row from table:
table.delete_if do |row|
row[:foo] == 'true'
end
Finally, they are completely replacing the original file with the new table minus the row:
File.open(#csvfile, 'w') do |f|
f.write(table.to_csv)
end
This is generally how you have to do this kind of operation when you are dealing with a file. It's not like a database.
EDIT - in your case:
delete_user(delete_input)
...
def delete_user(user)
...
table.delete_if { |row| row[:username] == user }
...
I'm writing a Call Detail Record (CDR) parser on Ruby. CDRs are files with lines, where every line is an action, and the fields of these lines are separated by tabs.
My problem happens after reading every line of the file using CDRFileParser. When I'm using gets.chomp to get some interactivity with the user, gets.chomp won't wait until I press enter, instead it starts using the lines from the file that was already closed. It seems to be a IO buffer problem. (In C I use fflush() for this kind of issue.)
The files of my program are:
command_line_loader.rb:
def comm_line_loader
begin
raise ArgumentError, 'Invalid number of arguments' unless ARGV.length == 1
return File.new(ARGV[0],"r")
rescue ArgumentError
warn "Debe ingresar el nombre del archivo que contiene los CDR"
exit
rescue Errno::ENOENT
warn "El archivo no existe o hay un error en su lectura"
exit
end
end
objects.rb:
class CDRFileParser
def initialize(cdr_source)
#cdr_source = cdr_source
#cdr_list = cdr_to_array
end
def cdr_to_array
cdr_list_aux = Array.new
cdr_list_aux.push #cdr_source.readline.split("\t") unless #cdr_source.eof?
return cdr_list_aux
end
attr_accessor :cdr_list
end
cdr_parser.rb (useless program that shows the problem):
#!/usr/bin/env ruby
require "./command_line_loader"
require "./objects"
cdr = CDRFileParser.new (comm_line_loader)
loop do
a = gets.chomp
puts a
end
Your help and coding suggestions will be really appreciated :)
The Kernel#gets method only reads from standard input if ARGV is empty. Try using $stdin.gets.chomp instead. Alternatively, clear ARGV after you are done reading from it with ARGV.clear and gets will work as you expect.
I don't understand why this method isn't working. when I put in a value that should pass the if statement it doesn't work.
def getBase
puts "What is the base URL for the test?"
x = gets
if (x.include? 'http://') && ((x.split('.').at(x.split('.').length - 1).length) == 3)
return x
else
puts "That is in the incorrect format."
puts "Please format your url like this"
puts "http://example.com"
getBase
end
end
input 'http://test.com'
result: statement repeats and does not exit recursion
When you get input with gets it includes the newline \n at the end (from the user hitting return). So your x is actually "http://test.com\n".
To get rid of this use String#chomp:
x = gets.chomp
That should do it.
If the purpose is to enforce correct URL format and/or make sure it's an HTTP URL, why don't you use a tool designed to do that? Ruby's URI class is your friend:
require 'uri'
URI.parse('http://foo.bar').is_a?(URI::HTTP)
=> true
URI.parse('ftp://foo.bar').is_a?(URI::HTTP)
=> false
URI.parse('file://foo.bar').is_a?(URI::HTTP)
=> false
URI.parse('foo.bar').is_a?(URI::HTTP)
=> false
I'd write the code more like this:
require 'uri'
def get_base
loop do
puts "What is the base URL for the test?"
x = gets.chomp
begin
uri = URI.parse(x)
return uri.to_s if uri.is_a?(URI::HTTP)
rescue URI::InvalidURIError
end
puts "That is in the incorrect format."
puts "Please format your URL like this:"
puts
puts " http://example.com"
end
end
puts "Got: #{ get_base() }"
I have a Ruby app which uses readline with command completion.
After the first string (the command) was typed, I would like to be able to complete its arguments. The arguments list should be based on the chosen command.
Does someone have a quick example?
These are the commands:
COMMANDS = [
'collect', 'watch'
].sort
COLLECT = [
'stuff', 'otherstuff'
].sort
comp = proc do |s|
COMMANDS.grep( /^#{Regexp.escape(s)}/ )
end
Readline.completion_proc = comp
Each time I press TAB, the proc block is executed and a command from the COMMANDS array is matched.
After one of the commands was fully matched I would like to start searching for the argument only in the COLLECT array.
Since your question popped up first every time I looked for something like this I want to share my code for any one else.
#!/usr/bin/env ruby
require 'readline'
module Shell
PROMPT = "shell> "
module InputCompletor
CORE_WORDS = %w[ clear help show exit export]
SHOW_ARGS = %w[ list user ]
EXPORT_ARGS = %w[ file ]
COMPLETION_PROC = proc { |input|
case input
when /^(show|export) (.*)/
command = $1
receiver = $2
DISPATCH_TABLE[$1].call($2)
when /^(h|s|c|e.*)/
receiver = $1
CORE_WORDS.grep(/^#{Regexp.quote(receiver)}/)
when /^\s*$/
puts
CORE_WORDS.map{|d| print "#{d}\t"}
puts
print PROMPT
end
}
def self.show(receiver)
if SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/).length > 1
SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/)
elsif SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/).length == 1
"show #{SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/).join}"
end
end
def self.export(receiver)
if EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/).length > 1
EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/)
elsif EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/).length == 1
"export #{EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/).join}"
end
end
DISPATCH_TABLE = {'show' => lambda {|x| show(x)} ,
'export' => lambda {|x| export(x)}}
end
class CLI
Readline.completion_append_character = ' '
Readline.completer_word_break_characters = "\x00"
Readline.completion_proc = Shell::InputCompletor::COMPLETION_PROC
def initialize
while line = Readline.readline("#{PROMPT}",true)
Readline::HISTORY.pop if /^\s*$/ =~ line
begin
if Readline::HISTORY[-2] == line
Readline::HISTORY.pop
end
rescue IndexError
end
cmd = line.chomp
case cmd
when /^clear/
system('clear')
when /^help/
puts 'no help here'
when /show list/
puts 'nothing to show'
when /^show\s$/
puts 'missing args'
when /export file/
puts 'nothing to export'
when /^export\s$/
puts 'missing args'
when /^exit/
exit
end
end
end
end
end
Shell::CLI.new
After thinking a while, the solution was very simple:
comp = proc do |s|
if Readline.line_buffer =~ /^.* /
COLLECT.grep( /^#{Regexp.escape(s)}/ )
else
COMMANDS.grep( /^#{Regexp.escape(s)}/ )
end
end
Now I just need to turn it into something more flexible/usable.