The situation is that there is a folder with some files (e.g. "1", "2", "3") and I need to request information about this file. One of the options is File.exists?, but it only searches by a strictly defined file name. In turn, I need to search for the required file by query from the input field, i.e. the name of the file is a variable that the user sets. Can you please tell me the best way to search for a file in a folder in this case?
I think what you want is something like this:
#!/bin/ruby
puts "What file are you looking for?"
filename = gets.chomp
if File.exists? filename
puts "File found! :)"
# do something else
else
puts "File not found! :("
# maybe do something else
end
It will take the user input and then determine if it the file exists with that name (exact match only).
Related
I want to remove the following characters from several files in a folder. What I have so far is this:
str.delete! '!##$%^&*()
which I think will work to remove the characters. What do I need to do to make it run through all the files in the folder?
You clarified your question, stating you want to remove certain characters from the contents of files in a directory. I created a straight forward way to traverse a directory (and optionally, subdirectories) and remove specified characters from the file contents. I used String#delete like you started with. If you want to remove more advanced patterns you might want to change it to String#gsub with regular expressions.
The example below will traverse a tmp directory (and all subdirectories) relative to the current working directory and remove all occurrences of !, $, and # inside the files found. You can of course also pass the absolute path, e.g., C:/some/dir. Notice I do not filter on files, I assume it's all text files in there. You can of course add a file extension check if you wish.
def replace_in_files(dir, chars, subdirs=true)
Dir[dir + '/*'].each do |file|
if File.directory?(file) # Traverse inner directories if subdirs == true
replace_in_files(file, chars, subdirs) if subdirs
else # Replace file contents
replaced = File.read(file).delete(chars)
File.write(file, replaced)
end
end
end
replace_in_files('tmp', '!$#')
I think this might work, although I'm a little shaky on the Dir class in Ruby.
Dir.foreach('/path/to/dir') do |file|
file.delete '!##$%^&*()
end
There's a more general version of your question here: Iterate through every file in one directory
Hopefully a more thorough answer will be forthcoming but maybe this'll get you where you need.
Dir.foreach('filepath') do |f|
next if Dir.exists?(f)
file = File.new("filepath/#{f}",'r+')
text = file.read.delete("'!##$%^&*()")
file.rewind
file.write(text)
file.close
end
The reason you can't do
file.write(file.read.delete("'!##$%^&*()"))
is that file.read leaves the "cursor" at the end of the text. Instead of writing over the file, you would be appending to the file, which isn't what you want.
You could also add a method to the File class that would move the cursor to the beginning of the file.
class File
def newRead
data = self.read
self.rewind
data
end
end
Dir.foreach('filepath') do |f|
next if Dir.exists?(f)
file = File.new("filepath/#{f}",'r+')
file.write(file.newRead.delete("'!##$%^&*()"))
file.close
end
I have a folder that contains files. I was wondering how I can chech every .txt file in the folder if it contains the word "BREAK". I know it must be very easy but I kinda miss the way of getting it done.
This is what I've tried so far
Dir.glob('/path/to/dir/*.txt') do |txt_file|
# And here I need a method that opens the 'txt_file'
# and checks if it contains "BREAK"
end
The below would return an array of files containing "BREAK"
files = Dir.glob('/path/to/dir/*.txt').select do |txt_file|
File.read(txt_file).include? "BREAK"
end
I'm trying to crawl FTP and pull down all the files recursively.
Up until now I was trying to pull down a directory with
ftp.list.each do |entry|
if entry.split(/\s+/)[0][0, 1] == "d"
out[:dirs] << entry.split.last unless black_dirs.include? entry.split.last
else
out[:files] << entry.split.last unless black_files.include? entry.split.last
end
But turns out, if you split the list up until last space, filenames and directories with spaces are fetched wrong.
Need a little help on the logic here.
You can avoid recursion if you list all files at once
files = ftp.nlst('**/*.*')
Directories are not included in the list but the full ftp path is still available in the name.
EDIT
I'm assuming that each file name contains a dot and directory names don't. Thanks for mentioning #Niklas B.
There are a huge variety of FTP servers around.
We have clients who use some obscure proprietary, Windows-based servers and the file listing returned by them look completely different from Linux versions.
So what I ended up doing is for each file/directory entry I try changing directory into it and if this doesn't work - consider it a file :)
The following method is "bullet proof":
# Checks if the give file_name is actually a file.
def is_ftp_file?(ftp, file_name)
ftp.chdir(file_name)
ftp.chdir('..')
false
rescue
true
end
file_names = ftp.nlst.select {|fname| is_ftp_file?(ftp, fname)}
Works like a charm, but please note: if the FTP directory has tons of files in it - this method takes a while to traverse all of them.
You can also use a regular expression. I put one together. Please verify if it works for you as well as I don't know it your dir listing look different. You have to use Ruby 1.9 btw.
reg = /^(?<type>.{1})(?<mode>\S+)\s+(?<number>\d+)\s+(?<owner>\S+)\s+(?<group>\S+)\s+(?<size>\d+)\s+(?<mod_time>.{12})\s+(?<path>.+)$/
match = entry.match(reg)
You are able to access the elements by name then
match[:type] contains a 'd' if it's a directory, a space if it's a file.
All the other elements are there as well. Most importantly match[:path].
Assuming that the FTP server returns Unix-like file listings, the following code works. At least for me.
regex = /^d[r|w|x|-]+\s+[0-9]\s+\S+\s+\S+\s+\d+\s+\w+\s+\d+\s+[\d|:]+\s(.+)/
ftp.ls.each do |line|
if dir = line.match(regex)
puts dir[1]
end
end
dir[1] contains the name of the directory (given that the inspected line actually represents a directory).
As #Alex pointed out, using patterns in filenames for this is hardly reliable. Directories CAN have dots in their names (.ssh for example), and listings can be very different on different servers.
His method works, but as he himself points out, takes too long.
I prefer using the .size method from Net::FTP.
It returns the size of a file, or throws an error if the file is a directory.
def item_is_file? (item)
ftp = Net::FTP.new(host, username, password)
begin
if ftp.size(item).is_a? Numeric
true
end
rescue Net::FTPPermError
return false
end
end
I'll add my solution to the mix...
Using ftp.nlst('**/*.*') did not work for me... server doesn't seem to support that ** syntax.
The chdir trick with a rescue seems expensive and hackish.
Assuming that all files have at least one char, a single period, and then an extension, I did a simple recursion.
def list_all_files(ftp, folder)
entries = ftp.nlst(folder)
file_regex = /.+\.{1}.*/
files = entries.select{|e| e.match(file_regex)}
subfolders = entries.reject{|e| e.match(file_regex)}
subfolders.each do |subfolder|
files += list_all_files(ftp, subfolder)
end
files
end
nlst seems to return the full path to whatever it finds non-recursively... so each time you get a listing, separate the files from the folders, and then process any folder you find recrsively. Collect all the file results.
To call, you can pass a starting folder
files = list_all_files(ftp, "my_starting_folder/my_sub_folder")
files = list_all_files(ftp, ".")
files = list_all_files(ftp, "")
files = list_all_files(ftp, nil)
I'm trying to do a simple regex to grab specific text out of a bunch of text files in a directory. The code I'm using is below:
input_dir = File.join('path/to/file/dir/', "*.txt")
Dir.glob(input_dir) do |file|
if /\.txt$/i.match file
File.open(file, "r") do |_file|
/==BEGIN==(.*)==END==/.match _file.read
puts $1
end
end
end
That works for exactly 1 of the files in the directory, but all other files return nil. Am I missing something here?
Hard to guess with so little data, but could it be that in most files (except one), ==BEGIN== and ==END== are on different lines?
Does /==BEGIN==(.*)==END==/m.match _file.read change anything? The /m modifier allows the dot to also match newlines in Ruby.
Their input should be a directory in c:\folder\subfolder\ format. Additionally I don't want it to try to run unless the directory contains .flv files. So it needs to exist AND contain .flv files. Otherwise it should ask the user to input another directory.
The code also cleans up the slashes, and adds a trailing slash, which I need for other parts of the program. What I have works when given a directory that exists and contains the .flv files, but if it doesn't contain .flv files it just ends the program instead of asking for additional input; meaning it porceeds as long as the directory exists, even if it doesn't have any .flv files.
def is_valid_dir()
input = "nil"
until File.directory?(input) && Dir.glob("#{input}*.flv")
puts "Enter the full directory path of the flv files."
input = gets.chomp
if input[-1..-1] == '/'
# Do nothing if it already
# ends with a forward slash.
else
input += '/'
end
end
input.gsub!('\\', '/')
return input
end
Dir.glob returns an empty array if there are no matches; check its length.
Also, you say the input should be backslashy, but are checking for a forward slash. That aside, idiomatically you're probably write that as:
input += '/' unless input[-1..1] == '/'