I have written some ruby to automate batch file creation, the problem lies with the resulting output in the GUI;
The files are outputted, but the formatting looks very strange indeed. Also the filenames are all ending in '.txt' but MacOS does not see it this way. i.e. You cannot click to open in Textedit.
Code is as follows;
puts "Please enter amount of files to create: "
file_count = gets.to_i
puts "Thanks! Enter a filename header: "
file_head = gets
puts "And a suffix?"
suffix = gets
puts "Please input your target directory:"
Dir.chdir(gets.chomp)
while file_count != 0
filename = "#{file_head}_#{file_count}#{suffix}"
File.open(filename, "w") {|x| x.write("This is #{filename}.")}
file_count -= 1
end
Tips on shortening length or refactoring are always welcome.
The Kernel#gets documentation contains:
The separator is included with the contents of each record.
By default the separator is a newline (see $/). So both file_head and suffix end with a newline character. filename also does, of course. Thus the extension of your files isn't .txt as it's actually ".txt\n" (in Ruby string notation). The application takes the newline character literally and continues writing the filename on a new line. That's why it looks so strange!
You already know a way to fix it: call String#chomp to get rid of the trailing newline (the separator). See the line in your code that contains Dir.chdir for an example.
Related
I'm reading simple text files using Ruby for further regex processing and suddenly I see that str NUL after each printable character. Totally lost, where it comes from, I tested typing simple text in Notepad, saving as txt file and still getting those. I'm on W machine, didn't have this before.
How I can process it, probably replace them, not sure how to refer to them.
My regex doesn't work with them, tried several ways, using SciTE for run.
e.g. use presented as uNULsNULeNUL and not equal to use
puts File.read(file_name)
puts '____________________'
File.open(file_name, "r") do |f|
f.each_line do |line|
puts 'Line.....' + line
end
end
---------------------- below pic on content of file and output:
This file is probably in UTF-16 format. You'll need to read it in that way:
File.open(file_name, "r:UTF-16LE") do |f|
# ...
end
That format is the default in Windows.
You can always fix this by re-saving the file as UTF-8.
I have the following layout in a txt file.
[item] label1: comment1 | label2: foo
I have the code below. The goal is to modify part of an existing line in text
def replace_info(item, bar)
return "please create a file first" unless File.exist?('site_info.txt')
IO.foreach('site_info.txt','a+') do |line|
if line.include?(item)
#regex should find the data from the whitespace after the colon all the way to the end.
#this should be equivalent to foo
foo_string = line.scan(/[^"label2: "]*\z/)
line.sub(foo_string, bar)
end
end
end
Please advise. Perhaps my regrex is off, but .sub is correct, but I cannot overwrite line.
Tiny problem: Your regular expression does not do what you think. /[^"label2: "]*\z/ means: any number of characters at the end of line that are not a, b, e, l, ", space, colon or 2 (see Character classes). And scan returns an array, which sub doesn't work with. But that doesn't really matter, because...
Small problem: line.sub(foo_string, bar) doesn't do anything. It returns a changed string, but you don't assign it to anything and it gets thrown away. line.sub!(foo_string, bar) would change line itself, but that leads us to...
Big problem: You cannot just change the read line and expect it to change in the file itself. It's like reading a book, thinking you could write a line better, and expecting it to change the book. The way to change a line in a text file is to read from one file and copy what you read to another. If you change a line between reading and writing, the newly written copy will be different. At the end, you can rename the new file to the old file (which will delete the old file and replace it atomically with the new one).
EDIT: Here's some code. First, I dislike IO.foreach as I like to control the iteration myself (and IMO, IO.foreach is not readable as IO#each_line). In the regular expression, I used lookbehind to find the label without including it into the match, so I can replace just the value; I changed to \Z for a similar reason, to exclude the newline from the match. You should not be returning error messages from functions, that's what exceptions are for. I changed simple include? to #start_with? because your item might be found elsewhere in the line when we wouldn't want to trigger the change.
class FileNotFoundException < RuntimeError; end
def replace_info(item, bar)
# check if file exists
raise FileNotFoundException unless File.exist?('site_info.txt')
# rewrite the file
File.open('site_info.txt.bak', 'wt') do |w|
File.open('site_info.txt', 'rt') do |r|
r.each_line do |line|
if line.start_with?("[#{item}]")
line.sub!(/(?<=label2: ).*?\Z/, bar)
end
w.write(line)
end
end
end
# replace the old file
File.rename('site_info.txt.bak', 'site_info.txt')
end
replace_info("item", "bar")
This is my code:
File.open(file_name) do |file|
file.each_line do |line|;
if line =~ (/SAPK/) || (line =~ /^\t/ and tabs == true) || (line =~ /^ / and spaces == true)
file = File.open("./1.log", "a"); puts "found a line #{line}"; file.write("#{line}".lstrip!)
end
end
end
File.open("./2.log", "a") { |file| file.puts File.readlines("./1.log").uniq }
I want to to insert all the lines that match a specific string, start with tab or start with space to a file 1.log, all lines should be with space/tab at the beginning so I removed them.
I want get the unique lines in 1.log and write them to 2.log
It will be great if some can go over the code and tell me if something is not correct.
When using files in Ruby, what is the difference between the w+ and a modes?
I know:
w+ - Create an empty file for both reading and writing.
a - Append to a file.The file is created if it does not exist.
But both options append to the file, I though w+ should behave like >, instead of >> ,so I guess w+ also like >> ?
Thanks !!
There's a lot of confusion in this code and it isn't helped by your habit of jamming things on a single line for no reason. Do try and keep your code clean, as the functionality should be obvious. There's also a lot of quirky anti-patterns like stringifying strings and testing booleans vs booleans which you should really avoid doing.
One thing you'll want to do is employ Tempfile for those situations where you need an intermediate file.
Here's a reworked version that's cleaned up:
Tempfile.open do |temp|
File.open(file_name) do |input|
input.each_line do |line|
if line.match(/SAPK/) || (line.match(/^\t/) and tabs) || (line.match(/^ /) and spaces)
puts "found a line #{line}"
temp.write(line.lstrip!)
end
end
end
File.open("./2.log", "w+") do |file|
# Rewind the temporary file to read data back
temp.rewind
file.write(temp.readlines.uniq)
end
end
Now a and w+ are largely similar, it's just two ways that are offered for people familiar with whatever notation. It's like how Array has both length and size which do the same thing. Pick one and use it consistently or your code will be confusing.
My criticism over things like x == true is because something that narrowly specific usually means that x could take on a multitude of values and true is one particular case we're trying to handle, something that implies that we should be aware it might be false and many other things. It's a red herring and will only invite questions.
I'm struggling with a script to target specific XML files in a directory and rename them as copies with a different name.
I put in the puts statements for debugging, and, from what I can tell, everything looks OK until the FileUtils.cp line. I tried this with simpler text and it worked, but my overly complicated cp(file, file.gsub()) seems to be causing problems that I can't figure out.
def piano_treatment(cats)
FileUtils.chdir('12Piano')
src = Dir.glob('*.xml')
src.each do |file|
puts file
cats.each do |text|
puts text
if file =~ /#{text}--\d\d/
puts "Match Found!!"
puts FileUtils.pwd
FileUtils.cp(file, file.gsub!(/#{text}--\d\d/, "#{text}--\d\dBass "))
end
end
end
end
piano_treatment(cats)
I get the following output in Terminal:
12Piano--05Free Stuff--11Test.xml
05Free Stuff
Match Found!!
/Users/mbp/Desktop/Sibelius_Export/12Piano
cp 12Piano--05Free Stuff--ddBass Test.xml 12Piano--05Free Stuff--ddBass Test.xml
/Users/mbp/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/fileutils.rb:1551:in `stat': No such file or directory - 12Piano--05Free Stuff--ddBass Test.xml (Errno::ENOENT)
Why is \d\d showing up as "dd" when it should actually be numbers? Is this a single vs. double quote issue? Both yield errors.
Any suggestions are appreciated. Thanks.
EDIT One additional change was needed to this code. The FileUtils.chdir('12Piano') would change the directory for the first iteration of the loop, but it would revert to the source directory after that. Instead I did this:
def piano_treatment(cats)
src = Dir.glob('12Piano/*.xml')
which sets the match path for the whole method.
Your replacement string is not a regex, so \d has no special meaning, but is just a literal string. You need to specify a group in your regex, and then you can use the captured group in your replacement string:
FileUtils.cp(file, file.gsub(/#{text}--(\d\d)/, "#{text}--\\1Bass "))
The parenthesis in the regex form the group, which can be used (by number) in the replacement string: \1 for the first group, \2 for the second, etc. \0 refers to the entire regex match.
Update
Replaced gsub!() with gsub() and escaped the backslash in the replacement string (to treat \1 as the capture group, not a literal character... Doh!).
I was following the advice from this question when trying to read in multi-line input from the command line:
# change line separator
$/ = 'END'
answer = gets
pp answer
However, I get weird behavior from STDIN#gets when I try to change $/ back:
# put it back to normal
$/ = "\n"
answer = gets
pp answer
pp 'magic'
This produces output like this when executed with Ruby:
$ ruby multiline_input_test.rb
this is
a multiline
awesome input string
FTW!!
END
"this is\n\ta multiline\n awesome input string\n \t\tFTW!!\t\nEND"
"\n"
"magic"
(I input up to the END and the rest is output by the program, then the program exits.)
It does not pause to get input from the user after I change $/ back to "\n". So my question is simple: why?
As part of a larger (but still small) application, I'm trying to devise a way of recording notes; as it is, this weird behavior is potentially devastating, as the rest of my program won't be able to function properly if I can't reset the line separator. I've tried all manner of using double- and single-quotes, but that doesn't seem to be the issue. Any ideas?
The problem you're having is that your input ends with END\n. Ruby sees the END, and there's still a \n left in the buffer. You do successfully set the input record separator back to \n, so that character is immediately consumed by the second gets.
You therefore have two easy options:
Set the input record separator to END\n (use double quotes in order to have the newline character work):
$/ = "END\n"
Clear the buffer with an extra call to gets:
$/ = 'END'
answer = gets
gets # Consume extra `\n`
I consider option 1 clearer.
This shows it working on my system using option 1:
$ ruby multiline_input_test.rb
this is
a multiline
awesome input string
FTW!!
END
"this is\n a multiline\n awesome input string\n FTW!!\nEND\n"
test
"test\n"
"magic"