Consider this Ruby code:
puts "*****"
puts " *"
puts " "
puts "*****"
puts " *"
My Output is like this:
*****
*
*****
*
Why the heck a whitespace doesn't fill the same space as * character in Scite?
I've tried it in Eclypse with Java and it works just fine.
Proportional fonts have characters of varying widths, ruining space-based alignment.
Switch to a monospace font (e.g., Courier) so all characters are the same size and it'll work.
In order to make it work in Scite You should add
style.errorlist.32=$(font.monospace) in
SciteUser.properties file
Related
I was wondering how to print unicode characters, such as Japanese or fun characters like 📦.
I can print hearts with:
hearts = "\u2665"
puts hearts.encode('utf-8')
How can I print more unicode charaters with Ruby in Command Prompt?
My method works with some characters but not all.
Code examples would be greatly appreciated.
You need to enclose the unicode character in { and } if the number of hex digits isn't 4 (credit : /u/Stefan) e.g.:
heart = "\u2665"
package = "\u{1F4E6}"
fire_and_one_hundred = "\u{1F525 1F4AF}"
puts heart
puts package
puts fire_and_one_hundred
Alternatively you could also just put the unicode character directly in your source, which is quite easy at least on macOS with the Emoji & Symbols menu accessed by Ctrl + Command + Space by default (a similar menu can be accessed on Windows 10 by Win + ; ) in most applications including your text editor/Ruby IDE most likely:
heart = "♥"
package = "📦"
fire_and_one_hundred = "🔥💯"
puts heart
puts package
puts fire_and_one_hundred
Output:
♥
📦
🔥💯
How it looks in the macOS terminal:
I have the following strings:
"4 sprigs of fresh rosemary"
"1 x 600 g jar of quality white beans"
and I would like to exclude everything that's before "of" like this:
"fresh rosemary"
"quality white beans"
I tried using gsub, but I can't find the proper regex.
Not sure why you are using gsub. It does not make sense.
"4 sprigs of fresh rosemary".sub(/.*(?=of)/, "")
# => "of fresh rosemary"
"1 x 600 g jar of quality white beans".sub(/.*(?=of)/, "")
# => "of quality white beans"
By the way, what you described and what you are expecting do not match.
Or,
"1 x 600 g jar of quality white beans".sub(/.*of\s*/, "")
# => "quality white beans"
"4 sprigs of fresh rosemary".sub(/.*of\s*/, "")
# => "fresh rosemary"
Not using a regex:
"4 sprigs of fresh rosemary".split('of ').last
# => "fresh rosemary"
Would not work if the sentence had the word "of" more than once.
You could use the match method on a string using a regex.
"4 sprigs of fresh rosemary".match(/of (.+)/)[1]
=> "fresh rosemary"
The brackets around .+ deterimne a substring to return in MatchData that you then call with [1]
Here is another option if you always want the end of the line after "of" even if there are multiples of "of" in a sentence
paragraph = "4 sprigs of fresh rosemary
1 x 600 g jar of quality white beans
I have a love of many things including a love of fresh rosemary
I have an of for all things but of the things I of, I of quality white beans the most
I will reject this offensive flower"
paragraph.scan(/(?<=\sof\s)(?!.*\sof\s).+/)
#=> ["fresh rosemary", "quality white beans",
# "fresh rosemary", "quality white beans the most"]
This regex say:
(?<=\sof\s) : Look behind for the literal " of "
(?!.*\sof\s) : Look ahead to make sure there are no more occurrences of " of "
.+ expect one or more characters after the final " of "
Example
I'm having trouble reading an IP from a text file and properly writing it to another text file. It shows the written IP in the file as: "ÿþ1 9 2 . 1 6 8 . 1 1 0 . 4"
#Read the first line for the IP
def get_server_ip
File.open("d:\\ip_addr.txt") do |line|
a = line.readline()
b = a.to_s
end
end
#append the ip to file2
def append_ip
FileUtils.cp('file1.txt', 'file2.txt')
file_names = ['file2.txt']
file_names.each do |file_name|
text = File.read(file_name)
b = get_server_ip
new_contents = text.gsub('ip_here', b)
File.open(file_name, "w") {|file| file.puts new_contents }
end
end
I've tried .strip and .delete(' ') with no luck. Can anyone see the issue?
Thank you
The file was generated with Notepad on Windows. It is encoded as UTF-16LE.
The first two bytes in the file have the codes 0xFF and 0xFE; this is the Bytes Order Mark of UTF-16LE.
Each character is encoded on 2 bytes (16 bits), the least significant byte first (Less Endian order).
The spaces between the printable characters in the output are, in fact NUL characters (characters with code 0).
What you can do (apart from converting the file to a more decent format like UTF-8 or even ISO-8859-1) is to pass 'rb:BOM|UTF-16LE' as the second argument of File#open.
r tells File#open to open the file in read-only mode (which is also does by default);
b means "binary mode"; it is required by BOM|UTF-16;
:BOM|UTF-16LE tells Ruby to read and ignore the BOM if it is present in the file and to expect the rest of the file being encoded as UTF16-LE.
If you can, I recommend you to convert the file encoding using a decent editor (even Notepad can be used) to UTF-8 or ISO-8859-1 and all these problems vanish.
0.upto(9) do
STDOUT.print "Flash!"
sleep 0.5
STDOUT.print "\b\b\b\b\b\b" # (6 backspaces, the length of "Flash!")
sleep 0.5
end
This code doesn't work. It prints Flash! to the screen, but it doesn't flash. It just stays there, as though the backspaces aren't taking effect. But I do this:
0.upto(9) do
STDOUT.print "Flash!"
sleep 0.5
STDOUT.print "\b\b\b\b\b" # (5 backspaces, the length of "Flash! - 1")
sleep 0.5
end
and it almost works. It prints this: FFFFFFFFFFlash!(after 9 loops) Why do the backspaces stop taking effect when their number is equal to the length of the string they're deleting?
How can I overcome this problem and create a flashing message, only using libraries that are part of rails?
I tried a workaround like this:
0.upto(9) do
STDOUT.print " Flash!"
sleep 0.5
STDOUT.print "\b\b\b\b\b\b"
sleep 0.5
end
(Note the space in " Flash!"), but what happens is the message appears to crawl across the screen! An interesting effect, but not what I want.
I'm using Command Prompt with Ruby and Rails in Windows 7
Typically this would be written something like:
0.upto(9) do
STDOUT.print "\rFlash!"
sleep 0.5
STDOUT.print "\r " # Send return and six spaces
sleep 0.5
end
Back in the days when we'd talk to TTY and dot-matrix printers, we'd rapidly become used to the carriage-control characters, like "\r", "\n", "\t", etc. Today, people rarely do that to start, because they want to use the web, and browsers; Learning to talk to devices comes a lot later.
"\r" means return the carriage to its home position, which, on a type-writer moved the roller all the way to the right so we could start typing on the left margin again. Printers with moving heads reversed that and would move the print-head all the way to the left, but, in either case, printing started on the left-margin again. With the console/telnet/video-TTY, it moves the cursor to the left margin. It's all the same, just different technology.
A little more usable routine would be:
msg = 'Flash!'
10.times do
print "\r#{ msg }"
sleep 0.5
print "\r#{ ' ' * msg.size }" # Send return and however many spaces are needed.
sleep 0.5
end
Change msg to what you want, and the code will automatically use the right number of spaces to overwrite the characters.
Anyway, it looks like backspace (at least in windows) just positions the cursor back, you need/want to overwrite the character with a space at that point (or 6 of them) to "blank" the text out.
Or, you can just use this
def text_flasher(text)
puts "\e[5m#{text}\e[0m"
end
use text_flasher in the console and you'll see the magic :)
Right, based on #rogerdpack 's input I have devised a solution:
def flashing_output(output)
message = output
backspace = "\b"
space = " "
backspace_array = []
space_array = []
length = message.length
length.times do
backspace_array << backspace
space_array << space
end
0.upto(9) do
print message
sleep 0.5
print backspace_array.join.to_s + space_array.join.to_s + backspace_array.join.to_s + backspace_array.join.to_s
sleep 0.5
end
end
flashing_output("Flashing Foobars! (not a euphemism)")
I am trying to handle an array with Ruby v1.9.2 but it has some strange behavior.
The best explanation may be done with examples:
CASE 1 TEST
#test1 = "image/bmp, image/gif, image/jpg".split(',')
Debug #test1:
---
- image/bmp # why this?!
- " image/gif"
- " image/jpg"
CASE 2 TEST
#test2 = ", image/bmp, image/gif, image/jpg".split(',')
Debug #test2:
---
- "" # why this?!
- " image/bmp"
- " image/gif"
- " image/jpg"
WHAT I NEED
Notice: I can use the CASE 2 TEST, but I would like to do things right and better.
Debug that I would like to have:
---
- " image/bmp"
- " image/gif"
- " image/jpg"
In the test case 1 there is no space before "image/bmp" in the result because there is no space before "image/bmp" in the original string.
In the test case 2 there is an empty string at the beginning because the string starts with a comma, and for every separator in the string there is a string in the resulting array, containing what comes before that separator (which in this case means the empty string).
If you want the result you've shown, you could just add a space (but no comma) before "image/bmp" in the source string. Alternatively you could split by /, */ and then add one space before each string with map. Though frankly I don't get why you want a space before each string.
>> ", image/bmp, image/gif, image/jpg".split(/\s*,\s*/).select{|x| x!=""}
=> ["image/bmp", "image/gif", "image/jpg"]