Ruby single backslash in string. Ruby regex gsub change within backreference.

Ruby single backslash in string I've read that ruby somehow parses string twice, maybe its somehow connected with my undesired output. But using a white space in front of the new line has no side effect on live build logs and their downloaded versions. See string literal for details about string literals. 3 on a 2018 MBP 13. quote(your_string)}/ For example, . We got our replacement right there and we can replace each hit at instatnt in one C function (I don't remember that YARV store return values, even if it do so, block receive different argument each time when it run). Related Discussions. Unlike in C, where single quotes denote a single character. Don't miss this chance to strengthen your skills! Visit the workshop here: Practice Strings in Ruby. I need to generate \\\hline which is used in Latex for table making. Connect and share knowledge within a single location that is I suspect that the ruby shell is simply escaping the backslashes for convenience, which is 16. read template = ERB. I just wanted to point out that that has nothing to do with backslashes. ruby remove backslash from string. so I suggest you write a unit test: # escape_token_test. I believe the fix should be to look two characters back. 34. Just using puts "\n" works fine for a vanilla Ruby execution, but it behaves weirdly in the Appcircle build log viewer. Commented Dec 29, 2016 at 1:20. 6. Commented Apr 4, Connect and share knowledge within a single location that is structured and easy to search. The same behavior for single and double quoted strings applies to In ruby, quotation marks can be printed in a string if it is immediately preceded with a backslash: print " \" ". \\\1 therefore requires "\\\\\1". The third backslash escapes the ` character (outputting one single ` ). Neither one needs a backslash to escape a . rindex( text ) return [ self ] if position_of_last_occurrence. Details about string-escaping and XSS protection are in this Asciicast. Thanks Phil. 39 of tr). When you need to use a backslash in the string in R, you need to put double backslash. If you actually have 'path\to\something' (which I think is likely), then you do not have the backslashes interpreted as escape characters. If you want to see what it actually is: puts "\\'e4" # => \'e4 Your first attempt is read as "literal quote e 4" and the second is "literal backslash quote e 4". I am trying to find a way of removing escaped characters in input strings from a file made by another program. But if you want to keep your double-quotes wrapping the Name of Person, you can escape them with a backslash \: from = "\"Name of Person\" <#{ENV['EMAIL just btw you dont have to explicitly put + sign in order to concatenate strings in ruby '"Name of (Escapes work differently in single-quoted and double-quoted Ruby strings. I understand there are three ways to have a long string span Connect and share knowledge within a single location that is structured and easy to search. What you get in your first example is exactly what you need. stringify("\/") returns "/" since it sees an escaped forward slash, so its just a forward slash. sub(’’, ‘’) Expected: “\\6” Got: j:4: unterminated string meets end of file j:4: parse error, unexpected $, expecting ‘)’ If I change the replacement to ‘c’, I get a new error: j:4: parse error, unexpected tIDENTIFIER, expecting ‘)’ puts a. 1:28. IMO, it's specifically related to the Appcircle's build log viewer. If you want an actual backslash in the string or regex, you have to write two: \\. Hot Network Questions Is it possible/ethical to try to publish results on ones own medical condition as a patient? Connect and share knowledge within a single location that is structured and easy to search. You might also note double quotes around the string in the REPL representation, which do not No, every Ruby String literal must escape backslashes. open("multi_line_string. puts '\\' # Output: \ puts '\n' # Output: \n It seems that backword slash is escaped but the newline character isn't. JSON. I found \\\hline as input generated \hline even though the string was inside %q. gsub Single Backslash inside ruby string. org and wikibooks. In a single-quoted string, any other character following a backslash is interpreted as is: a backslash and the character itself. Definition class String def split_on_last( text ) position_of_last_occurrence = self. But when knitr encounters the % it believes the string to be a comment, I am using this in knitr as \textit{\Sexpr{try}} – We've created a workshop where you can get additional practice with Ruby strings. The reason sub("'", "\'") does not work is because "\'" is the same as "'". Try this: puts "\\_" You'll see just \_ like you want. /,"") would do this, but no. Therefore, 'stackoverflow' and "stackoverflow" both will From Ruby Programming/Strings. So '\n\n\n' is three backslashes and three n, not three line feeds as you expected. When you use ' as the string delimiter in Ruby code, it still interprets \\ as an escape sequence. bytes == other. 2. gsub("&bsol;", "\\") Result: a\\b. And if you really want "path\to\something" (which I also doubt), then you don't have to do anything. Example: "a&bsol;b". For a string replacement, it contains everything in the string which exists following the matched text. So you need two levels of escaping, makes 2 * 2 = 4 backslashes on the screen for one literal replacement backslash. Is there an equivalent in Ruby to @ in C#? If you want to have a backslash in a double quoted string (as a result), you have to escape it with another backslash. So you give \\\\' in the replacement to make \\' in the string, which is a string containing one literal \ . There's a extremely slight performance uptick in using single-quoted strings because Ruby doesn't have to check for any interpolation or In Ruby single quotes around a string means that escape characters are not interpreted. /#{Regexp. rb user system total real 0. If you don't intend to use interpolation, it's recommended to If I had a string like the one below how would I split it at every 3rd character or any other specified character? Connect and share knowledge within a single location that is structured and easy to search. Ruby : Double- and single-quoting have different effects in some cases. How to convert a hash to JSON without the converted string being full of backslashes. For example, n by itself is simply a letter, but when you precede it with a backslash, it becomes \n, which is the newline character. for instance if you submit \\ ruby teats it as a single \\ is there anyway to stop this? I still require all the other 's such as \\n etc. escape \x. Hot Network Questions Shakespeare and his syntax: "we hunt not, we" Dative in front of accusative Merits of `cd && pwd` versus `dirname` How to read this Introduction. Additional explanation: the reason for this is that IRB by I am having some trouble with regular expressions in ruby, or otherwise finding a way to remove a slash from a string. gsub('/', '\/') It's due to the use of backslash in a sub replacement string. Remember to use a single-quoted string unless you want regular string interpolation to kick in, where backslash has a special meaning. WriteLine("\\") you will get only a single backslash. Backslashes in my params. Since this is a Rails project, we often have strings that are a little bit longer - i. sub(’’, ‘c I have to add backslash("\") to a string. will be escaped, since it's otherwise interpreted as 'any character'. Wrap the echo parameters in single quotes to include double quotes in the output. Within sub or gsub argument, a backslash followed by some characters have special meaning comparable to the See RubyDoc for how to use the percentage string literals. Also, as @Torxed mentioned in his answer, you can use the prefix r or R:. If you do a puts line , you will see that it prints just this\is\line . Remember that, since \ is special to Ruby, Ruby needs to know you want it as a literal. the problem is that when a user tries to shop escaping in there code the escaping actually happens. 2010/1/25 Xavier Noëlle [email protected]:. This special case is necessary to embed single quotes or apostrophes into a single-quoted string. Thanks for benchmarking these three methods! – likethesky. Otherwise, single quotes provide a performance Now, as the replacement string is not a plain string but is interpreted (otherwise \1 wouldn't work), backslashes there also need to be escaped, so the first two in the string (not the literal) give a single backslash for the replacement and It takes a string and escapes any 'dangerous' characters. Inside of the single quotes, Ruby will perform no interpolation or escape sequences other than escaping the single quote character and backslash itself (\' and \\ respectively). Backslash + captured group within Ruby regular expression. 3. I am taking one example for more understanding: >> '#{foo} bar' => "\#{foo} bar" Here you can see that return values using double-quoted strings, which requires backslash to escape special characters such as #. Backslashes have special meaning in both Ruby double quoted strings and JSON formatted strings. Modified 6 years ago. Addendum You cannot use string interpolation with single-quoted strings in Ruby. You can also just use single quotes instead of double The string you have stored in line already does contain single backslashes. How to perform String replacements without backslash escaping in Ruby. The reason sub("'", "\\'") does not work is because "\\'" expands to a backslash followed by a single quote. It didn't - each of those is just the single character '"'. And the result is different in PHP and Ruby when I'm using URL strings. Different OS have different way to express the path of a given file, and every modern programming language has own methods to handle paths and file system references. But the Ruby shell (IRB, byebug, whatever you're using) @AhmadLeoYudanto: THERE IS NO BACKSLASH IN THE STRING. so neither will put it there. To better understand this example may help: std::string s = "01234\6"; //\6 is treated differently already, as unicode character \6, not as backslash + 6 Unless what you mean is you want to have a text with backslash (say, from I/O). "\\" is a single backslash. How to replace single quote to backslash in ruby? 1. When you put them together you get the two character string \'. retained the backslash. 3 Amps? Lost calculation Do we know what the Create a String#split_on_last method. The following string starts with one backslash, the first one you see in the literal is an escape character starting an escape sequence. The first time the slashes do their job as escapes in the string, in the second time gsub will search the string for group references. restrict backslash while convering to JSON from ruby. replace; Ruby : string. As you can probably guess, \ also needs to be escaped so it Remember that the way it will show up is always "\\1", which means literal backslash, one, which is what you want. Examples: You have to escape the backslash: \\ From Python Docs:. gsub('\\', '') Note that the default output in a REPL uses inspect, which will double-quote the string and still include backslashes to escape the double-quotes. However, these all treat backslashes as a special character and require that it be escaped. ruby on rails replace single-quotes with double-quote in a string. Strings let you display and communicate with your I think there's a difference between reading that sequence of bytes from a file, and putting it in your Ruby code literally. You could also try clicking the small magnifying glass icon next to watched values and on debug tooltips. Your replacement string contains \' which is expanded to the global variable $' which is otherwise known as POSTMATCH. 7, trying to generate a string with the \' characteres, in order to create a script for running in MySQL. a backslash. ; Use some ruby method to print the string to console like puts or print (otherwise ruby will print a string to the console with double quotes escaped like \"); puts "echo '#{json_string}' > data. length # => 20 "a\ b irb(main):001:0> puts "\\" \ => nil irb(main):002:0> puts '\\' \ => nil. I do not understand why Ruby looks inside %q and escapes the \. Removing backslash (escape character) from a string. I want to remove the backslash from the string before saving. If you do this: "\_" I have a string in my ruby code which ends with a backslash: acc. You cannot preserve the "exact" string when you stringify, since parsing a json string will not escape To do that, we take our desired regexp input and double every backslash again to get through Ruby's string literal parser. $ ruby split3. , a single backslash. The problem is that when using sub (and gsub), without a block, ruby interprets special character sequences in the replacement parameter. When the string is inspected it uses double-quotes, and tries to produce a version of the string that you can copy and paste in to Ruby to get the same string - so it needs to double up the backslash remove the second backslash in a string: “c:\test” I need it with one backslash for a comparison in my db. Consider the following: '\'' # => "'" 'It\'s a baby boy!' # => "It's a baby boy!" Without the escape, Ruby will assume that the second quote mark terminates the string, leaving you with an unbalanced third quote mark. at one point in the intermediate steps there were 8 backslashes used to represent a single backslash in the file path. How to avoid starting and ending double quotes in rails string? 0. 8. In order to Because "Betty's" contains an apostrophe, which is the same character as the single quote, in the second line we need to use a backslash to escape the apostrophe so that How do a put a single backslash into a string in Ruby? irb(main):006:0&gt; &#39;\&#39; irb(main):007:0&#39; &#39; =&gt; &quot;&#39;\n&quot; irb(main):008:0&gt; How do a put a single backslash into a string in Ruby? irb(main):006:0> ‘’ irb(main):007:0’ ’ => “’\n” irb(main):008:0> ‘\’ => “\” irb(main):009:0> in 6, the backslash "Escape" with backslash. Example: Ruby The escape \" here is interpreted by Ruby parser, so that it can distinguish between the boundary of a string (the left most and the right most "), and a normal character " in a string (the escaped ones). A double-quoted string allows character escapes by a leading backslash, and the evaluation of embedded expressions using #{}. Learn more about Teams (note ERB is included with Ruby) require 'erb' multi_line_string = File. You should use double quoted strings only when you need more interpretation. result(binding) in ruby strings the backslash is the special first char to start an "escape sequence", therefore: \\ - means single backslash. txt" Javascript completely ignoring "\", I'm receiving the string with a single backslash. Initially, I would like to clarify that in the literal form of a string whatever is between single or double quotes gets evaluated as a string object, which is an instance of the Ruby String class. Unfortunately, sub uses the backslash as the escape character for these: \& (the entire regex) \+ (the last group) \` (pre-match string) \' (post-match string) \0 (same as \&) \1 (first captured group) \2 (second Ruby Newbie here. Learn more about Teams Ruby's string: Escape and unescape a custom character. \n means the newline character. constant as you entered it. The result should be like this: INSERT INTO table (name, description) I have a very large string that needs to escape all the single quotes in it, so I can feed it to JavaScript without upsetting it. You need to escape your backslash by preceding it with, yes, another backslash: print("\\") The \ character is called an escape character, which interprets the character following it differently. Hot Network Questions Is there any incentive for the 100 answerers to get the questions right? In your version there is block which must be called each time when there is & found. See also: %q: Non-Interpolable String Literals escape token '\' is always working in plain ruby code, but not always working in "ruby console". Is there a way I can do that in ruby or in postgres? When I try to remove it in ruby, it considers the quote after the backslash as an escape character. Right. The backslash followed by the single quote is called an escape sequence. Is that a string literal from your source code? Is yes, then you can do away with the ‘escaping the backslash’ fiasco by using single quoted strings. A back-reference is typically preceded by an additional backslash. In a single quoted string, only \ (backslash backslash) and \' (backslash quote) are taken as special characters. I'm receiving this string from an external source (with a single backslash): "Spool10072098_\P_18005389. I was hoping Ruby's own string escaping code might be available. stringify("\\/") sees a backslash being escaped, and then a forward slash next to that, so it returns "\/". I'm not sure if I should somehow add an additional \ to escape it, and how to do that. Here is MWE #!/usr/local/bin/ruby -w tmp = File. So long as the strings share the same encoding, byte comparison would be elegant solution without the need for additional escaping. Learn more about Teams Julia - Printing or Writing in a file a Backslash in a String. I am aware of this question but I am not asking about Because \n is a special keyword, you have to escape it, by adding a backslash before the special keyword (and because of that, backslashes must also be escaped), like so: abs\\nabc. \\&. If the string doesn't contain backslash all works fine PHP implementation introduces the backslashes. 000000 0. ex: “#{name}” => “Pradeep” ‘\’ does not do any of these. – neptune. secret_key = "ASJSJJDSJFJJFFJJFJF\\" acc. A string. This has a problem when there is an escaped slash before the quote: \\'. Hot Network Questions Thoughts and How can i say "all symbols except backslash" in Ruby character class? /'[^\]*'/. Hot Network Questions If you want to include a backslash character itself, you need two backslashes or use the @ verbatim string: var s = "\\Tasks"; // or var s = @"\Tasks"; Read the MSDN documentation/C# Specification which discusses the characters that are escaped using the backslash character and the use of the verbatim string literal. – Cary Swoveland. Then the JSON parser gets it. Hot Network Questions Disclaimer: I'm not familiar with the inner workings of ruby's regex engine, any info here is deducted from the article mentioned above. UPD: The problem is not in communication. You got to tell C to not use your backslash as an escape sequence by adding an extra backslash to your string. The \\ escape sequence tells the parser to put a single backslash in the string: var str = "\\I have one backslash"; Difference between single and double quotes: Ruby only interprets escape sequences in double quoted strings. str can be a non-string object that responds to to_s. json" The idea is that it will give you a string that you can write out a Ruby file that will later print the string. So if you want to split on \n you need I want to insert the following as the value for a variable in some Ruby: `~!@#$%^&*()_-+={}|[]\:";'<>?,. Double quotes support it, single quotes don't. \' – single quote \\ – single backslash Except for these two escape sequences, everything else between single quotes is treated literally. Escaping double quotes in Ruby's gsub. One option is to put your replacements in a data file (eg. But if you print it, it will output what you expected, i. This will show you the string as it will appear when printed - ie. Otherwise ruby will at this point try to resolve the hex-literal which is not possible because it is not followed by two valid hex characters (at the point where you use it). Note that a resulted string should be used unquoted and is not intended for use in double quotes nor in single quotes. You’ll use strings in almost every program you write. 1. Try taking a look at just your input: "'some string \ hello'". There are two characters that are special within a single quoted string literal: the backslash and the single quote itself. In this case '\n' is actually equivalent to "\\n". Percentage string literals start with a percentage sign % followed either an opening parenthesis or any non-alphanumeric character. . Let's update the I have several strings that look like this: "((String1)) Connect and share knowledge within a single location that is structured and easy to search. Hot Network Questions Searching Torah for words following an acrostic pattern Is there a safety concern using a 20 Amp circuit for a heater drawing 8. If quote marks are special Ruby notation for starting and ending a String, what happens when we want regular quotation marks as part of the text? In the context of a String, the backslash character \ Note that \\ is interpreted as an escape, i. Add a backslash in a replacement string one needs to escape it and hence have to backslashes. String#delete deletes a character set specified the first parameter, rather than a pattern. You should only add backslashes before characters that have a special meaning within double quoted bash context. 6. Learn more about Teams Get early access and see previews of new features. So if you type \n in the irb, you get back \\n. 9. One of the edicts is that no line should be wider than 80 characters. puts 'abc\nabc' # => abc\nabc puts "abc\nabc" # => abc # abc C and C++ deal with backslashes as escape sequences by default. A single-quoted string does not do this interpreting; what you see is what you get. Take for example '"' a single character ". I am using Ruby 1. String literals may optionally be prefixed with a letter 'r' or 'R'; such strings Connect and share knowledge within a single location that is structured and easy to search. save Above is the code snippet, when I try to save it using Active record I get an error, I ```ruby puts 'This is a single-quoted string with a backslash: \\' puts "This is a double-quoted string with a backslash: \\" ``` Performance: Single-quoted strings are slightly faster than double-quoted strings because they don’t require Ruby to search for interpolation and escape sequences. Hot Network Questions What does GB Shaw mean when he says "like the butcher's wife in the old catch" here? Quantum entanglement explained by non-local hidden variables when photons It will always show \\ in the debug and watch windows but if you do a Console. My first thought was to look at the string and if I see a quote without a backslash before it put the backslash there. 4. The backslash (\) character is used to escape characters that otherwise have a special meaning, such as newline, backslash itself, or the quote character. As the first backslash is the escape character and not used to match. This is why you have problems with delete Because strings with double and single backslashes get different results. Use puts to see the string’s exact contents: Hi, I'm trying to take a string and escape a single quote if it is not already escaped. There is a difference between what is written in your code and what the output will be. org. But escaping the backslash yields. These are the common escape sequences: \a - Bell(beep) \b - Backspace \f - Formfeed \n - New line \r - Carriage Return \t - Horizontal Tab \\ - Backslash \' - Single Connect and share knowledge within a single location that is structured and easy to search. Single quotes only support two escape sequences. txt','w') str = %q[\\\hline] You can break your string into two pieces to clarify things:. Does anyone know how to provide a single backslash as the replacement value in Ruby's gsub method? I thought using double backslashes for the replacement value would result in a single backslash but it results in two backslashes. But because \ has a special meaning as an escape character in both Ruby double quoted strings and JSON, a single \ will look like \\ because both have to escape the special mean of \ by, well, In addition to disabling interpolation, single-quoted strings also disable all escape sequences except for the single-quote (\') and backslash (\\). / Surrounding this in double quotes doesn't work, so is there Connect and share knowledge within a single location that is structured and easy to search. Using a backslash before a character, it tells Ruby that this character should be interpreted differently. Commented Aug 18, 2019 at 22:00. The selected answer finds a way: convert each newline to a backslash followed by "n", then split on backslashes. erb", 'r'). Learn more If your substring is at the beginning of in the end of a string, then Ruby 2. If your question is actually "What is the point of the language design requiring us to escape a backslash in single (as opposed to double) quotes", then that is to allow single quotes to appear within a string literal written with single quotes. And don't try to use double quotes for quoting an SQL string literal, that's what single quotes are for; double quotes are for quoting identifiers (such as table and column names) How to replace single quote to backslash in ruby? 1. 0. Escape Required for Slashes I would go with a heredoc if I'm starting to have to worry about escaping. In the other solution there is no need to call other function. You were only matching 1 backslash when replacing, which gave you the three \\\ at the start of your path. Can anyone do it? thanks! Niels. match("'some string it matches whole string, i added single quotes to show it – Vladimir There's actually not a backslash in your string to match against. to_source_string + “’” # puts ‘foo’ Or a string with special characters in it like ‘foo’ (5 characters, including enclosing single quotes): How to print backslash in single quoted string in ruby. The backslash is escaping the forward slash. I would have thought in my naivete that gsub(/\\. and ~ 1. When you enter this into irb the output will be: s = '"' #=> "\"" From the result "\"" the starting " and ending " mark the begin and ending of the string while \" is an escaped double quote, and represents a Is it possible to escape character within single quotes in ruby? The confusion is in following code. I have a string like "car\" which I will be storing in postgres db. path; Ruby: File and FileUtils; If you really need to handle strings: Python: string. To better understand this example may help: I use single quotes unless I need interpolation. This behavior applies to almost every kind of string "magic". Actually, 3 backslashes will yield one backslash. Only double quotes string can be escaped correctly. Therefore I don't quite understand what you want to achieve. I fixed the above bugs and this is the updated version: UNESCAPES = We recently decided at my job to a ruby style guide. You need to do 2 things to make this work. Remember that inside double-quoted strings the backslash is used for special characters and sequences like \t for tab or \n for newline. nil? Your example string contains only single backslash characters ("\\"), in some cases followed by an escaped character ("\\\S"). ". I also get the same result using a block: backslash in a replacement string one needs to escape it and hence have to backslashes. Hot Network Questions Why is “water take the steepest path downhill” a common approximation? Old story about the shape of a robot and its ability to not break down How to keep single backslash in Ruby string after to_json formating? 2. We could replace the newlines with I cannot seem to replace a double backslash with a single backslash in Ruby. but another way to think about it is that two backslashes written into a sting will resolve to a single backslash as soon as you do anything with it. Strings in Ruby are objects, and unlike other languages, strings are mutable, which means they can be changed in place instead of creating new strings. Hot As you face problem, while using interpolation in single quoted string because Ruby do not interpolate into single-quoted string. I would expect if you wanted \\ as an output you would only have \ as an input. Heavily inspired by halfelf's answer but permits more than just a single character, doesn't have a default param value and refactored for clarity. Firstly, are the strings input from a text file treated as single- or As you stated, if you want a literal backslash in a string, you need to write two of them. I've known of them from other Ruby language references as well. e. "User X wanted to send you a message about Thing Y" that doesn't always fit within the 80 character style limit. In single quoted strings, that's two characters I think you'll find that the backslashes are not in fact doubled in the string. Here is how my string looks: string = "word \/ word" I am trying to remove both the backslash and the slash; I want this result: string = "word word" I think I am missing something with escape characters, or who knows what! How to print backslash in single quoted string in ruby. For example, if you want to write a back-reference \& in replacement with a double-quoted string literal, you need to write ". 2 How to avoid starting and ending double quotes Escapes a string so that it can be safely used in a Bourne shell command line. Single Backslash in Ruby String. 1 Backslashes in my params. \\ inserts a single backslash character. The backslash is a regex escape character so \\ will be seen as, match only one \ and not two \\. Connect and share knowledge within a single location that is structured and easy to search. Surely Python and Ruby have it: Python: os. Hot Network Questions Evaluate the limit involving the summation of In Ruby, there is a distinction between strings that are between double quotes and strings in single quotes. Then you put your string and end the string literal with the associated closing parenthesis symbol or the non-alphanumeric character. In the context of a String, the backslash character \ tells Ruby that the character immediately following it is special. The backslash is shown to you to make clear that the quote is part of the string, Single Backslash inside ruby string. Within double quotes, escaping of a single quote is optional. in ruby strings the backslash is the special first char to start an "escape sequence", therefore: \\ - means single backslash. Ruby string escape characters. It will take care of it for you: string = <<MARKER I don't have to "worry" about escaping!!'"!! MARKER MARKER delineates the start/end of the string. Ruby: backslash all non-alphanumeric characters in a string. 5 has introduced the methods for this: Double-quoted strings will always show up with double backslashes in irb due to the way they're escaped. 1 Performing rails query with mysql with backslash in string. 9 and came upon the alternative delimited single and double-quoting methods (%q / %Q). ex: ‘#{name}’ => ‘#{name}’ Single-quoted strings are faster than double-quoted strings Using raw works fine, but all it's doing is converting the string to a string, and then calling html_safe. A string is a sequence of one or more characters that may consist of letters, numbers, or symbols. str. See ruby-doc. 3-p194 :001 > Single Backslash inside ruby string. The percent notation in Ruby is something inspired by the Perl programming language and gives us many shorthands for some common type definitions. The way to know that this is correct is to use puts: puts "\\1" # => \1 Inside of double-quoted strings, backslashes have significant meaning. The basic thing to know is that the replacement string gets evaluated 2 times. start string on the next line after opening the heredoc, then end the string by using the delineator again on it's own line. When I know I have a string, I prefer calling html_safe directly, because it skips an unnecessary step and makes clearer what's going on. Internally strings with backslashes will look like they have double backslashes because Ruby is escaping them: Single Backslash inside ruby string. Gruesome Details. Coincidentally a backslash is also special in a string (even in a single quoted string). So you get a string with the value of ["Company\","NN","Company\"]. In IRB/Pry the representation differs, because REPL is intended to support copy-paste, and the string you see is the exact string with single backward slashes, how one would type it inside double quotes. Note also that a string literal consumes backslashes. If you really do have "path\to\something" (which I doubt), then you already have tabs and spaces in that string. But how do i print \" in ruby without the backslash disappearing due to the presence of the quotation mark immediately before it? Thanks in advance. bytes To display a backslash, you simply escape it with a single backslash: puts '\\' \ Additionally, depending on your exact usage, could use the <=> operator: (str <=> other). See String Literals for details about string literals. Learn more about Teams Remove double backslash from string with Ruby. There are no "double backslashes" in the string. Replace all backslashes with empty string using gsub: json. You already have that. The second one is correct regardless of how it's displayed. How to print backslash in single quoted string in ruby. I need to encode my JSON using HMAC (SHA384). Hi, Why can’t I substitute a single backslash in a string? a = “\\6” p a # => “\\6” puts a # => \\6 p a. My code is as follows f=10 path = "My Documents\#{f} " For How to print backslash in single quoted string in ruby. For, example, let’s take the string, foo (3 characters): “puts '” + “foo”. I am using Ruby to generate Latex code. Single Backslash inside ruby string. So even if we have one value, we have to provide pack with an array. %q/I'm acting like a single-quoted string/ %Q|"I'm acting like a double-quoted string" --Anonymous| Misinterpreting what you see. Removing 1 backslash from String (Ruby) 4. 9 String literal without need to escape backslash. Any ideas? ruby; string; Share. I've been reading through Thomas' Programming Ruby 1. Something along the lines of Ruby. string = '\\' + '\'' Each part is a string of length one; '\\' is the single character \ and '\'' is the single character '. I want to insert backslash before apostrophe in "children's world" string. 080000 ( Hi, I’m trying to parse code snippets on a website that are submitted by the user. 080000 0. str must not contain NUL characters because of nature of exec system call. gsub for removing brackets and \ from string. open('foo. Percent notation for String. Hot Network Questions Is intelligence the ability to reduce entropy in systems? Solve this sudoku like 5*5 puzzle Can I program a navigational great circle? Chrome (command Single Backslash inside ruby string. Ruby Single BackSlash Stored in Variable. Is there some way in Ruby that I can avoid having to put double-backslash in Ruby strings (like what can be done in C#): For example, in C# was can prefix a string with @ and then the backslash in the string does not need to be escaped: @"C:\Windows, C:\ABC" Without @ we would need to escape the backslash: "C:\\Windows, C:\\ABC" When you have a double-quoted string such as str = "rua rua urua\nhuhuhucuhch", you obviously cannot split on backslashes because it contains none. “\” escapes the necessary characters, and also allows substitution. A backslash must be escaped if you want an actual backslash. In that case, you should put \\ to make your compiler understand that you mean it as real backslash not a unicode character: I want the string to be displayed as it is, my output pdf that I am generating should have the string "0% success" printed the way it is. How to escape slashes in ruby string. puts "\\x" # => \x The first backslash will escape the second one (outputting one single backslash). Is there a easy way to do it? irb(main):035:0> s = "children's world" => "children's world" Is it possible to have a string with a single backslash? I want var to have the value “\foo” And when I do something like: var = “\foo” I get “foo” But when I do: var = “\foo” I get Backslashes (\) are used as escape characters in Ruby strings. If you wanted to print \\n, you would have to replace it to be abs\\\\n, and so on (two backslashes to display a backslash). ) Probably the reason why omitting the \1 doesn't seem to change anything in the example you gave, is because there is no capturing group in the regex. string foo = "The integer division operator in VisualBASIC is written \"a \\ b\""; string bar = @"The integer division operator in VisualBASIC is written \"a \ b\"" In Ruby, I could use the single-quote string literal, but I'd like to use this in conjuction with string interpolation like "text #{value}". That's how single backslashes are displayed (in IRB and other places that use #inspect for displaying things) Try this instead (puts will not additionally escape backslashes or other chars) puts string. ymmv of course. String in single quotes is a raw string. 4k 3 3 gold badges 53 53 silver badges 64 64 bronze badges. I figured I would just escape the backslashes with another backslash. 9 hence Oniguruma. without all the escape sequences. It's not convenience, it's because Ruby strings expressed in their string literal format require escaping on Because "Betty's" contains an apostrophe, which is the same character as the single quote, in the second line we need to use a backslash to escape the apostrophe so that Ruby understands that the apostrophe is in the string literal instead of marking the end of the string literal. new(multi_line_string) template. Replacing `\` with `\\` in ruby. However, this performance difference is usually Then you need the four-backslash version. Hot Network Questions How to deal with overtaking personal space and decision making? The backslashes are part of the string representation, and are not actually in the string. Follow Replace single quote with backslash single quote. In order to put single or double quotes into a string, you have to precede them with a backslash. Hot Network Questions How does Mathematica MatrixExp Krylov method scale with sparse matrices? backslash in a replacement string one needs to escape it and hence have to backslashes. rb require 'test/unit' class EscapeTokenTest < Test::Unit::TestCase def test_how_to_escape hi = "hi\\backslash" puts hi end end and you will get result as: hi\backslash backslash in a replacement string one needs to escape it and hence have to backslashes. Backslashes (\) are used as escape characters in Ruby strings. Ask Question Asked 6 years ago. zero? EDIT You may have to escape all the backslashes: str = "\\\\ \\hline" puts str # => \\ \hline please notice that it also works if you use single quotes string and escape only the single backslashes: str = '\\\\ \hline' puts str # => \\ \hline and also if your backslash precedes something that may look like a char that can be escaped: There is a difference between single '' and double quotes "" in Ruby in terms of what gets to be evaluated to a string. Ruby regex gsub change within backreference. The argument about it being troublesome to change later when you need interpolation swings in the other direction, too: You have to change from double to single when you found that there was a # or a \ in your string that caused an escape you didn't intend. Your input seems suspicious to me because it is not following the convention of the rest of the string. 27. That is to say, two-character sequences in which the first character is a backslash. To check, instead of printing it using p (which uses String#inspect) just print it using puts. Array#pack("U*") is usually coupled with String#unpack("U*"), which takes every character of a string and puts its unicode bit value in an array. How to remove backslashes in ruby strings. Viewed 2k times 3 I once, long ago, I had to capture an xpath of an element whose only identifying feature was a windows file path, then generate a program (as a string) in which xpaths to be represented as strings. Also, when you use gsub("\\", "/", str) , the first argument is parsed as a regex, and it is not valid as it only contains a single literal backslash that must escape something. Ruby does allow arbitrary String delimiters like these: %q{A string} %Q<A string> %. In the case of single quotes one slash can be omitted as \1 is not a valid escape sequence in single quotes and is treated literally. Ruby - How do I escape both a back to back backslash and a single Hot Network Questions Advice needed: Team needs developers, but company isn't posting jobs Note also that a string literal consumes backslashes. So JSON. This is on Ruby 2. str = ‘c:\test’ which is equivalent to: str . Hot Network Questions When flying a great circle route, does the pilot have to continuously "turn the plane" to stay on the arc? What software shall I use for DFT on an organic molecule? That means "literal-backslash underscore". lyb llko tfhnfc bwgmz dnw uaic voktddw iro tkdkhq qsctpk