How to Escape Backslashes in R String

How to escape backslashes in R string

[...] If I want to get a string containing 5 \ ,should i write 10 \ [...]

Yes, you should. To write a single \ in a string, you write it as "\\".

This is because the \ is a special character, reserved to escape the character that follows it. (Perhaps you recognize \n as newline.) It's also useful if you want to write a string containing a single ". You write it as "\"".

The reason why \\\str is invalid, is because it's interpreted as \\ (which corresponds to a single \) followed by \s, which is not valid, since "escaped s" has no meaning.

How to escape a backslash in R?

I found a solution that works

str = gsub("([\\])","", str)

substitute single backslash in R

When you need to use a backslash in the string in R, you need to put double backslash. 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. In fact, you need to make gsub treat it as a plain text with fixed=TRUE.

However, you might want to use normalizePath, see this SO thread.

Escaping backslash (\) in string or paths in R

From R 4.0.0 you can use r"(...)" to write a path as raw string constant, which avoids the need for escaping:

r"(E:\RStuff\test.r)"
# [1] "E:\\RStuff\\test.r"

There is a new syntax for specifying raw character constants similar to the one used in C++: r"(...)" with ... any character sequence not containing the sequence )". This makes it easier to write strings that contain backslashes or both single and double quotes. For more details see ?Quotes.

Replace slash with a single backslash in R

The solution is to escape the escape character which means 4 '\' in the end.

cat(gsub('/', '\\\\', "file_path/file_name.txt"))

Look at the difference between your standard output with like 'print()' which escapes the escape character, or get the plain string by using 'cat()'.

str_replace_all(string = x, pattern = "/", replacement = "\\\\")
cat(str_replace_all(string = x, pattern = "/", replacement = "\\\\"))

Replace single backslash in R

Since there isn't any direct ways to dealing with single backslashes, here's the closest solution to the problem as provided by David Arenburg in the comments section

gsub("[^A-Za-z0-9]", "", str) #remove all besides the alphabets & numbers

How to automatically handle strings/paths with backslashes?

You can use this hack. Suppose you had copied your path as mentioned then you could use

scan("clipboard", "character", quiet = TRUE)

scan reads the text copied from the clipboard and takes care about the backslashes. Then copy again what is returned from scan

Ignore escape characters (backslashes) in R strings

You can try to use the 'allowEscapes' argument in scan()

X=scan(what="character",allowEscapes=F)
C:\Users\mhermans\somefile.csv

print(X)
[1] "C:\\Users\\mhermans\\somefile.csv"


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