You can easily match newline characters in R regex with the understanding of some control characters under the hood. Scroll down to learn more about them and how they can help you match newline characters in R.

Match Newline Characters In R Regex

Newline Characters In Different Platforms

Newline, also known as line break, next line (NEL), or end of line (EOL), is a sequence of one or multiple control characters that can be used to specify the end of a text line and signify the start of a new line. Each character encoding and platform has its own specification for this newline sequence.

The most popular characters used for this purpose are carriage return (CR or return) and line feed (LF). They are components of all popular encodings, including ASCII, EBCDIC, and Unicode. We can trace the roots of these control characters back to the days of typewriters.

EBCDIC even provides another character for newline codes (NL). Similarly, Unicode also comes with the new line control code (NEL) and other control codes for paragraph separator and line separator markets. Still, as far as newline characters are concerned, you only need to pay attention to carriage return and line feed.

The carriage return is used to tell the system console or the printer to move its cursor to the beginning of the current line. The line feed commands them to move to the next line. When used together, the CRLF sequence can start a new line as a result.

In a computer system, the actual control characters for a new line in a text file depend not only on the character encoding but also the operating system.

• On Unix and Unix-like systems (such as Linux and recent versions of macOS), the representation of a new line is LF (line feed).
• On DOS and Windows, the CRLF sequence represents this new line.
• On old versions of Mac OS, it is the CR character that signifies a new line.
• Other systems, such as z/OS, may have different specifications. Consult their documents to learn more about this.

Remember that in regular expressions, we have to use escape characters for patterns. This means, on Linux, you must use the “\n” string to indicate a new line in regular expressions. The corresponding escape characters on Windows are “\r\n“.

Note: you can learn some other escape characters in this guide.

Match NewLIne Characters In R Regex

Supposed you the text file sample.txt with this content:

> data <- read.csv("sample.txt", sep = "\n")
> data

      ITTutorial
1 Stack Overflow
2 Quora
3 Reddit

And you want to read the data line by line from this with read.csv. The read.csv() function has the parameter sep allowing to manually set the delimiting character between items. In the data file, all four items sit in separate lines, meaning the delimiter is also the newline character.

This is how you can set the newline character with the read.csv() function on Linux, for instance:

> data <- read.csv("sample.txt", sep = "\n")
> data

      ITTutorial
1 Stack Overflow
2 Quora
3 Reddit

On Windows, you must set it to “\r\n”:

> data <- read.csv("sample.txt", sep = "\r\n")

You can apply the same regular expressions to other functions and methods that accept them.

Summary

To match newline characters in R regex, you have to use the escape characters of newline characters. They are “\n” and “\r\n” on Unix/Unix-like and DOS/Windows systems, respectively.