r:tldr:a58d1

The command "R -e ${expr}" is used to run a specific expression or command within the R programming language directly from the command line.

Here is an explanation of each component of the command:

• "R" indicates that the R interpreter or R runtime environment should be invoked.
• "-e" stands for "expression" and signifies that the following argument will be interpreted as an R expression or command to be executed.
• "${expr}" is a placeholder for the actual R expression or command that you want to execute. You need to replace "${expr}" with your specific expression or command.

For example, if you want to calculate the sum of two numbers (3 and 5) using R, you can use the command: R -e "3 + 5". This will execute the expression "3 + 5" using the R interpreter and provide the result on the command line. In this case, the command will output "8".