rgpt:tldr:6310e

The command rgpt --i "$(git diff ${filename})" consists of two parts:

1. git diff ${filename}: This is a Git command that generates the differences (changes) between the current state of the file specified by ${filename} and its last committed version. The ${filename} variable is expected to be replaced with the actual file name.

2. rgpt --i "$(git diff ${filename})": This part executes a tool or script called rgpt with the input -i. The --i flag specifies that the input for rgpt should be taken from the standard input. The $(...) is known as command substitution, which means it will replace the command within the parentheses with its output. In this case, the output of git diff ${filename} will be passed as input to rgpt.

So, overall, this command combines the use of git diff to find the changes in a specific file and then uses the rgpt tool (likely a custom script) to process those changes.