patch:tldr:8e277

The command "patch -p1 < ${patch-diff}" is used to apply a patch file to a codebase.

Here's a breakdown of the command components:

• "patch": It is the command-line tool used to apply patches. It is typically available in Unix-like operating systems.

• "-p1": It is an option for the "patch" command, specifying the level of the path strip. The number indicates how many directory levels should be removed from the paths mentioned in the patch file.

• "<": It is a symbol used for input redirection, indicating that the patch file contents should be read from a file rather than the standard input.

• "${patch-diff}": It is a variable that holds the name or path of the patch file. The "$" denotes that it is a variable, and the curly braces "{}" are used to specify the variable name.

In summary, the command will take the given patch file (${patch-diff}), remove one level of directories from the paths in the patch file, and apply the changes to the codebase.