patch:tldr:3c070
patch: Apply a patch to a specific file.
$ patch ${filename} < ${patch-diff}
try on your machine
This command is used to apply a patch file to a specific file. The ${filename} placeholder should be replaced with the name of the file you want to apply the patch to. The < symbol is used to redirect the contents of the ${patch-diff} file (which should contain the patch) to be input for the patch command. Thus, the command will retrieve the patch from the ${patch-diff} file and apply it to the ${filename}.
This explanation was created by an AI. In most cases those are correct. But please always be careful and
never run a command you are not sure if it is safe.