The man pages is the best source of information you can find... and is at your fingertips: man mkdir yields this about -p switch: ... <看更多>

Have you tried running the man mkdir command in Terminal? Doing so results in the following explanation for the -p option:. ... <看更多>

They often take the form of single letters (following a dash). If we had used the -p option of the mkdir command we could have done this in one step. E.g.. ... <看更多>

4. replace first space by dash. # 5. replace second space by nothing ... RDNAVERSION := $(shell grep -P '^Version: . ... mkdir -p rDNA/inst/java/; \. ... <看更多>