diff --git a/README.md b/README.md index f18189f..b50166c 100644 --- a/README.md +++ b/README.md @@ -217,6 +217,11 @@ Notes: repren --full --preserve-case --from foo --to bar . ``` +- As the man page says, `rsync` really is a fast and extraordinarily versatile file copying tool. It's known for synchronizing between machines but is equally useful locally. It also is among the [fastest ways](https://web.archive.org/web/20130929001850/http://linuxnote.net/jianingy/en/linux/a-fast-way-to-remove-huge-number-of-files.html) to delete large numbers of files: +```sh +mkdir empty && rsync -r --delete empty/ some-dir && rmdir some-dir +``` + - Use `shuf` to shuffle or select random lines from a file. - Know `sort`'s options. For numbers, use `-n`, or `-h` for handling human-readable numbers (e.g. from `du -h`). Know how keys work (`-t` and `-k`). In particular, watch out that you need to write `-k1,1` to sort by only the first field; `-k1` means sort according to the whole line. Stable sort (`sort -s`) can be useful. For example, to sort first by field 2, then secondarily by field 1, you can use `sort -k1,1 | sort -s -k2,2`.