cp, mv — Copying and Moving

cp — copy with care

cp source dest copies one file. Common flags:

• -r — recursive, for directories
• -i — interactive, ask before overwrite
• -n — never overwrite (silently skips)
• -v — verbose, list each file copied
• -p — preserve mode, ownership, mtime
• -a (GNU) — archive: -rp plus symlinks etc.

Trailing slash matters: cp foo/ bar copies contents of foo into bar (if bar exists). Without the slash, cp foo bar renames or creates a child. Always test on a throwaway directory first.

mv — move and rename

mv is the same operation as rename when source and destination are on the same filesystem — it just relinks the inode. Across filesystems it copies then deletes, which is slower and not atomic.

Same flags as cp where they apply: -i, -n, -v. There is no -r because mv always moves whatever you point at, recursive or not.

When to reach for rsync instead

For anything bigger than a few files, switch to rsync -av source/ dest/. It can resume, skip unchanged files, preserve permissions, and tell you exactly what it did. We dig into it in the network-remote track.

The trailing-slash quiz

• cp -r dir1 dir2 — if dir2 exists, creates dir2/dir1. If not, creates dir2 as a copy.
• cp -r dir1/ dir2/ — copies the contents of dir1 into dir2.
• cp -r dir1/. dir2/ — same as above, more explicit.

Don't memorize. Always run cp -nv first, see the output, then drop the -n.