First steps / Stage 7 of 15 · step 8 of 10

Copy and move files

~12 min

Not running Starting usually ~20 s

Situation

There is an update on the server tomorrow. A colleague asks you to save the configs from ~/src into ~/backup and tidy ~/src while you are at it: mark the notes as old and move the tmp directory with the build log over to the backups.

Task

Make it so that:

~/backup holds copies of app.conf and db.conf from ~/src, with the originals left in place;
~/src/notes.txt gets the new name notes.bak in the same directory;
the ~/src/tmp directory, with everything in it, has moved to ~/backup/tmp.

Lab goals

0 of 3

Copies of app.conf and db.conf are in ~/backup, originals still in place — not checked yet
~/src/notes.txt renamed to notes.bak — not checked yet
Directory ~/src/tmp moved to ~/backup/tmp with everything in it — not checked yet

Hints

0 of 3 open · they open one at a time

Hint 1

Show the solution after 3 failed checks

Files and directories · picked for this lab

cp — copy files and directories

Cheat sheet

$_ — insert into the terminal

cp app.conf app.conf.bak a copy next to it, another name
cp app.conf /tmp/ into a directory, same name
cp a.txt b.txt docs/ several files into a directory
cp -r project project-copy a whole directory
cp -a /etc/nginx ~/nginx-backup keep permissions, owner, times
cp -i app.conf /etc/app.conf ask before overwriting
cp -n app.conf /etc/app.conf never overwrite an existing file
cp -u *.conf /srv/conf/ only if the source is newer
cp -v a.txt b.txt print what gets copied
cp -r project/. backup/ a directory's contents, not itself

cp and mv share many options: -i, -n, -u, -v, -b, -t. Full list — man cp.

Back up a config before editing

bash

sudo cp -a /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
sudo nano /etc/ssh/sshd_config
diff /etc/ssh/sshd_config.bak /etc/ssh/sshd_config   # what changed

-a keeps the owner and permissions, so the backup can be put back as is.

A directory into an existing directory, and "into" it

bash

cp -r src dst        # dst exists → dst/src; else dst is the copy
cp -r src/. dst/     # the contents of src straight into dst

The same command gives different results depending on whether dst exists. Check the result: ls dst.

Copy many files into one directory

bash

cp -t /srv/www/ index.html style.css app.js   # destination first
find . -name '*.conf' -exec cp -t /tmp/conf/ {} +   # what find found

Keep the previous version

bash

cp -b new.conf app.conf      # the old app.conf becomes app.conf~

Between machines

cp works within one machine. Over the network use rsync or scp (see ssh-client).

cp: -r not specified; omitting directory

The source is a directory and -r is missing. Add -r or -a: cp -a src dst.

cp: cannot stat 'x': No such file or directory

There's no source at that path. Check pwd and the name with ls; complete the path with Tab.

cp: cannot create regular file: Permission denied

You can't write to the destination directory. Check ls -ld dir; system directories need sudo cp.

The copy is owned by root, not the user

sudo cp creates new files as root. Keep the source's owner with -a, or fix the owner: sudo chown student:student file — see chmod-chown.

The copy has different permissions or times

Without -p or -a the copy gets the current time and permissions from the umask. For backups use cp -a.

No space left on device

The destination filesystem is full. df -h path shows the free space — see disk-usage.

Silent overwrite

cp new.conf /etc/app.conf replaces a working config without asking, and the old text is gone. Make a backup first (cp -a … .bak), then replace — or use cp -i.

`cp -r` into an existing directory

If the destination directory already exists, cp -r src dst puts the copy inside it — dst/src. A script that expects "dst becomes the copy" will start nesting directories when run a second time.

Copy and move files

Situation

Task

Signing in is needed to start the machine

Back up a config before editing

A directory into an existing directory, and "into" it

Copy many files into one directory

Keep the previous version

Between machines

cp: -r not specified; omitting directory

cp: cannot stat 'x': No such file or directory

cp: cannot create regular file: Permission denied

The copy is owned by root, not the user

The copy has different permissions or times

No space left on device

Silent overwrite

cp -r into an existing directory

`cp -r` into an existing directory