Copying in Linux: cp, cp -r, wildcards (* ?) and brace ranges

By Ravindra Bagale, trainer · LinkedIn · Last updated: 8 October 2026

1. Recap and today's practice tree

Why. Copying needs something to copy. We use the same small tree all class, so build it first.

What you should already know. Making folders and files: Linux files: touch, cat, nano, vi, brace shortcuts, ls -R and tree. Moving around with paths: Linux directories and paths.

How (from your home folder). Run these three lines:

cd
mkdir -p ravi/one/two
touch my.txt

Check it with tree ravi (or ls -R ravi):

ravi
└── one
    └── two

2 directories, 0 files

So /home/ec2-user holds the folder ravi and the file my.txt; ravi holds one; one holds two.

2. cp: source and destination

Why. On a laptop you right-click → Copy, open another folder, right-click → Paste. On a server you say both things in one line.

What. cp = copy. It needs two parts:

1. Source: what to copy.
2. Destination: where to put the copy.
3. The order is fixed: first the source, then the destination.

For example, this copies the file my.txt into the folder ravi:

cp my.txt ravi

How cp reads the destination:

1. If it is an existing folder, the copy goes inside it with the same name: cp my.txt ravi → ravi/my.txt.
2. If it is not an existing folder, cp makes a file with that name: cp my.txt backup.txt → a second file backup.txt.
3. The original always stays where it was. Copy never removes anything from the source.

3. Copy down the tree

Why. The most common copy: a file from where you are into a folder below you.

How (you are in /home/ec2-user):

1. pwd → /home/ec2-user
2. cp my.txt ravi/one/two
3. Check: ls ravi/one/two → my.txt

The destination ravi/one/two is a relative path going down: into ravi, then one, then two.

4. Copy up the tree: three ways

Why. Now you are deep inside the tree and want a file to go back up. This is where the paths from the earlier class pay off.

The task. You are in two, and you want my.txt copied up to /home/ec2-user.

How (all three do the same thing):

1. cd ~/ravi/one/two
2. Way 1, relative: cp my.txt ../../.. (up to one, up to ravi, up to ec2-user)
3. Way 2, absolute: cp my.txt /home/ec2-user
4. Way 3, tilde: cp my.txt ~
5. Check: ls -l ~/my.txt → the time shows it was just written.

ec2-user already had a my.txt, so each of these replaced it (both are the same empty file here). More on that in section 6.

Count the dots carefully. .. is one level up. From two, one .. is one, two are ravi, three are ec2-user.

5. Bring it here: . means this folder

Why. Sometimes the file is far away and you want it where you are standing.

What. A single dot . means the current directory. It's a destination like any other.

How (you are in /home/ec2-user):

1. cp ravi/one/two/my.txt .
2. The source is a path going down; the destination is . (here).

If my.txt is already here, this replaces it without asking (see the next section). Here it's the same empty file, so nothing is lost.

Keep the dots apart: . = here, .. = one level up, ~ = home.

6. Backup copies, renaming while copying, and the silent overwrite

Why. Before you edit an important file, keep a copy. If the edit goes wrong, you still have the old version.

A backup in the same folder. Give the copy a new name:

1. cp 1.txt 2.txt
2. 2.txt did not exist, so it's created as a copy of 1.txt.

Rename while copying. These four lines all copy my.txt into ravi:

1. cp my.txt ravi → ravi/my.txt
2. cp my.txt ravi/ → the same. Tab completion adds the slash for you; it's fine either way.
3. cp my.txt ravi/my.txt → the same, with the name written out.
4. cp my.txt ravi/my-backup.txt → the copy gets a new name inside ravi.

Careful: cp overwrites without asking. If 2.txt already exists, cp 1.txt 2.txt replaces it. No question, no message; the old content of 2.txt is gone.

The safe way: cp -i (interactive) asks first:

cp -i 1.txt 2.txt
cp: overwrite '2.txt'?

Type y to replace or n to keep the old file.

Same name, same place. That's not a copy at all:

cp my.txt my.txt
cp: 'my.txt' and 'my.txt' are the same file

A typo trap. If the destination folder doesn't exist, cp doesn't complain. It makes a file with that name. cp my.txt rav (you meant ravi) quietly creates a file called rav.

7. Names with spaces

Why. A space separates words on the command line. cp my.txt my folder means three names: my.txt, my and folder.

How. Put a name with a space in single quotes:

1. mkdir 'my folder'
2. cp my.txt 'my folder'
3. Check: ls 'my folder' → my.txt

Better still: don't use spaces in names. Use my-folder or my_folder.

8. Copying folders: cp -r

Why. A file is one item. A folder is a box with more boxes inside: ravi has one, one has two, two may have files. To copy a folder, cp has to go inside every box at every level.

What. -r = recursive: again and again, into every folder inside, copying everything. -R (capital) does exactly the same.

Try it without -r first:

cp ravi ravi1
cp: -r not specified; omitting directory 'ravi'

cp refuses, and tells you why. Nothing is copied.

Now with -r:

1. cp -r ravi ravi1
2. Check: tree ravi1 → the same one/two inside, with any files.

More examples:

1. mkdir -p one/two/three, then cp -r ravi one/two/three → a copy of ravi, with everything in it, inside three.
2. cp -r ravi ~/ravi-backup → a backup of the whole folder.

The trick: cp -r my.txt ravi also works on a single file. It adds nothing, though. A file has nothing inside to go into. Keep the habit clean: plain cp for files, cp -r for folders.

9. When the destination folder already exists

Why. cp -r ravi ravi1 behaves differently the second time you run it. Know this, or you'll end up with folders inside folders.

How it behaves:

1. First run, ravi1 doesn't exist: cp -r ravi ravi1 creates ravi1 as a full copy of ravi.
2. Second run, ravi1 now exists: cp -r ravi ravi1 puts a new copy inside it, as ravi1/ravi.
3. Check: ls ravi1 → one ravi

It's the same rule as for files: when the destination is an existing folder, the copy goes inside.

10. Copying sideways: into a sibling folder

Why. Folders next to each other (siblings) are common: dev and prod, old and new.

The setup. /home/ec2-user has two folders, ram and sham. You are in ram, and ram has a file m.txt.

cd
mkdir ram sham
touch ram/m.txt
cd ram

How (two ways):

1. cp m.txt ../sham → .. goes up to ec2-user, then into sham.
2. cp m.txt ~/sham → straight from home into sham.
3. Check: ls ~/sham → m.txt

11. A folder can't be copied into itself

Why. This looks like a normal copy, but it can't work. Understanding why teaches you how cp walks through folders.

The setup. one contains two (mkdir -p one/two). Now copy one into two.

Without -r, the usual message:

cp one one/two
cp: -r not specified; omitting directory 'one'

With -r, think it through:

1. cp copies one into two.
2. But two is inside one, so the copy of one must also contain two...
3. ...which must contain the copy of one again, which contains two again, and so on.
4. It would never end: an endless loop.

Linux blocks it straight away and copies nothing:

cp -r one one/two
cp: cannot copy a directory, 'one', into itself, 'one/two/one'

Rule: the destination must not be inside the source. cp -r one ~/backup is fine.

12. Copying many files at once

Why. Copying ten files with ten commands is slow. One cp can take many sources.

What.

1. You can name as many sources as you like.
2. The last name is always the destination.
3. With more than one source, the destination must be an existing folder.

How (you are in /home/ec2-user). Make the files, then copy all three in one go:

touch you.txt my.mp3
cp my.txt you.txt my.mp3 ravi

Check: ls ravi → my.mp3, my.txt and you.txt are now there, next to one and anything you copied earlier.

If the last name isn't a folder, cp stops:

cp my.txt you.txt my.mp3
cp: target 'my.mp3' is not a directory

Newer coreutils versions word it cp: target 'my.mp3': Not a directory; the meaning is the same.

That's why you always check with ls.

13. The * wildcard

Why. Typing every file name doesn't scale. Usually the names share something: all end in .txt, all start with my. Wildcards let you describe the pattern instead of listing names.

What. * matches any characters, any number of them, even none.

How:

1. cp *.txt ravi → every name that ends in .txt.
2. cp my* ravi → every name that starts with my (my.txt, my.mp3, my.mp4...).

Who does the matching? The shell, not cp. Before cp starts, bash swaps *.txt for the matching names. Preview it with echo, which creates and copies nothing:

1. echo *.txt → for example 1.txt 2.txt my.txt you.txt
2. echo my* → for example my.mp3 my.txt

When nothing matches, bash passes the pattern as it is, and cp looks for a file literally called *.pdf:

cp *.pdf ravi
cp: cannot stat '*.pdf': No such file or directory

When a folder matches, for example a folder my.logs, plain cp my* ravi copies the files and skips the folder with cp: -r not specified; omitting directory 'my.logs'.

Extensions like .txt are for people and programs; to Linux they're just part of the name. That's exactly why *.txt works: it's matching letters, nothing more.

14. Making test files fast: brace ranges

Why. To practise wildcards you need lots of files. Nobody types fifty touch commands.

What. Braces with two dots make a range:

1. touch file{1..50}.txt → file1.txt to file50.txt (50 files)
2. touch file{a..z}.txt → filea.txt to filez.txt (26 files)
3. touch file{10..20}.txt → file10.txt to file20.txt (11 files; any start and end work)
4. touch file{01..12}.txt → file01.txt to file12.txt (a leading zero pads every number)

Preview first with echo: echo file{1..5}.txt → file1.txt file2.txt file3.txt file4.txt file5.txt

This is the same brace shortcut as {Ram,Laxman} from the files chapter, but with a range instead of a list.

15. The ? wildcard: exactly one character

Why. * is greedy: it matches anything of any length. Sometimes you need "exactly one character here".

What. ? matches exactly one character. ?? matches exactly two.

How. Take four files, file1.txt, filea.txt, file11.txt and fileaa.txt:

1. cp file?.txt ravi → file1.txt and filea.txt (one character after file)
2. cp file??.txt ravi → file11.txt and fileaa.txt (two characters)

Count check. In a folder with file{1..50}.txt, file{a..z}.txt and fileaa.txt:

1. file?.txt → 35 names (file1 to file9, plus filea to filez)
2. file??.txt → 42 names (file10 to file50, plus fileaa)

16. The file11 to file19 problem

The task. The folder has file1.txt to file50.txt. Copy only file11.txt to file19.txt into ravi.

The tempting answer is wrong: cp file1* ravi. * can be empty, so file1* matches:

1. file1.txt itself (nothing after the 1)
2. file10.txt (one more digit, but it's 10, not 11 to 19)
3. file11.txt to file19.txt
4. and file100.txt, if it existed

The same trap with words: Ram* matches Ram, Rama and Ramayan.

Right answer 1: a brace range. It works for existing files too, because the shell writes out the names before cp starts:

cp file{11..19}.txt ravi

Right answer 2: brackets. [1-9] means one character from 1 to 9:

cp file1[1-9].txt ravi

The difference between the two:

1. Braces make names, whether the files exist or not. If one is missing, cp prints cp: cannot stat 'file19.txt': No such file or directory for it and copies the rest.
2. Wildcards and brackets only pick names that exist. A missing file is simply not picked.

17. Wildcards need a naming pattern

Why. A wildcard can only describe what the names have in common. If the names have nothing in common, there's no pattern to write.

In practice:

1. report-jan.txt, report-feb.txt, report-mar.txt → report-*.txt picks them all.
2. a.txt, notes, final_v2.doc → no useful pattern; name them one by one.
3. log01 to log30 (zero-padded) → log0? picks 01 to 09, log1? picks 10 to 19. Without the zero, log1* also catches log1.

18. Practice

Recap

Samjla ka? Ghari sagle tasks karun bagha ani pratyek cp nantar ls ne check kara.

Ravindra Bagale, trainer: linkedin.com/in/ravindra-bagale. The folder and file names (ravi, one, two, ram, sham, my.txt, file1.txt and the rest) are examples for learning. Command outputs and error messages were checked with GNU bash and coreutils, the same tools Amazon Linux 2023 uses.