Working with files & directories

Now you'll create, copy, move, rename and delete files and directories. These commands are simple, but some of them are irreversible: Linux has no recycle bin on the command line. Learn the safe habits from day one.

Creating directories: mkdir#

mkdir work
cd work
mkdir reports images
mkdir -p projects/2026/q4/drafts     # -p creates missing parents, and doesn't fail if it exists
ls -R projects

projects:
2026

projects/2026:
q4

projects/2026/q4:
drafts

projects/2026/q4/drafts:

Creating files: touch and redirection#

touch creates an empty file, or updates the timestamp of an existing one:

touch notes.txt
echo "first line" > hello.txt          # create/overwrite with content
echo "second line" >> hello.txt        # append
cat hello.txt

first line
second line

> overwrites without asking. >> appends. You'll learn redirection properly in Pipes & redirection. To avoid accidental overwrites, set -o noclobber makes > refuse to replace existing files.

Copying: cp#

cp hello.txt hello-backup.txt          # copy a file
cp hello.txt notes.txt reports/        # copy several files into a directory
cp -r projects projects-copy           # copy a directory recursively
ls reports

hello.txt  notes.txt

Watch the trailing-directory rule. If the destination is an existing directory, files go inside it. Otherwise the destination is the new name.

Moving and renaming: mv#

Linux has no separate rename command for single files. Renaming is moving:

mv hello-backup.txt hello-old.txt      # rename
mv hello-old.txt reports/              # move into a directory
mv reports summaries                   # rename a directory (no -r needed)
ls; ls summaries

hello.txt  images  notes.txt  projects  projects-copy  summaries
hello-old.txt  hello.txt  notes.txt

mv accepts -i (ask), -n (no overwrite) and -v (verbose) like cp. Moving within the same filesystem is instant, even for huge files, because only the name changes.

Deleting: rm and rmdir#

rm notes.txt                     # delete a file
rm -i hello.txt                  # asks "remove regular file 'hello.txt'?" (answer n to keep it)
rmdir images                     # remove an EMPTY directory
rm -r projects-copy              # remove a directory and everything in it
ls

There's no undo. Deleted files don't go to a trash can. Safety habits:

• Use rm -i (or -I, which asks once for big deletions) when unsure.
• Run ls with the same pattern first: ls *.log before rm *.log.
• Be very careful with rm -rf. -f silences all warnings. Never run rm -rf on a path built from a variable without quoting it and checking that it's set: rm -rf "${BUILD_DIR:?}/".
• On desktops, gio trash file (or the trash-cli package) sends files to the trash instead.

Wildcards (globbing)#

The shell expands wildcards into matching file names before the command runs:

touch report1.txt report2.txt report10.txt photo.jpg photo.png data.csv
ls report?.txt
ls *.txt
ls photo.*
ls report[12].txt
echo *.md               # no match: bash leaves the pattern as-is

report1.txt  report2.txt
hello.txt  report1.txt  report10.txt  report2.txt
photo.jpg  photo.png
report1.txt  report2.txt
*.md

Because the shell does the expansion, rm *.txt really runs rm hello.txt report1.txt …. You can preview any glob with echo.

Brace expansion#

Braces generate words. Unlike globs, they don't look at existing files:

mkdir -p site/{css,js,img}
touch site/{index,about,contact}.html
echo file{1..5}.txt
cp config.yml{,.bak} 2>/dev/null || echo "(config.yml{,.bak} expands to: config.yml config.yml.bak)"
ls site

file1.txt file2.txt file3.txt file4.txt file5.txt
(config.yml{,.bak} expands to: config.yml config.yml.bak)
about.html  contact.html  css  img  index.html  js

cp file{,.bak} is a classic shortcut for "make a backup copy next to the original".

Names with spaces and special characters#

touch "my notes.txt"
ls -l "my notes.txt"
mv my\ notes.txt my-notes.txt      # a backslash escapes a single character
ls my*

-rw-r--r-- 1 ada ada 0 Oct  1 10:51 my notes.txt
my-notes.txt

A file whose name starts with - looks like an option. Use ./-file or -- to end option parsing: rm -- -file.

Checking what a file is#

file hello.txt site photo.jpg 2>/dev/null
stat -c '%n: %s bytes, modified %y' data.csv

file inspects the content, not the extension. photo.jpg here is an empty file, whatever its name says.

Putting it together#

A safe, typical workflow for tidying a downloads folder:

mkdir -p ~/sorted/{images,docs}
ls *.jpg *.png 2>/dev/null           # 1. preview what matches
mv -v -n *.jpg *.png ~/sorted/images/ # 2. move, never overwriting
mv -v -n *.csv ~/sorted/docs/

photo.jpg  photo.png
renamed 'photo.jpg' -> '/home/ada/sorted/images/photo.jpg'
renamed 'photo.png' -> '/home/ada/sorted/images/photo.png'
renamed 'data.csv' -> '/home/ada/sorted/docs/data.csv'

Common mistakes#

• rm -rf with a typo or an empty variable (rm -rf "$DIR"/ with DIR unset). Double-check, and use ls with the same arguments first.
• Overwriting files with cp or mv, which replace targets silently. Use -i (ask) or -n (never overwrite) when it matters.
• Forgetting -r when copying directories: cp folder backup fails with "omitting directory".
• Unquoted names with spaces: rm my file.txt tries to delete two files. Quote it: rm "my file.txt".
• Expecting a trash can. rm deletes permanently.

What's next#

Next you'll read what's inside files with cat, less, head and tail, including following log files live.