Manage files from the command line

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$ als gewone gebruiker# als root (of met sudo)

Vaardigheden in dit hoofdstuk

Bestanden en mappen kopiëren, verplaatsen, linken en verwijderen

Create files and folders

mkdir makes folders, touch makes empty files (or updates the time of an existing file).

$mkdir reports
$mkdir -p projects/web/{html,logs,backup}
$mkdir -m 750 private
$touch notes.txt
$touch -d "2026-01-01 08:00" old.log
$ls -l old.log
-rw-r--r--. 1 student student 0 Jan  1  2026 old.log

mkdir -p makes all missing parent folders and gives no error if the folder exists — good in scripts.
mkdir -m 750 sets the rights at once.

7.2

Copy files and folders

cp SOURCE TARGET copies. For folders you need -r. Use -a to keep owner, rights and dates.

$cp /etc/hosts ~/hosts.bak
$cp file1 file2 file3 /tmp/
#cp -a /etc/ssh /root/ssh-backup-$(date +%F)
$cp -r projects /tmp/
$cp -i notes.txt /tmp/
cp: overwrite '/tmp/notes.txt'? n
$cp -v *.conf /backup/
$cp -u *.html /var/www/html/

Option	What it does
`-r`	Copy folders with everything inside
`-a`	Archive: like `-r`, and keep rights, owner, dates, links, SELinux context
`-i`	Ask before you overwrite
`-v`	Show each file
`-u`	Copy only when the source is newer
`-p`	Keep rights, owner and dates (for files)

Op het werk

Before you edit a config file, copy it: cp -a /etc/ssh/sshd_config{,.orig}. The braces make /etc/ssh/sshd_config /etc/ssh/sshd_config.orig.

7.3

Move and rename

mv moves a file to another folder or gives it a new name. There is no separate rename command.

$mv notes.txt notes-2026.txt
$mv notes-2026.txt ~/Documents/
$mv *.log /var/tmp/oldlogs/
$mv -i report.pdf /srv/share/
$mv -n data.csv archive/
$mv projects/web projects/website

-i asks before it overwrites, -n never overwrites.
Moving inside the same file system is fast (only the name changes). Moving to another disk copies the data and then deletes the source.

7.4

Delete files and folders

rm deletes files, rm -r deletes folders with all content, rmdir deletes only empty folders. There is no recycle bin on the command line.

$rm old.log
$rm -i *.tmp
$rmdir emptydir
$rm -r /tmp/test
$rm -rf /tmp/build-*
$rm -- -strange-name.txt

Option	What it does
`-i`	Ask for every file
`-I`	Ask once when you delete more than 3 files or go into folders
`-r`	Delete folders and everything inside
`-f`	Force: no questions, no error when a file is missing
`--`	End of options: the next word is a file name, even if it starts with `-`

Let op

rm -rf with a variable is dangerous: if $DIR is empty, rm -rf $DIR/* becomes rm -rf /*. In scripts write rm -rf "${DIR:?}"/* — Bash stops when the variable is empty.

Onthoud

Deleted = gone. Copy important data to a backup before big clean-ups.

7.5

Make hard links and soft links

A link is a second name for a file. A soft link (symbolic link) points to a path. A hard link is a second name for the same data on the disk.

$ln -s /var/log/httpd weblogs
$ls -l weblogs
lrwxrwxrwx. 1 student student 14 Oct 27 10:02 weblogs -> /var/log/httpd
$ln report.txt report-copy.txt
$ls -li report*.txt
1835015 -rw-r--r--. 2 student student 512 Oct 27 10:03 report-copy.txt
1835015 -rw-r--r--. 2 student student 512 Oct 27 10:03 report.txt

	Soft link (`ln -s`)	Hard link (`ln`)
Points to	A path (name)	The same inode (data)
Works for folders	Yes	No
Works across disks	Yes	No, only on the same file system
Original deleted	The link breaks ("dangling")	Data stays until the last name is gone
Seen in `ls -l`	`l` type and `->`	Link count higher than 1

Examentip

The order is always ln -s TARGET LINKNAME — the real thing first, like cp.

7.6

Find files

find searches the folder tree by name, size, owner, time or type, and can run a command on every hit.

$find /etc -name "*.repo"
$find / -user anna 2> /dev/null
#find /var/log -type f -size +100M
$find ~ -mtime -1
#find /tmp -type f -mtime +30 -delete
#find /srv -type f -name "*.sh" -exec chmod 750 {} \;
$locate sshd_config

Test	Finds
`-name "*.conf"` / `-iname`	By name (with `-iname` big and small letters are the same)
`-type f` / `-type d` / `-type l`	Files / folders / links
`-size +100M`	Bigger than 100 MiB (`-` = smaller)
`-user anna` / `-group sales`	By owner / group
`-mtime -1` / `-mtime +30`	Changed in the last day / more than 30 days ago
`-perm -4000`	With the SUID right
`-exec CMD {} \;`	Run CMD on every hit (`{}` = the file)

More options: the RHCSA lesson about find.

7.7

Look at file details

stat shows everything about a file: size, rights, owner, inode and the three times. file says what kind of data is inside.

$stat /etc/hosts
  File: /etc/hosts
  Size: 158             Blocks: 8          IO Block: 4096   regular file
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Modify: 2026-10-20 10:12:04.000000000 +0300
$file /usr/bin/passwd backup.tar.gz
/usr/bin/passwd: setuid ELF 64-bit LSB pie executable, x86-64
backup.tar.gz:   gzip compressed data
$du -sh ~/Downloads
1.2G    /home/student/Downloads

Oefenen

Lab 3.1Organize files, make links and back up a folderMakkelijk · 30 minNog niet begonnen

Oefenen

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