Exercise: Archive a project

Archive a project

• Create, list and extract tar archives.
• Extract into a chosen directory and extract a single member.
• Compare the restored tree with the original.

Start the exercise

On workstation, start the exercise. It removes /root/arch of an earlier run from servera.

[student@workstation ~]$ lab start sa-tar

Later tasks assume that you are logged in to the server they name: ssh student@servera from workstation, then sudo -i for a root shell.

Build the project

On servera as root (sudo -i), create /root/arch/project with docs/notes.md, src/data1.txt (the numbers 1 to 20000, from seq), and an executable script run.sh.

[student@workstation ~]$ ssh student@servera
[student@servera ~]$ sudo -i
[root@servera ~]# mkdir -p /root/arch/project/docs /root/arch/project/src
[root@servera ~]# cd /root/arch
[root@servera arch]# echo "# notes" > project/docs/notes.md
[root@servera arch]# seq 1 20000 > project/src/data1.txt
[root@servera arch]# printf '#!/bin/bash\necho hello\n' > project/run.sh
[root@servera arch]# chmod 750 project/run.sh
[root@servera arch]# ls -lR project | head -8
project:
total 8
drwxr-xr-x. 2 root root 4096 Oct  3 17:43 docs
-rwxr-x---. 1 root root   23 Oct  3 17:43 run.sh
drwxr-xr-x. 2 root root 4096 Oct  3 17:43 src
...output omitted...

Archive, list, compress

Create an uncompressed archive project.tar and a gzip archive project.tar.gz. Compare their sizes and list the first lines of the archive with details.

[root@servera arch]# tar -cvf project.tar project
project/
project/docs/
project/docs/notes.md
project/run.sh
project/src/
project/src/data1.txt
[root@servera arch]# tar -czf project.tar.gz project
[root@servera arch]# ls -l project.tar project.tar.gz
-rw-r--r--. 1 root root 122880 Oct  3 17:43 project.tar
-rw-r--r--. 1 root root  45396 Oct  3 17:43 project.tar.gz
[root@servera arch]# tar -tvf project.tar | head -4
drwxr-xr-x root/root         0 2026-10-03 17:36 project/
drwxr-xr-x root/root         0 2026-10-03 17:36 project/docs/
-rw-r--r-- root/root         8 2026-10-03 17:36 project/docs/notes.md
-rwxr-x--- root/root        23 2026-10-03 17:36 project/run.sh

Sizes will differ a little. The text compresses to roughly a third of its size.

Restore into a clean place

Extract the gzip archive into a new empty directory restore, and compare the result with the original.

[root@servera arch]# mkdir restore
[root@servera arch]# tar -xzf project.tar.gz -C restore
[root@servera arch]# ls restore/project
docs  run.sh  src
[root@servera arch]# diff -r project restore/project; echo "rc=$?"
rc=0
[root@servera arch]# ls -l restore/project/run.sh
-rwxr-x---. 1 root root 23 Oct  3 17:36 restore/project/run.sh

Extract just one file

Extract only project/run.sh from the archive into a directory one. Check its permissions.

[root@servera arch]# mkdir one
[root@servera arch]# tar -xzf project.tar.gz -C one project/run.sh
[root@servera arch]# find one -type f
one/project/run.sh
[root@servera arch]# ls -l one/project/run.sh
-rwxr-x---. 1 root root 23 Oct  3 17:36 one/project/run.sh

Exclude and absolute paths

Create notxt.tar.gz without any .txt files and list it. Then archive the absolute path /root/arch/project/docs and read the warning and the member names.

[root@servera arch]# tar --exclude='*.txt' -czf notxt.tar.gz project
[root@servera arch]# tar -tzf notxt.tar.gz
project/
project/docs/
project/docs/notes.md
project/run.sh
project/src/
[root@servera arch]# tar -cvf abs.tar /root/arch/project/docs
tar: Removing leading `/' from member names
/root/arch/project/docs/
/root/arch/project/docs/notes.md
[root@servera arch]# tar -tf abs.tar | head -2
root/arch/project/docs/
root/arch/project/docs/notes.md

tar removed the leading slash for safety, so extracting abs.tar would create root/arch/... below the current directory.

Grade and finish

Check your work with lab grade sa-tar, then put the exercise away with lab finish sa-tar.