Linux chmod Practices: 10 Exercises
Practice 1: Changing File Permissions to Read-Only
Objective: Use chmod to make a file read-only.
Instructions:
1. Create a file named Avengers.txt:
touch Avengers.txt
2. Set the file to be read-only for everyone:
chmod 444 Avengers.txt
3. Verify the permissions using ls -l.
Practice 2: Granting Execute Permission
Objective: Use chmod to allow execution of a script.
Instructions:
1. Create a script named BattlePlan.sh:
touch BattlePlan.sh
2. Grant execute permission to the owner:
chmod u+x BattlePlan.sh
3. Verify the permissions with ls -l and test running the script:
./BattlePlan.sh
Practice 3: Removing Write Permissions
Objective: Use chmod to prevent modifications to a file.
Instructions:
1. Create a file named InfinityGauntlet.txt:
touch InfinityGauntlet.txt
2. Remove write permissions for everyone:
chmod -w InfinityGauntlet.txt
3. Verify that you cannot edit the file.
Practice 4: Granting Full Access to the Owner
Objective: Use chmod to give full permissions to the owner only.
Instructions:
1. Create a file named WakandaSecrets.txt:
touch WakandaSecrets.txt
2. Grant the owner full permissions (read, write, execute):
chmod 700 WakandaSecrets.txt
3. Verify the permissions using ls -l.
Practice 5: Making a Directory Accessible to All
Objective: Use chmod to allow everyone access to a directory.
Instructions:
1. Create a directory named SHIELD:
mkdir SHIELD
2. Grant read, write, and execute permissions to everyone:
chmod 777 SHIELD
3. Verify the permissions with ls -ld SHIELD.
Practice 6: Granting Group Access
Objective: Use chmod to allow a group to access a file.
Instructions:
1. Create a file named MissionLog.txt:
touch MissionLog.txt
2. Grant the group read and write permissions:
chmod g+rw MissionLog.txt
3. Verify the permissions using ls -l.
Practice 7: Removing All Permissions
Objective: Use chmod to make a file completely inaccessible.
Instructions:
1. Create a file named VillainsPlan.txt:
touch VillainsPlan.txt
2. Remove all permissions for everyone:
chmod 000 VillainsPlan.txt
3. Verify that the file cannot be opened or edited.
Practice 8: Using Octal Notation
Objective: Use octal numbers to set precise permissions.
Instructions:
1. Create a file named ThorHammer.txt:
touch ThorHammer.txt
2. Set permissions to allow the owner full access, group read-only, and no
access for others:
chmod 740 ThorHammer.txt
3. Verify the permissions with ls -l.
Practice 9: Applying Recursive Permissions
Objective: Use chmod to set permissions for a directory and its contents.
Instructions:
1. Create a directory named Phase1 with files inside:
mkdir Phase1
touch Phase1/{IronMan.txt,Thor.txt,Hulk.txt}
2. Set all files and the directory to be read-only:
chmod -R 444 Phase1
3. Verify permissions using ls -lR Phase1.
Practice 10: Granting Execute Permissions to All
Objective: Use chmod to make a script executable by everyone.
Instructions:
1. Create a script named AvengersAssemble.sh:
touch AvengersAssemble.sh
2. Grant execute permissions to everyone:
chmod a+x AvengersAssemble.sh
3. Verify the permissions with ls -l and run the script:
./AvengersAssemble.sh
