What is the purpose of the chmod 755 command in Linux? Learn how chmod 755 sets file permissions to allow the owner full control and others to read and execute—essential knowledge for CompTIA Linux+ (Plus) XK0-005 exam success.
Table of Contents
Question
What is the purpose of the chmod 755 command on a file?
A. Sets the file to read-only for all users
B. Grants execute permission to the owner only
C. Allows the owner to read, write, and execute, and others to read and execute
D. Removes all permissions from the group
E. Makes the file a symbolic link
Answer
C. Allows the owner to read, write, and execute, and others to read and execute
Explanation
chmod 755 sets permissions to rwxr-xr-x (7 = rwx for owner, 5 = r-x for group, 5 = r-x for others), commonly used for executable scripts or binaries.
The chmod 755 command sets the permissions of a file so that the owner can read, write, and execute the file, while group members and others can read and execute it.
In Linux, file permissions are represented by three sets of values: owner, group, and others.
The numeric mode 755 breaks down as follows:
- 7 (owner): read (4) + write (2) + execute (1) = 7 (rwx)
- 5 (group): read (4) + execute (1) = 5 (r-x)
- 5 (others): read (4) + execute (1) = 5 (r-x)
This means:
- The file owner can read, write, and execute the file.
- Group members and all other users can read and execute the file, but cannot modify it.
This permission set is commonly used for executable scripts or binaries that should be usable by all users but only modifiable by the owner.
The chmod command is a fundamental tool for managing file permissions, aligning with Linux security best practices and system administration tasks.
chmod 755 sets permissions to rwxr-xr-x, granting the owner full control and others read and execute access, which is standard for shared executables.
CompTIA Linux+ (Plus) XK0-005 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the CompTIA Linux+ (Plus) XK0-005 exam and earn CompTIA Linux+ (Plus) XK0-005 certification.