How to Add Read Write Permissions in Linux

If you want to know how to add read write permissions in linux, the usual method is to use chmod to grant the needed access to the owner, group, or others. For example, chmod u+rw file.txt gives the file owner read and write access. If the wrong user owns the file or folder, you may need chown or chgrp instead of changing permissions alone.

What read and write permissions mean in Linux

Linux file access is built around three basic permissions: read, write, and execute. These permissions apply separately to the owner, group, and others.

• Read (r): Allows viewing the contents of a file or listing a directory.
• Write (w): Allows modifying a file or creating, deleting, or renaming files in a directory.
• Execute (x): Allows running a file as a program or entering a directory.

When people ask about adding read and write permissions, they usually mean changing permissions with chmod. In some cases, though, access problems come from ownership, not permissions, so chown or chgrp may be the better fix.

How to add read and write permissions with chmod

chmod is the main command for changing Linux permissions. You can use either symbolic mode or numeric mode.

Give the owner read and write access

To add read and write permissions for the file owner:

chmod u+rw file.txt

This adds read and write for u (user, meaning the owner) without changing other permissions.

Give the group read and write access

To allow the file’s group to read and write:

chmod g+rw file.txt

This is useful when several users need access through a shared group account.

Give everyone read and write access

To add read and write for owner, group, and others:

chmod a+rw file.txt

Use this carefully. It can make a file too open if the content is sensitive.

Symbolic vs numeric permission examples

Linux permissions can be changed in symbolic form, like u+rw, or numeric form, like 664. Both are valid, but they work a little differently.

Numeric modes are compact, while symbolic modes are often easier to read and safer when you only want to add specific permissions without removing others.

How to change permissions for a file

If your goal is to make a file editable by the owner, the most common options are:

chmod u+rw file.txt

or, if you want a standard owner-writable file with group readable access:

chmod 644 file.txt

That means:

• 6 = read and write for the owner
• 4 = read only for group
• 4 = read only for others

If the file is meant to be shared with a team, 660 is often more appropriate than 777, because it keeps access limited to the owner and group.

How to give write permission to a folder in Linux

Giving write permission to a folder is slightly different from giving write permission to a file. For directories, write access controls whether users can create, delete, or rename items inside the folder.

To let the owner read, write, and enter the directory:

chmod u+rwx foldername

To give group members the same access:

chmod g+rwx foldername

A common shared-folder setup is:

chmod 775 foldername

That gives full access to the owner and group, and read plus execute to others.

Why directories need execute permission

Many people are confused by directory permissions because write alone is not enough. A directory usually needs execute permission too, because execute on a directory means permission to enter or traverse it.

Without execute permission, a user may be able to see that a directory exists, but still be unable to access files inside it. For practical access to a directory, especially for normal use, rwx is often needed together.

When to use chown or chgrp instead

Changing permissions is not always the right fix. Sometimes the file or folder simply belongs to the wrong user or group.

If a user keeps getting permission denied errors, check ownership first. For example, if a file is owned by root, giving everyone write access with chmod may not be the best solution. Assigning the correct owner or group is usually safer.

How to change permissions for all files in a folder

If you need to apply changes recursively, use the -R option. Be careful, because it affects the folder and everything inside it.

chmod -R g+rw shared-folder

This adds read and write permission for the group on the folder and all contents inside it.

For directories, you may also need execute permission so users can enter subfolders:

chmod -R g+rwX shared-folder

Here, X adds execute only to directories and to files that already have execute permission. This is often safer than using x everywhere.

Be cautious with recursive changes on system folders or mixed-content directories. A broad command can accidentally open access more than intended.

Safe permission examples to use

Some permission patterns are common because they strike a reasonable balance between access and safety:

• 644 for normal files that should be readable by others but writable only by the owner
• 600 for private files such as personal configuration or secrets
• 664 for shared working files where the group needs write access
• 755 for executable programs and directories that need broad read access
• 775 for shared directories where the group must create and edit files

Avoid using 777 unless you fully understand the risk. It gives everyone read, write, and execute access, which can expose files or allow unwanted changes.

How to verify the change

After changing permissions, check them with ls -l:

ls -l file.txt

You will see output similar to:

-rw-rw-r-- 1 alice editors 1234 Nov 4  file.txt

That output tells you the permission bits, owner, group, size, and name. In this example, the owner and group can read and write, while others can only read.

If the permissions look correct but access still fails, check the file owner, parent directory permissions, mount status, and whether the filesystem is read-only.

Common mistakes and fixes

• Using chmod when ownership is the real problem, fix with chown or chgrp if needed.
• Forgetting execute permission on directories, add x when users need to enter the folder.
• Applying recursive changes too broadly, use -R only when you really want all nested items changed.
• Using 777 by default, prefer group-based access such as 664 or 775 instead.
• Changing a file but not its parent directory, remember a directory can block access even when the file permissions are correct.

Troubleshooting permission denied errors

If you still cannot read or write after changing permissions, check these common causes:

• You are not the owner, verify with ls -l.
• The group is wrong, confirm group membership and use chgrp if needed.
• The directory blocks access, make sure the parent directory has execute permission.
• The filesystem is mounted read-only, permissions will not help until it is remounted with write access.
• An ACL or security policy is interfering, some systems use additional access controls beyond standard Unix permissions.

Best way to choose the right command

If you want a simple rule, use this order:

1. Check who owns the file or folder.
2. If ownership is wrong, fix it with chown or chgrp.
3. If ownership is correct, use chmod to add the needed read and write permissions.
4. Verify the result with ls -l.

This approach avoids giving broader access than necessary and usually solves the problem faster than guessing at permission numbers.

Frequently Asked Questions About how to add read write permissions in linux

How do I add read and write permissions in Linux?

Use chmod, for example chmod u+rw file.txt to give the owner read and write access. Use g+rw or a+rw if you want to add access for the group or everyone.

What is the chmod command for read and write permissions?

Common examples are chmod u+rw file.txt and chmod 664 file.txt. The first adds permissions symbolically, the second sets them numerically.

How do I give write permission to a folder in Linux?

Use chmod u+rwx foldername for the owner or chmod 775 foldername for shared group access. For folders, write permission is usually not enough without execute permission too.

What is the difference between chmod and chown?

chmod changes permissions, while chown changes file ownership. If the wrong user owns the file, changing permissions alone may not solve the access problem.

Why does a directory need execute permission to be accessed?

Execute permission on a directory allows traversal into it. Without it, users may not be able to open files inside the directory even if they have read permission.

How do I change permissions for all files in a folder?

Use recursive mode, such as chmod -R g+rw foldername. Be careful, because this changes permissions on the folder and every file inside it.

Conclusion

The safest and most common way to add read and write permissions in Linux is to use chmod, then verify the result with ls -l. For files, 644 and 664 are common choices. For directories, remember that execute permission is needed for access, and group-based permissions are often better than opening everything with 777. If access still fails, check ownership with chown or chgrp before broadening permissions.