Which command is used to check and repair Linux file systems?

The command used to check and repair Linux file systems is fsck, which stands for "file system check." This command is essential for maintaining the integrity of the filesystem, especially after unclean shutdowns or potential data corruption. When executed, fsck verifies the connected filesystems for errors and attempts to repair them if any issues are found.

In addition to its primary function, fsck can take different options to specify which filesystem to check and how thoroughly to perform the check. It's commonly used during system maintenance and recovery processes, ensuring that data remains intact and accessible.

The other options do not represent valid or commonly used commands in this context. For instance, checkfs and repairfs are not standard commands in Linux distributions for filesystem checks and repairs, while rebooting the system does not address file system integrity issues directly.