pwck

Check password file integrity

$ pwck

$ pwck [/etc/passwd] [/etc/shadow]

$ pwck -r

$ pwck -q

pwck [options] [passwd] [shadow]

pwck verifies the integrity of /etc/passwd and /etc/shadow files by checking for proper formatting, valid field values, and internal consistency. It detects problems like duplicate usernames, invalid UIDs/GIDs, missing home directories, and entries that don't match between the password and shadow files.
By default pwck prompts to delete invalid entries, but the -r flag runs in read-only mode for auditing without making changes. The command is part of shadow-utils and is typically run by administrators after manual edits to password files or as part of system health checks.

PASSWD

Password file path.

Shadow file path.

Read-only mode.

Quiet output.

Sort by UID.

Requires root for shadow file. System administration tool.

pwck is a shadow-utils utility for password file verification.

grpck(8), passwd(1), shadow(5)