getent

getent is a command-line utility on many Unix-like systems that retrieves entries from administrative databases. It relies on the Name Service Switch (NSS) configuration to query databases defined in /etc/nsswitch.conf. Entries may come from local files such as /etc/passwd, /etc/group, and /etc/hosts, or from remote services like LDAP, NIS, or SSSD, depending on the system’s NSS setup. The tool provides a uniform way to obtain information about users, groups, hosts, and other entities regardless of the underlying source.

Usage and syntax: getent database [keys...]. The database is the name of the NSS source to query (for example, passwd, group, hosts, services, protocols, networks, ethers, or aliases). If no keys are given, getent prints all entries from the specified database. Examples include: getent passwd to list all user entries, getent passwd root to show the root user, getent hosts example.com to resolve a hostname, getent services http to find the service entry for HTTP, and getent group sudo to display the sudo group membership. Access to certain databases, such as shadow, may require elevated privileges.

Notes: Output is plain text and database-specific. For passwd and group, lines are typically colon-separated fields; for hosts, multiple records may be shown; for others, the format varies by database. getent is a common tool for testing NSS configuration, troubleshooting login and name resolution issues, and validating that various data sources are being consulted as expected.