etcpasswd

Etcpasswd refers to the /etc/passwd file, a foundational component of most Unix-like operating systems. It is a plain text file that stores basic information about user accounts and is consulted during login and account lookups. Historically, it also held password information, but modern systems separate passwords into a shadow file to improve security. While /etc/passwd is world-readable, sensitive password hashes are typically kept in /etc/shadow, which has restricted permissions.

Each line in /etc/passwd represents a single user and contains seven fields separated by colons: the login name, the password field (historically the encrypted password; on current systems often an x or * indicating a shadowed password), the User ID (UID), the Group ID (GID), a GECOS field for the user’s full name or description, the home directory, and the login shell. Example: root:x:0:0:root:/root:/bin/bash.

Security and access considerations are central to /etc/passwd’s design. Because the file is readable by all users, actual password hashes should not be stored there. Instead, the hashes live in /etc/shadow, which is readable only by root and certain trusted processes. The presence of shadow files allows password management and aging policies to be enforced more securely.

The file is used in conjunction with system libraries and services such as Name Service Switch (NSS) and Pluggable Authentication Modules (PAM), which may source account information from /etc/passwd or from network-backed services like LDAP or NIS depending on configuration.

Administration of accounts is typically performed with dedicated tools (for example, useradd, usermod, userdel, and passwd) rather than manual edits to /etc/passwd. To query account information, utilities like getent passwd consult NSS databases and files in a unified manner. See also /etc/shadow, /etc/group, and getent.