The file in UNIX systems that has the information about users.

The file name refers to "password", but these days passwords are rarely saved to this file, because passwd file has to be world readable and when exposed, the encrypted passwords could be cracked with even brute force. Most often shadow passwords are used, in which case this file only holds user information and actual password parameters are stored in /etc/shadow.

The format of the file is following (as used in Linux, but similiar format is used in other Unices):

wwwwolf:x:501:100:Weyfour WWWWolf:/home/wwwwolf:/bin/bash
1       2 3   4   5               6             7
  1. Login name
  2. Encrypted password (or not!)
  3. UID (numerical user ID)
  4. GID (numerical usergroup ID)
  5. User name and comments (see GECOS)
  6. User home directory
  7. The user's preferred shell

See: NIS

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