Editing Passwd (section)

== Password file ==
The <code>/etc/passwd</code> file is a text-based database of information about [[User (computing)|users]] that may [[login|log into]] the system or other operating system user identities that own running processes.

In many operating systems, this file is just one of many possible back-ends for the more general [[passwd (database)|passwd name service]].

The file's name originates from one of its initial functions as it contained the data used to verify [[password]]s of user accounts.  However, on modern [[Unix]] systems the security-sensitive password information is instead often stored in a different file using shadow passwords, or other database implementations.

The <code>/etc/passwd</code> file typically has [[file system permissions]] that allow it to be readable by all users of the system (''world-readable''), although it may only be modified by the [[superuser]] or by using a few special purpose privileged commands.

The <code>/etc/passwd</code> file is a [[text file]] with one record per [[Line (text file)|line]], each describing a [[User (computing)|user account]].
Each record consists of seven fields separated by [[Colon (punctuation)|colons]]. The ordering of the records within the file is generally unimportant.

An example record may be:
{{sxhl|
 jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8910,(234)555-0044,email:/home/jsmith:/bin/sh
|unixconfig}}
The fields, in order from left to right, are:<ref>[http://www.cyberciti.biz/faq/understanding-etcpasswd-file-format/ Understanding <code>/etc/passwd</code> File Format]</ref>
# {{code|jsmith}}: User name: the string a user would type in when logging into the operating system: the [[logname]].  Must be unique across users listed in the file.
# {{code|x}}: Information used to validate a user's [[password]]. The format is the same as that of the analogous field in the [[Passwd#Shadow file|shadow password]] file, with the additional convention that setting it to "x" means the actual password is found in the shadow file, a common occurrence on modern systems.<ref name=linuxman>{{cite web|url=http://man7.org/linux/man-pages/man5/passwd.5.html |title=passwd(5) - Linux manual page |publisher=Man7.org |access-date=2014-08-25}}</ref>
# {{code|1001}}: [[User identifier (Unix)|user identifier]] number, used by the operating system for internal purposes.  It must be unique as it identifies users uniquely.
# {{code|1000}}: [[Group identifier (Unix)|group identifier]] number, which identifies the primary group of the user; all files that are created by this user may initially be accessible to this group.
# {{code|Joe Smith,Room 1007...}}: [[Gecos field]], commentary that describes the person or account. Typically, this is a set of comma-separated values including the user's full name and contact details.<ref>{{Cite web|url=https://linuxhint.com/view-understand-etc-passwd-file-linux/|title=How to View and Understand the /etc/passwd file in Linux|first=David|last=Adams}}</ref>
# {{code|/home/jsmith}}: Path to the user's [[home directory]].
# {{code|/bin/sh}}: Program that is started every time the user logs into the system. For an interactive user, this is usually one of the system's [[command line interpreter]]s ([[Shell (computing)|shells]]).