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<H1>PASSWD</H1>
Section: File Formats and Conversions (5)<BR>Updated: 05/28/2020<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
passwd - the password file
<A NAME="lbAC">&nbsp;</A>
<H2>DESCRIPTION</H2>
<P>
/etc/passwd
contains one line for each user account, with seven fields delimited by colons (":"). These fields are:
<P>
<DL COMPACT><DT id="1"><DD>
&bull;
login name
</DL>
<P>
<DL COMPACT><DT id="2"><DD>
&bull;
optional encrypted password
</DL>
<P>
<DL COMPACT><DT id="3"><DD>
&bull;
numerical user ID
</DL>
<P>
<DL COMPACT><DT id="4"><DD>
&bull;
numerical group ID
</DL>
<P>
<DL COMPACT><DT id="5"><DD>
&bull;
user name or comment field
</DL>
<P>
<DL COMPACT><DT id="6"><DD>
&bull;
user home directory
</DL>
<P>
<DL COMPACT><DT id="7"><DD>
&bull;
optional user command interpreter
</DL>
<P>
If the
<I>password</I>
field is a lower-case
"x", then the encrypted password is actually stored in the
<B><A HREF="/cgi-bin/man/man2html?5+shadow">shadow</A></B>(5)
file instead; there
<I>must</I>
be a corresponding line in the
/etc/shadow
file, or else the user account is invalid.
<P>
The encrypted
<I>password</I>
field may be empty, in which case no password is required to authenticate as the specified login name. However, some applications which read the
/etc/passwd
file may decide not to permit
<I>any</I>
access at all if the
<I>password</I>
field is blank.
<P>
A
<I>password</I>
field which starts with an exclamation mark means that the password is locked. The remaining characters on the line represent the
<I>password</I>
field before the password was locked.
<P>
Refer to
<B><A HREF="/cgi-bin/man/man2html?3+crypt">crypt</A></B>(3)
for details on how this string is interpreted.
<P>
If the password field contains some string that is not a valid result of
<B><A HREF="/cgi-bin/man/man2html?3+crypt">crypt</A></B>(3), for instance ! or *, the user will not be able to use a unix password to log in (but the user may log in the system by other means).
<P>
The comment field is used by various system utilities, such as
<B><A HREF="/cgi-bin/man/man2html?1+finger">finger</A></B>(1).
<P>
The home directory field provides the name of the initial working directory. The
<B>login</B>
program uses this information to set the value of the
<B>$HOME</B>
environmental variable.
<P>
The command interpreter field provides the name of the user's command language interpreter, or the name of the initial program to execute. The
<B>login</B>
program uses this information to set the value of the
<B>$SHELL</B>
environmental variable. If this field is empty, it defaults to the value
/bin/sh.
<A NAME="lbAD">&nbsp;</A>
<H2>FILES</H2>
<P>
/etc/passwd
<DL COMPACT><DT id="8"><DD>
User account information.
</DL>
<P>
/etc/shadow
<DL COMPACT><DT id="9"><DD>
optional encrypted password file
</DL>
<P>
/etc/passwd-
<DL COMPACT><DT id="10"><DD>
Backup file for /etc/passwd.
<P>
Note that this file is used by the tools of the shadow toolsuite, but not by all user and password management tools.
</DL>
<A NAME="lbAE">&nbsp;</A>
<H2>SEE ALSO</H2>
<P>
<B><A HREF="/cgi-bin/man/man2html?3+crypt">crypt</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?1+getent">getent</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?3+getpwnam">getpwnam</A></B>(3),
<B><A HREF="/cgi-bin/man/man2html?1+login">login</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?1+passwd">passwd</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?8+pwck">pwck</A></B>(8),
<B><A HREF="/cgi-bin/man/man2html?8+pwconv">pwconv</A></B>(8),
<B><A HREF="/cgi-bin/man/man2html?8+pwunconv">pwunconv</A></B>(8),
<B><A HREF="/cgi-bin/man/man2html?5+shadow">shadow</A></B>(5),
<B><A HREF="/cgi-bin/man/man2html?1+su">su</A></B>(1),
<B><A HREF="/cgi-bin/man/man2html?8+sulogin">sulogin</A></B>(8).
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="11"><A HREF="#lbAB">NAME</A><DD>
<DT id="12"><A HREF="#lbAC">DESCRIPTION</A><DD>
<DT id="13"><A HREF="#lbAD">FILES</A><DD>
<DT id="14"><A HREF="#lbAE">SEE ALSO</A><DD>
</DL>
<HR>
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