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passwd.5: Various minor rewordings 

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
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Michael Kerrisk 2010-10-21 11:05:40 +02:00
parent 91567885b5
commit df0c9b98a7
1 changed files with 19 additions and 21 deletions
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man5/passwd.5
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@ -26,16 +26,14 @@
.\" Modified Sun Jun 18 01:53:57 1995 by Andries Brouwer (aeb@cwi.nl) .\" Modified Sun Jun 18 01:53:57 1995 by Andries Brouwer (aeb@cwi.nl)
.\" Modified Mon Jan 5 20:24:40 MET 1998 by Michael Haardt .\" Modified Mon Jan 5 20:24:40 MET 1998 by Michael Haardt
.\" (michael@cantor.informatik.rwth-aachen.de) .\" (michael@cantor.informatik.rwth-aachen.de)
.TH PASSWD 5 1998-01-05 "Linux" "Linux Programmer's Manual" .TH PASSWD 5 2010-10-21 "Linux" "Linux Programmer's Manual"
.SH NAME .SH NAME
passwd \- password file passwd \- password file
.SH DESCRIPTION .SH DESCRIPTION
.B Passwd The
is a text file, that contains a list of the system's accounts, .IR /etc/passwd
giving for each account some useful information like user ID, file is a text file that describes user login accounts for the system.
group ID, home directory, shell, etc. It should have read permission allowed for all users (many utilities, like
Often, it also contains the encrypted passwords for each account.
It should have general read permission (many utilities, like
.BR ls (1) .BR ls (1)
use it to map user IDs to usernames), but write access only for the use it to map user IDs to usernames), but write access only for the
superuser. superuser.
@ -43,33 +41,33 @@ superuser.
In the good old days there was no great problem with this general In the good old days there was no great problem with this general
read permission. read permission.
Everybody could read the encrypted passwords, but the Everybody could read the encrypted passwords, but the
hardware was too slow to crack a well-chosen password, and moreover, the hardware was too slow to crack a well-chosen password, and moreover the
basic assumption used to be that of a friendly user-community. basic assumption used to be that of a friendly user-community.
These days many people run some version of the shadow password suite, where These days many people run some version of the shadow password suite, where
.I /etc/passwd .I /etc/passwd
has asterisks (*) instead of encrypted passwords, has asterisks (*) instead of encrypted passwords,
and the encrypted passwords are in and the encrypted passwords are in
.I /etc/shadow .IR /etc/shadow ,
which is readable by the superuser only. which is readable by the superuser only.
.PP .PP
Regardless of whether shadow passwords are used, many sysadmins Regardless of whether shadow passwords are used, many system administrators
use an asterisk in the encrypted password field to make sure use an asterisk in the encrypted password field to make sure
that this user can not authenticate him- or herself using a that this user can not authenticate him- or herself using a
password. password.
(But see the Notes below.) (But see NOTES below.)
.PP .PP
If you create a new login, first put an asterisk in the password field, If you create a new login, first put an asterisk in the password field,
then use then use
.BR passwd (1) .BR passwd (1)
to set it. to set it.
.PP .PP
There is one entry per line, and each line has the format: Each line of the file describes a single user, and has the following format:
.sp .sp
.RS .RS
account:password:UID:GID:GECOS:directory:shell account:password:UID:GID:GECOS:directory:shell
.RE .RE
.sp .sp
The field descriptions are: The field are as follows:
.TP 12 .TP 12
.I account .I account
the name of the user on the system. the name of the user on the system.
@ -82,16 +80,16 @@ the encrypted user password, an asterisk (*), or the letter \(aqx\(aq.
for an explanation of \(aqx\(aq.) for an explanation of \(aqx\(aq.)
.TP .TP
.I UID .I UID
the numerical user ID. the numeric user ID.
.TP .TP
.I GID .I GID
the numerical primary group ID for this user. the numeric primary group ID for this user.
.TP .TP
.I GECOS .I GECOS
This field is optional and only used for informational purposes. This field is optional and used only for informational purposes.
Usually, it contains the full username. Usually, it contains the full username.
GECOS means General Electric GECOS stands for "General Electric Comprehensive Operating System",
Comprehensive Operating System, which has been renamed to GCOS when which was renamed to GCOS when
GE's large systems division was sold to Honeywell. GE's large systems division was sold to Honeywell.
Dennis Ritchie has reported: "Sometimes we sent printer output or Dennis Ritchie has reported: "Sometimes we sent printer output or
batch jobs to the GCOS machine. batch jobs to the GCOS machine.
@ -113,9 +111,9 @@ through
.SH FILES .SH FILES
.I /etc/passwd .I /etc/passwd
.SH NOTES .SH NOTES
If you want to create If you want to create user groups, there must be an entry in
user groups, their GIDs must be equal and there must be an entry in .IR /etc/group ,
\fI/etc/group\fP, or no group will exist. or no group will exist.
.PP .PP
If the encrypted password is set to an asterisk, the user will be unable If the encrypted password is set to an asterisk, the user will be unable
to login using to login using