From df0c9b98a769143fc7163f9951df03886363b02a Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Thu, 21 Oct 2010 11:05:40 +0200 Subject: [PATCH] passwd.5: Various minor rewordings Signed-off-by: Michael Kerrisk --- man5/passwd.5 | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/man5/passwd.5 b/man5/passwd.5 index cb0e99210..c2da9564a 100644 --- a/man5/passwd.5 +++ b/man5/passwd.5 @@ -26,16 +26,14 @@ .\" 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 .\" (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 passwd \- password file .SH DESCRIPTION -.B Passwd -is a text file, that contains a list of the system's accounts, -giving for each account some useful information like user ID, -group ID, home directory, shell, etc. -Often, it also contains the encrypted passwords for each account. -It should have general read permission (many utilities, like +The +.IR /etc/passwd +file is a text file that describes user login accounts for the system. +It should have read permission allowed for all users (many utilities, like .BR ls (1) use it to map user IDs to usernames), but write access only for the superuser. @@ -43,33 +41,33 @@ superuser. In the good old days there was no great problem with this general read permission. 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. These days many people run some version of the shadow password suite, where .I /etc/passwd has asterisks (*) instead of encrypted passwords, and the encrypted passwords are in -.I /etc/shadow +.IR /etc/shadow , which is readable by the superuser only. .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 that this user can not authenticate him- or herself using a password. -(But see the Notes below.) +(But see NOTES below.) .PP If you create a new login, first put an asterisk in the password field, then use .BR passwd (1) to set it. .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 .RS account:password:UID:GID:GECOS:directory:shell .RE .sp -The field descriptions are: +The field are as follows: .TP 12 .I account 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.) .TP .I UID -the numerical user ID. +the numeric user ID. .TP .I GID -the numerical primary group ID for this user. +the numeric primary group ID for this user. .TP .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. -GECOS means General Electric -Comprehensive Operating System, which has been renamed to GCOS when +GECOS stands for "General Electric Comprehensive Operating System", +which was renamed to GCOS when GE's large systems division was sold to Honeywell. Dennis Ritchie has reported: "Sometimes we sent printer output or batch jobs to the GCOS machine. @@ -113,9 +111,9 @@ through .SH FILES .I /etc/passwd .SH NOTES -If you want to create -user groups, their GIDs must be equal and there must be an entry in -\fI/etc/group\fP, or no group will exist. +If you want to create user groups, there must be an entry in +.IR /etc/group , +or no group will exist. .PP If the encrypted password is set to an asterisk, the user will be unable to login using