|Contents||Bulletin||Scripting in shell and Perl||Network troubleshooting||History||Humor|
|News||Programs - Staf Wagemakers||Recommended Books||Papers||Reference|
|Unix chpasswd||Expect||Admin Horror Stories||Unix History||Humor||Etc|
The external passwd command allows you to create or change the password associated with your user name. The super-user (system administrator) can change any user's password and is not prompted for the old password. As a user you can only change your password.
Following is the general format for the passwd command.
passwd [ user_name ] passwd [ -df ][ -n min ][ -x max ][ -w warn ]user_name passwd [ -fl ][ -n min ][ -x max ][ -w warn ]user_name passwd -s[-a ] passwd -s[ user_name ]
|passwd [ -fs ][ user_name ]|
The following list describes the options used to control how passwd functions.
|-d||Deletes the password for user_name. The user_name will not be prompted for a password.|
|-f||Force the password to expire. The user_name is forced to enter a new password at the next login.|
|-l||Lock the password entry for user_name. No changes may be made.|
|-n min||Set the minimum number of days between password changes.|
|-s||Display (show) password attributes for user user_name. If no user_name is specified, your login user_name is used. The format of the information is,|
|user-name status mm/dd/yy min max warn|
|or, if no password aging information is present|
|user_name||The login ID of a user|
|status||The password status|
|mm/dd/yy||The date the password was last changed|
|min||The minimum number of days between password changes. The label MINWEEKS specifies the default. It is located in the /etc/default/passwd file and is set to NULL. If min is greater than max, the user may not change the password. Always use with the -x option.|
|max||The maximum number of days the password is valid. The user is forced to change the password every max days. The label MAXWEEKS specifies the default. It is located in the /etc/default/passwd file and is set to NULL. If max is set to -1 then aging is turned off. If it is set to 0 then user_name is forced to change the password at the next login and aging is turned off.|
|warn||The number of days before the password expires, based on max, that the user_name will be warned.|
|-a||Display password attributes for all entries in the password file.|
|-w warn||Set the number of days before the password expires to notify the user_name.|
|-x max||Set the maximum number of days the password is valid.|
|-f||Allows you to change the information field of the /etc/passwd file for your login. Refer to chfn in Module 15 for further information.|
|-s||Allows you to change the login shell in the /etc/passwd file for your login.|
The following list describes the argument that may be passed to the passwd command.
|user_name||A valid user name in the /etc/passwd file. The user name is the first column (colon-separated columns) of the /etc/passwd file. Only the super-user can change another user's password.|
The use of passwords and their implementation is highly dependent upon your company's security policy and your system administrator. Some system administrators don't require passwords, while others require passwords, perform full accounting on every user, and implement password aging. Check with you system administrator for the requirements placed on your account.
The passwd command is capable of checking the elapsed time since the password was last changed, referred to as password aging. If the elapsed time is sufficient, then the user is allowed to change the password. Password aging also requires that a user must change passwords after a specified amount of time. The system administrator decides if password aging is activated and how long each password is aged.
|Most BSD based systems do not provide password aging. You should check your reference manual for specific password implementations on your system.|
The following is a list of requirements that a password must meet before passwd will allow it as your password.
|Berkeley is much more lenient about passwords. The following requirements must be met for a valid password.|
|1. Must contain four characters. Upper and lowercase.|
|2. Must contain six characters if only monocase.|
Refer to the login command described in Module 77 and the su command described in Module 127. To change your information field refer to the chfn command in Module 15.
The passwd utility reads the /etc/passwd file to retrieve the existing password and store the new password. The /etc/shadow file is used to store secure password information. Some BSD systems support a type of shadow file.
The passwd command returns the following return codes upon completion:
|2||Invalid combination of options|
|3||Unexpected failure, the password file is left unchanged|
|4||Unexpected failure, the password file is missing|
|5||The password file is busy, try again later|
|6||Invalid argument to an option|
The $? ($status-csh) shell variable contains the return code. So echo $? will display the return status.
The passwd utility is used to create a new password for a user or change an existing password. It provides a means of user security on the system. By changing your password once or twice a month you reduce the chance of another user learning your current password. The use of passwords is dependent on your company's security policy and your system administrator's implementation of security features. It is advisable to use a password and change it every two weeks even if it's not required of you.
TIP: Your password should be some meaningless string of intermixed numbers, characters, and symbols. Names of friends, wives, husbands, etc. are easily guessed by the criminal/jerk next door, down the street, or around the world.
In this activity you use the passwd command to change your password. The prompts that are returned from different password programs may vary but the requested response is the same.
cj> passwd Enter old passwd:
cj> passwd Enter old passwd: Enter new passwd:
cj> passwd Enter old passwd: Enter new passwd: Re-enter new passwd:
Mismatch - passwd not updated!
|Previous||Table of Contents||Next|
FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available in our efforts to advance understanding of environmental, political, human rights, economic, democracy, scientific, and social justice issues, etc. We believe this constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit exclusivly for research and educational purposes. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner.
ABUSE: IPs or network segments from which we detect a stream of probes might be blocked for no less then 90 days. Multiple types of probes increase this period.
Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers : Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism : The Iron Law of Oligarchy : Libertarian Philosophy
War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda : SE quotes : Language Design and Programming Quotes : Random IT-related quotes : Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce : Bernard Shaw : Mark Twain Quotes
Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 : Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law
Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds : Larry Wall : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS : Programming Languages History : PL/1 : Simula 67 : C : History of GCC development : Scripting Languages : Perl history : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history
The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month : How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Haterís Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite
Most popular humor pages:
Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor
The Last but not Least
Copyright © 1996-2016 by Dr. Nikolai Bezroukov. www.softpanorama.org was created as a service to the UN Sustainable Development Networking Programme (SDNP) in the author free time. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License.
Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.
FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.
This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...
|You can use PayPal to make a contribution, supporting development of this site and speed up access. In case softpanorama.org is down you can use the at softpanorama.info|
The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the author present and former employers, SDNP or any other organization the author may be associated with. We do not warrant the correctness of the information provided or its fitness for any purpose.
Last modified: October 20, 2015