I need to check if an account has a valid password.
Would something like this work?
I noticed every entry in my shadow file that has a password starts with $6 ... it works for my current setup, but would it always work? I can't test for ^$ACCNAME:*: since !!* is locked and !! has no password.
Hi Folks,
I'm using bash script. I would like to check whether input is a number or not.(Only positive numbers).. if space or non numeric is entered, it should say "invalid input". pls help..
thanks in adv.
Br///
Vijay. (1 Reply)
Hi,
I have a 5 gig file, no record terminators, field terminators are newline. The record length is 768 and I would like to check that every 768th byte is a newline and print out the byte position if it isn't. I would like to do this going either forward or backwards with one command if... (3 Replies)
the script on excution should take a directory path from useran a numric input and it should check indicate whether its write or not?
if the cmmd sh<script-name>,dir/path.<500>" is greater than 500 in size should be copied to dir ,temp in pwd and display the mesage'files of 2000 bytes hav been... (4 Replies)
1. The problem statement, all variables and given/known data:
The script usage will be as follows:
library.third source_directory
- Your script will display an appropriate error message and exit with status 3 if no parameters are given
- Your script will display an appropriate error... (2 Replies)
Hi All,
I am a newbie...I would like to have a function which ll check if a file contains valid strings before "=" operator. Just to give you my requirement:
assume my file has content:
hello= gsdgsd sfdsg sgdsg sgdgdg
world= gggg hhhh iiiii
xxxx= pppp ppppp pppp
my... (5 Replies)
How to check the user input to be valid using shell script?
The valid input is in the format like as follows.
1. It can only have r,w,x or a hyphen and nothing else.
2. ensure the r, w, x are in the correct order.
for example: rwxr-xr-x is a valid format.
Thanks (5 Replies)
I need a script that should print 'yes' if the argument is a valid shell variable name else 'No' if it is not a valid shell variable. A valid one begins with an alphabet or percentage (%) character and is followed by zero or more alphanumberic or percentage (%) characters.
For example:
$... (6 Replies)
How can I validate if time (HH:MM:SS) argument is valid? I got this from web but I can't modify it to exit the script if the time argument is invalid.
echo $1 | awk -F ':' '{ print ($1 <= 23 && $2 <= 59 && $3 <= 59) ? "good" : "bad" }'
ex:
./script.ksh 12:34:21 = okay
./script.ksh... (10 Replies)
Hello,
I am trying to develop a script to check for valid hostnames. Below are the prerequisites for a valid hostname which I got from wiki :
Hostnames are composed of series of labels concatenated with dots, as are all domain names. For example, "en.wikipedia.org" is a hostname. Each label... (8 Replies)
Discussion started by: rahul2662
8 Replies
LEARN ABOUT OPENDARWIN
shadow
SHADOW(5) File Formats and Conversions SHADOW(5)NAME
shadow - shadowed password file
DESCRIPTION
shadow is a file which contains the password information for the system's accounts and optional aging information.
This file must not be readable by regular users if password security is to be maintained.
Each line of this file contains 9 fields, separated by colons (":"), in the following order:
login name
It must be a valid account name, which exist on the system.
encrypted password
Refer to crypt(3) for details on how this string is interpreted.
If the password field contains some string that is not a valid result of crypt(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).
This field may be empty, in which case no passwords are required to authenticate as the specified login name. However, some
applications which read the /etc/shadow file may decide not to permit any access at all if the password field is empty.
A password field which starts with an exclamation mark means that the password is locked. The remaining characters on the line
represent the password field before the password was locked.
date of last password change
The date of the last password change, expressed as the number of days since Jan 1, 1970.
The value 0 has a special meaning, which is that the user should change her password the next time she will log in the system.
An empty field means that password aging features are disabled.
minimum password age
The minimum password age is the number of days the user will have to wait before she will be allowed to change her password again.
An empty field and value 0 mean that there are no minimum password age.
maximum password age
The maximum password age is the number of days after which the user will have to change her password.
After this number of days is elapsed, the password may still be valid. The user should be asked to change her password the next time
she will log in.
An empty field means that there are no maximum password age, no password warning period, and no password inactivity period (see below).
If the maximum password age is lower than the minimum password age, the user cannot change her password.
password warning period
The number of days before a password is going to expire (see the maximum password age above) during which the user should be warned.
An empty field and value 0 mean that there are no password warning period.
password inactivity period
The number of days after a password has expired (see the maximum password age above) during which the password should still be accepted
(and the user should update her password during the next login).
After expiration of the password and this expiration period is elapsed, no login is possible using the current user's password. The
user should contact her administrator.
An empty field means that there are no enforcement of an inactivity period.
account expiration date
The date of expiration of the account, expressed as the number of days since Jan 1, 1970.
Note that an account expiration differs from a password expiration. In case of an account expiration, the user shall not be allowed to
login. In case of a password expiration, the user is not allowed to login using her password.
An empty field means that the account will never expire.
The value 0 should not be used as it is interpreted as either an account with no expiration, or as an expiration on Jan 1, 1970.
reserved field
This field is reserved for future use.
FILES
/etc/passwd
User account information.
/etc/shadow
Secure user account information.
/etc/shadow-
Backup file for /etc/shadow.
Note that this file is used by the tools of the shadow toolsuite, but not by all user and password management tools.
SEE ALSO chage(1), login(1), passwd(1), passwd(5), pwck(8), pwconv(8), pwunconv(8), su(1), sulogin(8).
shadow-utils 4.5 01/25/2018 SHADOW(5)