09-05-2008
"" need this code in C language for UNIX"
Write or study a small program that mimics the most common login procedures in UNIX.
You have two options here. Either, you write it yourself according to the specification
below, or you copy the file
/cab/cestud/work/edu/course/EDA263_Computer_Security/
lib/login_linux/login_linux.c into your home directory. If you choose to write
it yourself the following should be implemented.
- The program begins with displaying ”login:” and takes the username as input.
- Then the program writes ”Password:” and waits for the password to be entered,
which should not be visible on the terminal (use the function getpass(3) that
among other things will see to that the text is not ”echoed” on the terminal).
- The program queries the system’s user database to see if the username exists. If
this is the case it encrypts the entered password (with a known algorithm) and
ensures it corresponds to the stored encrypted password belonging to the actual
user. Suitable library routines are getpwnam(3), crypt(3) and strncmp(3).
- If the username does not exist, or if the password is wrong, the program displays
”Login incorrect” and restarts from the beginning, otherwise it writes something
like ”Welcome to this System!” and terminates.
Test that your program works by compiling and running it.
6 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi all,
Can anyone provide me any checklists or a list of steps I should follow before executing my scripts.
Could also tell me if there are any other standards to be followed while shell programming like naming conventions for variables etc.
Your help would be much appreciated.
Regards,... (2 Replies)
Discussion started by: srikanth_ksv
2 Replies
2. Shell Programming and Scripting
Hi,
I want to know that if there are any methods, which check the MQ, is up or down. Actually I have to write one job which checks the status of any one MQ is up or down.
I don't know if there is any method of MQ, which tells the MQ, is up.
Could u please give some link for the study... (1 Reply)
Discussion started by: rinku
1 Replies
3. UNIX for Dummies Questions & Answers
Hello,
I am trying to learn Networking Programming in C in unix enviorment. I want to know how good it is to become a network programmer. i am crazy about Network programming but i also want to opt for the best carreer options. Anybody experienced Network Programmer, please tell me is my... (5 Replies)
Discussion started by: vibhory2j
5 Replies
4. What is on Your Mind?
Just a quick update; to speed up the forums, I have disabled the forum statistics on the home page for non registered users.
No changes for registered users. (0 Replies)
Discussion started by: Neo
0 Replies
5. Post Here to Contact Site Administrators and Moderators
https://www.unix.com/shell-programming-and-scripting/
The current description of Shell Programming and Scripting has:
Unix shell scripting - KSH, CSH, SH, BASH, PERL, PHP, SED, AWK and shell scripts and shell scripting languages here.
Perl, php are there. Is it possible to add PYTHON there too? (3 Replies)
Discussion started by: cola
3 Replies
6. What is on Your Mind?
For mobile users, I have just added a "first beta" Advanced Forum Statistics to the home page on mobile using CSS overflow:auto; so you can swipe if you need to see more. Google Search Console mobile usability says this page is "mobile friendly" so perhaps this will be useful for some of our... (12 Replies)
Discussion started by: Neo
12 Replies
dxchpwd(1X) dxchpwd(1X)
NAME
dxchpwd - Create or change password program
SYNOPSIS
dxchpwd
dxchpwd -r | -l
dxchpwd [-r | -l] -q
dxchpwd [-r | -l] -u username
OPTIONS
If dxchpwd is invoked without any options, it is assumed that the current user's password is to be changed. The following options are also
accepted: Tells dxchpwd that the password change is to be done for a Local user. This can be combined with the -u and -q options. Tells
dxchpwd that the password change is to be done for a NIS user. This can only be done from a NIS master and can be combined with the -u and
-q options. Tells dxchpwd to query the user for the user name of the account whose password is to be changed. Tells dxchpwd to change
this user's password.
DESCRIPTION
The dxchpwd command lets you change your password. When you invoke the dxchpwd command, the program prompts you for the old password and
then for the new password. Next, the program asks you for the new password again, to verify that you have typed it correctly. Note that
the passwords are not displayed on the screen.
Your new password must meet the length requirements specified by the authorization database for the user whose password is being changed.
If your system is running with enhanced security, you may have to choose a password from a list of randomly generated passwords or you may
be prohibited from changing your password until its minimum lifetime has expired, as specified in the authorization database.
EXAMPLES
The following example requests that the password be changed for user smith: dxchpwd -u smith
FILES
Password file Protected Password Database dxchpwd executable
SEE ALSO
X(1X), xdm(1X), passwd(1)
dxchpwd(1X)