For starters, you almost never need to use $?, a normal if-statement will do. Written this way, you can kind of see the logic. "If not sudo, then ..."
Not sure if it's really a simplification but I'd add >&2, the traditional place for error messages. That way if someone uses this in a stream they can direct data output and error output separately.
You should have an exit after exec, in case the exec fails for whatever reason (i.e. path problems or something).
Then I'd label the section which is always intended to run as root.
The "replace and re-run" bit comes down to how exec really works: It causes the running program to replace itself with what you ask. Whether it succeeds or fails, after an
The >&2's make more likely that these messages get printed to the terminal, where these messages usually belong.
More could probably be done with apt-get, like checking its return value rather than just assuming it operates correctly.
Last edited by Corona688; 11-02-2018 at 12:56 PM..
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
The system don't boot.
on the screen appears following:
press enter to maintenance (or type CTRL-D to continue)...I checked with format command.
... the slices "0-root","1-swap","2-backup" exist.
...the slises "3-var","6-usr" -unassigned. :( (16 Replies)
Hi All,
I'm completely new to bash scripting and still learning my way through albeit vey slowly.
I need to know where to insert my server names', my ip address numbers through out the script alas to no avail.
I'm also searching on how to save .sh (bash shell) script properly.... (25 Replies)
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Hi All,
i am trying to ssh to a remote machine and execute certain command to remote machine through script.
i am able to ssh but after its getting hung at the promt and after pressing ctrl +d i am gettin the out put as
expect: spawn id exp5 not open
while executing
"expect "$" {... (3 Replies)
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Hi 2 all,
i have had AIX 7.2
:/# /usr/IBMAHS/bin/apachectl -v
Server version: Apache/2.4.12 (Unix)
Server built: May 25 2015 04:58:27
:/#:/# /usr/IBMAHS/bin/apachectl -M
Loaded Modules:
core_module (static)
so_module (static)
http_module (static)
mpm_worker_module (static)
... (3 Replies)
Discussion started by: penchev
3 Replies
LEARN ABOUT LINUX
sudo_root
sudo_root(8) System Manager's Manual sudo_root(8)NAME
sudo_root - How to run administrative commands
SYNOPSIS
sudo command
sudo -i
INTRODUCTION
By default, the password for the user "root" (the system administrator) is locked. This means you cannot login as root or use su. Instead,
the installer will set up sudo to allow the user that is created during install to run all administrative commands.
This means that in the terminal you can use sudo for commands that require root privileges. All programs in the menu will use a graphical
sudo to prompt for a password. When sudo asks for a password, it needs your password, this means that a root password is not needed.
To run a command which requires root privileges in a terminal, simply prepend sudo in front of it. To get an interactive root shell, use
sudo -i.
ALLOWING OTHER USERS TO RUN SUDO
By default, only the user who installed the system is permitted to run sudo. To add more administrators, i. e. users who can run sudo, you
have to add these users to the group 'admin' by doing one of the following steps:
* In a shell, do
sudo adduser username admin
* Use the graphical "Users & Groups" program in the "System settings" menu to add the new user to the admin group.
BENEFITS OF USING SUDO
The benefits of leaving root disabled by default include the following:
* Users do not have to remember an extra password, which they are likely to forget.
* The installer is able to ask fewer questions.
* It avoids the "I can do anything" interactive login by default - you will be prompted for a password before major changes can happen,
which should make you think about the consequences of what you are doing.
* Sudo adds a log entry of the command(s) run (in /var/log/auth.log).
* Every attacker trying to brute-force their way into your box will know it has an account named root and will try that first. What they do
not know is what the usernames of your other users are.
* Allows easy transfer for admin rights, in a short term or long term period, by adding and removing users from the admin group, while not
compromising the root account.
* sudo can be set up with a much more fine-grained security policy.
* On systems with more than one administrator using sudo avoids sharing a password amongst them.
DOWNSIDES OF USING SUDO
Although for desktops the benefits of using sudo are great, there are possible issues which need to be noted:
* Redirecting the output of commands run with sudo can be confusing at first. For instance consider
sudo ls > /root/somefile
will not work since it is the shell that tries to write to that file. You can use
ls | sudo tee /root/somefile
to get the behaviour you want.
* In a lot of office environments the ONLY local user on a system is root. All other users are imported using NSS techniques such as
nss-ldap. To setup a workstation, or fix it, in the case of a network failure where nss-ldap is broken, root is required. This tends to
leave the system unusable. An extra local user, or an enabled root password is needed here.
GOING BACK TO A TRADITIONAL ROOT ACCOUNT
This is not recommended!
To enable the root account (i.e. set a password) use:
sudo passwd root
Afterwards, edit the sudo configuration with sudo visudo and comment out the line
%admin ALL=(ALL) ALL
to disable sudo access to members of the admin group.
SEE ALSO sudo(8), https://wiki.ubuntu.com/RootSudo
February 8, 2006 sudo_root(8)