I have seen this used several times but not really sure of what it actually does. I am confused with the second grep as the argument to the first.
some commands | grep -v grep | some other commands
Can anyone provide an explanation?
Thanks, (5 Replies)
I tried searching for answers but didn't find any.
When I grep a file results read
4.2.2.2
4.4.4.2
4.5.6.7
But I just want to select each result individually. For Example I want to be able to say
variable1="first grep result"
variable2="second grep result"
variable3="third grep... (8 Replies)
Hi, On the log Netscape log, I need to grep for 500 error. I am doing that but I also get 1500 in that same log.
cat access |grep "500"
Results:
"GET /css/RBR.css HTTP/1.1" 200 15000 304 - - - 399 639 523 164 0
This not what I need... Please advice. (4 Replies)
Hi all,
Here is my requirement
I have to search 'ORA' word in out.log file,if it is present then i need to send that file (out.log) content to some mail id.If 'ORA' word is not in that file then i need to send 'load succesful' message to some mail id.
The below the shell script is not... (5 Replies)
This should be so easy...
I want to find all the apps in /Applications that start with the lower case i (e.g. iTunes.app, iSync.app, iCal.app) They should all have the .app extension. I've tried:
ls /Applications |grep -o i*.app
ls /Applications/i*.app
Anyhow, I just want to see what apps... (2 Replies)
Hi guys, I have written this script, however the outcome is invalid. It contains grep search that is not needed:
Script:
#!/bin/bash
#this is a test script
FILES=$(ls /home/student/bin/dir1/*)
GREPFUNC=$(grep -E -i "login|Successfully" ORProxyTC`date '+%m%d%Y'`*.txt/ ${FILES})... (14 Replies)
I am currently having a problem with displaying multiple occurences of a line using grep/sed combination. Let's say that I do grep "$anything" $file.
When I do this it only displays a single line, but if I do grep -c "$anything" $file it says that there are 3 occurences of $anything, but how can... (15 Replies)
Hello,
I am trying to grep my log files for ORA errors, except ORA-00001.
I have tried:
grep 'ORA*!(-00001)' *.log
but it is not working.
Any help will be much appreciated.
Thank you. (5 Replies)
I hope someone can help me.
I have a folder e.g. /opt/application
Under that are many sub folders e.g.
Folder1
Folder2
Folder3
Folder4
Folder5
Folder6
etc
In some of these fodlers (not all of them) is a file called errors.log
I need to run a grep that will start at... (3 Replies)
Hello all!
This is my first post and I'm very new to programming. I would like help creating a simple perl or bash script that I will be using in my work as a junior bioinformatician.
Essentially, I would like to take a tab-delimted or .csv text with 3 columns and write them to a "3D" matrix:
... (16 Replies)
Discussion started by: torchij
16 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)