This question already has answers here:
How do I use sudo to redirect output to a location I don't have permission to write to? [closed]
(15 answers)
Closed 5 years ago.
I wish to write text from stdin to a file that is owned by root.
I'm doing this programmatically across an SSH connection - essentially from a script - so using a text editor is out of the question. There is no terminal. The process is entirely automated.
Given that [a] root elevation can be obtained via sudo, and [b] files can be written to using cat with redirection, I assumed the following would work:
ssh user#host sudo cat >the-file
Unfortunately, the redirection is applied to sudo, not to cat. How can I apply redirection to cat in this example?
The normal pattern to do this is:
ssh user#host 'cat | sudo tee the-file'
tee redirects output to a file and can be run with sudo.
If you want to mimic >> where the file is appended-to, use sudo tee -a.
You'll also need to be sure to quote your command as above, so that the pipe isn't interpreted by the local shell.
Edit
The tee command is part of POSIX, so you can rely on it existing.
To redirect Standard Error as well:
ssh user#host 'some_command 2>&1 | sudo tee output-file'
Related
This question already has answers here:
How to escape the single quote character in an ssh / remote bash command?
(5 answers)
Closed 9 months ago.
Im using ssh with a system that has a lot of security settings. The bash command I want to run is:
ssh –t user#address su –c ‘echo “user ALL=(ALL) NOPASSWD:ALL” >> /etc/sudoers.d/permissions’
This command does not work since su does not recognize the stuff after it as a command. EOF is disabled by default for ssh and EOSU is disabled by default on all computers in the network. Sudo is also disabled for the user on the host computer. Is there a clean way to do this while calling su as little as possible?
Note: I already did keygen stuff so the ssh login is passwordless, root login through ssh is disabled by default.
When you pass a command to ssh, it requires quoting both from the local shell and the remote shell.
A fix for your case would be to move the first single quote slightly, to prevent the local shell from messing with the command at all. In the internal quoting, we use nested double quotes where the inner ones are backslashed.
ssh –t user#address 'su –c "echo \"user ALL=(ALL) NOPASSWD:ALL\"" >> /etc/sudoers.d/permissions’
Im currently logged in as admin and I want to edit the /etc/hosts file which required root access.
I'm not able to make the changes. The script gets executed sucessfully but the changes arent made.
My Script - Runs Sucessfully when executed from terminal
sudo -s
echo "127.0.0.1" >> /etc/hosts
su admin
sudo -s - switches to root without password when executed from terminal
su admin - switches back to admin user when run on terminal
My /etc/hosts file remains empty after running the script
There is no need to actually switch your user within the script.
Also, you can't echo something as root like that because the redirect (>>) is executed by the shell.
A possible workaround is using tee:
echo "127.0.0.1" | sudo tee -a /etc/hosts
Further explanation:
tee basically takes the data from the standard input and writes it either to the standard output, or to a file. For more information see the commands manual ($ man tee)
I am trying to run the command while looping through
a series of sever addresses.
while read server
do
ssh -t $sever "sudo md5sum $fileName >> hashes"
done < serverNamesFile
within a script in bash but i keep getting this error
sudo: sorry, you must have a tty to run sudo
if I run the same line of commands in the command line though, it works perfectly fine.
Can someone tell me why this keeps happening?
you probably have
Defaults requiretty
in your /etc/sudoers file.
As the option's name suggests, that will cause sudo to require a tty
I solved my problem. apparently looping through a series of servers inside a script causes the "TTY" error for SSH.
a better practice is to create a script that takes in the address of the server you want to SSH in and then pass in the commands that way. you can still loop through a series of file or commands by calling SSH each time and use this command:
while read stuff
do
ssh -qtt $severName " command"
done < $fileStuff
I want to run multiple commands automatically like sudo bash, ssh server01, ls , cd /tmp etc at server login..
I am using Remote command option under SSH in putty.
I tried multiple commands with delimiter && but not working.
There is a some information lacking in your question.
You say you want to run sudo bash, then ssh server01.
Will sudo prompt for a password in your remote server?
Assuming there is no password in sudo, running bash will open another shell waiting for user input. The command ssh server01 will not be run until that bash shell is exited.
If you want to run 2 commands, try first simpler ones like:
ls -l /tmp ; echo "hi there"
or if you prefer:
ls -l /tmp && echo "hi there"
Does this work?
If what you want is to run ssh after running bash, you can try :
sudo bash -c "ssh server01"
That is probably because the command is expected to be a program name followed by parameters, which will be passed directly to the program. In order to get && and other functionality that is provided by a command line interpreter such as bash, try this:
/bin/bash -c "command1 && command2"
I tried what I suggested in my previous answer.
It is possible to run 2 simple commands in putty separated by a semicolon. As in my example I tried with ls and echo. The remote server runs them and then the session closes.
I also tried to ssh to a remote server that is configured for not asking for a password. In that case, it also works, I get connected to the 2nd server and I can run commands on it. Upon exit, the 2 connections are closed.
So please, let us know what you actually need / want.
You can execute two consecutive commands in PuTTY using a regular shell syntax. E.g. using ; or &&.
But you want to execute ssh server01 in sudo bash shell, right?
These are not two consecutive commands, it's ssh server01 command executed within sudo bash.
So you have to use a sudo command-line syntax to execute the ssh server01, like
sudo bash ssh server01
This question already has answers here:
Use sudo to change file in root directory [duplicate]
(2 answers)
Closed 6 months ago.
VLC is running. Got the PID from pgrep vlc.
I want now to pause it manually since I would like it to run "submerged" (right now from another tty but probably as a daemon)
I tried to simply do sudo "pause" > /usr/bin/vlc/ having got the path by doing sudo ls -l /proc/<PID>/exe.
The answer is, even running the sudo command, that the permission is denied.
For my surprise, if I enter root mode sudo bash and just type the same command, the answer is not that the permission is denied, but rather that the "text file is busy". I'd like to guess what text file. I thought that command (in that case) inputted data to the command input manually (apart from writing to a text file)
This is probably what you want to do.
Write to /proc/pid of the program/fd/0. The fd subdirectory contains the descriptors of all the opened files and file descriptor 0 is the standard input (1 is stdout and 2 is stderr).
Example
Terminal 1:
[ciupicri#hermes ~]$ cat
Xxx
Terminal 2:
[ciupicri#hermes ~]$ pidof cat
7417
[ciupicri#hermes ~]$ echo xxx > /proc/7417/fd/0
Taken from another stack overflow answer