I'm trying to decode my password through a script while it's being run but it seems like the script is being run with a literal and the password is not processed. Is there a better way of doing this?
#!/bin/bash
MYENC="Tk9UX1RIQVRfU1RVUElEX0xPTAo="
rdesktop -u FOO -d mgmt -p 'echo $(echo $MYENC) | base64 --decode' 192.0.0.0
I also tried to just pass in a variable but that failed as well.
Try this instead:
#!/bin/bash
MYENC="Tk9UX1RIQVRfU1RVUElEX0xPTAo="
rdesktop -u FOO -d mgmt -p $(echo $MYENC | base64 --decode) 192.0.0.0
Note that I wrapped the juicy stuff echo...base64... in $(...). This is called "command substitution" - basically you're telling bash that you want the code inside the $(...) to be executed before the rest of the line, with the result substituted in its place. More info here: http://www.tldp.org/LDP/abs/html/commandsub.html
Or this
#!/bin/bash
MYENC="Tk9UX1RIQVRfU1RVUElEX0xPTAo="
rdesktop -u FOO -d mgmt -p $(base64 --decode <<< "$MYENC") 192.0.0.0
Related
When I run the following command in a terminal it works, but not from a script:
eval $(printf "ssh foo -f -N "; \
for port in $(cat ~/bar.json | grep '_port' | grep -o '[0-9]\+'); do \
printf "-L $port:127.0.0.1:$port ";\
done)
The error I get tells me that printf usage is wrong, as if the -L argument within quotes would've been an argument to printf itself.
I was wondering why that is the case. Am I missing something obvious?
__
Context (in case my issue is an XY problem): I want to start and connect to a jupyter kernel running on a remote computer. To do so I wrote a small script that
sends a command per ssh for the remote to start the kernel
copies via scp a configuration file that I can use to connect to the kernel from my local computer
reads the configuration file and opens appropriate ssh tunnels between local and remote
For those not familiar with jupyter, a configuration file (bar.json) looks more or less like the following:
{
"shell_port": 35932,
"iopub_port": 37145,
"stdin_port": 42704,
"control_port": 39329,
"hb_port": 39253,
"ip": "127.0.0.1",
"key": "4cd3e12f-321bcb113c204eca3a0723d9",
"transport": "tcp",
"signature_scheme": "hmac-sha256",
"kernel_name": ""
}
And so, in my command above, the printf statement creates an ssh command with all the 5 -L port forwarding for my local computer to connect to the remote, and eval should run that command. Here's the full script:
#!/usr/bin/env bash
# Tell remote to start a jupyter kernel.
ssh foo -t 'python -m ipykernel_launcher -f ~/bar.json' &
# Wait a bit for the remote kernel to launch and write conf. file
sleep 5
# Copy the conf. file from remote to local.
scp foo:~/bar.json ~/bar.json
# Parse the conf. file and open ssh tunnels.
eval $(printf "ssh foo -f -N "; \
for port in $(cat ~/bar.json | grep '_port' | grep -o '[0-9]\+'); do \
printf "-L $port:127.0.0.1:$port ";\
done)
Finally, jupyter console --existing ~/foo.json connects to remote.
As #that other guy says, bash's printf builtin barfs on printf "-L ...". It thinks you're passing it a -L option. You can fix it by adding --:
printf -- "-L $port:127.0.0.1:$port "
Let's make that:
printf -- '-L %s:127.0.0.1:%s ' "$port" "$port"
But since we're here, we can do a lot better. First, let's not process JSON with basic shell tools. We don't want to rely on it being formatting a certain way. We can use jq, a lightweight and flexible command-line JSON processor.
$ jq -r 'to_entries | map(select(.key | test(".*_port"))) | .[].value' bar.json
35932
37145
42704
39329
39253
Here we use to_entries to convert each field to a key-value pair. Then we select entries where the .key matches the regex .*_port. Finally we extract the corresponding .values.
We can get rid of eval by constructing the ssh command in an array. It's always good to avoid eval when possible.
#!/bin/bash
readarray -t ports < <(jq -r 'to_entries | map(select(.key | test(".*_port"))) | .[].value' bar.json)
ssh=(ssh foo -f -N)
for port in "${ports[#]}"; do ssh+=(-L "$port:127.0.0.1:$port"); done
"${ssh[#]}"
This question already has answers here:
How do I set a variable to the output of a command in Bash?
(15 answers)
Closed 4 years ago.
I have a script like that
genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5
I want to get stream generated by genhash in a variable. How do I redirect it into a variable $hash to compare inside a conditional?
if [ $hash -ne 0 ]
then echo KO
exit 0
else echo -n OK
exit 0
fi
Use the $( ... ) construct:
hash=$(genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5)
TL;DR
To store "abc" into $foo:
echo "abc" | read foo
But, because pipes create forks, you have to use $foo before the pipe ends, so...
echo "abc" | ( read foo; date +"I received $foo on %D"; )
Sure, all these other answers show ways to not do what the OP asked, but that really screws up the rest of us who searched for the OP's question.
The answer to the question is to use the read command.
Here's how you do it
# I would usually do this on one line, but for readability...
series | of | commands \
| \
(
read string;
mystic_command --opt "$string" /path/to/file
) \
| \
handle_mystified_file
Here is what it is doing and why it is important:
Let's pretend that the series | of | commands is a very complicated series of piped commands.
mystic_command can accept the content of a file as stdin in lieu of a file path, but not the --opt arg therefore it must come in as a variable. The command outputs the modified content and would commonly be redirected into a file or piped to another command. (E.g. sed, awk, perl, etc.)
read takes stdin and places it into the variable $string
Putting the read and the mystic_command into a "sub shell" via parenthesis is not necessary but makes it flow like a continuous pipe as if the 2 commands where in a separate script file.
There is always an alternative, and in this case the alternative is ugly and unreadable compared to my example above.
# my example above as a oneliner
series | of | commands | (read string; mystic_command --opt "$string" /path/to/file) | handle_mystified_file
# ugly and unreadable alternative
mystic_command --opt "$(series | of | commands)" /path/to/file | handle_mystified_file
My way is entirely chronological and logical. The alternative starts with the 4th command and shoves commands 1, 2, and 3 into command substitution.
I have a real world example of this in this script but I didn't use it as the example above because it has some other crazy/confusing/distracting bash magic going on also.
read hash < <(genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5)
This technique uses Bash's "process substitution" not to be confused with "command substitution".
Here are a few good references:
http://www.linuxjournal.com/content/shell-process-redirection
http://tldp.org/LDP/abs/html/process-sub.html
http://tldp.org/LDP/abs/html/commandsub.html ☚ for comparison
I guess compatible way:
hash=`genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5`
but I prefer
hash="$(genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5)"
If a pipeline is too complicated to wrap in $(...), consider writing a function. Any local variables available at the time of definition will be accessible.
function getHash {
genhash --use-ssl -s $IP -p 443 --url $URL | grep MD5 | grep -c $MD5
}
hash=$(getHash)
http://www.gnu.org/software/bash/manual/bashref.html#Shell-Functions
You can do:
hash=$(genhash --use-ssl -s $IP -p 443 --url $URL)
or
hash=`genhash --use-ssl -s $IP -p 443 --url $URL`
If you want to result of the entire pipe to be assigned to the variable, you can use the entire pipeline in the above assignments.
I got error sometimes when using $(`code`) constructor.
Finally i got some approach to that here: https://stackoverflow.com/a/7902174/2480481
Basically, using Tee to read again the ouput and putting it into a variable.
Theres how you see the normal output then read it from the ouput.
is not? I guess your current task genhash will output just that, a single string hash so might work for you.
Im so neewbie and still looking for full output & save into 1 command.
Regards.
Create a function calling it as the command you want to invoke. In this case, I need to use the ruok command.
Then, call the function and assign its result into a variable. In this case, I am assigning the result to the variable health.
function ruok {
echo ruok | nc *ip* 2181
}
health=echo ruok *ip*
I am trying to write a bash script which simply acts as an emulator. It takes input from the user and executes the command while forwarding the command along with the result onto a file. I am unable to handle inputs which have either a | or a > in them.
The only option I could find was segregating the commands based on the | into an array and run them individually. However, this does not allow > redirects.
Thanking in advance.
$cmd is a command taken as input from the user
I used the command
$cmd 2>&1 | tee -a $flname
but this does not work if there is a | or a > in $cmd
/bin/bash -c "$cmd 2>&1 | tee -a $flname" does not run/store the command either
Try this:
#!/bin/bash
read -r -p "Insert command to execute"$'\n' cmd
echo "Executing '$cmd'"
/bin/bash -c "$cmd"
# or eval "$cmd"
Example of execution:
$ ./script.sh
Insert command to execute
printf '1\n2\n3\n4\n' | grep '1\|3'
Executing 'printf '1\n2\n3\n4\n' | grep '1\|3''
1
3
I wrote a small bash script in this post: How to search for a string in a text file and perform a specific action based on the result
I noticed that when I ran the script and check the logs, everything appears to be working but when I look at the Nagios UI, almost half of the servers listed in my text file did not get their notifications disabled. A revised version of the script is below:
host=/Users/bob/wsus.txt
password="P#assw0rd123"
while read -r host; do
region=$(echo "$host" | cut -f1 -d-)
if [[ $region == *sea1* ]]
then
echo "Disabling host notifications for: $host"
curl -vs -o /dev/null -d "cmd_mod=2&cmd_typ=25&host=$host&btnSubmit=Commit" https://nagios.$region.blah.com/nagios/cgi-bin/cmd.cgi" -u "bob:$password" -k 2>&1
else
echo "Disabling host notifications for: $host"
curl -vs -o /dev/null -d "cmd_mod=2&cmd_typ=25&host=$host&btnSubmit=Commit" https://nagios.$region.blah02.com/nagios/cgi-bin/cmd.cgi" -u "bob:$password" -k 2>&1
fi
done < wsus.txt >> /Users/bob/disable.log 2>&1
If i run the command against the servers having the issue manually, it does get disabled in the Nagios UI, so I'm a bit confused. FYI, I'm not well versed in Bash either so this was my attempt at trying to automate this process a bit.
1 - There is a missing double-quote before the first https occurence:
You have:
curl -vs -o /dev/null -d "cmd_mod=2&cmd_typ=25&host=$host&btnSubmit=Commit" https://nagios.$region.blah.com/nagios/cgi-bin/cmd.cgi" -u "bob:$password" -k 2>&1
Should be:
curl -vs -o /dev/null -d "cmd_mod=2&cmd_typ=25&host=$host&btnSubmit=Commit" "https://nagios.$region.blah.com/nagios/cgi-bin/cmd.cgi" -u "bob:$password" -k 2>&1
2 - Your first variable host is never used (overwritten inside the while loop).
I'm guessing what you were trying to do was something like:
hosts_file="/Users/bob/wsus.txt"
log_file="/Users/bob/disable.log"
# ...
while read -r host; do
# Do stuff with $host
done < $hosts_file >> $log_file 2>&1
3 - This looks suspicious to me:
if [[ $region == *sea1* ]]
Note: I haven't tested it yet, so this is my general feeling about this, might be wrong.
The $region isn't double-quoted, so make sure there could be no spaces / funny stuff happening there (but this should not be a problem inside a double-bracket test [[).
The *sea* looks like it would be expanded to match your current directory files matching this globbing. If you want to test this as a regular expression, you should use ~= operator or (my favorite for some reason) grep command:
if grep -q ".*sea.*" <<< "$region"; then
# Your code if match
else
# Your code if no match
fi
The -q keeps grep quiet
There is no need for test like [ or [[ because the return code of grep is already 0 if any match
The <<< simply redirects the right strings as the standard input of the left command (avoid useless piping like echo "$region" | grep -q ".*sea.*").
If this doesn't solve your problem, please provide a sample of your input file hosts_file as well as some output logs.
You could also try to see what's really going on under the hood by enclosing your script with set -x and set +x to activate debug/trace mode.
I am passing the following command straight through SSH:
ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i /key/path server#111.111.111.111 'bash -s' << EOF
FPM_EXISTS=`ps aux | grep php-fpm`
if [ ! -z "$FPM_EXISTS" ]
then
echo "" | sudo -S service php5-fpm reload
fi
EOF
I get the following error:
[2015-02-25 22:45:23] local.INFO: bash: line 1: syntax error near unexpected token `('
bash: line 1: ` FPM_EXISTS=root 2378 0.0 0.9 342792 18692 ? Ss 17:41 0:04 php-fpm: master process (/etc/php5/fpm/php-fpm.conf)
It's like it is trying to execute the output of ps aux | grep php-fpm instead of just capturing git the variable. So, if I change the command to try to capture ls, it acts like it tries to execute that as well, of course returning "command not found" for each directory.
If I just paste the contents of the Bash script into a file and run it it works fine; however, I can't seem to figure out how to pass it through SSH.
Any ideas?
You need to wrap starting EOF in single quotes. Otherwise ps aux | grep php-fpm would get interpreted by the local shell.
The command should look like this:
ssh ... server#111.111.111.111 'bash -s' << 'EOF'
FPM_EXISTS=$(ps aux | grep php-fpm)
if [ ! -z "$FPM_EXISTS" ]
then
echo "" | sudo -S service php5-fpm reload
fi
EOF
Check this: http://tldp.org/LDP/abs/html/here-docs.html (Section 19.7)
Btw, I would encourage you to use $() instead of backticks consequently for command substitution because of the ability to nest them. You will have more fun, believe me. Check this for example: What is the benefit of using $() instead of backticks in shell scripts?
You should wrap the EOF in single quotes.
ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i /key/path server#111.111.111.111 'bash -s' << 'EOF'
FPM_EXISTS=`ps aux | grep php-fpm`
if [ ! -z "$FPM_EXISTS" ]
then
echo "" | sudo -S service php5-fpm reload
fi
EOF