I have this shell script which ssh to other server, find few specific files(.seq files older than 50 mnts) and writes their name to another file.
#! /usr/bin/bash
while read line
do
#echo $line
if [[ $line =~ ^# ]];
then
#echo $line;
continue;
else
serverIP=`echo $line|cut -d',' -f1`
userID=`echo $line|cut -d',' -f2`
fi
done < sftp.conf
sshpass -p red32hat ssh $userID#$serverIP
cd ./perl
for files in `find -name "*.seq" -mmin +50`
do
#sshpass -p red32hat scp *.seq root#rinacac-test:/root/perl
echo $files>>abcde.txt
done
exit;
#EOF
Now problem is that when I run it.. neither it writes to abcde.txt file nor it is exiting from the remote server. when I manually execute the exit command...it exists saying "perl no such file or directory"... while I have perl sub directory in my home directory..
other thing is when I run the for loop portion of the script on the 2nd server(by directly logging into it) it is working fine and writing to abcde.txt filr...please help...
ssh takes commands either on standard input or as the last parameter. You can therefore do this (very dynamic but tricky to get the expansions right):
ssh user#host <<EOF
some
custom
commands
EOF
or this (less dynamic but can take simple parameters without escaping):
scp my_script.sh user#host:
ssh user#host './my_script.sh'
Related
I'm trying to run this command over multiple machines
sshpass -p 'nico' ssh -o 'StrictHostKeyChecking=no' nico#x.x.x.x "mkdir test"
The IPs are stored in the following .txt file
$ cat ips.txt
10.0.2.15
10.0.2.5
I created a bash script that reads this file line by line. If I run it with an echo:
#!/bin/bash
input="ips.txt"
while IFS= read -r line
do
echo "$line"
#sshpass -p 'nico' ssh -o 'StrictHostKeyChecking=no' nico#$line "mkdir test"
done < "$input"
It prints every line:
$ ./variables.sh
10.0.2.15
10.0.2.5
This makes me understand that the script is working as intended. However, when I replace the echo line with the command I want to run for each line:
#!/bin/bash
input="ips.txt"
while IFS= read -r line
do
#echo "$line"
sshpass -p 'nico' ssh -o 'StrictHostKeyChecking=no' nico#$line "mkdir test"
done < "$input"
It only performs the action for the first IP on the file, then stops. Why?
Managed to solve this by using a for instead of a while. Script ended up looking like this:
for file in $(cat ips.txt)
do
sshpass -p 'nico' ssh -o 'StrictHostKeyChecking=no' nico#$file "mkdir test"
done
While your example is a solution that works, it's not the explanation.
Your could find the explanation here : ssh breaks out of while-loop in bash
In two words :
"while" loop continue reading from the same file-descriptor that defined in the loop header ( $input in your case )
ssh (or sshpass) read data from stdin (but in your case from file descriptor $input). And here is the point that hide the things as we didn't exect "ssh" to read the data.
Just to understand the problem you could have same strange experience for example using commands like "ffmpeg" or "mplayer" in while loop. Mplayer and ffmpeg use the keyboards while they are running, so they will consume all the the file-descriptor.
Another good and funny example :
#!/bin/bash
{
echo first
for ((i=0; i < 16384; i++)); do echo "testing"; done
echo "second"
} > test_file
while IFS= read -r line
do
echo "Read $line"
cat | uptime > /dev/null
done < test_file
At first part we write 1st line : first
16384 lines : testing
then last line : second
16384 lines "testing" are equal to 128Kb buffer
At the second part, the command "cat | uptime" will consume exactly 128Kb buffer, so our script will give
Read first
Read second
As solution, as you did, we could use "for" loop.
Or use "ssh -n"
Or playing with some file descriptor - you could find the example in the link that I gave.
I want to change the name of a file if it is already present on a remote server via SSH.
I tried this from here (SuperUser)
bash
ssh user#localhost -p 2222 'test -f /absolute/path/to/file' && echo 'YES' || echo 'NO'
This works well with a prompt, echoes YES when the file exists and NO when it doesn't. But I want this to be launched from a crontab, then it must be in a script.
Let's assume the file is called data.csv, a condition is set in a loop such as if there already is a data.csv file on the server, the file will be renamed data_1.csv and then data_2.csv, ... until the name is unique.
The renaming part works, but the detection part doesn't :
while [[ $fileIsPresent!='false' ]]
do
((appended+=1))
newFileName=${fileName}_${appended}.csv
remoteFilePathname=${remoteFolder}${newFileName}
ssh pi#localhost -p 2222 'test -f $remoteFilePathname' && fileIsPresent='true' || fileIsPresent='false'
done
always returns fileIsPresent='true' for any data_X.csv. All the paths are absolute.
Do you have any idea to help me?
This works:
$ cat replace.sh
#!/usr/bin/env bash
if [[ "$1" == "" ]]
then
echo "No filename passed."
exit
fi
if [[ ! -e "$1" ]]
then
echo "no such file"
exit
fi
base=${1%%.*} # get basename
ext=${1#*.} # get extension
for i in $(seq 1 100)
do
new="${base}_${i}.${ext}"
if [[ -e "$new" ]]
then
continue
fi
mv $1 $new
exit
done
$ ./replace.sh sample.csv
no such file
$ touch sample.csv
$ ./replace.sh sample.csv
$ ls
replace.sh
sample_1.csv
$ touch sample.csv
$ ./replace.sh sample.csv
$ ls
replace.sh
sample_1.csv
sample_2.csv
However, personally I'd prefer to use a timestamp instead of a number. Note that this sample will run out of names after 100. Timestamps won't. Something like $(date +%Y%m%d_%H%M%S).
As you asked for ideas to help you, I thought it worth mentioning that you probably don't want to start up to 100 ssh processes each one logging into the remote machine, so you might do better with a construct like this that only establishes a single ssh session that runs till complete:
ssh USER#REMOTE <<'EOF'
for ((i=0;i<10;i++)) ; do
echo $i
done
EOF
Alternatively, you can create and test a bash script locally and then run it remotely like this:
ssh USER#REMOTE 'bash -s' < LocallyTestedScript.bash
In a script.sh,
source a.sh
source b.sh
CMD1
CMD2
CMD3
how can I replace the source *.sh with their content (without executing the commands)?
I would like to see what the bash interpreter executes after sourcing the files and expanding all variables.
I know I can use set -n -v or run bash -n -v script.sh 2>output.sh, but that would not replace the source commands (and even less if a.sh or b.sh contain variables).
I thought of using a subshell, but that still doesn't expand the source lines. I tried a combination of set +n +v and set -n -v before and after the source lines, but that still does not work.
I'm going to send that output to a remote machine using ssh.
I could use <<output.sh to pipe the content into the ssh command, but I can't log as root onto the remote machine, but I am however a sudoer.
Therefore, I thought I could create the script and send it as a base64-encoded string (using that clever trick )
base64 script | ssh remotehost 'base64 -d | sudo bash'
Is there a solution?
Or do you have a better idea?
You can do something like this:
inline.sh:
#!/usr/bin/env bash
while read line; do
if [[ "$line" =~ (\.|source)\s+.+ ]]; then
file="$(echo $line | cut -d' ' -f2)"
echo "$(cat $file)"
else
echo "$line"
fi
done < "$1"
Note this assumes the sourced files exist, and doesn't handle errors. You should also handle possible hashbangs. If the sourced files contain themselves source, you need to apply the script recursively, e.g. something like (not tested):
while egrep -q '^(source|\.)' main.sh; do
bash inline.sh main.sh > main.sh
done
Let's test it
main.sh:
source a.sh
. b.sh
echo cc
echo "$var_a $var_b"
a.sh:
echo aa
var_a="stack"
b.sh:
echo bb
var_b="overflow"
Result:
bash inline.sh main.sh
echo aa
var_a="stack"
echo bb
var_b="overflow"
echo cc
echo "$var_a $var_b"
bash inline.sh main.sh | bash
aa
bb
cc
stack overflow
BTW, if you just want to see what bash executes, you can run
bash -x [script]
or remotely
ssh user#host -t "bash -x [script]"
I need to read the variable from a remote file over SSH and compare it. But I get a variable in the wrong format. how to do it correctly?
#!/bin/bash
pass='dpassspass'
user='root#10.10.19.18'
IP="10.2.1.41"
path=/sys/variable/serv
#not work## No such file or directory# write=$(sshpass -p $ovhpass ssh -t $user echo "$IP" > $path)
sshpass -p $pass ssh -t $user << EOF
echo "$IP" > $path
EOF
my_var=$(sshpass -p $pass ssh -t $user "cd /sys_ovh; ./serv.bash")
echo mystart-"$my_var"-myend
read=$(sshpass -p $pass ssh -t $user cat $path)
echo start-"$read"-end
echo start-"$IP"-end
if [ "$read" == "$IP" ]; then
echo "run"
fi
output:
Connection to 10.10.19.18 closed.
-myendt-10.2.1.41
Connection to 10.10.19.18 closed.
-endt-10.2.1.41
start-10.2.1.41-end
Where I make a mistake? How to take data from the SSH?
The vars my_var and read are filled with a string ending with '\r', telling echo to go back to the first column. I think this is a problem with your local script. You can correct that with
tr -d "\r" < myfile > myfile2
Your fundamental problem comes from using unquoted here documents for the commands. You should properly understand in which order the shell interprets these contructs.
ssh remote cmd >file
executes cmd remotely, but first redirects the output from the ssh command to the local file.
ssh remote "cmd >’$file'"
The quotes cause the redirection to be part of the remote command line. The variable file is interpreted first, by the local shell, though.
ssh remote 'cmd >"$file"`
The single quotes prevent the local shell from modifying the command before sending it. Thus, he variable interpolation and the redirection are both handled by the remote shell, in this order.
So your commented-out "not work" command could easily be fixed with proper quoting. However, it will be much more elegant and efficient to use a single remote session, and execute all the commands in one go. Mixing the local variable IP with remote variables calls for some rather elaborate escaping, though. A major simplification would be to pass the value on standard input, so that the entire remote script can be single quoted.
#!/bin/bash
pass='dpassspass'
user='root#10.10.19.18'
IP="10.2.1.41"
result=$(echo "$IP" |
sshpass -p "$pass" ssh -t "$user" '
path=/sys/variable/serv
cat > "$path"
cd /sys_ovh
./serv.bash
cat "$path"')
echo mystart-"${result%$'\n'*}"-myend
echo start-"${result#*$'\n'}"-end
echo start-"$IP"-end
if [ "${result#*$'\n'}" == "$IP" ]; then
echo "run"
fi
The output from the remote shell is two lines; we pick it apart by using the shell's prefix and suffix substitution operators.
okay heres part of my code when I ssh to my servers from my server.txt list.
while read server <&3; do #read server names into the while loop
serverName=$(uname -n)
if [[ ! $server =~ [^[:space:]] ]] ; then #empty line exception
continue
fi
echo server on list = "$server"
echo server signed on = "$serverName"
if [ $serverName == $server ] ; then #makes sure a server doesnt try to ssh to itself
continue
fi
echo "Connecting to - $server"
ssh "$server" #SSH login
echo Connected to "$serverName"
exec < filelist.txt
while read updatedfile oldfile; do
# echo updatedfile = $updatedfile #use for troubleshooting
# echo oldfile = $oldfile #use for troubleshooting
if [[ ! $updatedfile =~ [^[:space:]] ]] ; then #empty line exception
continue # empty line exception
fi
if [[ ! $oldfile =~ [^[:space:]] ]] ; then #empty line exception
continue # empty line exception
fi
echo Comparing $updatedfile with $oldfile
if diff "$updatedfile" "$oldfile" >/dev/null ; then
echo The files compared are the same. No changes were made.
else
echo The files compared are different.
cp -f -v $oldfile /infanass/dev/admin/backup/`uname -n`_${oldfile##*/}_$(date +%F-%T)
cp -f -v $updatedfile $oldfile
fi
done
done 3</infanass/dev/admin/servers.txt
I keep on getting this error and the ssh doesn't actually connect and perform the code on the server its suppose to be ssh'd on.
Pseudo-terminal will not be allocated because stdin is not a terminal
I feel like everything the guy above just said is so wrong.
Expect?
It's simple:
ssh -i ~/.ssh/bobskey bob#10.10.10.10 << EOF
echo I am creating a file called Apples in the /tmp folder
touch /tmp/apples
exit
EOF
Everything in between the 2 "EOF"s will be run in the remote server.
The tags need to be the same. If you decide to replace "EOF" with "WayneGretzky", you must change the 2nd EOF also.
You seem to assume that when you run ssh to connect to a server, the rest of the commands in the file are passed to the remote shell running in ssh. They are not; instead they will be processed by the local shell once ssh terminates and returns control to it.
To run remote commands through ssh there are a couple of things you can do:
Write the commands you want to execute to a file. Copy the file to the remote server using scp, and execute it with ssh user#remote command
Learn a bit of TCL and use expect
Write the commands in a heredoc, but be careful with variable substitution: substitution happens in the client, not on the server. For example this will output your local home directory, not the remote:
ssh remote <<EOF
echo $HOME
EOF
To make it print the remote home directory you have to use echo \$HOME.
Also, remember that data files such as filelist.txt have to be explicitly copied if you want to read them on the remote side.