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.
Related
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 $i
done
EOF
Alternatively, you can create and test a bash script locally and then run it remotely like this:
ssh USER#REMOTE 'bash -s' < LocallyTestedScript.bash
Situation: we're feeding a list of filenames to an sshpass and it iterates correctly through a remote folder to check whether files with the given names actually exists, then build an updated list containing only the files that do exist, which is reused later in the bash script.
Problem: The list comprises sometimes tens of thousands of files, which means tens of thousands of ssh logins, which is harming performance and sometimes getting us blocked by our own security policies.
Intended solution: instead of starting the for-loop and calling sshpass each time, do it otherwise and pass the loop to an unique sshpass call.
I've got to pass the list to the sshpass instruction in the example test below:
#!/bin/bash
all_paths=(`/bin/cat /home/user/filenames_to_be_tested.list`)
existing_paths=()
sshpass -p PASSWORD ssh -n USER#HOST bash -c "'
for (( i=0; i<${#all_paths[#]}; i++ ))
do
echo ${all_paths[i]}
echo \"-->\"$i
if [[ -f ${all_paths[i]} ]]
then
echo ${all_paths[i]}
existing_paths=(${all_paths[i]})
fi
done
'
printf '%s\n' "${existing_paths[#]}"
The issue here is that it appears to loop (you see a series of echoed lines), but in the end it is not really iterating the i and is always checking/printing the same line.
Can someone help spot the bug? Thanks!
The problem is that bash first parses the string and substitutes the variables. That happens before it's sent to the server. If you want to stop bash from doing that, you should escape every variable that should be executed on the server.
#! /bin/bash
all_paths=(rootfs.tar derp a)
read -sp "pass? " PASS
echo
sshpass -p $PASS ssh -n $USER#$SERVER "
files=(${all_paths[#]})
existing_paths=()
for ((i=0; i<\${#files[#]}; i++)); do
echo -n \"\${files[#]} --> \$i\"
if [[ -f \${files[\$i]} ]]; then
echo \${files[\$i]}
existing_paths+=(\${files[\$i]})
else
echo 'Not found'
fi
done
printf '%s\n' \"\${existing_paths[#]}\"
This becomes hard to read very fast. However, there's an option I personally like to use. Create functions and export them to the server to be executed there to omit escaping a lot of stuff.
#! /bin/bash
all_paths=(rootfs.tar derp a)
function files_exist {
local files=($#)
local found=()
for file in ${files[#]}; do
echo -n "$file --> "
if [[ -f $file ]]; then
echo "exist"
found+=("$file")
else
echo "missing"
fi
done
printf '%s\n' "${found[#]}"
}
read -sp "pass? " PASS
echo
sshpass -p $PASS ssh -n $USER#$SERVER "
$(typeset -f files_exist)
files_exist ${all_paths[#]}
"
#!/bin/bash
ip route add 10.105.8.100 via 192.168.1.100
date
cat /home/xxx/Documents/list.txt | while read output
do
ping="ping -c 3 -w 3 -q 'output'"
if $ping | grep -E "min/avg/max/mdev" > /dev/null; then
echo 'connection is ok'
else
echo "router $output is down"
then
cat /home/xxx/Documents/roots.txt | while read outputs
do
cd /home/xxx/Documents/routers
php rebootRouter.php "outputs" admin admin
done
fi
done
The other documents are:
lists.txt
10.105.8.100
roots.txt
192.168.1.100
when i run the script, the result is a reboot of the router am trying to ping. It doesn't ping.
Is there a problem with the bash script.??
If your files only contain a single line, there's no need for the while-loop, just use read:
read -r router_addr < /home/xxx/Documents/list.txt
# the grep is unnecessary, the return-code of the ping will be non-zero if the host is down
if ping -c 3 -w 3 -q "$router_addr" &> /dev/null; then
echo "connection to $router_addr is ok"
else
echo "router $router_addr is down"
read -r outputs < /home/xxx/Documents/roots.txt
cd /home/xxx/Documents/routers
php rebootRouter.php "$outputs" admin admin
fi
If your files contain multiple lines, you should redirect the file from the right-side of the while-loop:
while read -r output; do
...
done < /foo/bar/baz
Also make sure your files contain a newline at the end, or use the following pattern in your while-loops:
while read -r output || [[ -n $output ]]; do
...
done < /foo/bar/baz
where || [[ -n $output ]] is true even if the file doesn't end in a newline.
Note that the way you're checking for your routers status is somewhat brittle as even a single missed ping will force it to reboot (for example the checking computer returns from a sleep-state just as the script is running, the ping fails as the network is still down but the admin script succeeds as the network just comes up at that time).
I need to read the variable from a remote file over SSH and compare it. But I get a variable in the wrong format. how to do it correctly?
#!/bin/bash
pass='dpassspass'
user='root#10.10.19.18'
IP="10.2.1.41"
path=/sys/variable/serv
#not work## No such file or directory# write=$(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.
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'