how to find a file exists in particular dir through SSH
for example :
host1 and dir /home/tree/TEST
Host2:- ssh host1 - find the TEST file exists or not using bash
ssh will return the exit code of the command you ask it to execute:
if ssh host1 stat /home/tree/TEST \> /dev/null 2\>\&1
then
echo File exists
else
echo Not found
fi
You'll need to have key authentication setup of course, so you avoid the password prompt.
This is what I ended up doing after reading and trying out the stuff here:
FileExists=`ssh host "test -e /home/tree/TEST && echo 1 || echo 0"`
if [ ${FileExists} = 0 ]
#do something because the file doesn't exist
fi
More info about test: http://linux.die.net/man/1/test
An extension to Erik's accepted answer.
Here is my bash script for waiting on an external process to upload a file. This will block current script execution indefinitely until the file exists.
Requires key-based SSH access although this could be easily modified to a curl version for checks over HTTP.
This is useful for uploads via external systems that use temporary file names:
rsync
transmission (torrent)
Script below:
#!/bin/bash
set -vx
#AUTH="user#server"
AUTH="${1}"
#FILE="/tmp/test.txt"
FILE="${2}"
while (sleep 60); do
if ssh ${AUTH} stat "${FILE}" > /dev/null 2>&1; then
echo "File found";
exit 0;
fi;
done;
No need for echo. Can't get much simpler than this :)
ssh host "test -e /path/to/file"
if [ $? -eq 0 ]; then
# your file exists
fi
Related
I want to check via sftp only (not ssh) if a directory exists before creating it.
The only solutions I have found so far are using ssh but I need to use sftp only due to permission-ing issues - does anyone know a way?
sftp_put () {
sftp -oidentityfile=/home/user/.ssh/host_usersftp usersftp#$1 <<EOF
-- Add a check here e.g -- IF exist $2 ( echo $2 exists ) ELSE ( echo create $2 )
mkdir $2
cd $2
put $3
EOF
}
echo "chdir my_test_dir" | sftp -b - -oidentityfile=/home/user/.ssh/host_usersftp usersftp#$1
if [ $? -eq 0 ]
then
echo "my_test_dir exists"
else
echo "create my_test_dir"
fi
sftp without -b will simply display a nonfatal warning message if you try to create a directory which already exists. (With -b you need -mkdir with a dash in front to make the script not abort if the command fails. For noninteractive use, -b is probably a good idea.)
I am trying to bash script a daily file transfer between 2 machines. The script runs on the destination machine and pulls a file from the source machine. Occasionally the source machine will not have a file ready, this is acceptable.
I would like the script to exit 0 on successful transfer, and when there is no file available to be transferred. I would like the script to exit non 0 on any other failure condition (connectivity, etc).
I tried the following 2 approaches, I found with SCP the return code is always 1 no matter what the actual error, so its hard for the script to differentiate between my acceptable error condition, and others.
The sftp method seems to always return 0 no matter what takes place during the command. Any suggestions?
scpGet(){
echo "Attempting File Transfer"
scp -P $REMOTEPORT $REMOTEHOST:$REMOTEPATH $LOCALPATH
echo $?
}
sftpGet(){
cd $LOCALPATH
sftp -P $REMOTEPORT $REMOTEHOST << EOF
get $REMOTEPATH
quit
EOF
echo $?
}
I haven't validated this, so please check that it actually does what you want -
but you are apparently running scp with no password, so you can probably execute arbitrary code remotely to test for the existence of the file. Just be careful.
scpGet() {
echo "Attempting File Transfer"
if scp -P $REMOTEPORT $REMOTEHOST:$REMOTEPATH $LOCALPATH
then echo "$( ls -l $LOCALPATH) - successfully retrieved"
elif ssh -P $REMOTEPORT ls -l $REMOTEHOST:$REMOTEPATH
then echo "$REMOTEHOST:$REMOTEPATH exists, but I can't retrieve it!" >&2
exit $oopsieCode
elif (( 2 == $rc )) # ls failed to find the file - verify this code
then echo "File not ready. Ignoring."
else : handle errors other than "not found"
fi
}
I made a script (below) that goes into a remote computer and runs C code on it. This script works perfectly but asks for the password multiple times. How can I make it only ask for the password once?
#!/bin/bash
USER=myusername
COMP=remote_computer_name
OUTPUT=$1
ARGS=${#:2}
CODE_DIR="Dir_$$"
SCRIPT_NAME=$(basename $0)
LAST_CREATED_DIR=$(ls -td -- */ | head -n 1)
#Check if we are on local computer. If so, we copy the
#current directory to the remote run this script on the remote
if [ "${HOSTNAME}" != "${COMP}" ]; then
if [ "$#" -lt 1 ]; then
echo "Incorrect usage."
echo "Usage: ./${SCRIPT_NAME} <compiled_c_output_name> <arg1> <arg2> ... <argN>"
exit
fi
# Check if there is no makefile in the current directory
if [ ! -e [Mm]akefile ]; then
echo "There is no makefile in this directory"
exit
fi
echo "On local. Copying current directory to remote..."
scp -r ./ ${USER}#${COMP}:/ilab/users/${USER}/${CODE_DIR}
ssh ${USER}#${COMP} "bash -s" < ./${SCRIPT_NAME} ${OUTPUT} ${ARGS}
else
echo "On remote. Compiling code..."
cd $LAST_CREATED_DIR
make clean
make all
if [ -e $OUTPUT ]; then
echo "EXECUTING \"./${OUTPUT} ${ARGS}\" ON REMOTE ($COMP)"
./${OUTPUT} ${ARGS}
fi
fi
You can use SSH-Key authentication technique for password less login -
Here are the steps :
Generate RSA key -
ssh-keygen -t rsa
This generates two files under /home/<user>/.ssh/ id_rsa
(Private) and id_rsa.pub (Public)
The second file is your public key. You have to copy the contents of
this file over to the remote computer you want to log into and append
it to /home/<user>/.ssh/authorized_keys or use ssh-copy-id
utility if available (ssh-copy-id username#remote_host)
After this, the authentication is done by the public-private key pair
and you may not require a password henceforth.
You can use sshpass. Here is an example:
sshpass -pfoobar ssh -o StrictHostKeyChecking=no user#host command_to_run
More info, here:
https://askubuntu.com/questions/282319/how-to-use-sshpass
I'm new to scripting and would like to understand how to print out the variables based on boolean logic.
#!/bin/bash
# set variables
WEBAPPS_YES="Successfully synced webapps folder"
WEBAPPS_NO="Could not sync webapps folder"
RSYNC_YES="Successfully synced rsync log file"
RSYNC_NO="Could not sync rsync log file"
# Command to rsync 'webapps' folder and write to a log file
rsync -azvh ~/webapps -e ssh user#something.com:/home/directories >> /path/to/rsync.log 2>&1
# Command to rsync 'rsync.log' to a log file on backup server 'Larry'
rsync -azvh --delete ~/rsync.log -e ssh user#something.com:/path/to/logs
if [ $? -eq 0 ]
then
echo
exit 0
else
echo >&2
exit 1
fi
I would like the whole if, then, else part to print out in the echo if both parts succeeded or not. I know I need some kind of logic statements but cannot figure it out.
You can check the result after running each rsync command, and display the result afterwards. I think that would work:
# Command to rsync 'webapps' folder and write to a log file
rsync -azvh ~/webapps -e ssh user#something.com:/home/directories >> /path/to/rsync.log 2>&1
RESULT1="$?"
# Command to rsync 'rsync.log' to a log file on backup server 'Larry'
rsync -azvh --delete ~/rsync.log -e ssh user#something.com:/path/to/logs
RESULT2="$?"
if [ "$RESULT1" != "0" ]; then
echo "$WEBAPPS_NO"
else
echo "$WEBAPPS_YES"
fi
if [ "$RESULT2" != "0" ]; then
echo "$RSYNC_NO"
else
echo "$RSYNC_YES"
fi
I'm writing a bash script to send files from a linux server to a remote Windows FTP server.
I would like to check using FTP if the folder where the file will be stored exists before attempting to create it.
Please note that I cannot use SSH nor SCP and I cannot install new scripts on the linux server. Also, for performance issues, I would prefer if checking and creating the folders is done using only one FTP connection.
Here's the function to send the file:
sendFile() {
ftp -n $FTP_HOST <<! >> ${LOCAL_LOG}
quote USER ${FTP_USER}
quote PASS ${FTP_PASS}
binary
$(ftp_mkdir_loop "$FTP_PATH")
put ${FILE_PATH} ${FTP_PATH}/${FILENAME}
bye
!
}
And here's what ftp_mkdir_loop looks like:
ftp_mkdir_loop() {
local r
local a
r="$#"
while [[ "$r" != "$a" ]]; do
a=${r%%/*}
echo "mkdir $a"
echo "cd $a"
r=${r#*/}
done
}
The ftp_mkdir_loop function helps in creating all the folders in $FTP_PATH (Since I cannot do mkdir -p $FTP_PATH through FTP).
Overall my script works but is not "clean"; this is what I'm getting in my log file after the execution of the script (yes, $FTP_PATH is composed of 5 existing directories):
(directory-name) Cannot create a file when that file already exists.
Cannot create a file when that file already exists.
Cannot create a file when that file already exists.
Cannot create a file when that file already exists.
Cannot create a file when that file already exists.
To solve this, do as follows:
To ensure that you only use one FTP connection, you create the input (FTP commands) as an output of a shell script
E.g.
$ cat a.sh
cd /home/test1
mkdir /home/test1/test2
$ ./a.sh | ftp $Your_login_and_server > /your/log 2>&1
To allow the FTP to test if a directory exists, you use the fact that "DIR" command has an option to write to file
# ...continuing a.sh
# In a loop, $CURRENT_DIR is the next subdirectory to check-or-create
echo "DIR $CURRENT_DIR $local_output_file"
sleep 5 # to leave time for the file to be created
if (! -s $local_output_file)
then
echo "mkdir $CURRENT_DIR"
endif
Please note that "-s" test is not necessarily correct - I don't have acccess to ftp now and don't know what the exact output of running DIR on non-existing directory will be - cold be empty file, could be a specific error. If error, you can grep the error text in $local_output_file
Now, wrap the step #2 into a loop over your individual subdirectories in a.sh
#!/bin/bash
FTP_HOST=prep.ai.mit.edu
FTP_USER=anonymous
FTP_PASS=foobar#example.com
DIRECTORY=/foo # /foo does not exist, /pub exists
LOCAL_LOG=/tmp/foo.log
ERROR="Failed to change directory"
ftp -n $FTP_HOST << EOF | tee -a ${LOCAL_LOG} | grep -q "${ERROR}"
quote USER ${FTP_USER}
quote pass ${FTP_PASS}
cd ${DIRECTORY}
EOF
if [[ "${PIPESTATUS[2]}" -eq 1 ]]; then
echo ${DIRECTORY} exists
else
echo ${DIRECTORY} does not exist
fi
Output:
/foo does not exist
If you want to suppress only the messages in ${LOCAL_LOG}:
ftp -n $FTP_HOST <<! | grep -v "Cannot create a file" >> ${LOCAL_LOG}