如何从 $SSH_CLIENT 获取 IP 地址

Question

$SSH_CLIENT has IP address with some port info, and echo $SSH_CLIENT gives me '10.0.40.177 52335 22', and Running

if [ -n "$SSH_CONNECTION" ] ; then for i in $SSH_CLIENT do echo $i done fi

gives me

• 10.0.40.177
• 52335
• 22

And I see the first element is the IP address.

Q : How can I get the first element of $SSH_CLIENT? ${SSH_CLIENT[0]} doesn't work.

Answer 1

sshvars=($SSH_CLIENT)
echo "${sshvars[0]}"

or:

echo "${SSH_CLIENT%% *}"

Answer 2

you can use set -- eg

$ SSH_CLIENT="10.0.40.177 52335 22"
$ set -- $SSH_CLIENT
$ echo $1  # first "element"
10.0.40.177
$ echo $2  # second "element"
52335
$ echo $3
22

Answer 3

For strings, as is the case here, the <<< operator may be used:

$ read ipaddress outport inport <<< $SSH_CLIENT

See eg: Linux Bash: Multiple variable assignment . Don't do this with binary input though: Is there a binary safe <<< in bash?

Answer 4

I use this in my .bash_profile, and it works beautifully.

if [ -n "$SSH_CONNECTION" ] ;
    then
    echo $SSH_CLIENT | awk '{print $1}'
fi

Answer 5

You can get it programmatic way via ssh library ( https://code.google.com/p/sshxcute )

public static String getIpAddress() throws TaskExecFailException{
    ConnBean cb = new ConnBean(host, username, password);
    SSHExec ssh = SSHExec.getInstance(cb);
    ssh.connect();
    CustomTask sampleTask = new ExecCommand("echo \"${SSH_CLIENT%% *}\"");
    String Result = ssh.exec(sampleTask).sysout;
    ssh.disconnect();   
    return Result;
}

Answer 6

If you prefer awk :

$ SSH_CLIENT="10.0.40.177 52335 22"
$ echo $SSH_CLIENT|awk '{print $1}' # first element
10.0.40.177
$ echo $SSH_CLIENT|awk '{print $2}' # second element
52335
$ echo $SSH_CLIENT|awk '{print $3}' # third element
22