Add one file's contents in other file on Remote host using command line

Add one file's text in another file on remote host :

If you have a file A and you want to add this whole file's text in file B but the problem is file B is on remote host.

You may be think to download the file B, update it and upload it again.

But you can do this using command line in a single command.

Suppose file A which is on your system is in  /root directory and file B which is on Remote host is in /root/Documents.

Now run following commands to add file A's text in file B.

# cat /root/fileA.txt | ssh 192.168.xx.xx "cat >> /root/Documents/fileB.txt"

or

# ssh 192.168.xx.xx "cat >> /root/Documents/fileB.txt" </root/fileA.txt

or

# scp /root/fileA.txt 192.168.xx.xx: /root/fileA.txt && ssh 192.168.xx.xx "cat /root/fileA.txt >>  /root/Documents/fileB.txt"

where:
192.168.xx.xx is IP of Remote Host

The commands do not remove the text of fileB instead they add the text at bottom of the fileB.