Extract string from file and assign to variable using scripting in Bash -

Currently I need to remove a number from one line in a file, add 1 to that number and write to the previous number Using a bash in the same file, my line looks like this:

  & lt; Server port = "8080" ... & gt;  

And I call it & lt; Server port = "8081" ... & gt;

I know that - I can find the command "8080" and change it with something, I do not know how to actually get 8080 And it is converted to 8081. How can I do this?

Thanks in advance. /p>

If you need additional, then awk is a better tool than Sed .

Consider the file:

  $ cat file & lt; Server port = "8080" ... & gt;  

We can increase the port number like this:

  $ awk -F \ "'/ & lt; server / {$ 2 ++} 1 This file was designed to work with sample input provided by you.  
 Set how  
 
 
  -F \ " 
 
 field separator to "  With this as the field separator, the port number is its own field. 
 
 
 
  /  
 
 Only the word  server . 
 
 
 
  {$ 2 ++}  
 
 For those selected lines, multiply another field by one.  
 
 
  1  
 
 This is a secret rhythm of awk for "Print All Rows."