file manipulation : shell script find and increment

Question

 #something here
 port 4444

 #something here

 port 4444

So I have file like above , I would to find the line with word "port" and increment the number(the number can be any number - not necessary it's fixed at 4444) next to it by 1.

For example,result file should be of the form

 #something here
 port 4444

 #something here

 port 4445

Any thoughts, I think we need use sed , but not sure about incrementing it.

EDIT: Sorry again,I thought I get answer based in sed , so didn't think about positions. Here is the exact file contents

$cat file
data dev-1
type client
option type tcp
option host 99.160.131.163
option nodelay on
option port 6996
end

data dev-2
type client
option type tcp
option host 99.160.131.164
option nodelay on
option port 6996
end

I would like to change the port number and increment it.Sorry again for inconvenience.

Answer 1

port=444
((port+=1))
echo $port

the reference The Double-Parentheses Construct

Answer 2

I would use awk:

awk '
    BEGIN{p=-1}
    { if($2=="port"){if(p==-1){p=$3}else{p++};print $1,$2,p} else {print} }' file

Answer 3

$ awk 'f && $2=="port"{ $NF=num} $2=="port"{ num=$NF+1; f=1 } 1 ' file
data dev-1
type client
option type tcp
option host 99.160.131.163
option nodelay on
option port 6996
end

data dev-2
type client
option type tcp
option host 99.160.131.164
option nodelay on
option port 6997
end

Answer 4

Perl script will be:

$ perl -pe 'if (/^(port )(\d+)/) { $_ = "$1" . ($2+$count) . "\n" if $count; $count++; }' < aaa.txt
#something here
port 4444

#something here


port 4445
port 4446

input data:

$ cat aaa.txt
#something here
port 4444

#something here


port 4444
port 4444