get parts of string using shell script

Another pure bash way using arrays:

$ s="/ip/192.168.0.1/port/8080/"        # initial string
$ a=(${s//// })                         # substitute / with " " and make array
$ echo ${a[1]}                          # Array index 1 (zero-based indexing)
192.168.0.1
$ echo ${a[3]}                          # Array index 3 (zero-based indexing)
8080
$ 

Or similar to the above, but using IFS instead of parameter expansion to split the string:

$ OLDIFS="$IFS"                         # save IFS
$ IFS="/"                               # temporarily set IFS 
$ a=($s)                                # make array from string, splitting on "/"
$ IFS="$OLDIFS"                         # restore IFS
$ echo "${a[2]}"                        # Array index 2
192.168.0.1
$ echo "${a[4]}"                        # Array index 4
8080
$ 

Note this method is potentially more general than the other two in this answer in that it should still work if the fields of interest contain whitespace.

Or using positional parameters:

$ s="/ip/192.168.0.1/port/8080/"        # initial string
$ set -- ${s//// }                      # substitute / with " " and assign params
$ echo $2                               # Param 2
192.168.0.1
$ echo $4                               # Param 4
8080
$ 

You can simply use cut as follows:

cut -d '/' -f 3,5

Example:

$ echo '/ip/192.168.0.1/port/8080/' | cut -d '/' -f 3,5
192.168.0.1/8080

This will cut with delimiter / and prints 3rd and 5th fields.

Or following may you want:

$ echo ip=`cut -d '/' -f 3 input_file` port=`cut -d '/' -f 5 input_file`
ip=192.168.0.1 port=8080

With bash

s=/ip/192.168.0.1/port/8080/
IFS=/ read -r _ _ ip _ port <<<"$s"
echo "$ip"
192.168.0.1
echo "$port"
8080

expr /ip/192.168.0.1/port/8080/ : '.*/port/\(.*\)/'

.* matches the initial part of the string before /port

This is another way

$ cut -d '/' -f 3,5 <<< "/ip/192.168.0.1/port/8080/"|tr -s '/' ' '
192.168.0.1 8080

perl solutions:

echo /ip/192.168.0.1/port/8080/ | perl -F'/' -nae 'print "ip: ".$F[2]." port: ".$F[4]."\n"'

OUTPUT:

ip: 192.168.0.1 port: 8080