secureinfo42 / ipgrep

Match IP using grep via PCRE regex

ipgrep

Match IP using grep via PCRE regex

What ?

The regex exclude network adress, IPv4 class D and E (for casting).

Explanation

| = "or"

\. = dot .

\b = border, every char that is a separator : space, return, end of line, tab, ...

( and ) are used to capture result so add a condition

For the 1st byte :

(
 2[0-2][0-3]  = 200 upto 223
|1[0-9][0-9]  = 100 upto 199
 |[1-9][0-9]  =  10 upto 99
      |[0-9]  =   0 upto 9
)

For the 2nd and 3rd bytes :

(
  2[0-5][0-5] = 200 upto 255
 |1[0-9][0-9] = 100 upto 199
 |[1-9]?[0-9] =   0 upto 199
)

For the 4th byte :

(
  2[0-5][0-4] = 200 upto 254
 |1[0-9][0-9] = 100 upto 199
  |[1-9][0-9] =  10 upto 99
       |[1-9] =   1 upto 9
)