Matching serialized strings [duplicate] - regex

Question

This question already has answers here:
Regexp won't match
(2 answers)
Closed 4 years ago.
I am receiving this string "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80J\x13\x80SQ\x80L\xe0\x80#\x92\x80L?\x80H\xe0" from a function (which runs a GET command on a redis bitmap and gives me the serialized string)
But due to escape sequences I am having trouble matching this kind of pattern. Can some please tell me the regex sequence that will match this kind of string?

Answer 1

First, I'd try to find out how to get that same data from Redis in its direct, binary, form (as []byte); the rest would be way more simple then.
But to deal with this stuff in its present form,
I would first normalize the input string—replacing all those
backslash-escaped hex-encoded characters with their equivalent bytes.
This would allow easily searchig for the exact values of these
bytes—possibly using backslash-escaped hex-encoded characters
in the patterns:
package main
import (
"fmt"
"strconv"
"strings"
)
func main() {
s := "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80J\x13\x80SQ\x80L\xe0\x80#\x92\x80L?\x80H\xe0"
s, err := strconv.Unquote(`"` + s + `"`)
if err != nil {
panic(err)
}
fmt.Println(strings.Index(s, "\x80SQ\x80L"))
}
Playground link.

Answer 2

An introduction to Redis data types and abstractions
Bitmaps
Bitmaps are not an actual data type, but a set of bit-oriented
operations defined on the String type.
Regular expressions are not the best solution. Write a simple Go function to do the conversion. For example,
package main
import (
"fmt"
"strconv"
)
func redisBits(s string) (string, error) {
s, err := strconv.Unquote(`"` + s + `"`)
if err != nil {
return "", err
}
return s, nil
}
func main() {
s := "\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x80J\x13\x80SQ\x80L\xe0\x80#\x92\x80L?\x80H\xe0"
fmt.Printf("%x\n", s)
b, err := redisBits(s)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("%x\n", b)
}
Playground: https://play.golang.org/p/rbE9iG3tOTx
Output:
0100000000000000000000804a13805351804ce0804092804c3f8048e0
0100000000000000000000804a13805351804ce0804092804c3f8048e0