regexp (Match atleast 1 lower case , 1 uppercase , 1 number & 1 special character

[DEXTER]

Hi
How do i check for the existence of atleast 1 lowercase character, 1
uppercase character, 1 number and 1 special character.

The below code does not match the given word

pword = "upperlower01"
var validId = regexp.MustCompile(`^[a-zA-Z0-9]*$`)
if validId.MatchString(srch) {
fmt.Println("This is a valid word")
}

Dexter

[chris dollin]

That RE matches when there's zero or more of (any lowercase
letter, any uppercase letter, and any digit), completely filling the
string you supply. It's rather a long way from what you want.
REs don't do ANY well.

My intial suggestion would be to use four calls to strings.ContainsAny
and AND the results together.

Chris

--
Chris "allusive" Dollin

[chris dollin]

On 16 May 2012 11:12, chris dollin <ehog....@googlemail.com> wrote:

I said:

> REs don't do ANY well.

(a) ANY should have been AND.

(b) AND over the whole string, rather than AND in sequences.

Chris

--
Chris "typoed to fast" Dollin

[roger peppe]

On 16 May 2012 11:12, chris dollin <ehog....@googlemail.com> wrote:

i'd forgotten about the functions in strings, doh!
the passwordOK function can be simpler.

func passwordOK(p string) bool {
for _, testRune := range mustHave {
if strings.IndexFunc(p, testRune) == -1 {
return false
}
}
return true
}

[Kyle Lemons]

I wouldn't use regex for this.  A very naive (but still unicode-aware) option is:

http://play.golang.org/p/ASpzrX0nta

package main




import (


        "fmt"
        "unicode"

)



func validPassword(s string) error {

next:

        for name, classes := range map[string][]*unicode.RangeTable{

                "upper case": {unicode.Upper, unicode.Title},

                "lower case": {unicode.Lower},

                "numeric":    {unicode.Number, unicode.Digit},

                "special":    {unicode.Space, unicode.Symbol, unicode.Punct, unicode.Mark},

        } {

                for _, r := range s {

                        if unicode.IsOneOf(classes, r) {

                                continue next

                        }


                }
                return fmt.Errorf("password must have at least one %s character", name)

        }


        return nil


}



func main() {

        for _, s := range []string{

                "bad",

                "testPassword",

                "testPa##word",

                "b3tterPa$$w0rd",

        } {

                fmt.Printf("validPassword(%q) = %v\n", s, validPassword(s))

        }


}

(also here)

[roger peppe]

oops, it seems i didn't Reply-All with my original reply.
this is what i wrote (superseded by later message
using strings.Index).

On 16 May 2012 10:41, DEXTER <djc...@gmail.com> wrote:

it seems to match to me:
http://play.golang.org/p/gtPbui2CDw

but to answer your question, i don't think it's easy to use a single
regexp for this
problem. i'd probably define/use a single function for each character
class and then loop, checking that the string has an instance of each class:

package main

import (
       "fmt"
       "unicode"
)

func main() {
       for _, p := range []string{"", "Hello1", "overTheHills&FarAway999"} {
               fmt.Printf("%q: %v\n", p, passwordOK(p))
       }
}

var mustHave = []func(rune) bool{
       unicode.IsUpper,
       unicode.IsLower,
       unicode.IsPunct,
       unicode.IsDigit,

}

func passwordOK(p string) bool {
       for _, testRune := range mustHave {

               found := false
               for _, r := range p {
                       if testRune(r) {
                               found = true
                       }
               }
               if !found {
                       return false
               }
       }
       return true
}