MIME Type in GO
Validate MIME media type strings like text/html, application/json, or image/png; charset=utf-8.
Try it in the GO tester →Pattern
regexGO
^([a-z]+)\/([a-z0-9][a-z0-9!#$&\-^_.]*)(?:;\s*[a-z]+=\S+)*$ (flags: i)Go (RE2) code
goGo
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`(?i)^([a-z]+)\/([a-z0-9][a-z0-9!#$&\-^_.]*)(?:;\s*[a-z]+=\S+)*$`)
input := `application/json`
for _, match := range re.FindAllString(input, -1) {
fmt.Println(match)
}
}Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.
How the pattern works
Group 1 captures the primary type (text, image, application, etc). Group 2 captures the subtype using the allowed MIME subtype character set. The optional trailing group (?:;\s*[a-z]+=\S+)* matches parameters like charset=utf-8 or boundary=something.
Examples
Input
application/jsonMatches
application/json
Input
text/html; charset=utf-8Matches
text/html; charset=utf-8
Input
not a mime typeNo match
—