user group file language

group/group.peg

@@ -0,0 +1,27 @@
+# Adapted from "Linux Programmer's Manual" group(5)
+# group - user group file
+package group
+
+type Grammar Peg {}
+
+group <- (entry '\n')* !.
+
+# There is one entry per line, with the following format:
+# group_name:password:GID:user_list
+entry <- group_name ':' password ':' GID ':' user_list
+
+# group_name  the name of the group.
+group_name <- (![:\n].)+
+
+# password    the (encrypted) group password.  If this field is empty, no password is needed.
+password <- _shadow &':' / _null / _encrypted_password
+_encrypted_password <- (![:\n].)+
+_null <- &':'
+_shadow <- 'x'
+
+# GID         the numeric group ID.
+GID <- [0-9]+
+
+# user_list   a list of the usernames that are members of this group, separated by commas.
+user_list <- (_user (',' _user)*)?
+_user <- [a-z0-9._\-]+

main.go

@@ -1,5 +1,6 @@
 //go:generate peg -strict crontab/crontab.peg
 //go:generate peg -strict golang/golang.peg
+//go:generate peg -strict group/group.peg
 //go:generate peg -strict offside/offside.peg
 //go:generate peg -strict passwd/passwd.peg
 //go:generate peg -strict peg/peg.peg
@@ -19,6 +20,7 @@ import (
 
 	"github.com/heyitsanthony/grammars/crontab"
 	"github.com/heyitsanthony/grammars/golang"
+	"github.com/heyitsanthony/grammars/group"
 	"github.com/heyitsanthony/grammars/offside"
 	"github.com/heyitsanthony/grammars/passwd"
 	"github.com/heyitsanthony/grammars/peg"
@@ -42,6 +44,7 @@ type g interface {
 
 func newCrontab(s string) g { return &crontab.Grammar{Buffer: s, Pretty: true} }
 func newGo(s string) g      { return &golang.Grammar{Buffer: s, Pretty: true} }
+func newGroup(s string) g   { return &group.Grammar{Buffer: s, Pretty: true} }
 func newOffside(s string) g { return &offside.Grammar{Buffer: s, Pretty: true} }
 func newPasswd(s string) g  { return &passwd.Grammar{Buffer: s, Pretty: true} }
 func newPeg(s string) g     { return &peg.Grammar{Buffer: s, Pretty: true} }
@@ -54,6 +57,7 @@ func newShadow(s string) g  { return &shadow.Grammar{Buffer: s, Pretty: true} }
 var grammars = map[string](func(string) g){
 	"crontab": newCrontab,
 	"go":      newGo,
+	"group":   newGroup,
 	"offside": newOffside,
 	"passwd":  newPasswd,
 	"peg":     newPeg,