[ruby-dev:37999] [Feature:1.9] Etc.each_passwd, each_group

なかだです。

Etc.each_passwdやEtc.each_groupというものを思いつきました。
また、別名としてEtc::Passwd.eachやEtc.::Group.eachも。

  # パスワードを設定していないユーザ名のリスト
  Etc::Passwd.find_all {|u| u.passwd == ""}.map(&:name)

とか。


Index: ext/etc/etc.c
===================================================================
--- ext/etc/etc.c	(revision 22104)
+++ ext/etc/etc.c	(working copy)
@@ -187,4 +187,14 @@ passwd_iterate(void)
     return Qnil;
 }
+
+static void
+each_passwd(void)
+{
+    if (passwd_blocking) {
+	rb_raise(rb_eRuntimeError, "parallel passwd iteration");
+    }
+    passwd_blocking = Qtrue;
+    rb_ensure(passwd_iterate, 0, passwd_ensure, 0);
+}
 #endif
 
@@ -212,11 +222,7 @@ etc_passwd(VALUE obj)
     rb_secure(4);
     if (rb_block_given_p()) {
-	if (passwd_blocking) {
-	    rb_raise(rb_eRuntimeError, "parallel passwd iteration");
-	}
-	passwd_blocking = Qtrue;
-	rb_ensure(passwd_iterate, 0, passwd_ensure, 0);
+	each_passwd();
     }
-    if (pw = getpwent()) {
+    else if (pw = getpwent()) {
 	return setup_passwd(pw);
     }
@@ -225,4 +231,32 @@ etc_passwd(VALUE obj)
 }
 
+/* Iterates for each entry in the /etc/passwd file if a block is given.
+ * If no block is given, returns the enumerator.
+ *
+ * The code block is passed an Struct::Passwd struct; see getpwent above for 
+ * details.
+ *
+ * Example:
+ *
+ *     require 'etc'
+ *
+ *     Etc.each_passwd {|u|
+ *       puts u.name + " = " + u.gecos
+ *     }
+ *
+ *     Etc.each_passwd.collect {|u| u.gecos}
+ *     Etc::Passwd.collect {|u| u.gecos}
+ *
+ */
+static VALUE
+etc_each_passwd(VALUE obj)
+{
+#ifdef HAVE_GETPWENT
+    RETURN_ENUMERATOR(obj, 0, 0);
+    each_passwd();
+#endif
+    return obj;
+}
+
 /* Resets the process of reading the /etc/passwd file, so that the next call
  * to getpwent will return the first entry again.
@@ -391,4 +425,14 @@ group_iterate(void)
     return Qnil;
 }
+
+static void
+each_group(void)
+{
+    if (group_blocking) {
+	rb_raise(rb_eRuntimeError, "parallel group iteration");
+    }
+    group_blocking = Qtrue;
+    rb_ensure(group_iterate, 0, group_ensure, 0);
+}
 #endif
 
@@ -416,11 +460,7 @@ etc_group(VALUE obj)
     rb_secure(4);
     if (rb_block_given_p()) {
-	if (group_blocking) {
-	    rb_raise(rb_eRuntimeError, "parallel group iteration");
-	}
-	group_blocking = Qtrue;
-	rb_ensure(group_iterate, 0, group_ensure, 0);
+	each_group();
     }
-    if (grp = getgrent()) {
+    else if (grp = getgrent()) {
 	return setup_group(grp);
     }
@@ -429,4 +469,32 @@ etc_group(VALUE obj)
 }
 
+/* Iterates for each entry in the /etc/group file if a block is given.
+ * If no block is given, returns the enumerator.
+ *
+ * The code block is passed an Struct::Group struct; see getpwent above for 
+ * details.
+ *
+ * Example:
+ *
+ *     require 'etc'
+ *
+ *     Etc.each_group {|g|
+ *       puts g.name + ": " + g.mem.join(', ')
+ *     }
+ *
+ *     Etc.each_group.collect {|g| g.name}
+ *     Etc::Group.select {|g| !g.mem.empty?}
+ *
+ */
+static VALUE
+etc_each_group(VALUE obj)
+{
+#ifdef HAVE_GETPWENT
+    RETURN_ENUMERATOR(obj, 0, 0);
+    each_group();
+#endif
+    return obj;
+}
+
 /* Resets the process of reading the /etc/group file, so that the next call
  * to getgrent will return the first entry again.
@@ -505,8 +573,10 @@ Init_etc(void)
     rb_define_module_function(mEtc, "getpwent", etc_getpwent, 0);
     rb_define_module_function(mEtc, "passwd", etc_passwd, 0);
+    rb_define_module_function(mEtc, "each_passwd", etc_each_passwd, 0);
 
     rb_define_module_function(mEtc, "getgrgid", etc_getgrgid, -1);
     rb_define_module_function(mEtc, "getgrnam", etc_getgrnam, 1);
     rb_define_module_function(mEtc, "group", etc_group, 0);
+    rb_define_module_function(mEtc, "each_group", etc_each_group, 0);
     rb_define_module_function(mEtc, "setgrent", etc_setgrent, 0);
     rb_define_module_function(mEtc, "endgrent", etc_endgrent, 0);
@@ -539,4 +609,6 @@ Init_etc(void)
 				NULL);
     rb_define_const(mEtc, "Passwd", sPasswd);
+    rb_extend_object(sPasswd, rb_mEnumerable);
+    rb_define_singleton_method(sPasswd, "each", etc_each_passwd, 0);
 
 #ifdef HAVE_GETGRENT
@@ -548,4 +620,6 @@ Init_etc(void)
 
     rb_define_const(mEtc, "Group", sGroup);
+    rb_extend_object(sGroup, rb_mEnumerable);
+    rb_define_singleton_method(sGroup, "each", etc_each_group, 0);
 #endif
 }


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦