Compile for non OpenBSD systems

Previously the compilation would fail for non OpenBSD systems & the
user had to manage it themselves. Now it compiles on non OpenBSD
systems but returns nil immediately because unveil isn't supported on
those systems.

block.go

@@ -1,3 +1,5 @@
+// +build openbsd
+
 package lynx
 
 import "golang.org/x/sys/unix"

block_other.go

@@ -0,0 +1,9 @@
+// +build !openbsd
+
+package lynx
+
+// UnveilBlock is just a wrapper around unix.UnveilBlock, it does
+// nothing on non OpenBSD systems.
+func UnveilBlock() error {
+	return nil
+}

commands.go

@@ -1,3 +1,5 @@
+// +build openbsd
+
 package lynx
 
 import (

commands_other.go

@@ -0,0 +1,9 @@
+// +build !openbsd
+
+package lynx
+
+// UnveilCommands takes a slice of commands & unveils them one by one,
+// it does nothing on non OpenBSD systems.
+func UnveilCommands(_ []string) error {
+	return nil
+}

path.go

@@ -1,3 +1,5 @@
+// +build openbsd
+
 package lynx
 
 import "golang.org/x/sys/unix"

path_other.go

@@ -0,0 +1,15 @@
+// +build !openbsd
+
+package lynx
+
+// UnveilPath takes a path, permission & unveils it, it does nothing
+// on non OpenBSD systems.
+func UnveilPath(_ string, _ string) error {
+	return nil
+}
+
+// UnveilPathStrict is just a wrapper around unix.Unveil. It does
+// nothing on non OpenBSD systems.
+func UnveilPathStrict(_ string, _ string) error {
+	return nil
+}

paths.go

@@ -1,3 +1,5 @@
+// +build openbsd
+
 // Package lynx is a simple wrapper to unveil.
 package lynx
 

paths_other.go

@@ -0,0 +1,15 @@
+// +build !openbsd
+
+package lynx
+
+// UnveilPaths takes a map of path, permission & unveils them one by
+// one, it does nothing on non OpenBSD systems.
+func UnveilPaths(_ map[string]string) error {
+	return nil
+}
+
+// UnveilPathsStrict takes a map of path, permission & unveils them
+// one by one, it does nothing on non OpenBSD systems.
+func UnveilPathsStrict(_ map[string]string) error {
+	return nil
+}