guestfish: Add tilde expansion for paths (RHBZ#511372).

This commit adds tilde expansion for local users in guestfish:

  ><fs> echo "~"
  ~
  ><fs> echo ~
  /home/rjones
  ><fs> echo ~foo
  ~foo
  ><fs> echo ~rjones/bar
  /home/rjones/bar
  ><fs> echo ~roo
  ~roo
  ><fs> echo ~root/foo
  /root/foo
  ><fs> echo ~root
  /root

1 files changed, 14 insertions, 0 deletions

diff --git a/guestfish.pod b/guestfish.pod
index 4f8cf95d..32a30901 100644
--- a/guestfish.pod
+++ b/guestfish.pod
@@ -328,6 +328,20 @@ to quote it, eg:
 
  echo "|"
 
+=head1 HOME DIRECTORIES
+
+If a parameter starts with the character C<~> then the tilde may be
+expanded as a home directory path (either C<~> for the current user's
+home directory, or C<~user> for another user).
+
+Note that home directory expansion happens for users known I<on the
+host>, not in the guest filesystem.
+
+To use a literal argument which begins with a tilde, you have to quote
+it, eg:
+
+ echo "~"
+
 =head1 EXIT ON ERROR BEHAVIOUR
 
 By default, guestfish will ignore any errors when in interactive mode