1 files changed, 20 insertions, 0 deletions
diff --git a/tclfile.tcl b/tclfile.tcl
index 7700a5d..61db3f2 100644
--- a/tclfile.tcl
+++ b/tclfile.tcl
@@ -1,3 +1,4 @@
+
 package require Tclpd 0.2.3
 
 package provide tclfile 0.1
@@ -12,3 +13,22 @@ proc tclfile::make_symbol {argslist} {
     }
     return $output
 }
+
+# expand things like ~ $HOME $ProgramFiles
+proc tclfile::expand_vars {filename} {
+    set sub $filename
+    foreach var [regexp -all -inline -- {\$\w+} $filename] {
+        regexp -- {\$(\w+)} $var -> varname
+        if {[catch {set got $::env($varname)} fid]} {
+            #puts stderr "caught $fid"
+        } else {
+            set sub [string map [list "\$$varname" $got \{ "" \} ""] $filename]
+            # TODO this should really be a regex that properly
+            # recognizes {} around the symbol as separate from just {}
+            # used in a filename.  But first, Pd will need a full
+            # escaping mechanism so it can allow {}
+            #set sub [regsub "\(.+\)HOME\(.+\)" $sub "==\1==$got==\2=="]
+        }
+    }
+    return $sub
+}