provide a realpath implementation

Not all distros have a `realpath` command. Provide a function that uses the
real command if available else use the fish builtin.

Fixes #2932

1 files changed, 13 insertions, 0 deletions

diff --git a/share/functions/realpath.fish b/share/functions/realpath.fish
new file mode 100644
index 00000000..3d33ae0f
--- /dev/null
+++ b/share/functions/realpath.fish
@@ -0,0 +1,13 @@
+# Provide a minimalist realpath implementation to help deal with platforms that may not provide it
+# as a command. If a realpath command is available simply pass all arguments thru to it. If not
+# fallback to alternative solutions.
+
+# The following is slightly subtle. The first time `realpath` is invoked this script will be read.
+# If we see that there is an external command by that name we just return. That will cause fish to
+# run the external command. On the other hand, if an external command isn't found we define a
+# function that will provide fallback behavior.
+if not type -q -P realpath
+    function realpath --description 'fallback realpath implementation'
+        builtin fish_realpath $argv[-1]
+    end
+end