Best effort dependency resolution

Add a new check_install function that checks if a tool is installed and
tries to install it on a best effort basic. Modify all scripts that
benefit from it. Small indentation and correctness fixes.

	modified:   functions/7za.fish
	modified:   functions/alert.fish
	new file:   functions/check_install.fish
	modified:   functions/lscmd.fish
	modified:   functions/rchmod.fish
	modified:   functions/renlow.fish
	modified:   functions/rlsxattr.fish
	modified:   functions/rsdos.fish
	modified:   functions/rsmac.fish
	modified:   functions/rsxattr.fish
	modified:   functions/uz.fish

1 files changed, 2 insertions, 9 deletions

diff --git a/functions/rsdos.fish b/functions/rsdos.fish
index 6efec55..eabe440 100644
--- a/functions/rsdos.fish
+++ b/functions/rsdos.fish
@@ -1,17 +1,10 @@
 function rsdos --description 'Recursively delete all user.DOSATTRIB xattrs'
 
-if not command -sq 'find'
-  echo "Can't find find."
-  return 1
-end
-
-if not command -sq 'setfattr'
+if not check_install 'setfattr' 'attr'
   echo "Can't find setfattr."
   return 1
 end
 
-find . -exec setfattr -x user.DOSATTRIB {} + 2>/dev/null
-
-return 0
+command find . -exec setfattr -x user.DOSATTRIB {} + 2>/dev/null
 
 end