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, 12 deletions

diff --git a/functions/rlsxattr.fish b/functions/rlsxattr.fish
index 0e71e49..e52d820 100644
--- a/functions/rlsxattr.fish
+++ b/functions/rlsxattr.fish
@@ -1,20 +1,10 @@
 function rlsxattr --description 'Recursively list all files with xattrs'
 
-if not command -sq 'getfattr'
+if not check_install 'getfattr' 'attr'
   echo "Can't find getfattr."
   return 1
 end
 
-if not command -sq 'sed'
-  echo "Can't find sed."
-  return 1
-end
-
-if not command -sq 'awk'
-  echo "Can't find awk."
-  return 1
-end
-
-getfattr -R -h -d . 2>/dev/null | grep '^# file:' | sed 's/^# file: //'
+command getfattr -R -h -d . 2>/dev/null | grep '^# file:' | sed 's/^# file: //'
 
 end