Allow selective updates

README.md

@@ -33,10 +33,15 @@ fish install
 
 Oh My Fish includes a small utility `omf` to fetch and install new packages and themes.
 
-#### `omf update`
+#### `omf update` _`[omf]`_ _`[<package>...]`_
 
 Update the framework and installed packages.
 
+- When called without arguments, update core and all installed packages.
+- You can choose to update only the core, by running `omf update omf`.
+- For selective package update, list only the names of packages you wish to
+  update. You may still include "omf" in the list to update the core as well.
+
 #### `omf install` _`[<name>|<url>]`_
 
 Install one _or more_ packages.

pkg/omf/functions/cli/omf.cli.update.fish

 function omf.cli.update
+  set -l update_core
+  set -l packages $argv
+  if test (count $packages) -gt 0
+    # If several packages are listed, only update core if "omf" is listed among them.
+    # Also keep "omf" out of the list of packages to update.
+    set index (contains -i -- omf $packages)
+      and set -e packages[$index]
+      or set -e update_core
+  else
+    set packages (omf.packages.list --installed)
+  end
+
+  if set -q update_core
     if omf.core.update
       echo (omf::em)"Oh My Fish is up to date."(omf::off)
     else
       echo (omf::err)"Oh My Fish failed to update."(omf::off)
       echo "Please open a new issue here → "(omf::em)"github.com/oh-my-fish/oh-my-fish/issues"(omf::off)
     end
+  end
 
-  for package in (omf.packages.list --installed)
+  for package in $packages
     omf.packages.update $package
   end
 end

pkg/omf/functions/omf.fish

@@ -59,7 +59,7 @@ function omf -d "Oh My Fish"
       omf.cli.theme $arguments
 
     case "u" "update"
-      omf.cli.update
+      omf.cli.update $arguments
 
     case "*"
       echo (omf::err)"$argv[1] option not recognized"(omf::off) 1^&2