Add copy and paste aliases to clipboard commands

Interact with the clipboard through the `copy` and `paste` aliases.

`copy` is defined when:

1. An `ssh` connection is detected, using OSC-52.
2. macOS is detected, using `pbcopy`.
3. `xsel` is detected.

`paste` is define when:

1. macOS is detected, using `pbpaste`.
2. `xsel` is detected.

utilities/utilities.plugin.zsh

@@ -2,6 +2,25 @@
 
 autoload colors && colors
 
+# Abstract different ways to copy to the clipboard.
+if [ -n "$SSH_CONNECTION" ] ; then
+  # Use OSC-52 to set the clipboard
+  alias copy='base64 | xargs -0 printf "\033]52;c;%s\a"'
+elif [ "`uname`" = "Darwin" ]; then
+  # Use pbcopy to set the clipboard
+  alias copy='pbcopy'
+elif which xclip &> /dev/null; then
+  # Use xclip to set the clipboard
+  alias copy='xclip -selection c'
+fi
+
+# Abstract different ways to paste from the clipboard.
+if [ "`uname`" = "Darwin" ]; then
+  alias paste='pbpaste'
+elif which xclip &> /dev/null; then
+  alias paste='xclip -selection c -o'
+fi
+
 # Detect the type and extract an archive file.
 extract() {
   if [ -f $1 ]; then
@@ -25,6 +44,16 @@ extract() {
   fi
 }
 
+if which bat &> /dev/null; then
+  # Wrap bat to specify a theme, always enable color, pipe the output to less.
+  # Both --theme and --color can be specified multiple times and will override
+  # these defaults.
+  bat() {
+    command bat --theme='Solarized (dark)' --color always \
+                --paging always --pager 'less -R' "$@"
+  }
+fi
+
 if which docker-machine &> /dev/null; then
   # Wrap the docker command to print a message if a docker-machine is not
   # running, rather than just stating it can not find it's socket.