Add clipcopy() and clippaste() generic cross-platform CLI clipboard functions.

Change copydir, copyfile, and coffee plugins to use them, instead of the Mac-only `pbcopy` command.

lib/clipboard.zsh

@@ -0,0 +1,67 @@
+# System clipboard integration
+#
+# This file has support for doing system clipboard copy and paste operations
+# from the command line in a generic cross-platform fashion.
+#
+# On OS X and Windows, the main system clipboard or "pasteboard" is used. On other
+# Unix-like OSes, this considers the X Windows CLIPBOARD selection to be the
+# "system clipboard", and the X Windows `xclip` command must be installed.
+
+# clipcopy - Copy data to clipboard
+#
+# Usage:
+#
+#  <command> | clipcopy    - copies stdin to clipboard
+#
+#  clipcopy <file>         - copies a file's contents to clipboard
+#
+function clipcopy() {
+  emulate -L zsh
+  local file=$1
+  if [[ $OSTYPE == darwin* ]]; then
+    if [[ -z $file ]]; then
+      pbcopy
+    else
+      cat $file | pbcopy
+    fi
+  elif [[ $OSTYPE == cygwin* ]]; then
+    if [[ -z $file ]]; then
+      cat > /dev/clipboard
+    else
+      cat $file > /dev/clipboard
+    fi
+  else
+    which xclip &>/dev/null
+    if [[ $? != 0 ]]; then
+      print "clipcopy: Platform $OSTYPE not supported or xclip not installed" >&2
+      return 1
+    fi
+    if [[ -z $file ]]; then
+      xclip -in -selection clipboard
+    else
+      xclip -in -selection clipboard $file
+    fi
+  fi
+}
+
+# clippaste - "Paste" data from clipboard to stdout
+#
+# Usage:
+#
+#   clippaste   - writes clipboard's contents to stdout
+#
+function clippaste() {
+  emulate -L zsh
+  if [[ $OSTYPE == darwin* ]]; then
+    pbpaste
+  elif [[ $OSTYPE == cygwin* ]]; then
+    cat /dev/clipboard
+  else
+    which xclip &>/dev/null 
+    if [[ $? != 0 ]]; then
+      print "clipcopy: Platform $OSTYPE not supported or xclip not installed" >&2
+      return 1
+    fi
+    xclip -out -selection clipboard
+  fi
+}