Add CrOS bashrc sample

cros-bashrc.sample.bash

+#!/bin/bash
+[[ $- != *i* ]] && return
+[ "$(pwd)" = / ] && cd ~/Downloads
+
+alias ls='ls -CF --color=auto'
+alias l='ls -lF'
+alias lh='ls -hAl'
+alias la='ls -la'
+alias ll='ls -l'
+
+export EDITOR=vim
+
+tree() {
+  python -Sc 'import sys, os
+aa = sys.argv[1:] or ["."]
+for a in aa:
+  o = len(a.split(os.sep))
+  for r, dd, ff in os.walk(a):
+    dp = len(r.split(os.sep)) - o + 1
+    print "%s- %s" % ((dp - 1) * "  ", os.path.basename(r))
+    for f in ff:
+      print "%s- %s" % (dp * "  ", f)' "$@"
+}
+
+showzip() {
+  [ $# = 1 ] || { echo "Usage: showzip ZIPFILE" >&2 ; return 1 ; }
+  python -Sc 'import sys, zipfile
+zfile = zipfile.ZipFile(sys.argv[1])
+zfile.printdir()
+zfile.close()' "$@"
+}
+
+zip() {
+  [ $# -gt 1 ] || { echo "Usage: zip ZIPFILE FILE..." >&2 ; return 1 ; }
+  python -Sc 'import sys, zipfile, os
+if os.path.lexists(sys.argv[1]):
+  sys.stderr.write("zip: file %r already exists\n" % sys.argv[1])
+  sys.exit(1)
+zfile = zipfile.ZipFile(sys.argv[1], "w", zipfile.ZIP_DEFLATED)
+def arc(arg):
+  if os.path.islink(arg):
+    sys.stderr.write("zip: symlink %r ignored\n" % arg)
+  elif os.path.isdir(arg):
+    for r, _, ff in os.walk(arg):
+      zfile.write(r)
+      for f in ff: arc(os.path.join(r, f))
+  else:
+    zfile.write(arg)
+for arg in sys.argv[2:]: arc(arg)
+zfile.close()' "$@"
+}
+
+unzip() {
+  [ $# != 0 ] || { echo "Usage: unzip ZIPFILE [TARGET]" >&2 ; return 1 ; }
+  python -Sc 'import sys, zipfile
+zfile = zipfile.ZipFile(sys.argv[1])
+zfile.extractall(sys.argv[2] if len(sys.argv) > 2 else ".")
+zfile.close()' "$@"
+}
+
+__PS1_last_code() {
+  local res=$?
+  [ $res = 0 ] || echo -n $'\1'$'\033[01;31m'$'\2'"$res "
+  return $res
+}
+# chronos@localhost ~/Downloads $ false
+# chronos@localhost ~/Downloads 1 $
+export PS1="$(echo "$PS1" | head -c -16)\$(__PS1_last_code)$(echo "$PS1" | tail -c -16)"