implemented dirs

xonsh/dirstack.py

@@ -0,0 +1,96 @@
+import os
+import builtins
+
+from argparse import ArgumentParser
+
+DIRSTACK = []
+
+def get_dirstack():
+    global DIRSTACK
+    return [builtins.__xonsh_env__['PWD']] + DIRSTACK
+
+def set_dirstack(x):
+    global DIRSTACK
+    DIRSTACK = DIRSTACK[1:]
+
+pushd_parser = ArgumentParser(description="pushd: push onto the directory stack")
+def pushd(args, stdin=None):
+    dirstack = get_dirstack()
+    return None, None
+
+popd_parser = ArgumentParser(description="popd: pop from the directory stack")
+def popd(args, stdin=None):
+    dirstack = get_dirstack()
+    return None, None
+
+
+def dirs(args, stdin=None):
+    dirstack = get_dirstack()
+
+    try:
+        args = dirs_parser.parse_args(args)
+    except SystemExit:
+        return None, None
+
+    if args.clear:
+        dirstack = []
+        return None, None
+
+    if args.long:
+        o = dirstack
+    else:
+        d = os.path.expanduser('~')
+        o = [i.replace(d, '~') for i in dirstack]
+
+    if args.verbose:
+        out = ''
+        pad = len(str(len(o)-1))
+        for (ix, e) in enumerate(o):
+            blanks = ' ' * (pad - len(str(ix)))
+            out += '\n{0}{1} {2}'.format(blanks, ix, e)
+        out = out[1:]
+    elif args.print_long:
+        out = '\n'.join(o)
+    else:
+        out = ' '.join(o)
+
+    N = args.N
+    if N is not None:
+        try:
+            num = int(N[1:])
+        except:
+            return None, 'Invalid argument to dirs: {0}\n'.format(N)
+        if num >= len(o):
+            e = 'Too few elements in dirstack ({1} elements)\n'.format(len(o))
+            return None, e 
+        if N.startswith('-'):
+            idx = num
+        elif N.startswith('+'):
+            idx  = len(o)-1-num
+        else:
+            return None, 'Invalid argument to dirs: {0}\n'.format(N)
+
+        out = o[idx]
+
+    return out+'\n', None
+
+
+dirs_parser = ArgumentParser(description="dirs: view and manipulate the directory stack", )
+dirs_parser.add_argument('-c',
+        dest='clear',
+        help='Clears the directory stack by deleting all of the entries',
+        action='store_true')
+dirs_parser.add_argument('-p',
+        dest='print_long',
+        help='Print the directory stack with one entry per line.',
+        action='store_true')
+dirs_parser.add_argument('-v',
+        dest='verbose',
+        help='Print the directory stack with one entry per line, prefixing each entry with its index in the stack.',
+        action='store_true')
+dirs_parser.add_argument('-l',
+        dest='long',
+        help='Produces a longer listing; the default listing format uses a tilde to denote the home directory.',
+        action='store_true')
+dirs_parser.add_argument('N', nargs='?')
+