diff options
Diffstat (limited to 'cmd2/parsing.py')
| -rw-r--r-- | cmd2/parsing.py | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/cmd2/parsing.py b/cmd2/parsing.py index a1e21175..d7feeb48 100644 --- a/cmd2/parsing.py +++ b/cmd2/parsing.py @@ -142,15 +142,21 @@ class StatementParser: ) # aliases have to be a word, so make a regular expression - # that matches the first word in the line. This regex has two - # parts, the first parenthesis enclosed group matches one - # or more non-whitespace characters with a non-greedy match - # (that's what the '+?' part does). The second group must be - # dynamically created because it needs to match either whitespace, - # something in REDIRECTION_CHARS, one of the terminators, - # or the end of the string. We use \A and \Z to ensure we always - # match the beginning and end of a string that may have multiple - # lines (if it's a multiline command) + # that matches the first word in the line. This regex has three + # parts: + # - the '\A\s*' matches the beginning of the string (even + # if contains multiple lines) and gobbles up any leading + # whitespace + # - the first parenthesis enclosed group matches one + # or more non-whitespace characters with a non-greedy match + # (that's what the '+?' part does). The non-greedy match + # ensures that this first group doesn't include anything + # matched by the second group + # - the second parenthesis group must be dynamically created + # because it needs to match either whitespace, something in + # REDIRECTION_CHARS, one of the terminators, or the end of + # the string (\Z matches the end of the string even if it + # contains multiple lines) second_group_items = [] second_group_items.extend(constants.REDIRECTION_CHARS) second_group_items.extend(terminators) @@ -162,7 +168,7 @@ class StatementParser: # join them up with a pipe second_group = '|'.join(second_group_items) # build the regular expression - expr = r'\A(\S+?)({})'.format(second_group) + expr = r'\A\s*(\S+?)({})'.format(second_group) self.command_pattern = re.compile(expr) def tokenize(self, line: str) -> List[str]: |