def parse(self, spec):
lexer = shlex.shlex(spec)
lexer.whitespace_split = True
current = Command(self.logger)
cmds = []
redirecting_from = redirecting_to = False
for arg in lexer:
if redirecting_from:
current.redirect_from(arg)
continue
elif redirecting_to:
current.redirect_to(arg)
continue
if current.runnable():
# Start of a new command
cmds.append(current)
current = Command(self.logger)
if arg[0] == '"' or arg[0] == "'":
# Argument is a string so strip the delimiters
arg = arg[1:-1]
elif arg == '&':
self.background = True
# The ampersand must be at the end of a command specification
break
elif arg == ';':
current.end()
continue
elif arg == '|':
current.end(piped = True)
continue
elif arg == '<':
# Record that the next argument will be the input file
redirecting_from = True
continue
elif arg == '>':
# Record that the next argument will be the output file
redirecting_to = True
continue
else:
# Argument could be a file glob so attempt expansion in case
expanded = glob.glob(arg)
if len(expanded) > 0:
current.extend(expanded)
arg = None
if arg:
current.append(arg)
if not current.runnable():
current.end()
if len(cmds) == 0 or cmds[-1] != current:
cmds.append(current)
return cmds
