def __new__(cls, executable):
try:
parse(executable)
except SyntaxError:
raise ValueError("«%s» is not a valid shell command" % executable)
# Value is OK, now we maintain original.
return str.__new__(cls, executable)
def __new__(cls, executable):
try:
parse(executable)
except SyntaxError:
raise ValueError("«%s» is not a valid shell command" % executable)
# Value is OK, now we maintain original.
return str.__new__(cls, executable)
single_line_cmd = "ls -la /tmp 2>&1 && echo foo'bar'\ "
print("DEMO: shnake.lex()")
print("The shnake lexer handles single line commands:")
print()
print("Raw command: %r" % single_line_cmd)
result = shnake.lex(single_line_cmd)
print("Lexed command: %r" % result)
print()
print()
# parser behavior
multi_line_cmd = "cmd1-part1\\\ncmd1-part2\ncmd2"
print()
print("DEMO: shnake.parse()")
print("The shnake parser is a wrapper for the lexer.")
print("Its handles multi-line strings, so it can parse file buffers")
print()
print("Raw command: %r" % multi_line_cmd)
result = shnake.parse(multi_line_cmd)
print("Parsed command: %r" % result)
print()
print()
# command interpreter demo
print("DEMO: shnake.Shell()")
print("This shnake shell is a command line interpreter.")
print("Type: `help` in the shell interface")
interpreter = shnake.Shell()
interpreter.prompt = "shnake > "
interpreter.cmdloop()