from dal_6 import DAL6, Context
from sys import exit
################################################################################
def main():
welcome()
loop()
def welcome():
print '+---------------------+'
print '| DISK DEMO |'
print '| by Stephen Chappell |'
print '+---------------------+'
def loop():
valid_disk = False
while True:
print
print 'PROGRAM MENU'
print '============'
print '(1) Create Disk'
print '(2) Load Disk'
if valid_disk:
print '(3) Save Disk'
print '(4) Use Disk'
while True:
try:
select = raw_input('Select: ')
except:
exit(0)
try:
select = int(select)
if 0 < select < 3 or (2 < select < 5 and valid_disk):
break
else:
print 'Select should be between 1 and',
if valid_disk:
print '4.'
else:
print '2.'
except:
print 'Select should be a number.'
print
if select == 1:
disk = create_disk()
disk.seed(False)
valid_disk = True
elif select == 2:
disk = load_disk()
disk.seed(False)
valid_disk = True
elif select == 3:
save_disk(disk)
else:
use_disk(disk)
def create_disk():
while True:
try:
print
print 'CREATE A DISK'
blocks = int(raw_input('BLOCKS: '))
size = int(raw_input('SIZE: '))
return DAL6(blocks, size)
except:
print 'INCORRECT VALUE'
def load_disk():
while True:
try:
print
print 'LOAD A DISK'
name = raw_input('FILENAME: ')
disk = DAL6(10, 10)
disk.load(name, False)
return disk
except:
print 'INVALID FILENAME'
def save_disk(disk):
while True:
try:
print
print 'SAVE THE DISK'
name = raw_input('FILENAME: ')
disk.dump(name)
break
except:
print 'INVALID FILENAME'
################################################################################
def use_disk(disk):
set_fail_rate(disk)
context = disk.new_context()
print
print 'CREATING A SHELL ...'
Shell(context)
print 'EXITING THE SHELL ...'
def set_fail_rate(disk):
while True:
try:
print
print 'SET DISK FAIL RATE'
probability = float(raw_input('PROBABILITY: '))
disk.fail(probability)
break
except:
print '0 <= PROBABILITY <= 1'
################################################################################
class Shell:
# The Users Interface
def __init__(self, context):
assert context.__class__ is Context
self.__context = context
self.__commands = ['chdir', 'getcwd', 'listdir', \
'mkdir', 'rmdir', 'remove', 'exit']
self.__programs = ['type', 'edit']
print 'Welcome to DAL'
print '=============='
while True:
try:
prompt = raw_input('>>> ')
except:
continue
if prompt == 'help':
print 'COMMANDS:'
print ' chdir: change current working directory'
print ' getcwd: get current working directory'
print ' listdir: display directory contents'
print ' mkdir: make a new directory'
print ' rmdir: remove an old directory'
print ' remove: remove a file'
print ' exit: terminates this shell'
print 'PROGRAMS:'
print ' type: display the contents of a file'
print ' edit: create a new file'
else:
prompt = prompt.split(' ')
command = prompt[0]
path = ' '.join(prompt[1:])
if command in self.__commands:
if command == 'chdir':
self.__chdir(path)
elif command == 'getcwd':
self.__getcwd()
elif command == 'listdir':
self.__listdir(path)
elif command == 'mkdir':
self.__mkdir(path)
elif command == 'rmdir':
self.__rmdir(path)
elif command == 'remove':
self.__remove(path)
else:
break
elif command in self.__programs:
if command == 'type':
try:
Type(self.__context, path)
except:
print 'Type has crashed.'
else:
try:
Edit(self.__context, path)
except:
print 'Edit has crashed.'
else:
print repr(command), 'is an unrecognized command or program.'
# Changes Current Directory
def __chdir(self, path):
try:
if self.__context.exists(path):
if self.__context.isdir(path):
self.__context.chdir(path)
else:
print 'PATH IS NOT A DIRECTORY'
else:
print 'PATH DOES NOT EXIST'
except:
print 'COULD NOT CHANGE CURRENT WORKING DIRECTORY'
# Get Current Directory
def __getcwd(self):
print self.__context.getcwd()
# Lists Directory Contents
def __listdir(self, path):
try:
if self.__context.exists(path):
if self.__context.isdir(path):
names = self.__context.listdir(path)
for name in names:
if len(name) > 40:
temp = name[:37] + '...'
else:
temp = name
print temp + ' ' * (41 - len(temp)) + '<>',
if path:
temp = path + ' ' + name
else:
temp = name
if self.__context.isdir(temp):
print 'DIR'
else:
print 'FILE'
else:
print 'PATH IS NOT A DIRECTORY'
else:
print 'PATH DOES NOT EXIST'
except:
print 'COULD NOT DISPLAY DIRECTORY CONTENTS'
# Create New Directory
def __mkdir(self, path):
try:
if self.__context.exists(path):
if self.__context.isfile(path):
print 'NAME IS ALREADY IN USE'
else:
print 'THE DIRECTORY ALREADY EXISTS'
else:
self.__context.mkdir(path)
except:
print 'DIRECTORY COULD NOT BE CREATED'
# Remove A Directory
def __rmdir(self, path):
try:
if self.__context.exists(path):
if self.__context.isdir(path):
self.__context.rmdir(path)
else:
print 'PATH IS NOT A DIRECTORY'
else:
print 'PATH DOES NOT EXIST'
except:
print 'DIRECTORY COULD NOT BE REMOVED'
# Remove A File
def __remove(self, path):
try:
if self.__context.exists(path):
if self.__context.isfile(path):
self.__context.remove(path)
else:
print 'PATH IS NOT A FILE'
else:
print 'PATH DOES NOT EXIST'
except:
print 'FILE COULD NOT BE REMOVED'
################################################################################
class Type:
# Display A File
def __init__(self, context, path):
assert context.__class__ is Context
assert type(path) is str
try:
print context.file(path, 'r').read()
except:
print 'FILE COULD NOT BE FOUND'
################################################################################
class Edit:
# Create A File
def __init__(self, context, path):
assert context.__class__ is Context
assert type(path) is str
while True:
try:
option = raw_input('write OR append? ')
assert option == 'write' or option == 'append'
break
except:
pass
if option[0] == 'a':
if context.exists(path):
if context.isfile(path):
self.__menu(context, path, 'a')
else:
print 'PATH IN NOT A FILE'
else:
print 'FILE DOES NOT EXIST AND WILL NOT BE CREATED'
else:
try:
if context.exists(path):
if context.isfile(path):
self.__menu(context, path, 'w')
else:
print 'PATH IS NOT A FILE'
else:
self.__menu(context, path, 'w')
except:
print 'FILE COULD NOT BE CREATED'
# Display A Menu
def __menu(self, context, path, mode):
file_object = context.file(path, mode)
data = self.__edit()
file_object.write(data)
file_object.close(False)
# Get New Lines
def __edit(self):
lines = []
while True:
try:
lines.append(raw_input())
except:
break
return '\n'.join(lines)
################################################################################
if __name__ == '__main__':
main()
