ANSI 转义码(ANSI escape code)解析
ANSI 转义序列是命令行终端下用来控制光标位置、字体颜色以及其他终端选项的一项 in-bind signaling 标准。
ANSI escape sequences are a standard for in-band signaling to control the cursor location, color, and other options on video text terminals and terminal emulators.
In telecommunications, in-band signaling is the sending of control information within the same band or channel used for data such as voice or video. This is in contrast to out-of-band signaling which is sent over a different channel, or even over a separate network. In-band signals may often be heard by telephony participants, while out-of-band signals are inaccessible to the user.
利用script命令，我们可以记录下终端操作的所有输入输入，
记录下来的数据包含着 ANSI 转义码，
这使得它非常不便于阅读，我们可以根据 ANSI 转义码来解析这些数据。
ANSI 转义码的 wiki基本覆盖了这个标准的核心内容，
部分terminal模拟器可能使用了标准以外的转义序列，可以参考VT510 Video Terminal Programmer Information。
根据 ANSI 转义序列规范实现的 ANSI 转义码解析 demo（该 demo 只用来演示说民工，并未完成所有 ANSI 转义序列的解析）：
# coding: utf-8
import sys
with open('typescript', 'rb') as fp:
data = fp.read()
ESC = '\x1b'
BEL = '\x07'
STATUS_NORMAL = 'NORMAL'
STATUS_ESC = 'ESC'
STATUS_CSI = 'CSI'
STATUS_QMARK = '?'
status = 'NORMAL'
val = ''
# print(len(data))
class VTParser(object):
def __init__(self, data):
self.data = data
self.sz = len(data)
self.pos = 0
self.ch = None
self.status = STATUS_NORMAL
def eat_digit(self):
if self.ch is None:
raise Exception('ch is None')
v = ''
while (self.ch >= '0' and self.ch <= '9'):
if self.pos >= self.sz:
raise Exception('malformed data')
v += self.ch
self.ch = self.data[self.pos]
self.pos += 1
return v
def eat_ctrl_string(self):
if self.ch is None:
raise Exception('ch is None')
ctrls = ''
while (self.ch != BEL and not (self.ch == ESC and self.peek_next_ch() == '\\')):
if self.pos >= self.sz:
raise Exception('malformed data')
ctrls += self.ch
self.ch = self.data[self.pos]
self.pos += 1
if self.ch == ESC:
self.next_ch()
return ctrls
def next_ch(self):
if self.pos >= self.sz:
return False
self.ch = self.data[self.pos]
self.pos += 1
return True
def peek_next_ch(self):
if self.pos >= self.sz:
return None
ch = self.data[self.pos]
# print("peek next: %c" % (ch))
return ch
def parse(self):
while self.next_ch():
if self.status == 'NORMAL':
if self.ch == ESC:
self.status = STATUS_ESC
else:
sys.stdout.write(self.ch)
elif self.status == STATUS_ESC:
if self.ch == '[':
self.status = STATUS_CSI
elif self.ch == '>':
self.status = STATUS_NORMAL
elif self.ch == '=':
self.status = STATUS_NORMAL
elif self.ch == ']':
if not self.next_ch():
raise Exception('malform data')
ctrls = self.eat_ctrl_string()
# print('\nOperating System Command: %s' % (ctrls))
self.status = STATUS_NORMAL
else:
print('ESC, ch: %c, v: 0x%x' % (self.ch, ord(self.ch)))
break
elif self.status == STATUS_CSI:
if self.ch == '?':
if not self.next_ch():
raise Exception('malform data')
v = self.eat_digit()
o = self.ch
self.status = STATUS_NORMAL
elif self.ch == '>':
if not self.next_ch():
raise Exception('malform data')
v = self.eat_digit()
if self.ch != 'c':
raise Exception('malform data, CSI > %s %c' % (v, self.ch))
self.status = STATUS_NORMAL
elif self.ch == 's':
sef.status = STATUS_NORMAL
elif self.ch == 'u':
self.status = STATUS_NORMAL
else:
v = self.eat_digit()
if v == '6' and self.ch == 'n':
self.status = STATUS_NORMAL
elif (v == '4' or v == '5') and self.ch == 'i':
self.status = STATUS_NORMAL
elif self.ch == 'K':
# erase line
self.status = STATUS_NORMAL
elif self.ch == 'H':
# erase line
self.status = STATUS_NORMAL
elif self.ch == 'J':
self.status = STATUS_NORMAL
elif self.ch == 'm':
self.status = STATUS_NORMAL
elif self.ch == ';':
if not self.next_ch():
raise Exception('malform data')
u = self.eat_digit()
o = self.ch
self.status = STATUS_NORMAL
# print('CSI %s; %s %c' % (v, u, o))
else:
# TODO
print('CSI n: %s, ch: %c, v: 0x%x' % (v, self.ch, ord(self.ch)))
break
# print('csi ch: %c, v: %s' % (ch, v))
# break
else:
print('ch: %c, v: 0x%x' % (self.ch, ord(self.ch)))
break
parser = VTParser(data)
parser.parse()