Final answer:
In a data stream using byte-stuffing, the output after stuffing for the given fragment 'a b esc c esc flag flag d' would be 'a b esc esc c esc esc esc flag esc flag d', where each 'esc' or 'flag' in the data is preceded by an 'esc' to distinguish it from control characters.
Step-by-step explanation:
The byte-stuffing algorithm described in the question is a data link layer protocol used to delimit frames in a data stream. When the flag or escape sequences appear in the actual data, they need to be stuffed (or escaped) to ensure they are not interpreted as control characters. The escape character (commonly 'esc') is inserted before the actual flag or escape characters in the data stream.
Given the data fragment 'a b esc c esc flag flag d', the output after byte-stuffing would be 'a b esc esc c esc esc esc flag esc flag d'. Here's the step-by-step process:
- Whenever the escape character 'esc' is encountered in the original data, it is replaced with 'esc esc'.
- Whenever the flag sequence 'flag' is encountered in the original data, it is replaced with 'esc flag'.
This ensures that the actual data can be distinguished from the control characters when the data stream is being transmitted.