Good design pattern for a tool to combine many log files

I have a lot of log files in different formats. Each log files has different kinds of data from which I can make out the the time and source of the log message along with other details.

I need to combine all the log messages into one big log file with my own format and which should be sorted by time of the log messages.

I also plan to implement a GUI as well as a command line interface for the tool.

Is strategy pattern a good design strategy for this? Since I want to develop a CUI as well as a GUI, would the strategy pattern be a good fit?