It’s difficult to be specific without your file. If you know how many lines you want to read, you can set that limit as a parameter.
From the documentation:
- C = textscan(fileID,formatSpec,N) reads file data using the formatSpec N times, where N is a positive integer. To read additional data from the file after N cycles, call textscan again using the original fileID. If you resume a text scan of a file by calling textscan with the same file identifier (fileID), then textscan automatically resumes reading at the point where it terminated the last read.