Reading parts of a file in Swift

Question

I have a rather large text file. I have about 40 million unique alpha numeric codes in it. I know how to write to files and read the whole thing. But not specify how many lines to read instead of contectsOf.

To elaborate, my file goes like this.
AF3D1
D8U9X
5GN11
.... and so on for 40 million strings.

I just just want to loop through for X amount of strings and write to one file, then rewrite the remaining codes over the others since I am ultimately deleting them out. I just need to figure out how to loop through X amount of a txt file.

I know there is this question, but not the same. Read and write data from text file

Put the data into a database file. Far more efficient than trying to read from a text file. — rmaddy, Sep 28 '16 at 23:23
Yes it is all the same length. It is already in the text file and completed. — JohnV, Sep 29 '16 at 16:15

score 0 · Answer 1 · answered Sep 29 '16 at 16:22

0

Since every line in the text file is the same length (6 bytes - 5 for the key and 1 for the newline), then you can open a FileHandle and use the seek(toFileOffset:) method to just to a specific position in the file.

answered Sep 29 '16 at 16:22

rmaddy

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Reading parts of a file in Swift

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