How do I split a file into n no of parts

In bash, you can use the split command to split it based on number of lines desired. You can use wc command to figure out how many lines are desired. Here's wc combined with with split into one line.

For example, to split onepiece.log into 5 parts

    split -l$((`wc -l < onepiece.log`/5)) onepiece.log onepiece.split.log -da 4

This will create files like onepiece.split.log0000 ...

Note: bash division rounds down, so if there is a remainder there will be a 6th part file.

On linux, there is a split command,

split --lines=1m /path/to/large/file /path/to/output/file/prefix

Output fixed-size pieces of INPUT to PREFIXaa, PREFIXab, ...; default size is 1000 lines, and default PREFIX is 'x'. With no INPUT, or when INPUT is -, read standard input.

...

-l, --lines=NUMBER put NUMBER lines per output file

...

You would have to calculate the actual size of the splits beforehand, though.