split: To split a file based on line or byte size

The command "split" can be used to split a file into parts or pieces of various sizes based on byte size or number of lines.
Let us say we have a file, temp, with the following contents

temp:

Line one Line two Line three Line four Line five Line six Line seven Line eight

We can use the command split to create new files with parts of the above file in it, by default split breaks a file into different files in the size of 1000 bytes, i.e. one new file for every 1000 bytes of data in the original file.

The new files created by split are named by default with a prefix "x" followed by the alphabets in the format xaa,xab etc.

example:

$ split temp $ ls temp xaa

We can see that along with temp, we have new file xaa. As the file temp does not have more than 1000 bytes of data it was not broken up into multiple files.

We can reduce the size of number of bytes per file by using the option -b.

Example:

$ split -b 10 temp $ ls temp xaa xab xac xad xae xaf xag xah xai

We can see that there are 9 files created, each having 10 bytes of data from the original file temp.

$ cat xaa Line one L

By using byte size as the limiting factor we can not be sure as to how much of each line gets split. As we can see in the above example,file xaa has first line and one character of the next line.

To make sure that the splitting happens at exact line boundaries we can use the option -l along with the number of lines per file.

example:

$split -l 1 temp $ ls temp xaa xab xac xad xae xaf xag xah xai

Each file created will have exactly one line of the file "temp".

$ cat xaa Line one $ cat xab Line two

If we don't like using alphabets to be used with "x" for the names of the files, we can use numbers by using the options -d

example: $ split -l 1 -d temp $ ls temp x00 x01 x02 x03 x04 x05 x06 x07 x08 $

The prefix "x" can also be changed to whatever prefix we need by passing the prefix after the file name.

example :

$ split -l1 -d temp file $ ls file00 file01 file02 file03 file04 file05 file06 file07 file08 temp $

We can see that by passing the string "file" after the filename "temp" we could create the new files with prefix as file.