If you have installed Git for Windows, you should have Git Bash installed, since that comes with Git.

Use the split command in Git Bash to split a file:

• into files of size 500MB each: split myLargeFile.txt -b 500m

• into files with 10000 lines each: split myLargeFile.txt -l 10000

Tips:

• If you don't have Git/Git Bash, download at https://git-scm.com/download

• If you lost the shortcut to Git Bash, you can run it using C:\Program Files\Git\git-bash.exe

That's it!

I always like examples though...

Example:

You can see in this image that the files generated by split are named xaa, xab, xac, etc.

These names are made up of a prefix and a suffix, which you can specify. Since I didn't specify what I want the prefix or suffix to look like, the prefix defaulted to x, and the suffix defaulted to a two-character alphabetical enumeration.

Another Example:

This example demonstrates

• using a filename prefix of MySlice (instead of the default x),
• the -d flag for using numerical suffixes (instead of aa, ab, ac, etc...),
• and the option -a 5 to tell it I want the suffixes to be 5 digits long:

Set Arg = WScript.Argumentsset WshShell = createObject("Wscript.Shell")Set Inp = WScript.StdinSet Outp = Wscript.Stdout    Set rs = CreateObject("ADODB.Recordset")    With rs        .Fields.Append "LineNumber", 4         .Fields.Append "Txt", 201, 5000         .Open        LineCount = 0        Do Until Inp.AtEndOfStream            LineCount = LineCount + 1            .AddNew            .Fields("LineNumber").value = LineCount            .Fields("Txt").value = Inp.readline            .UpDate        Loop        .Sort = "LineNumber ASC"        If LCase(Arg(1)) = "t" then            If LCase(Arg(2)) = "i" then                .filter = "LineNumber < " & LCase(Arg(3)) + 1            ElseIf LCase(Arg(2)) = "x" then                .filter = "LineNumber > " & LCase(Arg(3))            End If        ElseIf LCase(Arg(1)) = "b" then            If LCase(Arg(2)) = "i" then                .filter = "LineNumber > " & LineCount - LCase(Arg(3))            ElseIf LCase(Arg(2)) = "x" then                .filter = "LineNumber < " & LineCount - LCase(Arg(3)) + 1            End If        End If        Do While not .EOF            Outp.writeline .Fields("Txt").Value            .MoveNext        Loop    End With

Cut

filter cut {t|b} {i|x} NumOfLines

Cuts the number of lines from the top or bottom of file.

t - top of the fileb - bottom of the filei - include n linesx - exclude n lines

Example

cscript /nologo filter.vbs cut t i 5 < "%systemroot%\win.ini"

Another way This outputs lines 5001+, adapt for your use. This uses almost no memory.

Do Until Inp.AtEndOfStream         Count = Count + 1         If count > 5000 then            OutP.WriteLine Inp.Readline         End IfLoop

Of course there is! Win CMD can do a lot more than just split text files :)

Split a text file into separate files of 'max' lines each:

Split text file (max lines each):: Initializeset input=file.txtset max=10000set /a line=1 >nulset /a file=1 >nulset out=!file!_%input%set /a max+=1 >nulecho Number of lines in %input%:find /c /v "" < %input%: Split filefor /f "tokens=* delims=[" %i in ('type "%input%" ^| find /v /n ""') do (if !line!==%max% (set /a line=1 >nulset /a file+=1 >nulset out=!file!_%input%echo Writing file: !out!)REM Write next fileset a=%iset a=!a:*]=]!echo:!a:~1!>>out!set /a line+=1 >nul)

If above code hangs or crashes, this example code splits files faster (by writing data to intermediate files instead of keeping everything in memory):

eg. To split a file with 7,600 lines into smaller files of maximum 3000 lines.

1. Generate regexp string/pattern files with set command to be fed to /g flag of findstr

list1.txt

\[[0-9]\]
\[[0-9][0-9]\]
\[[0-9][0-9][0-9]\]
\[[0-2][0-9][0-9][0-9]\]

list2.txt

\[[3-5][0-9][0-9][0-9]\]

list3.txt

\[[6-9][0-9][0-9][0-9]\]

2. Split the file into smaller files:

type "%input%" | find /v /n "" | findstr /b /r /g:list1.txt > file1.txttype "%input%" | find /v /n "" | findstr /b /r /g:list2.txt > file2.txttype "%input%" | find /v /n "" | findstr /b /r /g:list3.txt > file3.txt

3. remove prefixed line numbers for each file split:
   eg. for the 1st file:

for /f "tokens=* delims=[" %i in ('type "%cd%\file1.txt"') do (set a=%iset a=!a:*]=]!echo:!a:~1!>>file_1.txt)

Notes:
Works with leading whitespace, blank lines & whitespace lines.

Tested on Win 10 x64 CMD, on 4.4GB text file, 5651982 lines.