Extract N lines from file using single windows com

Question

Is there a way to extract/copy the fist X number of lines from a file and input them into another file with a single command using the windows command prompt?

I can delete the first X number of lines using:
more +X [file_containing data] > [file_to_export_data_to]

If the head command would work I think I could just do this:
head -X [file_containing data] > [file_to_export_data_to]

But that unfortunately does not work.

It would be great if Windows had a "less" command but again no luck.

I'm a complete novice when it comes to this stuff so I'm sure I'm missing something obvious. I don't want to install anything or use something other than the command prompt.

Thanks

Answer 1

You can use PowerShell from the cmd.exe console:

 powershell -command "& {get-content input.txt|select-object -first 10}" >output.txt

You could create a DOSKEY macro to make it easier to use from the command line:

doskey head=powershell -command "& {get-content $1|select-object -first $2}"

Usage:

head input.txt 10 >output.txt

But you cannot use a DOSKEY macro within a batch script.

You could create a head.bat script instead and place it in a folder that is included in your PATH:

head.bat

@powershell -command "& {get-content %1|select-object -first %2}"

From the command line, you would use head input.txt 10 >output.txt

From within a batch script, you would use call head input.txt 10 >output.txt

I chose not to have the output file as a parameter in case you want to simply display the result to the screen instead of writing to a file.

Answer 2

the simplest one-command solution is to use Powershell Get-Content.

N - number of lines.

From the begining of file:

Get-Content -Head N file.txt

From the end of file:

Get-Content -Tail N file.txt

Answer 3

you can use this:

break>"%temp%\empty"&&fc "%temp%\empty" "%file_to_process%" /lb  X /t |more +4 | findstr /B /E /V "*****"

where you should replace the X with the lines you want.Or name this head.bat :

break>"%temp%\empty"&&fc "%temp%\empty" "%file_to_process%" /lb  %~1 /t |more +4 | findstr /B /E /V "*****"

Answer 4

(@FOR /f "tokens=1* delims=:" %a IN ('findstr /n "^" "standardwaffle.txt"') DO @IF %a leq 7 ECHO(%b)>u:\junk.txt

would extract the first 7 lines of standardwaffle.txt to u:\junk.txt so here it is in one cmd line - but I'd defy you to enter that reliably.

It would also remove any leading : on a source line.

@ECHO OFF
SETLOCAL
IF %1 lss 0 (SET /a line=-%1) ELSE (SET /a line=%1)
FOR /f "tokens=1* delims=:" %%a IN ('findstr /n "^" "%~2"') DO IF %%a leq %line% ECHO(%%b

GOTO :EOF

This batch, saved as head.bat placed anywhere on your path would allow you to use

head -n standardwaffle.txt >junk.txt

to extract the first n lines of standardwaffle.txt to junk.txt

the - would be optional

but this involves installing the batch on your machine. Is that banned by your "no installing" requirement, or is "installing" meant only for 3rd party utilities?

Answer 5

Set Inp = WScript.Stdin
Set Outp = Wscript.Stdout
x = 0
    Do Until Inp.AtEndOfStream
              x = x + 1
        OutP.WriteLine Inp.Readline
              If x = 5 then Exit Do
    Loop

This prints lines 1 to 5. To use

cscript //nologo <path to script.vbs> <inputfile >outputfile

Answer 6

In order to get correct utf8 output, do the following in powershell

chcp 65001

$OutputEncoding = New-Object -typename System.Text.UTF8Encoding

get-content input.txt -encoding UTF8 |select-object -first 10000 > output.txt

This will get first 10000 lines of input.txt (file in utf8 format) to output.txt with correct encoding.