How can I read the first line from a text file using a Windows batch file? Since the file is large I only want to deal with the first line.
Reading of files in a Batch Script is done via using the FOR loop command to go through each line which is defined in the file that needs to be read. Since there is a no direct command to read text from a file into a variable, the 'for' loop needs to be used to serve this purpose.
The Windows command prompt ( cmd.exe ) has an optional /s parameter, which modifies the behavior of /c (run a particular command and then exit) or /k (run a particular command and then show a shell prompt).
So %%k refers to the value of the 3rd token, which is what is returned.
%%a refers to the name of the variable your for loop will write to. Quoted from for /? : FOR %variable IN (set) DO command [command-parameters] %variable Specifies a single letter replaceable parameter. (set) Specifies a set of one or more files. Wildcards may be used.
uh? imo this is much simpler
set /p texte=< file.txt echo %texte%
Here's a general-purpose batch file to print the top n
lines from a file like the GNU head
utility, instead of just a single line.
@echo off
if [%1] == [] goto usage
if [%2] == [] goto usage
call :print_head %1 %2
goto :eof
REM
REM print_head
REM Prints the first non-blank %1 lines in the file %2.
REM
:print_head
setlocal EnableDelayedExpansion
set /a counter=0
for /f ^"usebackq^ eol^=^
^ delims^=^" %%a in (%2) do (
if "!counter!"=="%1" goto :eof
echo %%a
set /a counter+=1
)
goto :eof
:usage
echo Usage: head.bat COUNT FILENAME
For example:
Z:\>head 1 "test file.c"
; this is line 1
Z:\>head 3 "test file.c"
; this is line 1
this is line 2
line 3 right here
It does not currently count blank lines. It is also subject to the batch-file line-length restriction of 8 KB.
Uh you guys...
C:\>findstr /n . c:\boot.ini | findstr ^1:
1:[boot loader]
C:\>findstr /n . c:\boot.ini | findstr ^3:
3:default=multi(0)disk(0)rdisk(0)partition(1)\WINNT
C:\>
You might give this a try:
@echo off
for /f %%a in (sample.txt) do (
echo %%a
exit /b
)
edit Or, say you have four columns of data and want from the 5th row down to the bottom, try this:
@echo off
for /f "skip=4 tokens=1-4" %%a in (junkl.txt) do (
echo %%a %%b %%c %%d
)
Thanks to thetalkingwalnut with answer Windows batch command(s) to read first line from text file I came up with the following solution:
@echo off
for /f "delims=" %%a in ('type sample.txt') do (
echo %%a
exit /b
)
Slightly building upon the answers of other people. Now allowing you to specify the file you want to read from and the variable you want the result put into:
@echo off
for /f "delims=" %%x in (%2) do (
set %1=%%x
exit /b
)
This means you can use the above like this (assuming you called it getline.bat)
c:\> dir > test-file
c:\> getline variable test-file
c:\> set variable
variable= Volume in drive C has no label.
powershell Get-Content file.txt -Head 1
This one is much quicker than the other powershell examples above, where the full file is read.
One liner, useful for stdout redirect with ">":
@for /f %%i in ('type yourfile.txt') do @echo %%i & exit
Try this
@echo off
setlocal enableextensions enabledelayedexpansion
set firstLine=1
for /f "delims=" %%i in (yourfilename.txt) do (
if !firstLine!==1 echo %%i
set firstLine=0
)
endlocal
To cicle a file (file1.txt
, file1[1].txt
, file1[2].txt
, etc.):
START/WAIT C:\LAERCIO\DELPHI\CICLADOR\dprCiclador.exe C:\LAERCIUM\Ciclavel.txt
rem set/p ciclo=< C:\LAERCIUM\Ciclavel.txt:
set/p ciclo=< C:\LAERCIUM\Ciclavel.txt
rem echo %ciclo%:
echo %ciclo%
And it's running.
Another way
setlocal enabledelayedexpansion
@echo off
for /f "delims=" %%i in (filename.txt) do (
if 1==1 (
set first_line=%%i
echo !first_line!
goto :eof
))
The problem with the EXIT /B
solutions, when more realistically inside a batch file as just one part of it is the following. There is no subsequent processing within the said batch file after the EXIT /B
. Usually there is much more to batches than just the one, limited task.
To counter that problem:
@echo off & setlocal enableextensions enabledelayedexpansion
set myfile_=C:\_D\TEST\My test file.txt
set FirstLine=
for /f "delims=" %%i in ('type "%myfile_%"') do (
if not defined FirstLine set FirstLine=%%i)
echo FirstLine=%FirstLine%
endlocal & goto :EOF
(However, the so-called poison characters will still be a problem.)
More on the subject of getting a particular line with batch commands:
How do I get the n'th, the first and the last line of a text file?" http://www.netikka.net/tsneti/info/tscmd023.htm
[Added 28-Aug-2012] One can also have:
@echo off & setlocal enableextensions
set myfile_=C:\_D\TEST\My test file.txt
for /f "tokens=* delims=" %%a in (
'type "%myfile_%"') do (
set FirstLine=%%a& goto _ExitForLoop)
:_ExitForLoop
echo FirstLine=%FirstLine%
endlocal & goto :EOF
Here is a workaround using powershell
:
powershell (Get-Content file.txt)[0]
(You can easily read also a range of lines with powershell (Get-Content file.txt)[0..3]
)
If you need to set a variable inside a batch script as the first line of file.txt
you may use:
for /f "usebackq delims=" %%a in (`powershell ^(Get-Content file.txt^)[0]`) do (set "head=%%a")
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