How to count no of lines in text file and store the value into a variable using batch script?

Question

I want to count the no of lines in a text file and then the value has to be stored into a environment variable. The command to count the no of lines is

findstr /R         


        

Answer 1

I found this solution to work best for creating a log file that maintains itself:

setlocal enabledelayedexpansion
SET /A maxlines= 10
set "cmd=findstr /R /N "^^" "filename.txt" | find /C ":""
 for /f %%a in ('!cmd!') do set linecount=%%a
GOTO NEXT

:NEXT 
 FOR /F %%A IN ("filename.txt") DO ( 
  IF %linecount% GEQ %maxlines% GOTO ExitLoop
  echo %clientname% %Date% %Time% >> "filename.txt")
 EXIT

:ExitLoop
 echo %clientname% %Date% %Time% > "filename.txt"
 EXIT

Environmental variables included are %clientname% the computername of the remote client %Date% is the current date and %Time% the current time. :NEXT is called after getting the number of lines in the file. If the file line count is greater than the %maxlines% variable it goes to the :EXITLOOP where it overwrites the file, creating a new one with the first line of information. if it is less than the %maxlines% variable it simply adds the line to the current file.