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Asked: 2021-12-10T07:40:33+00:00 In:

Solved FOR Loop – Variable Number Of Lines To Skip

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I’m working on a batch script where I use a variable to tell the FOR how many lines to skip.

for /f "skip=!lines! tokens=1-3* delims=," %%A in (_!file!.txt)

However this does not seem to work. When I put a static number (replacing !lines! with a number) it works. Is there a way to make this work?

99 little bugs in the code,
99 little bugs.
Take one down, patch it around,
129 little bugs in the code.

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    1. Best Answer
      Ok, having looked more closely, you need TWO loops (which you prob’ly already know). I made a testing setup and ran the following with fair results:

      @echo off & setlocal
      :: this version is NOT optimized! It passes through all files for each line
      :: until the last line in the longest file is reached.
      :: for speed, use ATTRIB to select the files and then disqualify each file
      :: when it reaches its last line.
      set c=0
      :: var TEST is a flag that says no files have any more unprocessed lines
      set test=—-

      :: main loop – pass through all files
      :aa

      :: clear flag for the next iteration of ‘aa’
      set test=
      :: secondary loop – pass through all files pulling the current line from each
      for %%z in (*.txt) do (
      call :xx !c! %%z
      )
      set /a c+=1
      if defined test goto :aa
      goto :eof

      :xx
      set /a k=%1+1
      :: ‘SKIP=0’ is not accepted by batch, so this is a workaround
      set sk=
      if %1 neq 0 set sk=skip=%1
      for /f “%sk% tokens=*” %%a in (%2) do (
      if “%%a” equ “” echo no more lines in file %2 & goto :eof
      echo line %k% from file %2: %%a
      pause
      :: set flag for loop-repeat: does not have to be %%a. Just needs some/any value
      set test=%%a
      goto :eof
      )

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