read one line of txt file into variable

[ka3qyk]

I need a way to read one line of a txt file into a variable based on a number stored in another variable.

Example
If "var-a" = 45 then read the 45th line of file.txt into "var-b"
Or
If "var-a" = 87 then read the 87th line of file.txt into "var-b"

Would also like to do this based on errorlevel but really need it for a variable

Would really appreciate your help
Thanks

[Vernon Frazee]

Hopefully the following example will come close to meeting your requirements. Once you get it saved to your hard drive as "GetLine.bat", get into the same directory with it and type

• GetLine /?

for brief instructions. A quick example of usage would be:

• GetLine 28 c:\windows\system.ini

This would display (and store) a string containing the first six words from the 28th line of the file "c:\windows\system.ini".

@echo off
 if (%2)==() goto Syntax
 if (%2)==(?) goto Syntax
 if (%2)==(/?) goto Syntax
 if (%1)==() goto NoVarA
 if not exist %2 goto NoFile
 goto Begin
:Syntax
 cls
 echo.
 echo     Name: GetLine.bat - (For U.S.A.'s MS-DOS 5.nn/6.nn and Windows 95/98/Me).
 echo.
 echo  Purpose: Display (and store) the first six words from the "nth" line in the
 echo           text file specified.
 echo.
 echo   Syntax: GetLine ## [d:][\path\]filename
 echo.
 echo    Where: "##" is the line number you want to see.
 echo.
 echo      and: "[d:][\path\]filename" is the complete "drive:\path\filename.ext" of
 echo           the file you want to use. (Note: The "[d:]" (drive) and "[\path\]"
 echo           are optional. Whether you need either or both depends on the file's
 echo           location in relation to your current location.
 echo.
 echo  Example: GetLine 28 c:\windows\system.ini
 echo.
 echo           Would return a string containing the first six words from the 28th
 echo           line of the file "c:\windows\system.ini".
 echo.
 echo Requires: FIND.EXE (anywhere in the PATH) and enough room in the environment
 echo           to hold the length of: the line number (times two), the complete
 echo           filename as well as the line retrieved, plus 41 characters.
 echo.
 goto End
:Begin
 for %%x in (File VarA VarB) do set %%x=
 for %%x in (~ enter) do if exist %%x.bat del %%x.bat
 set VarA=%1
 set File=%2
 :FindIt
 type %File%|find /n /v "!@#"|find "[%VarA%]">~.bat
 if errorlevel 1 goto NotFound
 echo.>>~.bat
 date<~.bat | find "Enter">~.bat
 echo set VarB=%%4 %%5 %%6 %%7 %%8 %%9>enter.bat
 for %%x in (call del) do %%x ~.bat
 del enter.bat
:Display
 echo.
 echo File: %File%
 echo VarA: %VarA%
 echo VarB: %VarB%
 echo.
 set cmdline=
 goto End
:NoFile
 echo.
 echo   Error: File "%2" does not exist
 echo.
 goto End
:NoVarA
 echo.
 echo   Error: You must specify a line number
 echo.
 goto End
:NotFound
 echo.
 echo   Error: File "%File%" does not contain a line number "%VarA%"
 echo.
:End

BTW, GetLine.bat sets three environment variables: "VARA" will contain the specified line number, "VARB" the returned six-word string and "FILE" the filename specified.