如何在批处理脚本中将特定数据从一个文件复制到另一个文件

Question

I am trying to copy data from a.txt to b.txt using .batch file. But i dont want the all data from a.txt. I just trying to copy perticular data.

For Example: a.txt contains

line 1:this is a.txt file
line 2: name= abc
line 3: age= 24
line 4: country= xyz
line 5: contact no= 123456778
line 6: end of a.txt

Now, I want to read that a.txt and copy particular data to new b.txt:

b.txt:

abc 21 xyz

Any suggestions?

Thanks for help.

Naren

Answer 1

Assuming that you meant abc 24 xyz . (Shortest answer at bottom)

This provides you with the most flexibility and cleanest variables.

@echo off
setlocal enabledelayedexpansion

:: Just making sure that %data% is empty
set data=

for /f "tokens=1,2* delims==" %%x in (a.txt) do call :work %%x "%%y"

:: Removes leading space and sends to b.txt
echo %data:~1%>b.txt
goto :eof

:work
set var=%1
set val=%~2

:: Remove any leading spaces.
:work-loop
if "!val:~0,1!"==" " (
  set val=!val:~1!
  goto :work-loop
)

if "%var%"=="name"    set data=%data% %var%
if "%var%"=="age"     set data=%data% %var%
if "%var%"=="country" set data=%data% %var%

goto :eof

Or a little shorter.

@echo off
setlocal enabledelayedexpansion

set data=
for /f "tokens=1,2* delims==" %%x in (a.txt) do call :work %%x "%%y"

:: Removes leading space and sends to b.txt
echo %data:~1%>b.txt
echo %data%>b.txt

goto :eof

:work
set var=%1
set val=%~2

:since leading spaces have not been removed, there need be no space between %data% and %var%
if "%var%"=="name"    set data=%data%%var%
if "%var%"=="age"     set data=%data%%var%
if "%var%"=="country" set data=%data%%var%

goto :eof

Shortest answer

@echo off
setlocal
for /f "tokens=1,2* delims== " %%x in (a.txt) do (
    if "%%x"=="name" set %%x=%%y
    if "%%x"=="age" set %%x=%%y
    if "%%x"=="country" set %%x=%%y
)
echo %name% %age% %country%>b.txt
endlocal

In this last one the use of setlocal and endlocal are not ness :: Removes leading space and sends to b.txt echo %data:~1%>b.txt icary, they just make sure your variables die when the batch file ends.