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这个网页显示如何阅读的具体行从一个文本文件。有许多方法可以有供/ F命令读取输入文件 for instance:- for /f "delims=" %%a in (input.txt) do ... for /f "delims=" %%a in ('type input.txt') do ... for /f "delims=" %%a in ('more ^< input.txt') do ... However, only the last method (using the more command) will give consistent results across Windows NT, 2000, XP and 2003. The first method does not recognise unicode files. Also, the usebackq switch must be used if the input filename contains spaces. The second method, using the type command, also fails to recognise unicode files on Windows 2000, XP and 2003 if the input file does not begin with a bit order mark (BOM). In all the examples, assume the contents of of the file numbers.txt to be:- one two three four five six seven eight nine ten Displaying the first line This example prints one. @echo off & setlocal ENABLEEXTENSIONS set "first=" for /f "delims=" %%a in ('more ^< numbers.txt') do ( if not defined first set first=%%a ) echo/%first% Displaying the first X lines This example prints one, two and three. @echo off & setlocal ENABLEEXTENSIONS set "lines=3" set i=-1 set "ok=" for /f "delims=" %%a in ('more ^< numbers.txt') do ( set/a i+=1 & for /f %%z in ('echo/%%i%%') do ( if "%%z"=="%lines%" set ok=1 ) if not defined ok echo/%%a ) Displaying the last line This example prints ten. @echo off & setlocal ENABLEEXTENSIONS for /f "delims=" %%a in ('more ^< numbers.txt') do set "last=%%a" echo/%last% Displaying the last X lines This example prints nine and ten. @echo off & setlocal ENABLEEXTENSIONS set "lines=2" for /f %%a in ('find/c /v "" ^< numbers.txt') do set/a skip=%%a-lines for /f "delims=" %%a in ('more/e +%skip% ^< numbers.txt') do ( echo/%%a ) Displaying the Nth line This example prints three. Note that instead of using the more command's /e switch, the skip option could have been used with the for /f command, however, this fails is it is set to any number less than one. @echo off & setlocal ENABLEEXTENSIONS set LineNo=3 set "line=" set/a LineNo-=1 for /f "delims=" %%a in ('more/e +%LineNo% ^< numbers.txt') do ( if not defined line set "line=%%a" ) echo/%line% Displaying the Nth line plus X number of lines This example prints five and six. @echo off & setlocal ENABLEEXTENSIONS set start=5 set "lines=2" set/a i=-1,start-=1 set "ok=" for /f "delims=" %%a in ('more/e +%start% ^< numbers.txt') do ( set/a i+=1 & for /f %%z in ('echo/%%i%%') do ( if "%%z"=="%lines%" set ok=1 ) if not defined ok echo/%%a ) |
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