我有几百个文件，其中大部分在末尾（结束行）包含“exit”。并非所有文件的末尾都有这个“exit”。如何检查内容文件的最后一行，如果是 'exit' 则将其删除？
【问题讨论】：
HEAD.EXE 和 TAIL.EXE。尝试使用这些。 TAIL 会从文件的末尾返回指定的行数，HEAD 会从文件的开头返回指定的行数。
标签： batch-file window
我编写了一个名为 REPL.BAT 的混合 JScript/批处理实用程序，它使这项任务非常简单，而且速度非常快。该实用程序读取标准输入，执行任何正则表达式搜索和替换，并将输出写入 stout。
该实用程序是一个脚本，可在任何现代版本的 Windows（从 XP 开始）上运行，并且不需要安装任何 3rd 方工具。
以下批处理脚本处理给定路径中的所有文件，并且仅当每个文件的最后一行是单词 exit 且没有其他字符时才删除它。我使用I 选项使搜索不区分大小写。还需要M 选项以允许跨多行搜索。正则表达式可以根据需要轻松改进。例如，如果最后一行包含带有空格的 EXIT，您也可以匹配并删除它。
@echo off
for %%F in (\somePath\*) do (
type "%%F"|repl "^exit\r?\n?(?!\S|\s)" "" im >"%%F.new"
move /y "%%F.new" "%%F" >nul
)
REPL.BAT 文件必须位于您当前的文件夹（您从中运行的文件夹）中，或者更好的是，位于您的 PATH 文件夹之一中。
这是 REPL.BAT 脚本。我发现它对于这么小的脚本非常有用。完整的文档嵌入在脚本中。
@if (@X)==(@Y) @end /* Harmless hybrid line that begins a JScript comment
::************ Documentation ***********
:::
:::REPL Search Replace [Options [SourceVar]]
:::REPL /?
:::
::: Performs a global search and replace operation on each line of input from
::: stdin and prints the result to stdout.
:::
::: Each parameter may be optionally enclosed by double quotes. The double
::: quotes are not considered part of the argument. The quotes are required
::: if the parameter contains a batch token delimiter like space, tab, comma,
::: semicolon. The quotes should also be used if the argument contains a
::: batch special character like &, |, etc. so that the special character
::: does not need to be escaped with ^.
:::
::: If called with a single argument of /? then prints help documentation
::: to stdout.
:::
::: Search - By default this is a case sensitive JScript (ECMA) regular
::: expression expressed as a string.
:::
::: JScript regex syntax documentation is available at
::: http://msdn.microsoft.com/en-us/library/ae5bf541(v=vs.80).aspx
:::
::: Replace - By default this is the string to be used as a replacement for
::: each found search expression. Full support is provided for
::: substituion patterns available to the JScript replace method.
::: A $ literal can be escaped as $$. An empty replacement string
::: must be represented as "".
:::
::: Replace substitution pattern syntax is documented at
::: http://msdn.microsoft.com/en-US/library/efy6s3e6(v=vs.80).aspx
:::
::: Options - An optional string of characters used to alter the behavior
::: of REPL. The option characters are case insensitive, and may
::: appear in any order.
:::
::: I - Makes the search case-insensitive.
:::
::: L - The Search is treated as a string literal instead of a
::: regular expression. Also, all $ found in Replace are
::: treated as $ literals.
:::
::: B - The Search must match the beginning of a line.
::: Mostly used with literal searches.
:::
::: E - The Search must match the end of a line.
::: Mostly used with literal searches.
:::
::: V - Search and Replace represent the name of environment
::: variables that contain the respective values. An undefined
::: variable is treated as an empty string.
:::
::: M - Multi-line mode. The entire contents of stdin is read and
::: processed in one pass instead of line by line. ^ anchors
::: the beginning of a line and $ anchors the end of a line.
:::
::: X - Enables extended substitution pattern syntax with support
::: for the following escape sequences:
:::
::: \\ - Backslash
::: \b - Backspace
::: \f - Formfeed
::: \n - Newline
::: \r - Carriage Return
::: \t - Horizontal Tab
::: \v - Vertical Tab
::: \xnn - Ascii (Latin 1) character expressed as 2 hex digits
::: \unnnn - Unicode character expressed as 4 hex digits
:::
::: Escape sequences are supported even when the L option is used.
:::
::: S - The source is read from an environment variable instead of
::: from stdin. The name of the source environment variable is
::: specified in the next argument after the option string.
:::
::************ Batch portion ***********
@echo off
if .%2 equ . (
if "%~1" equ "/?" (
findstr "^:::" "%~f0" | cscript //E:JScript //nologo "%~f0" "^:::" ""
exit /b 0
) else (
call :err "Insufficient arguments"
exit /b 1
)
)
echo(%~3|findstr /i "[^SMILEBVX]" >nul && (
call :err "Invalid option(s)"
exit /b 1
)
cscript //E:JScript //nologo "%~f0" %*
exit /b 0
:err
>&2 echo ERROR: %~1. Use REPL /? to get help.
exit /b
************* JScript portion **********/
var env=WScript.CreateObject("WScript.Shell").Environment("Process");
var args=WScript.Arguments;
var search=args.Item(0);
var replace=args.Item(1);
var options="g";
if (args.length>2) {
options+=args.Item(2).toLowerCase();
}
var multi=(options.indexOf("m")>=0);
var srcVar=(options.indexOf("s")>=0);
if (srcVar) {
options=options.replace(/s/g,"");
}
if (options.indexOf("v")>=0) {
options=options.replace(/v/g,"");
search=env(search);
replace=env(replace);
}
if (options.indexOf("l")>=0) {
options=options.replace(/l/g,"");
search=search.replace(/([.^$*+?()[{\\|])/g,"\\$1");
replace=replace.replace(/\$/g,"$$$$");
}
if (options.indexOf("b")>=0) {
options=options.replace(/b/g,"");
search="^"+search
}
if (options.indexOf("e")>=0) {
options=options.replace(/e/g,"");
search=search+"$"
}
if (options.indexOf("x")>=0) {
options=options.replace(/x/g,"");
replace=replace.replace(/\\\\/g,"\\B");
replace=replace.replace(/\\b/g,"\b");
replace=replace.replace(/\\f/g,"\f");
replace=replace.replace(/\\n/g,"\n");
replace=replace.replace(/\\r/g,"\r");
replace=replace.replace(/\\t/g,"\t");
replace=replace.replace(/\\v/g,"\v");
replace=replace.replace(/\\x[0-9a-fA-F]{2}|\\u[0-9a-fA-F]{4}/g,
function($0,$1,$2){
return String.fromCharCode(parseInt("0x"+$0.substring(2)));
}
);
replace=replace.replace(/\\B/g,"\\");
}
var search=new RegExp(search,options);
if (srcVar) {
WScript.Stdout.Write(env(args.Item(3)).replace(search,replace));
} else {
while (!WScript.StdIn.AtEndOfStream) {
if (multi) {
WScript.Stdout.Write(WScript.StdIn.ReadAll().replace(search,replace));
} else {
WScript.Stdout.WriteLine(WScript.StdIn.ReadLine().replace(search,replace));
}
}
}
【讨论】：
setlocal enabledelayedexpansion
for /f "delims=" %%Z in ('dir /s /b /a-d .') do (
for /f "delims=" %%a in (%%Z) do set last_line=%%a
echo !last_line! | find "exit" && del /f /q %%Z
)
endlocal
编辑（foxidrive 读起来比我仔细）：
@echo off
setlocal enabledelayedexpansion
for /f "delims=" %%Z in ('dir /s /b /a-d') do (
set /a counter=1
set "yes=no"
for /f "usebackq delims=" %%a in ("%%Z") do set last_line=%%a&& set /a counter=counter+1
echo !last_line! | find /I "exit" >nul&& set "yes=yes"
if "!yes!" equ "yes" (
break >"%%Z.tmp"
for /f "usebackq delims=" %%a in ("%%Z") do (
set /a counter=counter-1
if "!counter!" neq "1" (
endlocal
echo %%a | find "ECHO is off.">nul&&echo\>>"%%Z.tmp"
echo %%a | find "ECHO is off.">nul||echo %%a>>"%%Z.tmp"
)
)
echo "Exit" found in at the end of --%%Z--
copy /y "%%Z.tmp" "%%Z" >nul
)
)
endlocal
edit:工作和一点点改进。仍然不能处理空行，但现在更好了。
【讨论】：
exit而不是删除文件。
对于sed“仅”：
for %i in (*) do @sed -i"%~i.bak" "$ {s/exit/exit/i;/exit/d}" "%~i"
【讨论】：
从@npocmaka 借用代码并使用 GNUsed 那么这应该非常健壮，并且可以保留空白行并处理长文件名等。它处理整个目录树。未经测试。
@echo off
setlocal enabledelayedexpansion
for /f "delims=" %%Z in ('dir /s /b /a-d') do (
for /f "delims=" %%a in ('type "%%Z"') do set "last_line=%%a"
echo !last_line! | find /i "exit" >nul && (
sed $d "%%Z" > "%%Z.tmp"
move /y "%%Z.tmp" "%%Z" >nul
)
)
endlocal
【讨论】：
@echo off
setlocal EnableDelayedExpansion
rem "I have a few hundred files"
for %%a in (*.*) do (
rem "most of which contains 'exit' at the end line."
set "lastLine="
(for /F "usebackq delims=" %%b in ("%%a") do (
if not defined lastLine (
set "lastLine=%%b"
) else (
echo(!lastLine!
set "lastLine=%%b"
)
)) > "%%~Na.tmp"
rem "Not all of the files have this 'exit' at the end."
rem "How can I check the content of last line of the files"
if "!lastLine!" equ "exit" (
rem "and then remove it if it's 'exit'?"
move /Y "%%~Na.tmp" "%%a"
) else (
del "%%~Na.tmp"
)
)
【讨论】：