识别或删除 Windows 命令脚本环境变量中的等号 (=)

Question

有没有办法做这个主题？例如，我们不能简单地通过子字符串替换语法%variable:substring1=substring2%来替换等号，因为substring1不能包含等号。

Answer 1

这是一种方法（想法是用 for /f 拆分它，并用相同数量的替换替换等号，用 strlen 函数计算它们的长度）：

@echo off


rem ===== testing the function =======

set "eqs====abcd=abcd===abcdabcd======~*"
set replace_with=X1
echo %eqs%

call :eqreplacer "%eqs%" %replace_with% res
echo %res%
exit /b %errorlevel%

rem ===============================


:eqreplacer String Replacer [RtnVar]
setlocal
rem  the result of the operation will be stored here
set "result=#%~1#"
set "replacer=%~2"
call :strlen0  result wl
call :strlen0  replacer rl

:start

  set "part1="
  set "part2="

  rem splitting the string on two parts
  for /f "tokens=1* delims==" %%w in ("%result%") do (
   set "part1=%%w"
   set "part2=%%x"
  )

  rem calculating the count replace strings we should use
  call :strlen0  part1 p1l
  call :strlen0  part2 p2l
  set /a iteration_end=wl-p1l-p2l

  rem creating a sequence with replaced strings
  setlocal enableDelayedExpansion
  set "sequence="
  for /l %%i in (1,1,%iteration_end%) do (
   set sequence=!sequence!%replacer%
  )
  endlocal & set "sequence=%sequence%"

  rem adjust the string length
  set /a wl=wl+iteration_end*(rl-1)

  rem replacing for the current iteration
  set result=%part1%%sequence%%part2%
  rem if the second part is empty the task is over
  if "%part2%" equ "" (
   set result=%result:~1,-1%
   goto :endloop
  )


  goto :start

:endloop
endlocal & if "%~3" neq "" (set %~3=%result%) else echo %result%
exit /b

:strlen0  StrVar  [RtnVar]
  setlocal EnableDelayedExpansion
  set "s=#!%~1!"
  set "len=0"
  for %%N in (4096 2048 1024 512 256 128 64 32 16 8 4 2 1) do (
    if "!s:~%%N,1!" neq "" (
      set /a "len+=%%N"
      set "s=!s:~%%N!"
    )
  )
  endlocal&if "%~2" neq "" (set %~2=%len%) else echo %len%
exit /b

here you can find more solutions.看看dbenham的post。

Answer 2

识别=的简单方法。

echo "%variable%"|find "=">nul
if not errorlevel 1 echo equal sign detected

Answer 3

一个遍历字符串并根据=检查每个字符的简单循环怎么样？

@echo off
setlocal EnableExtensions DisableDelayedExpansion

rem // Define constants here:
set "STRING=%~1" & rem // (string from first command line argument)
set "SEARCH==" & rem // (specify a single character here)
set "REPLAC=" & rem // (specify an arbitrary string here)

rem // Check search string for validity (one character):
if not defined SEARCH ((>&2 echo ERROR: no search string defined!) & exit /B 1)
setlocal EnableDelayedExpansion
if not "!SEARCH:~1!"=="" ((>&2 echo ERROR: search string too long^^!) & exit /B 1)
rem // Loop through each character of the string:
set "RESULT="
:LOOP
if not defined STRING goto :QUIT
rem // Compare current character with search string:
set "CHAR=!STRING:~,1!"
if "!CHAR!"=="!SEARCH!" (
    rem // Match found, so replace character:
    set "RESULT=!RESULT!!REPLAC!"
) else (
    rem // No match found, so keep character:
    set "RESULT=!RESULT!!CHAR!"
)
rem // Remove processed character from (remaining) string:
set "STRING=!STRING:~1!"
goto :LOOP
:QUIT
rem // Return result here finally:
echo(!RESULT!
endlocal

endlocal
exit /B

---

这在性能方面应该会好一点，因为字符串操作较少：

@echo off
setlocal EnableExtensions DisableDelayedExpansion

rem // Define constants here:
set "STRING=%~1" & rem // (string from first command line argument)
set "SEARCH==" & rem // (specify a single character here)
set "REPLAC=" & rem // (specify an arbitrary string here)

rem // Check search string for validity (one character):
if not defined SEARCH ((>&2 echo ERROR: no search string defined!) & exit /B 1)
setlocal EnableDelayedExpansion
if not "!SEARCH:~1!"=="" ((>&2 echo ERROR: search string too long^^!) & exit /B 1)
rem // Loop through each character of the string:
set /A "INDEX=0" & set "RESULT="
if not defined STRING goto :QUIT
:LOOP
rem // Compare currently indexed character with search string:
set "CHAR=!STRING:~%INDEX%,1!"
if not defined CHAR goto :QUIT
if "!CHAR!"=="!SEARCH!" (
    rem // Match found, so replace character:
    set "RESULT=!RESULT!!REPLAC!"
) else (
    rem // No match found, so keep character:
    set "RESULT=!RESULT!!CHAR!"
)
rem // Increment character index:
set /A "INDEX+=1"
goto :LOOP
:QUIT
rem // Return result here finally:
echo(!RESULT!
endlocal

endlocal
exit /B