我需要测试是否设置了一个变量。我尝试了几种技术，但每当%1被引号包围时，它们似乎都失败了，例如%1是“c:\一些带空格的路径”。
IF NOT %1 GOTO MyLabel // This is invalid syntax
IF "%1" == "" GOTO MyLabel // Works unless %1 has double quotes which fatally kills bat execution
IF %1 == GOTO MyLabel // Gives an unexpected GOTO error.
根据这个网站，这些是支持的IF语法类型。所以，我不知道该怎么做。
IF [NOT] ERRORLEVEL number command
IF [NOT] string1==string2 command
IF [NOT] EXIST filename command
更新:在2020-10-25，我更新了接受的答案，从使用括号到使用波浪号。每个人都说波浪更好，因为它更安全。我有点撕裂，因为波浪线看起来更复杂，不太清楚它的目的是什么，但尽管如此，我改变了它。
空字符串是一对双引号/""，我们可以直接测试长度:
set ARG=%1
if not defined ARG goto nomore
set CHAR=%ARG:~2,1%
if defined CHAR goto goon
然后用双引号测试它的2个字符:
if ^%ARG:~1,1% == ^" if ^%ARG:~0,1% == ^" goto blank
::else
goto goon
这里有一个您可以使用的批处理脚本。我觉得它正好接住了空弦。
这只是一个例子，你只需要根据你的脚本定制上面的2(或3?)步骤。
@echo off
if not "%OS%"=="Windows_NT" goto EOF
:: I guess we need enableExtensions, CMIIW
setLocal enableExtensions
set i=0
set script=%0
:LOOP
set /a i=%i%+1
set A1=%1
if not defined A1 goto nomore
:: Assumption:
:: Empty string is (exactly) a pair of double-quotes ("")
:: Step out if str length is more than 2
set C3=%A1:~2,1%
if defined C3 goto goon
:: Check the first and second char for double-quotes
:: Any characters will do fine since we test it *literally*
if ^%A1:~1,1% == ^" if ^%A1:~0,1% == ^" goto blank
goto goon
:goon
echo.args[%i%]: [%1]
shift
goto LOOP
:blank
echo.args[%i%]: [%1] is empty string
shift
goto LOOP
:nomore
echo.
echo.command line:
echo.%script% %*
:EOF
酷刑测试结果:
.test.bat :: "" ">"""bl" " "< "">" (")(") "" :: ""-" " "( )"">\>" ""
args[1]: [::]
args[2]: [""] is empty string
args[3]: [">"""bl" "]
args[4]: ["< "">"]
args[5]: [(")(")]
args[6]: [""] is empty string
args[7]: [::]
args[8]: [""-" "]
args[9]: ["( )"">\>"]
args[10]: [""] is empty string
command line:
.test.bat :: "" ">"""bl" " "< "">" (")(") "" :: ""-" " "( )"">\>" ""
空字符串是一对双引号/""，我们可以直接测试长度:
set ARG=%1
if not defined ARG goto nomore
set CHAR=%ARG:~2,1%
if defined CHAR goto goon
然后用双引号测试它的2个字符:
if ^%ARG:~1,1% == ^" if ^%ARG:~0,1% == ^" goto blank
::else
goto goon
这里有一个您可以使用的批处理脚本。我觉得它正好接住了空弦。
这只是一个例子，你只需要根据你的脚本定制上面的2(或3?)步骤。
@echo off
if not "%OS%"=="Windows_NT" goto EOF
:: I guess we need enableExtensions, CMIIW
setLocal enableExtensions
set i=0
set script=%0
:LOOP
set /a i=%i%+1
set A1=%1
if not defined A1 goto nomore
:: Assumption:
:: Empty string is (exactly) a pair of double-quotes ("")
:: Step out if str length is more than 2
set C3=%A1:~2,1%
if defined C3 goto goon
:: Check the first and second char for double-quotes
:: Any characters will do fine since we test it *literally*
if ^%A1:~1,1% == ^" if ^%A1:~0,1% == ^" goto blank
goto goon
:goon
echo.args[%i%]: [%1]
shift
goto LOOP
:blank
echo.args[%i%]: [%1] is empty string
shift
goto LOOP
:nomore
echo.
echo.command line:
echo.%script% %*
:EOF
酷刑测试结果:
.test.bat :: "" ">"""bl" " "< "">" (")(") "" :: ""-" " "( )"">\>" ""
args[1]: [::]
args[2]: [""] is empty string
args[3]: [">"""bl" "]
args[4]: ["< "">"]
args[5]: [(")(")]
args[6]: [""] is empty string
args[7]: [::]
args[8]: [""-" "]
args[9]: ["( )"">\>"]
args[10]: [""] is empty string
command line:
.test.bat :: "" ">"""bl" " "< "">" (")(") "" :: ""-" " "( )"">\>" ""
脚本1:
输入(“删除引号。”cmd"这是一个测试")
@ECHO OFF
REM Set "string" variable to "first" command line parameter
SET STRING=%1
REM Remove Quotes [Only Remove Quotes if NOT Null]
IF DEFINED STRING SET STRING=%STRING:"=%
REM IF %1 [or String] is NULL GOTO MyLabel
IF NOT DEFINED STRING GOTO MyLabel
REM OR IF "." equals "." GOTO MyLabel
IF "%STRING%." == "." GOTO MyLabel
REM GOTO End of File
GOTO :EOF
:MyLabel
ECHO Welcome!
PAUSE
输出(没有，%1不是空的，空的，或NULL):
使用上面的脚本运行("Remove Quotes.cmd")，不带任何参数
输出(%1为空白、空或NULL):
Welcome!
Press any key to continue . . .
注意:如果你在If () ELSE()语句中设置了一个变量，它将在退出If语句后才对DEFINED可用(除非“延迟变量扩展”被启用;一旦启用，请使用感叹号“!”来代替百分比“%”符号}。
例如:
脚本2:
输入(“删除引号。”cmd"这是一个测试")
@ECHO OFF
SETLOCAL EnableDelayedExpansion
SET STRING=%0
IF 1==1 (
SET STRING=%1
ECHO String in IF Statement='%STRING%'
ECHO String in IF Statement [delayed expansion]='!STRING!'
)
ECHO String out of IF Statement='%STRING%'
REM Remove Quotes [Only Remove Quotes if NOT Null]
IF DEFINED STRING SET STRING=%STRING:"=%
ECHO String without Quotes=%STRING%
REM IF %1 is NULL GOTO MyLabel
IF NOT DEFINED STRING GOTO MyLabel
REM GOTO End of File
GOTO :EOF
:MyLabel
ECHO Welcome!
ENDLOCAL
PAUSE
输出:
C:\Users\Test>"C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd" "This is a Test"
String in IF Statement='"C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd"'
String in IF Statement [delayed expansion]='"This is a Test"'
String out of IF Statement='"This is a Test"'
String without Quotes=This is a Test
C:\Users\Test>
注意:它还会从字符串中删除引号。
例如(使用脚本1或2):
c:\ users \ test \ documents \批处理文件>"删除引号。cmd"这是"一个"测试"
输出(脚本2):
String in IF Statement='"C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd"'
String in IF Statement [delayed expansion]='"This is "a" Test"'
String out of IF Statement='"This is "a" Test"'
String without Quotes=This is a Test
在脚本2中不带任何参数地执行("Remove Quotes.cmd"):
输出:
Welcome!
Press any key to continue . . .
