what does NEQ was not expected at this time me?-CodePudding

Every time I run this code:

 %SystemRoot%\System32\choice.exe /C:12345 /M "1M(1)1F(2)2M(3)2N(4)3rd(5)"
IF ERRORLEVEL ==5 goto n3
IF ERRORLEVEL NEQ 5 echo incorrect try again
:n3

it gives me this error: NEQ was not expected at this time
what does this mean? I have tried different syntaxes but can't find anything online about what this means.

CodePudding user response：

errorlevel is just a string, the same was as are socks and banana and 62.

62 has a secondary meaning - it's a string but it's also a number.

errorlevel also has a secondary meaning - it's a number that describes the result of executing a command.

Originally, we could use

if %zombies%==62 ...

which would mean if the *contents* of the variable "zombies" was exactly "62" (then do something)

OR we could use

if errorlevel n ...

which would mean if the current errorlevel (ie the code returned from the last command [athough some commands do not alter the errorlevel value]) was n **OR greater than ** n then do something.

This functionality remains.

Later, the comparison operator == was supplemented by {EQU NEQ GTR LSS GEQ LEQ} to enhance flexibility. Also by the else clause to specify instructions whould the comparison not be evaluated to true.

IF ERRORLEVEL ==5 compares the STRING ERRORLEVEL to the STRING 5. Since these two are different, it will not execute the echo command

IF ERRORLEVEL NEQ 5 yields a syntax error because batch is expecting a number after errorlevel or == (old syntax); but it finds NEQ (new syntax in conflict with old).

IF %ERRORLEVEL% NEQ 5 would work as you apparently expect because %errorlevel% retrieves the value of the current errorlevel.

BUT there's a trap. %errorlevel% retrieves the value of the user-defined variable errorlevel and only goes on to the system-defined value if there is no user-defined variable errorlevel.

Hence, of errorlevel is 6, then executing

ECHO %ERRORLEVEL%
SET "errorlevel=banana"
ECHO %ERRORLEVEL%
SET "errorlevel="
ECHO %ERRORLEVEL%

will report

6
banana
6

Hence, it's highly unusual to assign a value to errorlevel or to the other magic variables like random or cd.