Often such problems occur. Why do they occur? And how to solve them?
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中国DOS联盟论坛 » DOS批处理 & 脚本技术（批处理室） » [Help]Often when writing batch processing, there is "There should not be goto here at this time"
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Posted 2011-01-15 18:22 · 中国 黑龙江 哈尔滨 联通
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Posted 2011-01-15 22:35 · 中国 吉林 延边朝鲜族自治州 电信
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1. A single `goto` alone will not cause such a problem.
2. `goto` combined with other commands. Of course, it is most combined with `if`.
The first type, character comparison: `if %a%==1 goto b`
When `%a%` is empty, an error is returned: at this time, `goto` should not be present.
Solution: Add quotes `if "%a%"=="1" goto b`
The second type, numerical comparison: `if %a% lss 1 goto b`
Because numerical comparison needs to be performed, so quotes cannot be added to avoid the situation where `%a%` is empty.
Solution 1: Handle the situation where `%a%` is empty alone before this.
Solution 2: Use delayed variables, for example `if !a! lss 1 goto b`
[ Last edited by Hanyeguxing on 2011-1-15 at 22:36 ]
2. `goto` combined with other commands. Of course, it is most combined with `if`.
The first type, character comparison: `if %a%==1 goto b`
When `%a%` is empty, an error is returned: at this time, `goto` should not be present.
Solution: Add quotes `if "%a%"=="1" goto b`
The second type, numerical comparison: `if %a% lss 1 goto b`
Because numerical comparison needs to be performed, so quotes cannot be added to avoid the situation where `%a%` is empty.
Solution 1: Handle the situation where `%a%` is empty alone before this.
Solution 2: Use delayed variables, for example `if !a! lss 1 goto b`
[ Last edited by Hanyeguxing on 2011-1-15 at 22:36 ]
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Posted 2011-01-17 02:33 · 中国 吉林 长春 电信
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So you mean that CMD's handling of spaces is between "%variable%" and "!variable!", right? (PS: I guess it's also after %%I in FOR, otherwise how could you delete blank lines)
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