请分析以下代码:PATH: A {PWD:~A}$IFS????.???
时间: 2023-12-19 21:31:57 浏览: 55
这段代码是一条shell命令,其中包含了一些特殊变量和环境变量。具体解释如下:
- PATH:环境变量,用于指定系统查找可执行文件的路径。
- A:自定义变量,值为字符串"A"。
- PWD:环境变量,表示当前工作目录的路径。
- $IFS:特殊变量,表示shell的内部字段分隔符,通常为" "、"\t"、"\n"三个字符的组合。
- ????.????:这是一个通配符,表示匹配任意四个字符的文件名,后缀为".????"。
根据上述解释,这段代码的作用是在A目录下查找所有后缀为".????"的文件。其中,IFS变量的值被设置为"????",这样在执行查找命令时,文件名中的任意四个字符就会被当作文件名的前缀和后缀进行匹配。
相关问题
INCLUDEPATH += $$PWD/../onviflibs/onvifcore/OnvifDiscoveryLib/onvif\ $$PWD/../onviflibs/onvifcore/OnvifDeviceLib/onvif\ $$PWD/../onviflibs/onvifcore/OnvifEventLib/onvif\ $$PWD/../onviflibs/OnvifAnalyticsLib/onvif\ $$PWD/../onviflibs/OnvifReceiverLib/onvif\ $$PWD/../onviflibs/OnvifVideoAnalyticsDeviceLib/onvif\ $$PWD/../onviflibs/OnvifRecordingControlLib/onvif\ $$PWD/../onviflibs/OnvifRecordingSearchLib/onvif\ $$PWD/../onviflibs/OnvifReplayControlLib/onvif\ $$PWD/../onviflibs/OnvifDisplayLib/onvif\ $$PWD/../onviflibs/OnvifPTZLib/onvif\ $$PWD/../onviflibs/OnvifMediaLib/onvif,上面代码正确吗
这段代码看起来也没有语法错误,但是同样需要将路径中的反斜杠`\`改成斜杠`/`。因此正确的写法是:
```
INCLUDEPATH += $$PWD/../onviflibs/onvifcore/OnvifDiscoveryLib/onvif \
$$PWD/../onviflibs/onvifcore/OnvifDeviceLib/onvif \
$$PWD/../onviflibs/onvifcore/OnvifEventLib/onvif \
$$PWD/../onviflibs/OnvifAnalyticsLib/onvif \
$$PWD/../onviflibs/OnvifReceiverLib/onvif \
$$PWD/../onviflibs/OnvifVideoAnalyticsDeviceLib/onvif \
$$PWD/../onviflibs/OnvifRecordingControlLib/onvif \
$$PWD/../onviflibs/OnvifRecordingSearchLib/onvif \
$$PWD/../onviflibs/OnvifReplayControlLib/onvif \
$$PWD/../onviflibs/OnvifDisplayLib/onvif \
$$PWD/../onviflibs/OnvifPTZLib/onvif \
$$PWD/../onviflibs/OnvifMediaLib/onvif
```
需要注意的是,这个代码片段中的`$$PWD`表示当前文件所在的目录。
e,pwd,lasttime from admin where name=? and pwd=? Parameters: [user, 111111]
This is a SQL query that selects three columns from the "admin" table where the "name" column matches "user" and the "pwd" column matches "111111". The three columns returned are "e" (presumably an email address), "pwd" (the password), and "lasttime" (the last time the admin account was accessed).
The question mark placeholders suggest that this query is being used with parameterized queries, where the actual values for "name" and "pwd" are provided separately from the query itself. This is a common practice in web applications to prevent SQL injection attacks.