Co "&&" w tym pliku wsadowym?

Question

Otrzymałem wiersz kodu od kogoś, kto odpowiedział na jedno z moich pytań, ale jestem zdezorientowany: co robi "& &" w tym pliku wsadowym.

@echo off 
set /p Quest="How are you today? " 
echo %Quest% > Results.txt 
findstr /r /i "not.*good not.*well" Results.txt >nul && echo Sorry && goto pause 
findstr /i "good well" Results.txt >nul && echo My day is doing good as well 
:pause 
pause 

Answer 1

&& uruchamia drugie polecenie w wierszu, gdy pierwsza komenda wraca pomyślnie, lub z errorlevel 0. Przeciwieństwem && jest ||, który prowadzi drugą komendę, gdy pierwsza komenda nie powiedzie, lub z errorlevel z 1.

Answer 2

& seperates commands on a line. 

&& executes this command only if previous command's errorlevel is 0. 

|| (not used above) executes this command only if previous command's errorlevel is NOT 0 

> output to a file 

>> append output to a file 

< input from a file 

| output of one command into the input of another command 

^ escapes any of the above, including itself, if needed to be passed to a program 

" parameters with spaces must be enclosed in quotes 

+ used with copy to concatinate files. E.G. copy file1+file2 newfile 

, used with copy to indicate missing parameters. This updates the files modified date. E.G. copy /b file1,, 

%variablename% a inbuilt or user set environmental variable 

!variablename! a user set environmental variable expanded at execution time, turned with SelLocal EnableDelayedExpansion command 

%<number> (%1) the nth command line parameter passed to a batch file. %0 is the batchfile's name. 

%* (%*) the entire command line. 

%<a letter> or %%<a letter> (%A or %%A) the variable in a for loop. Single % sign at command prompt and double % sign in a batch file. 


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