6 replies to this topic

[trids]

I just stumbled across this sublime technique of concatenating DOS commands with &&, in order to run them on the same line.

EXAMPLE -- Does all of this in ONE execution of RunWait()..

• set current drive to C:
• change path to WINNT folder
• collect the list of files there into a temporary file
• open the file in your text editor

    RunWait( @COMSPEC & " /c C:&&cd \winnt&&dir>D:\temp\multi.txt&&D:\temp\multi.txt", "", @SW_SHOW )

[BrettF]

Pure awesomeness

[lordofthestrings]

in dos what this does is the following:

Command A & Command B --> execute command A, then execute command B. (no evaluation of nothing)
Command A | command B --> execute command A, and redirect all it's output into the input of command B.
Command A && Command B ---> means execute command A, Evaluate the errorlevel after running Command A, and if the exit code (errorlevel) is 0, only then execute command B.
Command A || command B ---> execute Command A, evalutate the exit code of this command and if it's anything but 0, Only then execute command B.
command A >> outputfile.txt 2>&1 ---> means execute command A, and write the STDERR Output to STDOUT
examples:
dir c:\ & echo All done!
help | more
or
type c:\windows\system32\drivers\etc\hosts | find /I "Microsoft"
dir c:\windows || echo I can't find this directory c:\windows
dir>c:\file.txt 1<&2 (explain me why you see the dir command send it's output to the dosbox, while I clearly specify that I should output it to c:\file.txt......


if you want to read more about this look use command redirection operators

http://www.microsoft.com/resources/documen...n.mspx?mfr=true


--reason edit-- More examples of all commands

Edited by lordofthestrings, 10 October 2007 - 12:26 PM.

[trids]

Great! Thanks, lots, it's nice to have the whole picture

[drtrobridge]

I just stumbled across this sublime technique of concatenating DOS commands with &&, in order to run them on the same line.

EXAMPLE -- Does all of this in ONE execution of RunWait()..

• set current drive to C:
• change path to WINNT folder
• collect the list of files there into a temporary file
• open the file in your text editor

    RunWait( @COMSPEC & " /c C:&&cd \winnt&&dir>D:\temp\multi.txt&&D:\temp\multi.txt", "", @SW_SHOW )

 

I had to create and account to let you know that this info just turned my project from a disaster to a success. Thank you for your help!! This forum is spectacular.

[TheSaint]

Great find, thanks for sharing.

[spudw2k]

loves me some &&.  I use it quite often