8 replies to this topic

[Logan]

in dos help...

SET /P variable=[prompt string]

but unless you understand german... i don't.. it looks like there's extra words..
the ? character is a wildcard, meaning 1 character is suppost to be there, but it doesn't matter which... only having one at that location doesn't look right

~ is used in FOR loops (and maybe somewhere else)...
%~a (can be any letter, but must be the same both places in loop)
the ~ removes quotes
more help on FOR loops? go to CMD and type "FOR /?"
Example:
FOR %x IN (\random\directory\*) DO ECHO %~x
shows everything in that directory...

btw, in for loops, %fx would be full path, full file name is default, if i remember correctly

EDIT:
just noticed it was a number... numbers work like this..
Filename Special Words would go around here
(%0---------%1-----%2---%3-%4----%5--%6)
and can be used like this:
IF %1 == "Gary" THEN ECHO "You suck"

[dmg]

Yeah, that's my question. I saw several batch scripts using this ~ character. But what is it for?

And I've got another question:

SET /P %homedir%=Welches Verzeichnis soll gepackt werden?
IF NOT EXISTS %targetdir% GOTO NOTEXISTS
echo Quellverzeichnis auf "%homedir%" gesetzt.
SET /P targetdir=Wohin sollen die ZIP-Dateien? 
IF NOT EXISTS %targetdir% GOTO NOTEXISTS
echo Zielverzeichnis auf "%homedir%" gesetzt.

The text is crap, but I wonder why the SET /P doesn't work. Whatever I enter, it always says: ""blabla" is syntatically not processable at this place." (I translated, so it isn't right ) But what it generally says is, that this entered string is not placed correct there.

Anybody help?

It should work better like this:

SET /P %homedir%="Welches Verzeichnis soll gepackt werden? "
IF NOT EXIST "%homedir%" GOTO NOTEXISTS
echo Quellverzeichnis auf "%homedir%" gesetzt.
SET /P targetdir="Wohin sollen die ZIP-Dateien? "
IF NOT EXIST "%targetdir%" GOTO NOTEXISTS
echo Zielverzeichnis auf "%targetdir%" gesetzt.

Damn I hate the german language.... (yes I CAN read/write/speak it).

ps: ~ is also used with the "set" command like this:

%PATH:~10,5%


would expand the PATH environment variable, and then use only the 5 characters that begin at the 11th (offset 10) character of the expanded result.
If the length is not specified, then it defaults to the remainder of the variable value.
If either number (offset or length) is negative, then the number used is the length of the environment variable value added to the offset or length specified.


%PATH:~-10%


would extract the last 10 characters of the PATH variable.


%PATH:~0,-2%


would extract all but the last 2 characters of the PATH variable.

[DanM]

Sometimes, a ~ (or any other arbitrary character) may appear in a batch file "IF "command to avoid a possible null field in the interpreted command.

For example, to determine if a first parameter was passed to the batch file, I might write "If ~%1 == ~ ..."
If there were no first parameter, this would test true; if there were a first parameter, this would test false.

In execution, with a first parameter of dog, the test would interpret as "If ~dog == ~ ..." (false) and with no first parameter the test would interpret as "If ~ == ~ ..." (true). In the latter case, if you didn't include the "~" (or any other arbitrary character) the test would interpret as "If == ...", which would be invalid syntax.

I've seen people use "a" and other letters for this purpose, but I prefer the "~" for readability: it doesn't blend in with my actual data argument.

[dmg]

Sometimes, a ~ (or any other arbitrary character) may appear in a batch file "IF "command to avoid a possible null field in the interpreted command.

For example, to determine if a first parameter was passed to the batch file, I might write "If ~%1 == ~ ..."
If there were no first parameter, this would test true; if there were a first parameter, this would test false.

In execution, with a first parameter of dog, the test would interpret as "If ~dog == ~ ..." (false) and with no first parameter the test would interpret as "If ~ == ~ ..." (true). In the latter case, if you didn't include the "~" (or any other arbitrary character) the test would interpret as "If == ...", which would be invalid syntax.

I've seen people use "a" and other letters for this purpose, but I prefer the "~" for readability: it doesn't blend in with my actual data argument.

In fact you can use any character for that.... Even more then one:

if .%1==. echo Empty input
if ~%1==~ echo Empty input
if "%1"=="" echo Empty input
if blaat%1==blaat echo Empty input