What does :/= mean in %date:/=%? - variables

While searching for a way to create a date-named directory in Windows, I came accross this question with that accepted answer.
There's a comment below the accepted answer:
To make it more easy: mkdir %date:/=%
So, %date% prints the current date, but what does :/= do?

It means substitute for the string between the : and the = with the string after the = and before the closing %
So it strips out any / from the variable %date% which is set by default to the current date.

The form of the command is
%variable:text=replace%
and it removes text and inserts replace in the same spot.
In your case the replace is empty so it just removes any / characters from the date string.

Related

REGEX check only when start of line

Suppose we want to keep the entire line of a string only if a particular word say e.g 'test' appears at starting of line.
If it appears anywhere then the entire line should be removed
e.g
if function_test()=5; //here this entire line should be removed
test sample =5; //here this entire should be there
From Oracle 10g R2 on you should be able to use the anchor \A to require the match at the beginning of the string (will only work for single-line strings thus).
http://www.regular-expressions.info/oracle.html
What do you mean by keep / remove lines? Where is this regex supposed to run? I.e. is it a part of an SQL command, or part of a grep, or sg else?
Regarding SQL you can use LIKE operator:
WHERE line LIKE 'test%'
You can use substring too:
WHERE substring(line, 1, 4) = 'test'
Using grep or any other language, you can specify start of line, e.g.:
grep '^test' bigfile.txt
Try...
...
WHEN REGEXP_LIKE(string,'^test','i') THEN
//this is a good line, do what you want or return string;
END
...

batch-file variable %CD% adding a backslash when run from drive root

I have a problem with the variable %CD% in a batch-file. It adds a backslash if the script is run from the root of a drive.
as an example: updatedir=%CD%\Update & echo %updatedir% will return something like
From a folder E:\New Folder\Update
From a drive root E:\\Update
Is there any way to get rid of the extra backslash if run from root?
Yes %CD% only has a trailing \ if the current directory is the root. You could get rid of any trailing backslash that might be there. But there is a simpler solution.
Use the undocumented %__CD__% instead, which always appends the trailing backslash. This makes it easy to build a clean path, regardless of the current directory.
set "updatedir=%__CD__%Update
You can do something like this:
set "CurrentDir=%CD%"
if "%CD:~-1%"=="\" set "CurrentDir=%CD:~0,-1%"
Since you don't want to go changing the system variable %CD%, this sets a new variable %CurrentDir% to the current value of %CD%. Then, it checks to see if the last character in %CD% is a \, and if it is, sets %CurrentDir% to the value of %CD%, minus the last character.
This question/answer has more information on using substrings in batch files.
replace every occurence of \\ with \.
echo %updatedir:\\=\%

How to use FILE_MASK parameter in FM EPS2_GET_DIRECTORY_LISTING

I am trying to filter files using FILE_MASK parameter in EPS2_GET_DIRECTORY_LISTING to reduce time searching all files in the folder (has thousands of files).
File mask I tried:
TK5_*20150811*
file name in the folder is;
TK5_Invoic_828243P_20150811111946364.xml.asc
But it exports all files to DIR_LIST table, so nothing filtered.
But when I try with;
TK5_Invoic*20150811*
It works!
What I think is it works if I give first 10 characters as it is. But in my case I do not have first 10 characters always.
Can you give me an advice on using FILE_MASK?
Haven’t tried, but this sounds plausible:
https://archive.sap.com/discussions/thread/3470593
The * wildcard may only be used at the end of the search string.
It is not specified, what a '*' matches to, when it is not the last non-space character in the FILE parameter value.

Concatenating php date type variable with other strings while creating a custom file name in php

I have been trying to use my variable $date of type date to concatenate with some other string so as to make a custom file name which I will use it in my program.I tried the following ways after going through some links but I failed.
$bar="foo".$date.".txt";
$bar="foo".string($date).".txt";
$bar="foo"."$date".".txt";
It always omits $date variable and creates a file with name foo.txt. But I am looking for some thing like foo4/2/15.txt if value of $date is 4/2/15.
That would be great if some one help me with this.
Got the bug. It seems silly but may help some one in the same situation one or the other day.
My definition for $date is in a loop and the last definition was becoming null.So it always doesn't take any value for $date resulting foo.txt instead of foo2/4/15.txt.
As we discussed in the comments we also gotta take care of illegal file names.
Thanks for people above for their time.

why does using "\" shows error in jython

I am trying to use a copy command for Windows and we have directories such as c:\oracle.
While trying to execute one such, we get the following error:
source_file=folder+"\"
^
SyntaxError: Lexical error at line 17, column 23. Encountered: "\r" (13), after : ""
Here folder is my path of c:\oracle and while trying to add file to it like:
source=folder+"\"+src_file
I am not able to do so. Any suggestion on how to solve this issue?
I tried with / but my copy windows calling source in os.command is getting "the syntax is incorrect" and the only way to solve it is to use \ but I am getting the above error in doing so.
Please suggest. Thanks for your help
Thanks.
Short answer:
You need:
source_file = folder + "\\" + src_file
Long answer:
The problem with
source_file = folder + "\" + src_file
is that \ is the escape character. What it's doing in this particular case is escaping the " so that it's treated as a character of the string rather than the string terminator, similar to:
source_file = folder + "X + src_file
which would have the same problem.
In other words, you're trying to construct a string consisting of ", some other text and the end of line (\r, the carriage return character). That's where your error is coming from:
Encountered: "\r" (13)
Paxdiablo is absolutely correct about why \ isn't working for you. However, you could also solve your problem by using os.path.normpath instead of trying to construct the proper platform-specific path characters yourself.
In all programming languages I know of, you can't put a quote inside a string like this: "this is a quote: "." The reason for this is that the first quote opens the string, the second then closes it (!), and then the third one opens another string - with the following two problems:
whatever is between the quotes #2 and #3 is probably not valid code;
the quote #3 is probably not being closed.
There are two common mechanisms of solving this: doubling and escaping. Escaping is far more common, and what it means is you put a special character (usually \) in front of characters that you don't want to be interpreted in their usual value. Thus, "no, *this* is a quote: \"." is a proper string, where the quote #2 is not closing the string - and the character \ does not appear.
However, now you have another problem - how do you actually make the escape character appear in a string? Simple: escape it! "This is an escape: \\!" is how you do it: the backslash #1 is the escape character, and the backslash #2 is the escapee: it will not be interpreted with its usual escape semantics, but as a simple backslash character.
Thus, your line should say this:
source=folder+"\\"+src_file
BTW: upvote for both #paxdiablo (who got in before my diatribe) and #Nick (who has a proper Pythonic way to do what you want to do)