I was writing a small cheatsheet for some of the vim commands I use frequently, just for personal reference. I ran into a problem when I realized that [square brackets] were used in the regex formatting, but I had been using them to show values. For example, I had the substitute command written as
%s/[existing string]/[replacement string]/g
Is there a standard format in documentation for values like these?
Thanks in advance!
For vim you would write:
%s/<EXISTING STRING>/<REPLACEMENT STRING>/g
Square brackets are commonly used in conjunction with the perl Template module:
[% EXISTING_STRING %]
Documentation:
https://metacpan.org/pod/Template
Related
In vue, is there a way to have a value span multiple lines in an .env file. Ex:
Instead of:
someValue=[{"someValue":"Here is a really really long piece which should be split into multiple lines"}]
I want to do something like:
someValue=`[{"someValue":"Here is a really
really long piece which
should be split into multiple lines"}]`
Doing the latter gives me a JSON parsing error if I try to do JSON.parse(someValue) in my code
I don't know if this will work, but I can't format a comment appropriately enough to get the point across so see if this will work:
someValue=[{"someValue":"Here is a really\
really long piece which\
should be split into multiple lines"}]
Where "\" should escape the newline similar to how you can write long bash commands while escaping the newline. I'm not certain the .env interpreter will support it though.
EDIT
Looks like this won't work. This syntax was actually proposed, but I don't think it was incorporated. See motdotla/dotenv#333 (which is what Vue uses to parse .env).
Like #zero298 said, this isn't possible. Likely you could delimit the entry with a character that wouldn't show up normally in the text (^ is a good candidate), then parse it within the application using string.replace('^', '\n');
We have files to load where field values are separated by the "unit separator", 0x1f
As per the doc, if not printable, it should be encoded in UTF-8.
Using the bq CLI, I tried passing the -F argument with U+001F to no avail though:BigQuery error in load operation: Field delimiter must be a single character, found:"U+001F".
No luck either with 0x1F or `\x1f, with or without quotes.
Have I the encoding wrong or is it a bug in bq, or the API ?
EDIT:
Turns out after playing with the explorer that it's the API that doesn't like the delimiter.
Besides the printable delimiters, you can use \t but also the undocumented \b (backspace) and \f (form field) apparently.
tab could be a valid user-entered character in a free-form text field so we need to use a control char (after conversion from 'unit sep')
EDIT2::
Note that \f as delimiter does work fine through the API directly but not the bq CLI (Field delimiter must be a single character, found:"\f").
Actually, courtesy of GCP support, this works on Linux:
bq load --autodetect --field_delimiter=$(printf '\x1f') [DATASET].[TABLE] gs://[BUCKET]/simple.csv
On Windows, it's not that straightforward to return/generate a control character on the command-line. Easier if you use PowerShell.
I agree with #Felipe, this is currently a limitation in the bq CLI tool, but one that can easily be fixed in the source code in my mind with a .decode('utf-8') on the argument in bytes, so that
--field_delimiter=\x1f
can work as-is on any platform.
Closing with the hope the bq CLI team will consider the enhancement.
You can specify bq load --field_delimiter=$'\x01'
You found a limitation of the CLI: It won't accept all characters that the API would.
As said in edit2, the solution is to go straight to the API through alternative methods.
I'm trying to make a console-based program that makes use of ANSI escape codes with GNU Smalltalk. I can't seem to figure out how to go about printing a string object formatted with ANSI escape codes. I've tried the following.
'\x1b[31mHi' displayNl
This prints the entire string, including the escape code, without any formatting. I would have expected this to print "Hi" in red (and then everything else in the console after that, as I didn't reset the color.)
After googling a bit, I was able to find a couple issues on mailing lists where people were trying to produce things like newlines using "\n". Most of the answers were using the Transcript object's cr method, but I didn't find anything about colors in the textCollector class.
It looks like it shouldn't be all that hard to create my own module in C to achieve this functionality, but I'd like to know if there's a better way first.
I'm aware of the ncurses bindings, but I'm not sure that'd be practical for just making certain pieces of text in the program colored. So, is there a standard way of outputting colored text to the terminal in GNU Smalltalk using ANSI escape sequences?
Ended up getting an answer on the GNU Smalltalk mailing list. Looks like you can use an interpolation operator to achieve this.
For example ('%1[31mHi' % #($<16r1B>)) displayNl. would change the color to red, and ('%1[34mHi' % #($<16r1B>)) displayNl. would change the color to blue.
Basically, the % operator looks for a sequences that look like "%(number)" and replaces them with the objects in the array to the right of the operator. In our case, the array has one item, which is the ascii escape character in hexadecimal. So the "%1" in "%1[31mHi' is being replaced with the escape character, and then printed.
(This answer was stolen almost verbatim from Paolo on the GNU Smalltalk mailing list.)
I'm using Lua and I want to use a so called "native variable" that will be read-only and they will be recognized with a "$" mark in front of them e.g. $variable. But in what I've found Lua only accepts normal alphabetic characters and underscore as variable names. Is there some way that I can modify the Lua code to do this?
consider pre-processing your lua source to replace $identifier with __NATIVE.identifier using a simple parser, then send the modified source to a regular lua interpreter. Then implement __NATIVE to be a global table with the appropriate metatable to implement your desired behaviour.
You are not allowed to use special characters in the Lua language:
See here: http://lua.gts-stolberg.de/en/Variablen.php
You can use metatables to prevent a variable from being altered. The Lua source is free under MIT, which is permissive enough for virtually any use, but I have no specific advice on how you can modify it to allow $.
I would like to be able to extract a number from within a string formatted as follows:
"<[1085674730]> hello foo1, how are you doing?"
I'm a novice with regular expressions, I only want to be able to extract a number that is enclosed in the greater/less-than and bracket symbols, but I'm not sure how to go about it. I have to match numeric digits only, but I'm not sure what syntax is used for only searching within these symbols.
UPDATE:
Thank you all for you input, sorry for not being more specific, as I explained to kiamlaluno, I'm using VB.Net as the language for my application. I was wondering why some of the implementations were not working. In fact, the only one that did work was the one described by Matthew Flaschen. But that captures the symbols around the number as well as the number itself. I would like to only capture the number that is encased in the symbols and filter out the symbols themselves.
Use:
<\[(\d+)\]>
This is tested with ECMAScript regex.
It means:
\[ - literal [
( - open capturing group
\d - digit
+ - one or more
) - close capturing group
\] - literal ]
The overall functionality is to capture one or more digits surrounded by the given characters.
Combine Mathews post with lookarounds http://www.regular-expressions.info/lookaround.html. This will exclude the prefix and suffix.
(?<=<\[)\d+(?=\]>)
I didn't test this regex but it should be very close to what you need. Double check at the link provided.
Hope this helps!
$subject = "<[1085674730]> hello foo1, how are you doing?";
preg_match('/<\[(\d+)\]>/', $subject, $matches);
$matches[1] will contain the number you are looking for.
Use:
/<\[([[:digit:]]+)\]>/
If your implementation doesn't support the handy [:digit:] syntax, then use this:
/<\[([\d]+)\]>/
And if your implementation doesn't support the handy \d syntax, then use this:
/<\[([0-9]+)\]>/