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Hi, Aia.
Yes, I noted that. His title was What is the meaning the $ special character?
He also asked ...explain to me how it's categorized and it's extract [sic] definition?
He did not restrict the meaning to any special instance.
I appreciate that he used Google, but I think he may not have had enough time to internalize the information. I know that I don't always understand something just after I read it.
For example from the Wikipedia article: In most shell scripting languages, $ is used for interpolating environment variables, special variables ... -- it seems hard to imagine an alternate definition.
Thanks for the comment, it's always useful to have feedback and more than one set of dispassionate eyes looking over things ... cheers, drl
[..]
I know that I don't always understand something just after I read it.
For example from the Wikipedia article: In most shell scripting languages, $ is used for interpolating environment variables, special variables ... -- it seems hard to imagine an alternate definition.
[..]
Indeed, I was looking at that on the wiki page and reread it several times and still do not know what it means.
Full quote:
Quote:
$ is used for interpolating environment variables, special variables, arithmetic computations and special characters, and for performing translation of localised strings
Hi drl, yes of course we know what they meant to say, but not thanks to that wiki content.
I was just trying understand the words "interpolating" and "performing translation of localised strings" in that sentence, which I think are either wrong, obfuscating or needlessly complicated and most certainly will make someone new to the subject glaze over..
This User Gave Thanks to Scrutinizer For This Post:
The word interpolate is one of many English words with several meanings. I certainly agree that the mathematical meaning of interpolate ("insert an intermediate value or term into a series by estimating or calculating it from known surrounding values") makes no sense in this context. And this is how interpolate is most frequently used in this forum.
But, one of the other meanings of interpolate ("alter (a book or text) by insertion of new material") fits what parameter expansion, arithmetic expansion, command substitution, and special variable expansion (each of which are introduced by a leading $ in the shell command language) do if you consider shell commands to be text.
Location: Saint Paul, MN USA / BSD, CentOS, Debian, OS X, Solaris
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Hi, Don.
Quote:
Originally Posted by Don Cragun
... I certainly agree that the mathematical meaning of interpolate ("insert an intermediate value or term into a series by estimating or calculating it from known surrounding values") makes no sense in this context. And this is how interpolate is most frequently used in this forum ...
I searched for interpolate in the forum, and got 56 hits. Looking at a sample of 10 (trying to be objective), I found 9 referred to variables, 1 to the math ... cheers, drl
---------- Post updated at 09:01 ---------- Previous update was at 08:43 ----------
Hi.
Apologies for the long post. Here is a sample of results of a Google search:
From my perspective, there is a lot of information about the use of a $, and if the OP was referring to its use in bash, there are many places that explain it, as well as in many books.
I tend to think of the variables as a location in memory that has the string that is the name of variable as its content. Along with that, there is a link (pointer, etc., method unspecified) that allows us to view and change that value, and we can see that value with a $.
My recollection is that when this level of detail came up in class, I told the students my visualization. I think that usually satisfied the more technical, curious students.
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