Is there a way in XQuery to do something like a tail() function?
What I m trying to accomplish is to get the contents of a file (using "xdmp:filesystem-file($path)") and then display only the last 100 lines. I can t seem to find a good way to do this. Any ideas?
Thank you.
In plain XQuery, this can be accomplished by splitting into lines and getting the desired number of lines from the end of the sequence, then rejoining them, if necessary, i.e.
declare function local:tail($content as xs:string, $number as xs:integer)
{
let $linefeed := " "
let $lines := tokenize($content, $linefeed)
let $tail := $lines[position() > last() - $number]
return string-join($tail, $linefeed)
};
A pure and short XPath 2.0 solution -- can be used not only in XQuery but in XSLT or in any other PL hosting XPath 2.0:
for $numLines in count(tokenize(., 
 ))
return
tokenize(., 
 )[position() gt $numLines -100]
Or:
for $numLines in count(tokenize(., 
 ))
return
subsequence(tokenize(., 
 ), $numLines -100 +1)
if your xdmp:file-xx is a nature of text file then you could use something like
let $f := any file system path
return fn:tokenize(xdmp:filesystem-file($f), [
]+ )[ fn:last() - 2 to fn:last()]
here i have used newline & carriage return as my token splitter. if you need something else to tokenize u could. but simple log file tailing then this solution works fine.
given example tails last 2 lines of a given file. if you want more than alter fn:last()-2 to fn:last() - x
I have a function: int get_symbol(tab *tp, FILE *fp, char delim) and I call it like this: get_symbol(tp, fp, ; ) I always have it declared in the header as: int get_symbol(tab *, FILE *, char); ...
I am trying to build a small program and I have my own library libfoo. I have a camera class that is calling a static function from my Vector3 class (i.e. crossProduct). My camera class and Vector3 ...
Suppose i have this ($ = jquery): $.fn.my_function = function() { function foo() { //do something }; function bar() { //do something other }; } I lauch ...
All, I want to create a function that takes a symbol representing a java method and applies it to some object: (user=> (defn f [m] (. "foo" (m))) When I execute this, I get a result much ...
I tried to print all the possible combination of members of several vectors. Why the function below doesn t return the string as I expected? #include <iostream> #include <vector> #...
I have been studying JavaScript from one book. Once I was playing with the codes concerning the client-server site communication, I wanted to do a POST request with the code below (which uses IE ...
Are there some good ways to know how a function performs in C? I would like to, for example compare my own function to a library function.
Recently, I ve been learning different programming langages, and come across many different names to initalize a function construct. For instance, ruby and python use the def keyword, and php and ...