Find URI in text: Difference between revisions

<lang rexx>/*REXX program scans a text (contained within the REXX pgmprogram) to extract URIs. and IRIs*/

text$$= 'this URI contains an illegal character, parentheses and a misplaced full stop:',

'http://en.wikipedia.org/wiki/Erich_Kästner_(camera_designer). (which is handled by http://mediawiki.org/).',

'and another one just to confuse the parser: http://en.wikipedia.org/wiki/-)',

'")" is handled the wrong way by the mediawiki parser.',

'ftp://domain.name/path(balanced_brackets)/foo.html',

'ftp://domain.name/path(balanced_brackets)/ending.in.dot.',

'ftp://domain.name/path(unbalanced_brackets/ending.in.dot.',

'leading junk ftp://domain.name/path/embedded?punct/uation.',

'leading junk ftp://domain.name/dangling_close_paren)',

'if you have other interesting URIs for testing, please add them here:'

@abc= 'abcdefghijklmnopqrstuvwxyz'; @abcs=@abc||translate /*construct lowercase (@abcLatin) alphabet.*/

@unreservedscheme= @abcs || 0123456789 || '+-._~' /*add decimal digits & some punctuation*/

@reserved= @unreserved"/?#[]@!$&)(*+,;=\'" /*add other punctuation & special chars*/

#$=0 space($$)' ' /*countvariable of URI's$ found sois far.a working copy of $$ */

#= 0 /*▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄the count of URI's found (so far).*/

y=pos(':',t) do while $\=''; y= pos(':', $) /*locate a colon (:) in the text body.$*/

if y==0 then leave /*ColonWas a colon found? NoNope, we're done. */

if y==1 then do; parse var $ . $ /*handle a bare colon by itself. */

parse var t . t iterate /*ignorego theand barekeep colonscanning (:).for a colon. */

iterateend /*go &[↑] keep scanning for (a colonrare special case.) */

sr= reverse( left($, y - 1) end ) /*extract [↑]the ascheme rare specialand casereverse it. */

srse=reverse(left verify(tsr,y-1) @scheme) /*extractlocate the scheme andend reverse of the scheme. */

se$=verify substr(sr$,@scheme y + 1) /*locateassign thean endadjusted ofnew the schemetext. */

tif se\=substr(t,y+1)=0 then sr= left(sr, se - 1) /*possibly "crop" /*assignthe an adjustedscheme new textname. */

if se\=s=0 then sr=leftreverse(sr,se-1) /*possiblyreverse cropit theagain schemeto rectify the name. */

she=reverse verify(sr$, @reserved) /*reverselocate againthe toend rectifyof namethe hier─part. */

hes=verify s':'left(t$,@reserved he - 1) /*locateextract and append the endhier─part. of the hier-part*/

s$=s':'left substr(t$, he-1) /*extractassign &an appendadjusted thenew hier-part of text. */

t#=substr(t,he) # + 1 /*assignbump anthe adjusted newURI text counter. */

!.#=#+1 s /*bumpassign the URI counter. to an array (!.) */

!.#=send /*while*/ /*assign [↑] scan the text for URI's. to an array. */

do k=1 for #; say !.k; end /*stick a fork in it, we're all done. */*▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀*</lang>