regex - Perl Modifiers /^ AND $ -

-

somebody please explain me in layman terms use of modifiers /^ , $ in below statement;

elsif ($keyword =~ /^verse$/gi)

i information ^ matches beginning of line , $ matches end of line, supposed mean? explain me if condition considered above statement.

these characters "zero-width assertions". don't stand group of characters, positions in string.

  • ^ means expect pattern @ beginning of line or record.
  • $ means expect pattern @ end of line or record

in standard matching mode (without trailing switch /m), perl considers first record in string total searchable space. /m switch, perl considers records in string, each record delimited current value of $/ (also $rs useenglishqw($rs);).

so if you're searching through couple of records , know pattern occurs @ beginning or end, can use characters specify that. (absolute start of string \a , absolute end \z place before record separator ends entire string or \z place after every single character in string. perl best practices prefers uniform use of \z.)

to clarify, standard record line of input, delimited systems' line separator.

to answer specific question: condition true if first record in string in $keyword matches 'verse'. strings aren't expected contain that, might use 

if ($keyword eq 'verse' ) {      ... }

Comments

Post a Comment

Popular posts from this blog

django - How can I change user group without delete record -

-
on website user have 1 group. , user can change group. it's made user.groups.clear() and user.groups.add(new_group) but it's not efficient, because there 2 sql query: delete, insert. how can change group update query? user , group related each other using manytomanyfield . means intersection table exists relating both entities, , if don't specify model map (using through attribute) django creates 1 you. looking @ sources django.contrib.auth.models see that's case. fortunatly, can access intermediary model using through attribute of manager (in case, user.groups.through ). can use regular model. example: >>> alice = user.objects.create_user('alice', 'alice@example.com', 'alicepw') >>> employee = group.objects.create(name='employee') >>> manager = group.objects.create(name='manager') >>> alice.groups.add(employee) >>> alice.groups.all() [<group: employee...
Read more

java - Need to add SOAP security token -

-
i need set custom soap header attribute on jax-ws generated webservice client. case webservice calls must go through proxy server requiring specific token (recieved web request header) present in soap request header. e.g.: 1 carserviceservice service = null; 2 service = new carserviceservice(new url(url), new qname(qname); 3 carserviceendpoint port = service.getcarserviceport(); it seems in line 3 wsdl retrieved , call fails due missing security token. 1 point direction on how done? a detailed example has been mentioned here: creating , deploying jax-ws web service on tomcat 6 this article shows how create , use security token .
Read more

java - EclipseLink JPA Object is not a known entity type -

-
i have strange problem eclipselink , object want persist. have 1 object (keypointlistimpl) stores object keypointimpl in list. persisting keypointimpl objects works great if try persist keypointlistimpl object java.lang.illegalargumentexception says object keypointimpl isn't known entity type. here keypointimpl code: @entity @table(name="keypoints") public class keypointimpl implements keypoint { @id @generatedvalue(strategy = generationtype.identity) private int id; @enumerated(enumtype.string) private detectortype keypointtype; private float x; private float y; private float size; private float angle; private float response; private int octave; private int classid; ... } here keypointlistimpl code: @entity @table(name="keypointlists") public class keypointlistimpl implements keypointlist { @id @generatedvalue(strategy = generationtype.identity) private int id; @onetoone(cascade={ca...
Read more