sockets - sending erlang records to a c program -

-

i working on assignment , part of sending erlang terms c program able communicate each other through established tcp connection.

i able send numbers, lists, boolean, binaries , able decode them in c program sent message. using ei module stuff. on erlang side, encoding using etf term_to_binary/1 , others.

that said, wondering how can send records on socket encoded on erlang side , decoding on c -side. ei has many functions primitives data types decoded binary format not composite 1 records.

records simple -rd(person, {name = "", email = ""}) can send 

gen_tcp:send(socket, term_to_binary(#person{name="stack", age = 16})).

how decode on c-side.

i have googled not lot of resources on this. please help! thank you!

erlang external term format in detail described in documentation. there erlang interface library application contain ei library detailed encoding, decoding , sending erlang terms documentation. note there more low-level interface ei working directly buffers encoded in erlang external term format , erl_interface working eterms equivalent erlang terms internally used in beam vm.

there whole chapter devoted topic in book erlang , otp in action shows practical example using ei scratches surface. official documentation far more detailed , complete. official documentation contains interoperability tutorial user's guide complete examples of working code erl_interface although doesn't contain complete examples of using low-level ei.


Comments

Post a Comment

Popular posts from this blog

java - nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet Hibernate+SpringMVC -

-
i trying fetch records database , having above error this classs appropriate getters , setters public class user { private int id; private string username; private string password; private string email; i have create database , inserted data below configuration <bean id="datasource" class="org.apache.commons.dbcp2.basicdatasource" destroy-method="close"> <property name="driverclassname" value="com.mysql.jdbc.driver"/> <property name="url" value="jdbc:mysql://localhost:3306/usersdb"/> <property name="username" value="root"/> <property name="password" value=""/> </bean> this complete stacktrace severe: servlet.service() servlet [appservlet] in context path [/spring] threw exception [request processing failed; nested exception org.hibernate.exception.sqlgrammarexception: not ...
Read more

sql - Postgresql tables exists, but getting "relation does not exist" when querying -

-
Image
i have postgresql db number of tables. if query: select column_name information_schema.columns table_name="my_table"; i list of columns returned properly. however, when query: select * "my_table"; i error: (programmingerror) relation "my_table" not exist 'select *\n "my_table"\n' {} any thoughts on why can columns, can't query table? goal able query table. you have include schema if isnt public one select * <schema>."my_table" or can change default schema show search_path; set search_path my_schema; check table schema here select * information_schema.columns for example if table on default schema public both works ok select * parroquias_region select * public.parroquias_region but sectors need specify schema select * map_update.sectores_point
Read more

asp.net mvc - breakpoint on javascript in CSHTML? -

-
i have .cshtml file has javascript tag. within script tag have few lines of javascript. first line of javascript refers property in @viewbag. other javascript lines plain script without mvc related references. observation: can place breakpoints (visual studio 2015) on each of these javascript lines. however, breakpoints has white dot in center of breakpoint symbol (red circle) except line @viewbag reference (this particular line not have white dot in center). it seems breakpoint without white dot hit during run-time. question: can explain going on here? white dot mean? why plain red breakpoint line line hitting breakpoint? the visual studio debugger expecting debug actual server-side code within .cshtml file opposed client-side javascript within it. iirc, visual studio allow debug javascript code expected in internet explorer (and possibly edge), other browsers want use either third-party tool or developer tools (f12) within browser. an easy approach take advant...
Read more