Scripting Tcl 大小事

2019-10-29

tablelist 6.7

ANNOUNCE: Multi-column listbox and tree widget package Tablelist 6.7

Tablelist 釋出了一個新版 6.7，所以我也更新了自己的 RPM spec 測試。

2019-09-19

RabbitMQ/MQTT

RabbitMQ 是實現進階訊息佇列協議 AMQP (Advanced Message Queuing Protocol) 的中間件軟體，支援的協議版本為 0.9.1，也有 plugin 可以支援 1.0。

官網上有提供安裝檔案可以使用，如果在 openSUSE 15.1，可以使用下列的指令安裝：

sudo zypper in rabbitmq-server rabbitmq-server-plugins

如果要啟動服務，可以使用下列的指令：

sudo service rabbitmq-server start

如果要重啟服務，可以使用下列的指令：

sudo service rabbitmq-server restart

如果知道服務的狀態，可以使用下列的指令：

sudo service rabbitmq-server status

如果要停止服務，可以使用下列的指令：

sudo service rabbitmq-server stop

RabbitMQ 有支援 MQTT 3.1 的 plugin。下面是啟用的方式（啟用後需要重開 server 才會生效）：

sudo rabbitmq-plugins enable rabbitmq_mqtt

設定檔案在 /etc/rabbitmq/rabbitmq.conf，因為只是要測試，所以我把 port 改為 1883，啟用預設的 username/password，並且關閉允許匿名連線：

## ----------------------------------------------------------------------------
## RabbitMQ MQTT Adapter
##
## See https://github.com/rabbitmq/rabbitmq-mqtt/blob/stable/README.md
## for details
## ----------------------------------------------------------------------------

# =======================================
# MQTT section
# =======================================

## TCP listener settings.
##
mqtt.listeners.tcp.1 = 127.0.0.1:1883
mqtt.listeners.tcp.2 = ::1:1883

## TCP listener options (as per the broker configuration).
##
# mqtt.tcp_listen_options.backlog = 4096
# mqtt.tcp_listen_options.recbuf  = 131072
# mqtt.tcp_listen_options.sndbuf  = 131072
#
# mqtt.tcp_listen_options.keepalive = true
# mqtt.tcp_listen_options.nodelay   = true
#
# mqtt.tcp_listen_options.exit_on_close = true
# mqtt.tcp_listen_options.send_timeout  = 120

## TLS listener settings
## ## See https://rabbitmq.com/mqtt.html and https://rabbitmq.com/ssl.html for details.
#
# mqtt.listeners.ssl.default = 8883
#
# ssl_options.cacertfile = /path/to/tls/ca_certificate_bundle.pem
# ssl_options.certfile   = /path/to/tls/server_certificate.pem
# ssl_options.keyfile    = /path/to/tls/server_key.pem
# ssl_options.verify     = verify_peer
# ssl_options.fail_if_no_peer_cert  = true
#


## Number of Erlang processes that will accept connections for the TCP
## and TLS listeners.
##
# mqtt.num_acceptors.tcp = 10
# mqtt.num_acceptors.ssl = 10

## Whether or not to enable proxy protocol support.
## Once enabled, clients cannot directly connect to the broker
## anymore. They must connect through a load balancer that sends the
## proxy protocol header to the broker at connection time.
## This setting applies only to STOMP clients, other protocols
## like STOMP or AMQP have their own setting to enable proxy protocol.
## See the plugins or broker documentation for more information.
##
# mqtt.proxy_protocol = false

## Set the default user name and password used for anonymous connections (when client
## provides no credentials). Anonymous connections are highly discouraged!
##
mqtt.default_user = guest
mqtt.default_pass = guest

## Enable anonymous connections. If this is set to false, clients MUST provide
## credentials in order to connect. See also the mqtt.default_user/mqtt.default_pass
## keys. Anonymous connections are highly discouraged!
##
mqtt.allow_anonymous = false

## If you have multiple vhosts, specify the one to which the
## adapter connects.
##
mqtt.vhost = /

## Specify the exchange to which messages from MQTT clients are published.
##
mqtt.exchange = amq.topic

## Specify TTL (time to live) to control the lifetime of non-clean sessions.
##
mqtt.subscription_ttl = 1800000

## Set the prefetch count (governing the maximum number of unacknowledged
## messages that will be delivered).
##
mqtt.prefetch = 10

下面是使用 tcl.mqttc 測試 Subscribe 與 Publish 功能的測試程式：

package require Thread
package require mqttc
catch {console show}

set ::gThread [thread::create {thread::wait} ]
set result 0

proc subscribe { } {
    thread::send -async $::gThread {
        package require mqttc

        mqttc client "tcp://localhost:1883" "USERTest1" 1 -cleansession 1 \
                     -username guest -password guest
        client subscribe  "MQTT Examples" 1
        while 1 {
            if {[catch {set result [client  receive]}]} {
                puts "Receive error!!!"
                break
            }
            if {[llength $result] > 0} {
                puts "[lindex $result 0] - [lindex $result 1]"
                if {![string compare -nocase [lindex $result 1] "Exit"]} {
                    break
                }
            }
        }
        client unsubscribe  "MQTT Examples"
        client close
    } ::result
}

subscribe
puts "started test..."

after 250

mqttc client "tcp://localhost:1883" "USERTest2" 1 -timeout 1000 \
             -username guest -password guest
client publishMessage "MQTT Examples" "Hello MQTT!" 1 0
client publishMessage "MQTT Examples" "Exit" 1 0
client close

vwait ::result

2019-09-10

tcl.mqttc v0.6

因為 paho.mqtt.c 有一個新的版本 1.3.1，所以我做了 tcl.mqttc 相關的更新，同時將版本設成 v0.6。

不過我只有測試 tcp 部份，使用 ActiveMQ 測試 MQTT 3.1，以及使用 EMQX 測試 MQTT 3.1 以及 5 的部份。

我忘記是不是有在這個部落格貼過了，下面是 MQTT 3.1 測試 Subscribe 與 Publish 功能的測試程式：

package require Thread
package require mqttc
catch {console show}

set ::gThread [thread::create {thread::wait} ]
set result 0

proc subscribe { } {
    thread::send -async $::gThread {
        package require mqttc

        mqttc client "tcp://localhost:1883" "USERTest1" 1 -cleansession 1
        client subscribe  "MQTT Examples" 1
        while 1 {
            if {[catch {set result [client  receive]}]} {
                puts "Receive error!!!"
                break
            }
            if {[llength $result] > 0} {
                puts "[lindex $result 0] - [lindex $result 1]"
                if {![string compare -nocase [lindex $result 1] "Exit"]} {
                    break
                }
            }
        }
        client unsubscribe  "MQTT Examples"
        client close
    } ::result
}

subscribe
puts "started test..."

after 250

mqttc client "tcp://localhost:1883" "USERTest2" 1 -timeout 1000
client publishMessage "MQTT Examples" "Hello MQTT!" 1 0
client publishMessage "MQTT Examples" "Exit" 1 0
client close

vwait ::result

2019-08-19

casstcl 2.13.2

我發現有新的版本，所以更新了我自己的 openSUSE RPM spec。

casstcl 需要 cassandra cpp driver，我也有寫一個 openSUSE RPM spec，在安裝 casstcl 前需要先安裝 cassandra cpp driver。

2019-08-05

MAWT (Movie Automation With Tcl) 0.2.0

MAWT - Movie Automation With Tcl 已經在 2019/06/20 釋出了 0.2.0。

0.2.0 更新的資訊：
Improved video generation functionality.

所以我也更新了我自己的 openSUSE 套件。

2019-06-08

2019-06-02

Functional Programming (Tcler's Wiki)

Tcl 是個很奇妙的語言，就如同下面說的：

As with many things, Tcl is rather unique in this area. Commands themselves can not be passed as arguments to other commands, but their names can, which provides something very similar to first-class functions. Additionally, apply can be used to interpret a value as a function and evaluate it, providing the equivalent of lambda functions.

Tcl 的表達方式與波蘭表示法 (Polish notation) 一樣，和 Lisp 的 S-expression 的精神十分相像，特點是操作符置於操作數的前面（就是如果是一連串資料所組合成的述句，Tcl 述句的第一個是一個 command，後面是 command 要處理的資料）。

Tcl 也跟 Lisp 一樣，並不是純粹的 Functional Language，而是支援多重典範的語言。

2019-05-24

Tcl：奇數和偶數

#!/usr/bin/env tclsh

puts -nonewline "Please input a number: "
flush stdout
gets stdin var
 
if { [ regexp {^[0-9]+$} $var ] == 0} {
    puts "It is not a number!!!"
    exit
}

if { [expr $var % 2] == 0} {
    puts "It is even!!!"
} else {
    puts "It is odd!!!"
}

也是一個很簡單的練習，只是使用正規表示式判斷是否為數字。

2019-05-21

Tcl：九九乘法表

這只是一個簡單的 Tcl 練習。

所以第一個是 for loop 的版本。

#!/usr/bin/env tclsh

for {set nx 0} {$nx < 10} {incr nx} {
    for {set ny 0} {$ny < 10} {incr ny} {
        puts "[format "%d x %d = %2d" $nx $ny [expr $nx  * $ny]]"
    }
}

第二個版本是我在寫同樣的東西（也是九九乘法表），因為 Erlang 沒有 for 和 while 迴圈，所以我先建立一個 list，然後再使用 Erlang 提供的 lists:foreach 印出結果。我用同樣的精神寫 Tcl 九九乘法表的第二個版本（同時測試 mathop)。

#!/usr/bin/env tclsh

set x [list 1 2 3 4 5 6 7 8 9]
set y [list 1 2 3 4 5 6 7 8 9]

foreach nx $x {
    foreach ny $y {
        set z [::tcl::mathop::* $nx $ny]
        puts "[format "%d x %d = %2d" $nx $ny $z]"
    }
}

最後是遞迴的版本：

#!/usr/bin/env tclsh

namespace path {::tcl::mathop ::tcl::mathfunc}

proc mul {x y} {
    puts [format "%d x %d = %2d" $x $y [* $x $y]]
    if {$y < 9} {
        mul $x [+ $y 1]
    } else {
        if {$x < 9} {
            mul [+ $x 1] 1
        } else {
            return
        }
    }
}

mul 1 1

2019-05-13

Next Scripting Framework 2.3.0

ANNOUNCE: Next Scripting Framework 2.3.0 is available

NSF 釋出了 2.3.0，所以我更新了我自己的 openSUSE RPM spec，這可以比較方便進行測試。我在下載的時候 SourceForge 似乎出現問題，所以無法順利下載，我把下載檔案的地址切到 NSF 在 Github 的 mirror。

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