OPEN
OPEN file [FOR {INPUT|OUTPUT|APPEND}] AS #fileN
Makes a file, device or network connection available for sequential
input, sequential output.
file - A string expression that follows OS file naming
conventions.fileN - A file-handle (integer 1 to 256).
Open a file
open "test.txt" for INPUT as #1
| Expression |
Description |
| INPUT |
Sequential input (reading from file) |
| OUTPUT |
Sequential output ( writing to file) |
| APPEND |
Sequential output, beginning at current EOF |
If an existing file is opened for output, the file will be deleted
and an empty file will be created. The files are always opened as
shared. You can use FREEFILE to get the next unused file-handle. Use
PRINT, INPUT, BGETC and BPUTC to read from or write to a file or
device.
Open a COM port (RS232)
You can open a connection to a device using the serial port with
open "COMn:speed" AS #1, where n is the number
of the port and speed is the baud rate. To open the first
serial port with a baud rate of 19200 use:
open "COM1:19200" as #1. In Windows COM1 and
in Linux /dev/ttys1 would be opened. Instead of
COMn you can open in Linux every port starting with
/dev/tty, for example /dev/ttyUSB1 or
/dev/ttyACM1.
Open a TCP/IP socket
You can open a connection to a device using a TCP/IP socket with
open "SOCL:IP:PORT" AS #1, where IP is a valid
host name or IP address and port is an open port.
open "SOCL:192.168.178.76:8080" as #1
If you omit the host name or IP address in the SOCL:
string passed to the OPEN command, SmallBASIC will listen for
connections from another host/process.
open "SOCL:8080" as #1
Open an image
Use the prefix HTTP: with the OPEN command
to open an image file over the network. You can then pass the file
number to the IMAGE command. This returns an system object
which can then be used to manipulate images in the graphical version of
SmallBASIC.
open "http://img2.wikia.nocookie.net/__cb20150113215904/farmville/images/9/92/Lumberjack_Gnome-icon.png" as #1
Open a HTTP connection
Use the prefix HTTP: with the OPEN command
to open a network HTTP connection. You can then use the file number with
the TLOAD command to read the data.
open "http://api.duckduckgo.com/?q=Cars&format=json" as #1
Example 1: Open a file:
' create a text file
open "MyDemoFile.txt" for output as #1
for i = 1 to 10
print #1, i
next
close #1
' open text file and print content line by line
open "MyDemoFile.txt" for input as #1
while(!eof(1)) ' eof works only without #
input #1, c
print c
wend
close #1
Example 2: Open a
socket for listening (server)
open "SOCL:10000" as #1 ' Open socket at port 10000
while (!eof(1)) ' Loop until connection is closed
l = lof(1) ' Querry how much data is in the queue
if(l) then ' if data is available
s = INPUT(l, 1) ' get all data
print s
endif
wend
close #1
Example 3: Open a socket as
client
open "SOCL:192.168.1.10:10000" as #1 ' Connect to server
print #1, "Hello world" ' Send string to server
close #1
Example 4: Open a COM port
(RS232)
open "COM1:19200" as #1 ' Open COM1 with 19200 bauds
while (!eof(1)) ' Loop until connection is closed
l = lof(1) ' Querry how much data is in the queue
if(l) then ' if data is available
s = INPUT(l, 1) ' get all data
print s
endif
wend
close #1
' Works only in Linux
open "/dev/ttyACM1:19200" as #1 ' Open ttyACM1 with 19200 bauds
while (!eof(1)) ' Loop until connection is closed
l = lof(1) ' Querry how much data is in the queue
if(l) then ' if data is available
s = INPUT(l, 1) ' get all data
print s
endif
wend
close #1
Example 5: Open an image
over network
' open some random image I found on the net
open "http://img2.wikia.nocookie.net/__cb20150113215904/farmville/images/9/92/Lumberjack_Gnome-icon.png" as #1
i = image(#1)
i.show(100,50)
Example 6: Connect to an
HTTP server
print "DuckDuckGo Search"
while 1
print '<=== when cycle around need to isolate input prompt
input "(Just enter quits) Term? ", queryTerm
if trim(queryTerm)="" then ? "Cheers!":end '<=== need a way out
url = "http://api.duckduckgo.com/?q=" + trim(queryTerm) + "&format=json"
open url as #1
if (eof(1)) then
throw "Connection failed: " + url
fi
dim results
tload #1, results
json = array(results)
num_results = len(json.RelatedTopics)
for i = 0 to num_results - 1
if (isarray(json.RelatedTopics(i).topics)) then
num_topics = len(json.RelatedTopics(i).Topics)
for t = 0 to num_topics - 1
print cat(1); " "; json.RelatedTopics(i).Topics(t).FirstURL; cat(0)
print " "; json.RelatedTopics(i).Topics(t).text
next t
else
print cat(1); " "; json.RelatedTopics(i).FirstURL; cat(0)
print " "; json.RelatedTopics(i).Text
endif
next i
Close #1 '<===== oh this helps!
wend