Downloading Files - mkilgore/QB64pe GitHub Wiki

CRLF$ = CHR$(13) + CHR$(10)
Request$ = "GET " + File_Path + " HTTP/1.1" + CRLF$ + "Host:" + Web_Address + CRLF$ + CRLF$

HTTP/1.1 200 OK
Server: dbws
Date: Tue, 25 Oct 2011 04:41:03 GMT
Content-Type: text/plain; charset=ascii
Connection: keep-alive
<span style="color:blue;">content-length: 4087</span>
x-robots-tag: noindex,nofollow
accept-ranges: bytes
etag: 365n
pragma: public
cache-control: max-age=0 '' ''

'' ''
IF...THEN Download("www.qb64.net/qb64.png", "qb64logo.png", 10) THEN ' timelimit = 10 seconds
 SCREEN _LOADIMAGE("qb64logo.png",32)
ELSE: PRINT "Couldn't download QB64 logo."
END IF
SLEEP
SYSTEM
' ---------- program end -----------

FUNCTION Download (url$, file$, timelimit) ' returns -1 if successful, 0 if not
url2$ = url$
x = INSTR(url2$, "/")
IF...THEN x THEN url2$ = LEFT$(url$, x - 1)
client = _OPENCLIENT("TCP/IP:80:" + url2$)
IF...THEN client = 0 THEN EXIT FUNCTION
e$ = CHR$(13) + CHR$(10) ' end of line characters
url3$ = RIGHT$(url$, LEN(url$) - x + 1)
x$ = "GET " + url3$ + " HTTP/1.1" + e$
x$ = x$ + "Host: " + url2$ + e$ + e$
PUT (TCP/IP statement) #client, , x$
t! = TIMER ' start time
DO
    _DELAY 0.05 ' 50ms delay (20 checks per second)
    GET (TCP/IP statement) #client, , a2$
    a$ = a$ + a2$
    i = INSTR(a$, "Content-Length:")
    IF...THEN i THEN
      i2 = INSTR(i, a$, e$)
      IF...THEN i2 THEN
      l = VAL(MID$(a$, i + 15, i2 - i -14))
      i3 = INSTR(i2, a$, e$ + e$)
        IF...THEN i3 THEN
          i3 = i3 + 4 'move i3 to start of data
          IF...THEN (LEN(a$) - i3 + 1) = l THEN
            CLOSE client ' CLOSE CLIENT
            d$ = MID$(a$, i3, l)
            fh = FREEFILE
            OPEN file$ FOR OUTPUT AS #fh: CLOSE #fh 'Warning! Clears data from existing file
            OPEN file$ FOR BINARY AS #fh
            PUT #fh, , d$
            CLOSE #fh
            Download = -1 'indicates download was successfull
            EXIT FUNCTION
          END IF ' availabledata = l
        END IF ' i3
      END IF ' i2
    END IF ' i
LOOP UNTIL TIMER > t! + timelimit ' (in seconds)
CLOSE client
END FUNCTION '' ''

CR$ = CHR$(13) + CHR$(10) 'crlf carriage return line feed characters
' Change this to the file's public link
DownFile$ = "http://a5.sphotos.ak.fbcdn.net/hphotos-ak-snc7/293944_10150358253659788_151813304787_8043392_486717139_n.jpg?dl=1"

' Get base URL
BaseURL$ = DownFile$
IF...THEN INSTR(BaseURL$, "http://") THEN BaseURL$ = RIGHT$(BaseURL$, LEN(BaseURL$) - 7) 'trim http://
Path$ = MID$(BaseURL$, INSTR(BaseURL$, "/")) 'path to file
BaseURL$ = LEFT$(BaseURL$, INSTR(BaseURL$, "/") - 1) 'site URL


' Connect to base URL
PRINT "Connecting to "; BaseURL$; "...";
Client& = _OPENCLIENT("TCP/IP:80:" + BaseURL$)
IF...THEN Client& = 0 THEN PRINT "Failed to connect...": END
PRINT "Done."

' Send download request
PRINT "Sending download request...";
Request$ = "GET " + Path$ + " HTTP/1.1" + CR$ + "Host:" + BaseURL$ + CR$ + CR$
PUT #Client&, , Request$
PRINT "Done."

' Download the header
PRINT "Getting HTML header...";
Dat$ = ""
DO
   _LIMIT 20
   GET #Client&, , gDat$
   Dat$ = Dat$ + gDat$
LOOP UNTIL INSTR(Dat$, CR$ + CR$) ' Loop until 2 CRLFs (end of HTML header) are found
PRINT "Done."

' Get file size
FileSizePos = INSTR(UCASE$(Dat$), "CONTENT-LENGTH: ") + 16
FileSizeEnd = INSTR(FileSizePos, Dat$, CR$)
FileSize& = VAL(MID$(Dat$, FileSizePos, (FileSizeEnd - FileSizePos) + 1))

PRINT "File size:"; FileSize&
PRINT "Downloading file...";

' Trim off HTML header
EndHeaderPos = INSTR(Dat$, CR$ + CR$) + 4
Dat$ = RIGHT$(Dat$, (LEN(Dat$) - EndHeaderPos) + 1)

' Get the file name tucked at the end of the URL if necessary
FOR...NEXT S = LEN(DownFile$) TO 1 STEP -1
   IF...THEN MID$(DownFile$, S, 1) = "/" THEN
      OutFile$ = RIGHT$(DownFile$, (LEN(DownFile$) - S))
      EXIT FOR...NEXT
   END IF
NEXT S
' Remove some kind of tag at the end of the file name in some URLs
IF...THEN INSTR(OutFile$, "?") THEN OutFile$ = LEFT$(OutFile$, INSTR(OutFile$, "?") - 1)

' Download the rest of the data
OPEN OutFile$ FOR OUTPUT AS #1: CLOSE #1 'Warning! Clears data from an existing file
OPEN OutFile$ FOR BINARY AS #1 'write data to binary image file
DO
   _LIMIT 20
   PUT #1, , Dat$
   GET #Client&, , Dat$
LOOP UNTIL LOF(1) >= FileSize&
CLOSE #1, #Client&
PRINT "Done!" '' ''

Host = _OPENHOST("TCP/IP:319")
IF...THEN Host THEN
  PRINT "> Server started succesfully."

  '// Change this to the file's public link
  IP_File$ = "dl.dropbox.com/u/8440706/QB64.INI" 'a Drop Box link
  URL$ = LEFT$(IP_File$, INSTR(IP_File$, "/") - 1)
  Path$ = MID$(IP_File$, INSTR(IP_File$, "/"))
  Client& = _OPENCLIENT("TCP/IP:80:" + URL$)
  IF...THEN Client& THEN
    Request$ = "GET " + Path$ + " HTTP/1.1" + CrLf$ + "Host:" + URL$ + CrLf$ + CrLf$
    PUT #Client&, , Request$
    DO: _LIMIT 20 '              load response header
      GET #Client&, , Dat$
      Header$ = Header$ + Dat$
    LOOP UNTIL INSTR(Header$, CrLf$ + CrLf$) ' Loop until 2 CRLFs (end of HTML header) are found
    PRINT "Header Done."

    ' Get file size from header
    SizePos = INSTR(UCASE$(Header$), "CONTENT-LENGTH:") + 16
    SizeEnd = INSTR(SizePos, Header$, CrLf$)
    FileSize& = VAL(MID$(Header$, SizePos, (SizeEnd - SizePos) + 1))
    PRINT "File size is"; FileSize&; "bytes"
    EndPos = INSTR(Header$, CrLf$ + CrLf$) + 4
    Response$ = MID$(Header$, EndPos) ' get data after header already downloaded

    start = 1  '// Get file name from original URL path if necessary
    DO...LOOP '// Change this to destination local file name and path...
      posit = INSTR(start, IP_File$, "/")
      IF...THEN posit THEN lastpos = posit: start = posit + 1
    LOOP UNTIL posit = 0
    File$ = MID$(IP_File$, lastpos + 1) 'beware of tag suffixes
    OPEN File$ FOR...NEXT BINARY AS #1
    DO: _LIMIT 20
      PUT #1, , Response$
      GET #Client&, , Response$
    LOOP UNTIL LOF(1) >= FileSize&
    PRINT "File download completed!"
    CLOSE #1
  ELSE
    PRINT "Failed to connect."
  END IF
ELSE
  PRINT "Failed to create server connection..."
END IF '' ''