Fun with libcurl....

[AIR]

On the Bacon Website, Peter has an example of using libcurl to download a file over http, using the CURL module by Doyle Wisenant.

It works, but there is no progress indicator so you don't know how far in the download process you actually are.

I decided to add a progressbar to Peter's code; here is the code with a screenshot showing how it will look...

Code: Text

1. '
2. ' Download a binary file example over HTTP using CURL - PvE december 2010
3. '
4. ' Added progressbar callback, redirect support, and save filename - AIR october 2018
5. '
6.  
7.  
8. ' ADAPTED FROM: https://stackoverflow.com/questions/1637587/c-libcurl-console-progress-bar
9. FUNCTION progress_callback(void* clientp, double dltotal, double dlnow, double ultotal, double ulnow )
10.     LOCAL totaldotz, dotz, ii TYPE int
11.     LOCAL fractiondownloaded TYPE double
12.  
13.     IF dltotal <= 0.0 THEN RETURN 0
14.    
15.     totaldotz = 40
16.     fractiondownloaded = dlnow/dltotal
17.     dotz = ROUND(fractiondownloaded * totaldotz)
18.  
19.     PRINT fractiondownloaded * 100 FORMAT "%3.0f%% [";
20.  
21.     WHILE ii < dotz DO
22.         PRINT "=";
23.         INCR ii
24.     WEND
25.  
26.     WHILE ii < totaldotz DO
27.         PRINT " ";
28.         INCR ii
29.     WEND
30.  
31.     PRINT (STRING)clientp FORMAT "] %s\r";
32.  
33.     RETURN 0
34. END FUNCTION
35.  
36. ' Include the CURL context
37. INCLUDE "curl.bac"
38.  
39. CONST filename$ = "documentation.pdf"
40. CONST savefilename$ = "Bacon.pdf"
41.  
42. CLEAR
43. PRINT "Downloading Bacon Documentation in PDF format...\n"
44. ' File where we store the download
45. OPEN savefilename$ FOR WRITING AS download
46.  
47. ' Create the handle
48. curl = curl_easy_init()
49.  
50. ' Set the options
51. curl_easy_setopt(curl, CURLOPT_URL, CONCAT$("http://www.basic-converter.org/", filename$))
52. curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION,1)
53. curl_easy_setopt(curl, CURLOPT_WRITEDATA, download)
54. curl_easy_setopt(curl, CURLOPT_NOPROGRESS,0)
55. curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION,progress_callback)
56. curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, ADDRESS(savefilename$))
57.  
58. ' Perform the GET
59. success = curl_easy_perform(curl)
60.  
61. ' Cleanup
62. curl_easy_cleanup(curl)
63.  
64. ' Close filehandle
65. CLOSE FILE download
66.  
67. PRINT "\n\nDownload Complete.\n"
68.  

This was pretty easy to implement because Bacon is a phenomenal language!

Tested on both macOS and Linux (64bit Ubuntu Server and Raspbian on a RasPi).

For macOS, you'll need to change the name of the library in the curl.bac file from:

Just change the $lib= section towards the top of the curl.bac file to

Code: Text

1. IF INSTR(OS$, "Darwin") THEN
2.     lib$ = "libcurl.dylib"
3. ELSE
4.     lib$ = "libcurl.so"
5. END IF

AIR.

[John]

By far BaCon is the best Linux/Unix BASIC compiler/translator available today.

Its syntax is an extension of Script BASIC which makes it a natural migration path to binary executables.