On Wed, 6 May 2015, Henrique Andrade wrote:

Dear Gretl Team,

As a part of my job in function package maintenance, I'm trying to make a
Hansl script to (1) create a list of functions available in the Gretl
internet server, (2) download them using the new "install" command and, (3)
execute the examples.

I really appreciate your help to build a list with the names of the
functions. I'm using the following code to retrieve the names:

<hansl>
string functions_page = readfile("
http://ricardo.ecn.wfu.edu/gretl/cgi-bin/gretldata.cgi?opt=SHOW_FUNCS")

string line = ""
scalar i = 1

loop while getline(functions_page, line) --quiet
   string line_name = sprintf("line_%d", i++)
   string @line_name = strstr(line, "current_fnfiles/")
   string @line_name = strstr(@line_name, "<tt>")
   string @line_name = strsub(@line_name, "</td><td>", "  ")
   string @line_name = strsub(@line_name, "</a>", "")
   string @line_name = strsub(@line_name, "</td></tr>", "")
   string @line_name = strsub(@line_name, "<p>", "'")
   string @line_name = strsub(@line_name, "<tt>", "'")
   string @line_name = strsub(@line_name, "</tt>", "'")
   string @line_name = strsub(@line_name, "</p>", "'")
   string @line_name = strstrip(@line_name)
   if @line_name = ""
       delete @line_name
   else
       print @line_name
   endif
endloop
</hansl>

It gives me something like this:

(...)
'addlist.gfn'  'Allin Cottrell'  '1.2'  '2010-12-17'  'Sequential addition
of variables to a model'
(...)

Now I need to use just the first piece of the string ("addlist") to combine
it with the install command. Something like this:

<hansl>
install addlist.gfn
</hansl>

Now my question: How could I extract the first "element" of my string?

Here's a suggestion:

<hansl>
string page = \
readfile("http://ricardo.ecn.wfu.edu/gretl/cgi-bin/gretldata.cgi?opt=SHOW_FUNCS")
string line
string fname
loop while getline(page, line) --quiet
  string s = strstr(line, "current_fnfiles/")
  if strlen(s) > 0 && sscanf(s + 16, "%[^\"]", fname)
    printf "got '%s'\n", fname
  endif
endloop
</hansl>

The sscanf format '%[^\"]' says: read a string until you encounter '"' then stop (the leading '^' represents negation in this context).

Allin
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