OpenEuphoria

Re: program directory

• Posted by "Boehme, Gabriel" <gboehme at MUSICLAND.COM> Apr 27, 1999
• 371 views

Martin and Ralf,

Here's my solution to the program directory problem.  This is based on some
very old and klunky code of mine, which I have updated and repaired with
some ideas from you and Hawke'.  This should work for every situation you
have addressed.  If you have any problems, let me know.


 ------------------------------------------------------------------------

 ------------------------------------
 -- sequence manipulation routines --
 ------------------------------------

function find_last(object value, sequence s)
 -- return the LAST occurrence of value in sequence s
   for i = length(s) to 1 by -1 do
      if equal(s[i], value) then
         return i
      end if
   end for
   return 0
end function

function find_all(object value, sequence s)
 -- return a list of all indexes where value is found in s
 -- [Hawke''s routine -- thanks!  :) ]
sequence list   list = {}
   for i = 1 to length(s) do
      if equal(s[i], value) then
         list = append(list, i)
      end if
   end for
   return list
end function

function parse(sequence s, object x)
 -- parse s based on delimiter x into a sequence of values
 -- NOTE: we append x to s so we have at least one delimiter, at the end
sequence list
integer len, prev, curr

   list = find_all(x, append(s, x)) -- list of delimiter positions
   len = length(list)

   prev = 0
   for i = 1 to len do
      curr = list[i]
      list[i] = s[prev+1..curr-1]
      prev = curr
   end for

   return list -- now, a list of the delimited values
end function


 ------------------------
 -- program_location() --
 ------------------------
include file.e

function program_location()
 -- returns a string value containing the program's location
 -- returns -1 if an error occurs
sequence cmd, program, s, list
integer loc

   cmd = command_line()
   program = cmd[2]
   loc = find_last('\\', program)
   if loc then
      -- the program location is included in the name
      return program[1..loc]

   elsif find(':', program) = 2 then
      -- the program location is included in the name
      return program[1..2]

   else
      -- verify that we have a file extension on our program name
      if not find('.', program) then
         cmd = cmd[1]
         if match("EX.EXE", cmd) then
            program &= ".ex"
         elsif match("EXW.EXE", cmd) then
            program &= ".exw"
         else
            -- ?!? This should never happen, but...
            return -1
         end if
      end if

      if sequence(dir(program)) then
         -- it's in the current directory
         return ""
      else
         -- it's somewhere in our PATH
         list = parse(getenv("PATH"), ';')
         for i = 1 to length(list) do
            s = list[i]
            if length(s) then
               if sequence(dir(s & '\\' & program)) then
                  return s & '\\'
               end if
            end if
         end for
      end if
   end if

   -- the program's location was not found!
   -- (this should never happen, but just in case...)
   return -1
end function

 ------------------------------------------------------------------------


Be seeing you,
   Gabriel Boehme


 ------
Men do not differ much about what things they will call evils; they differ
enormously about what evils they will call excusable.

G.K. Chesterton
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