1. file exists function
- Posted by efapon4 at juno.com
Jun 27, 2001
is there a function in euphoria to determine if a file exists in a
specified directory?
2. Re: file exists function
efapon4 wrote:
> is there a function in euphoria to determine if a file exists in a
> specified directory?
function exists(sequence filename)
-- filename can contain the whole path if required
integer fh
fh = open(filename, "rb")
if fh != -1 then
close(fh)
return 1
end if
return 0
end function
HTH,
Carl
--
Carl R White - aka - Cyrek
eMail: carlw at legend.co.uk
cyrek at bigfoot.com
URL: nope none nada zip
3. Re: file exists function
efapon4 at juno.com wrote:
>
> is there a function in euphoria to determine if a file exists in a
> specified directory?
>
The dir() function will tell you: If the file doesn't exist it will
return the atom '-1' otherwise a sequence containing file information,
use: help, library, dir().
Have a nice day, Rolf
4. Re: file exists function
- Posted by otter at FULL-MOON.COM
Jun 27, 2001
there are 2 ways to see if a file exists all depending on your intentions.
Example 1: if you want to know if it exists for copying or moving or something
then use this. Note: this function works to check both files and also directories
themselves.
constant false = 0, true = not false
function exists(sequence filename)
-- return true or false if file or directory is found
object temp_object
temp_object = dir(filename)
if atom (temp_object) then
return false
else
return true
end if
end function
usage:
if exists(filename) then
-- good code goes here
else
-- nasty message goes here
end if
also works for:
if exists("c:\\temp\\") then
-- good code goes here
else
-- nasty message goes here
end if
Example 2: if you are planning on opening the file if it does exist then use
something like this. this method looks more complex but is actually much more
efficient than Example 1. at least in my world a dir() takes MUCH more time to
execute than open():
constant false = 0, true = not false
function open_if_exists(sequence filename)
-- open file if it exists and pass back file number
-- if file doesn't exist then pass back false (0)
atom temp_atom
temp_atom = open(filename,"r") -- change the open attributes according to your
needs
if temp_atom < 1 then
return false
else
return temp_atom
end if
end function
usage: atom file_handle
file_handle = open_if_exists(filename)
if file_handle then
-- good code goes here
else
-- nasty message goes here
end if
there are probably more elegant ways to do it, but these 2 methods work for me.
hope it helps!
~OD~
Windows 95 Error 23042: Virus error - A virus has been activated in a DOS-box.
The virus, however, requires Windows. All tasks will automatically be closed
and the virus will be activated again.
