1. How check for "path/file exists"?
Wolf, all,
How can I check for whether a specified "path/file" exists??
I'm trying to use Wolf's "jumpto" (or perhaps his "ShellExecute2") to run
another program from within my program (to jump to it); when this is a
program with a "stable" path, no problem. But I'm wanting to be able to
jump to Wolf's tutorial, which isn't always at a known place in the Euphoria
folder, so I need to be able to *test* for whether the path/file I
tentatively specify actually exists or not, so I can activate the "open
file" dialog if it doesn't.
I changed Wolf's "jumpto" to a function, thinking to use the return as a
test, but while it worked if the path was correct, when the path/file wasn't
correct it just bombed & output an error message about "can't open file".
Any thoughts?
Dan Moyer
2. Re: How check for "path/file exists"?
- Posted by Kat <gertie at PELL.NET>
Sep 03, 2000
-
Last edited Sep 04, 2000
On 3 Sep 2000, at 19:13, Dan B Moyer wrote:
> Wolf, all,
>
> How can I check for whether a specified "path/file" exists??
>
> I'm trying to use Wolf's "jumpto" (or perhaps his "ShellExecute2") to run
> another program from within my program (to jump to it); when this is a
> program with a "stable" path, no problem. But I'm wanting to be able to
> jump to Wolf's tutorial, which isn't always at a known place in the Euphoria
> folder, so I need to be able to *test* for whether the path/file I
> tentatively specify actually exists or not, so I can activate the "open
> file" dialog if it doesn't.
>
> I changed Wolf's "jumpto" to a function, thinking to use the return as a
> test, but while it worked if the path was correct, when the path/file wasn't
> correct it just bombed & output an error message about "can't open file".
>
> Any thoughts?
Try opening the file for a read before you try to exec it. If it cannot be
opened, then it's
not there or it's locked,, either way, you can't run it.
Kat
3. Re: How check for "path/file exists"?
- Posted by Dan B Moyer <DANMOYER at PRODIGY.NET>
Sep 03, 2000
-
Last edited Sep 04, 2000
Kat,
Ok, I did consider that, but thought there might be a better or more
"elegant" way. Thanks.
Dan
----- Original Message -----
From: "Kat" <gertie at PELL.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Sunday, September 03, 2000 8:35 PM
Subject: Re: How check for "path/file exists"?
> On 3 Sep 2000, at 19:13, Dan B Moyer wrote:
>
> > Wolf, all,
> >
> > How can I check for whether a specified "path/file" exists??
> >
> > I'm trying to use Wolf's "jumpto" (or perhaps his "ShellExecute2") to
run
> > another program from within my program (to jump to it); when this is a
> > program with a "stable" path, no problem. But I'm wanting to be able to
> > jump to Wolf's tutorial, which isn't always at a known place in the
Euphoria
> > folder, so I need to be able to *test* for whether the path/file I
> > tentatively specify actually exists or not, so I can activate the "open
> > file" dialog if it doesn't.
> >
> > I changed Wolf's "jumpto" to a function, thinking to use the return as a
> > test, but while it worked if the path was correct, when the path/file
wasn't
> > correct it just bombed & output an error message about "can't open
file".
> >
> > Any thoughts?
>
> Try opening the file for a read before you try to exec it. If it cannot be
opened, then it's
> not there or it's locked,, either way, you can't run it.
>
> Kat
4. Re: How check for "path/file exists"?
- Posted by Dan B Moyer <DANMOYER at PRODIGY.NET>
Sep 03, 2000
-
Last edited Sep 04, 2000
Kat,
Tried it, but when no file exists, I get a dos window with message "can't
open" filename instead of going on through the if-then.
Here's what I wrote:
--<code>
integer filethere
filethere = open("c:\\Euphoria\\Win32Lib\\A new Tutorial\\Tutor3.exw","r")
if filethere != -1 then -- is a file there
close(filethere)
Jump_to(
-- passing YOUR main window's id:
MainWindow,
-- with the program to call:
"exw.exe",
-- this is MY current 'tutorials' default path !!
"c:\\Euphoria\\Win32Lib\\A new Tutorial\\",
-- the parameter to pass to exw.exe:
"xTutor3.exw", -- for purpose of test, there is no such file
-- and last, the 'show' parameter:
SW_SHOWDEFAULT )
else
end if
<code ends>
Dan
----- Original Message -----
From: "Kat" <gertie at PELL.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Sunday, September 03, 2000 8:35 PM
Subject: Re: How check for "path/file exists"?
> On 3 Sep 2000, at 19:13, Dan B Moyer wrote:
>
> > Wolf, all,
> >
> > How can I check for whether a specified "path/file" exists??
> >
> > I'm trying to use Wolf's "jumpto" (or perhaps his "ShellExecute2") to
run
> > another program from within my program (to jump to it); when this is a
> > program with a "stable" path, no problem. But I'm wanting to be able to
> > jump to Wolf's tutorial, which isn't always at a known place in the
Euphoria
> > folder, so I need to be able to *test* for whether the path/file I
> > tentatively specify actually exists or not, so I can activate the "open
> > file" dialog if it doesn't.
> >
> > I changed Wolf's "jumpto" to a function, thinking to use the return as a
> > test, but while it worked if the path was correct, when the path/file
wasn't
> > correct it just bombed & output an error message about "can't open
file".
> >
> > Any thoughts?
>
> Try opening the file for a read before you try to exec it. If it cannot be
opened, then it's
> not there or it's locked,, either way, you can't run it.
>
> Kat
5. Re: How check for "path/file exists"?
- Posted by Dan B Moyer <DANMOYER at PRODIGY.NET>
Sep 03, 2000
-
Last edited Sep 04, 2000
Nevermind, I found it, sigh. Tested for a file that *does* exist, so it
then tried to open file that *doesn't*, which failed. argh.
Dan
----- Original Message -----
From: "Dan B Moyer" <DANMOYER at prodigy.net>
To: "Euphoria Programming for MS-DOS" <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Sunday, September 03, 2000 9:29 PM
Subject: Re: How check for "path/file exists"?
> Kat,
>
> Tried it, but when no file exists, I get a dos window with message "can't
> open" filename instead of going on through the if-then.
>
> Here's what I wrote:
>
> --<code>
> integer filethere
>
> filethere = open("c:\\Euphoria\\Win32Lib\\A new Tutorial\\Tutor3.exw","r")
> if filethere != -1 then -- is a file there
> close(filethere)
> Jump_to(
> -- passing YOUR main window's id:
> MainWindow,
> -- with the program to call:
> "exw.exe",
> -- this is MY current 'tutorials' default path !!
> "c:\\Euphoria\\Win32Lib\\A new Tutorial\\",
> -- the parameter to pass to exw.exe:
> "xTutor3.exw", -- for purpose of test, there is no such file
> -- and last, the 'show' parameter:
> SW_SHOWDEFAULT )
> else
>
> end if
> <code ends>
>
> Dan
>
> ----- Original Message -----
> From: "Kat" <gertie at PELL.NET>
> To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
> Sent: Sunday, September 03, 2000 8:35 PM
> Subject: Re: How check for "path/file exists"?
>
>
> > On 3 Sep 2000, at 19:13, Dan B Moyer wrote:
> >
> > > Wolf, all,
> > >
> > > How can I check for whether a specified "path/file" exists??
> > >
> > > I'm trying to use Wolf's "jumpto" (or perhaps his "ShellExecute2") to
> run
> > > another program from within my program (to jump to it); when this is a
> > > program with a "stable" path, no problem. But I'm wanting to be able
to
> > > jump to Wolf's tutorial, which isn't always at a known place in the
> Euphoria
> > > folder, so I need to be able to *test* for whether the path/file I
> > > tentatively specify actually exists or not, so I can activate the
"open
> > > file" dialog if it doesn't.
> > >
> > > I changed Wolf's "jumpto" to a function, thinking to use the return as
a
> > > test, but while it worked if the path was correct, when the path/file
> wasn't
> > > correct it just bombed & output an error message about "can't open
> file".
> > >
> > > Any thoughts?
> >
> > Try opening the file for a read before you try to exec it. If it cannot
be
> opened, then it's
> > not there or it's locked,, either way, you can't run it.
> >
> > Kat
>
6. Re: How check for "path/file exists"?
--returns 1 if file exists, 0 if it doesn't
global function file_exists(sequence fpath)
integer a
a=open(fpath,"r")
if a=-1 then
--not found
a=0
else
--found
close(a)
a=1
end if
return a
end function
7. Re: How check for "path/file exists"?
TESTING FOR A VALID PATH
Dan,
The problem with opening a file to test for validity is that you
can't open a directory name, so here's what i use:
--------------------------------------------------------------
-- Path Validation Check --
-- checks for valid directory or filename
--------------------------------------------------------------
include file.e
include get.e --for this sample only
atom retv,ink
function ValidatePath(sequence TargetPathName,sequence TargetFileName)
object DirEntries
DirEntries=dir(TargetPathName&TargetFileName)
if atom(DirEntries) then
--doesnt exist
return 0
else
return 1
end if
end function
--testing for a valid specific filename:
?retv
--testing for a valid directory name:
?retv
printf(1,"%s\n",{"Press a key..."})
ink=wait_key()
----------------------------------------------------------------
Good luck.
--Al
8. Re: How check for "path/file exists"?
Huh?
I did it & it worked as far as I could tell. I did this:
fileHandle = open(DefaultPath & DefaultFileName, "r")
if fileHandle != -1 then -- tutorial is in default directory:
Dan
----- Original Message -----
From: "Al Getz" <xaxo at AOL.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, September 04, 2000 3:46 AM
Subject: Re: How check for "path/file exists"?
> TESTING FOR A VALID PATH
>
> Dan,
>
> The problem with opening a file to test for validity is that you
> can't open a directory name, so here's what i use:
>
> --------------------------------------------------------------
>
> -- Path Validation Check --
>
> -- checks for valid directory or filename
>
> --------------------------------------------------------------
>
> include file.e
> include get.e --for this sample only
>
> atom retv,ink
>
> function ValidatePath(sequence TargetPathName,sequence TargetFileName)
>
> object DirEntries
>
> DirEntries=dir(TargetPathName&TargetFileName)
> if atom(DirEntries) then
> --doesnt exist
> return 0
> else
> return 1
> end if
> end function
>
> --testing for a valid specific filename:
> retv=ValidatePath("c:\\euphoria\\projects\\tests\\","test.txt")
> ?retv
>
> --testing for a valid directory name:
> retv=ValidatePath("c:\\euphoria\\projects\\emptydir\\","*.*")
> ?retv
>
>
> printf(1,"%s\n",{"Press a key..."})
>
> ink=wait_key()
>
> ----------------------------------------------------------------
>
> Good luck.
> --Al
9. Re: How check for "path/file exists"?
Skoda,
Thanks, that's close to what I did, except I didn't put it into a function,
just put it directely in the code since I only used it once.
Dan
----- Original Message -----
From: "Skoda" <tone.skoda at SIOL.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, September 04, 2000 2:17 AM
Subject: Re: How check for "path/file exists"?
> --returns 1 if file exists, 0 if it doesn't
> global function file_exists(sequence fpath)
> integer a
> a=open(fpath,"r")
> if a=-1 then
> --not found
> a=0
> else
> --found
> close(a)
> a=1
> end if
> return a
> end function
10. Re: How check for "path/file exists"?
Dan,
Glad it worked for you. My code was used to test for a valid
filename OR directory name. You can't open a directory name with
'open()' so you need another way to test for that. If your only
testing for valid filenames i guess it doesnt matter.
--Al
11. Re: How check for "path/file exists"?
Al,
Oh, ok, now I understand: you're providing for making a specific check for
whether a *directory* exists or not. I didn't really need that, as what I
am doing is asserting a "default" pathname for Wolf's Tutorial, and if it
isn't there (which I can & do check with open filename), then I open the
"open file" dialog to find it & then use it.
But that *is* an interesting routine you shared with us! :)
Dan
----- Original Message -----
From: "Al Getz" <xaxo at AOL.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, September 04, 2000 3:46 AM
Subject: Re: How check for "path/file exists"?
> TESTING FOR A VALID PATH
>
> Dan,
>
> The problem with opening a file to test for validity is that you
> can't open a directory name, so here's what i use:
>
> --------------------------------------------------------------
>
> -- Path Validation Check --
>
> -- checks for valid directory or filename
>
> --------------------------------------------------------------
>
> include file.e
> include get.e --for this sample only
>
> atom retv,ink
>
> function ValidatePath(sequence TargetPathName,sequence TargetFileName)
>
> object DirEntries
>
> DirEntries=dir(TargetPathName&TargetFileName)
> if atom(DirEntries) then
> --doesnt exist
> return 0
> else
> return 1
> end if
> end function
>
> --testing for a valid specific filename:
> retv=ValidatePath("c:\\euphoria\\projects\\tests\\","test.txt")
> ?retv
>
> --testing for a valid directory name:
> retv=ValidatePath("c:\\euphoria\\projects\\emptydir\\","*.*")
> ?retv
>
>
> printf(1,"%s\n",{"Press a key..."})
>
> ink=wait_key()
>
> ----------------------------------------------------------------
>
> Good luck.
> --Al
12. Re: How check for "path/file exists"?
A simpler version:
function ValidatePath(sequence TargetPathName)
return sequence(dir(TargetPathName))
end function
No need to separate file and path just so the function can recombine them.
-- Mike Nelson
----- Original Message -----
From: "Al Getz" <xaxo at AOL.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, September 04, 2000 3:46 AM
Subject: Re: How check for "path/file exists"?
> TESTING FOR A VALID PATH
>
> Dan,
>
> The problem with opening a file to test for validity is that you
> can't open a directory name, so here's what i use:
>
> --------------------------------------------------------------
>
> -- Path Validation Check --
>
> -- checks for valid directory or filename
>
> --------------------------------------------------------------
>
> include file.e
> include get.e --for this sample only
>
> atom retv,ink
>
> function ValidatePath(sequence TargetPathName,sequence TargetFileName)
>
> object DirEntries
>
> DirEntries=dir(TargetPathName&TargetFileName)
> if atom(DirEntries) then
> --doesnt exist
> return 0
> else
> return 1
> end if
> end function
>
> --testing for a valid specific filename:
> retv=ValidatePath("c:\\euphoria\\projects\\tests\\","test.txt")
> ?retv
>
> --testing for a valid directory name:
> retv=ValidatePath("c:\\euphoria\\projects\\emptydir\\","*.*")
> ?retv
>
>
> printf(1,"%s\n",{"Press a key..."})
>
> ink=wait_key()
>
> ----------------------------------------------------------------
>
> Good luck.
> --Al
13. Re: How check for "path/file exists"?
Al,
Turns out I did need have them separate, because Wolf's "jump to" has
separate parameter fields for path & file .
Dan
----- Original Message -----
From: "Michael Nelson" <MichaelANelson at WORLDNET.ATT.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, September 04, 2000 7:32 AM
Subject: Re: How check for "path/file exists"?
> A simpler version:
>
> function ValidatePath(sequence TargetPathName)
> return sequence(dir(TargetPathName))
> end function
>
> No need to separate file and path just so the function can recombine them.
>
> -- Mike Nelson
>
> ----- Original Message -----
> From: "Al Getz" <xaxo at AOL.COM>
> To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
> Sent: Monday, September 04, 2000 3:46 AM
> Subject: Re: How check for "path/file exists"?
>
>
> > TESTING FOR A VALID PATH
> >
> > Dan,
> >
> > The problem with opening a file to test for validity is that you
> > can't open a directory name, so here's what i use:
> >
> > --------------------------------------------------------------
> >
> > -- Path Validation Check --
> >
> > -- checks for valid directory or filename
> >
> > --------------------------------------------------------------
> >
> > include file.e
> > include get.e --for this sample only
> >
> > atom retv,ink
> >
> > function ValidatePath(sequence TargetPathName,sequence TargetFileName)
> >
> > object DirEntries
> >
> > DirEntries=dir(TargetPathName&TargetFileName)
> > if atom(DirEntries) then
> > --doesnt exist
> > return 0
> > else
> > return 1
> > end if
> > end function
> >
> > --testing for a valid specific filename:
> > retv=ValidatePath("c:\\euphoria\\projects\\tests\\","test.txt")
> > ?retv
> >
> > --testing for a valid directory name:
> > retv=ValidatePath("c:\\euphoria\\projects\\emptydir\\","*.*")
> > ?retv
> >
> >
> > printf(1,"%s\n",{"Press a key..."})
> >
> > ink=wait_key()
> >
> > ----------------------------------------------------------------
> >
> > Good luck.
> > --Al
14. Re: How check for "path/file exists"?
Dan:
(that's me, always late)
----- Original Message -----
From: Dan B Moyer <DANMOYER at PRODIGY.NET>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Monday, September 04, 2000 1:29 AM
Subject: Re: How check for "path/file exists"?
> --<code>
> integer filethere
>
> filethere = open("c:\\Euphoria\\Win32Lib\\A new Tutorial\\Tutor3.exw","r")
> if filethere != -1 then -- is a file there
> close(filethere)
> Jump_to(
> -- passing YOUR main window's id:
> MainWindow,
> .....etc. etc.....
> <code ends>
>
> Dan
>
Try it the other way round:
if filethere = -1 then screamforhelp() else processhappily();
or maybe even the Perl way:
open(file) or die "Someone swiped my file!";
Gerardo E. Brandariz
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