topic Re: E_NOENT while file exist ! in Operating System - HP-UX

E_NOENT while file exist !

Laurent Laperrousaz — Fri, 21 May 2004 11:40:08 GMT

Could this error be related to a kernel limit?

Re: E_NOENT while file exist !

Navin Bhat_2 — Fri, 21 May 2004 11:43:30 GMT

check the directory path and permissions also. Not related to kernel parameters.

Re: E_NOENT while file exist !

Bharat Katkar — Fri, 21 May 2004 11:44:09 GMT

When and where did you see the this error. Please give more details regarding the same.
Regards,

Re: E_NOENT while file exist !

A. Clay Stephenson — Fri, 21 May 2004 11:46:46 GMT

Generally not but ENOENT can be set my many system calls --- some of which have nothing to do with files. An errno value out of context (at a minimum the system call that it is related to) is of little value.

Ideally, you need errno and the system call that set it along with the actual parameters passed to the system call. Tusc can actually be used to yield these results for a process.

Re: E_NOENT while file exist !

Laurent Laperrousaz — Fri, 21 May 2004 11:58:07 GMT

I already posted a question for this problem:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=216102
and i thought it was gone...

Alas, it is back!

here is the code where I test the existence of the file:
It may say "file not exist" or it works fine (with the same file)

// Pour vÃ©rifier l'existence d'un fichier
bool fileExists(const char *filename)
{
// Initialise Ã NULL
FILE *fichier = NULL;

// Ouvre le fichier en lecture seulement
fichier = fopen(filename, "r");

// Si NULL est renvoyÃ© c'est parce que le fichier n'a pas Ã©tÃ© trouvÃ© ou bien qu'il est dÃ©jÃ ouvert(pas accessible...) ou autres...
if (fichier == NULL)
{
cout << "erreur fileExists " << string(filename, strlen(filename)) <<" , errno = " << errno < return false;
}
// Ferme le fichier
fclose(fichier);

// Renvoie true, le fichier existe bien

Re: E_NOENT while file exist !

A. Clay Stephenson — Fri, 21 May 2004 12:24:02 GMT

The first thing that I notice is that there is no return for this function when the file is able to be opened. This may be because you have posted only a snippit of code or i you may have an defined result.

In any event, sometimes it's nice to fall back on the old standards to print errors. I would replace the cout with
(void) fprintf(stderr,"Filename: \"%s\" errno: %d\n",filename,errno);
int i = 0,len = 0;
len = strlen(filename);
while (i < len)
{
if (filename[i] >= ' ' && filename[i] <= '~') (void) fprintf(stderr,"%c",filename[i])
else (void) fprintf(stderr,"|%03o|",(int) filename[i]);
++i;
}
(void) fprintf(stderr,"\n");
(void) fflush(stderr);

The idea is to detect any non-printable characters embedded in the filename.

One other observation, fopen is slightly removed from the actual system call open() so if you are really fighting a mysterious problem, you may want to use open instead so that you know it is what actually set errno although fopen should be close enough to the scene of the crime.

Re: E_NOENT while file exist !

Laurent Laperrousaz — Fri, 21 May 2004 12:29:38 GMT

you are right, I forgot 2 lines in my cut and paste!

Anyway I will try your suggestions and let you know...

Thanks

Laurent