NAME_MAX

[occhiverdi]

Hi,

I would like to know which file do I need to include to get NAME_MAX? I'm
trying to read filenames of a directory but it gave me error saying that
the NAME_MAX is undefined. I've looked into the /usr/include directory and
I see that it's not defined anywhere.

#include <dirent.h>
....
struct dirent * file;
char filename[NAME_MAX + 1];
....
while ((file = readdir(queue_dir)) != NULL) {
filename = file -> d_name;
....

Thanks for help.

occhiverdi

 

[Ben Pfaff]

I would like to know which file do I need to include to get NAME_MAX?

Standard C doesn't have a NAME_MAX. There is a FILENAME_MAX in
<stdio.h>.

 

[Quentarez]

I believe you must #include <limits.h>.

 

[osmium]

I would like to know which file do I need to include to get NAME_MAX? I'm
trying to read filenames of a directory but it gave me error saying that
the NAME_MAX is undefined. I've looked into the /usr/include directory and
I see that it's not defined anywhere.

#include <dirent.h>
...
struct dirent * file;
char filename[NAME_MAX + 1];
...
while ((file = readdir(queue_dir)) != NULL) {
filename = file -> d_name;
...

Perhaps you want FILENAME_MAX? I would expect it to be in <stdio.h>.

 

[Ben Pfaff]

I believe you must #include <limits.h>.

<limits.h> does not contain NAME_MAX.

 

[occhiverdi]

#include <dirent.h>
...
struct dirent * file;
char filename[NAME_MAX + 1];
...
while ((file = readdir(queue_dir)) != NULL) {
filename = file -> d_name;
...

Thanks for the replies.

I see that I only have to declare filename as
char * filename;
It works.

occhiverdi

 

[Martin Ambuhl]

Hi,

I would like to know which file do I need to include to get NAME_MAX?

Include <stdio.h> to get FILENAME_MAX. There is no standard C macro
named 'NAME_MAX'.

 

[Emmanuel Delahaye]

I see that I only have to declare filename as
char * filename;
It works.

What works? I'm scared...

 

[Jens.Toerring]

What works? I'm scared...

In that case it might even work, because he's just copying the
pointer to some member of a structure the function returns,
he's not calling e.g. strcpy() with that pointer.
<OT>
Of course, that only works as expected if the OP doesn't want to
keep what the pointer is pointing to after the next invocation of
the readdir() function, i.e. when he uses 'filename' only as an
abbreviation for 'file->d_name'.
</OT>
Regards, Jens

 

[Keith Thompson]

What works? I'm scared...

When I first read occhiverdi's response, I was also concerned that he
was incorrectly using an uninitialized char*. But if you'll read
the full article (including the part that you snipped), you'll see

filename = file -> d_name;

which is perfectly legitimate assuming that file->d_name is valid.

 

[Emmanuel Delahaye]

When I first read occhiverdi's response, I was also concerned that he
was incorrectly using an uninitialized char*. But if you'll read
the full article (including the part that you snipped), you'll see


which is perfectly legitimate assuming that file->d_name is valid.

Agreed. I have read too fast. My bad.