Return of struct

[JR]

I need some help. I am trying to return a dirent struct location so i
can access what the function found in main(). I dont understand
pointers very well and think that is were i am getting it wrong. If i
print everything from getdirlist everything is fine. I just cant pass
along the namelist scandir creates. Any help would be great.

JR



#include <dirent.h>


struct dirent getdirlist(char *dirstart)
{
struct dirent **namelist;
int n;

n = scandir(dirstar t, &namelist, 0, alphasort);
if (n < 0) perror("scandir ");
return **namelist;
}

int main()

{

struct dirent *dirlist;

int c=0;
char currentdir;
currentdir='.';
dirlist = getdirlist("/root");
while(c<sizeof( dirlist))

{

printf("%s\n",d irlist[c]->d_name);
c=c+1;

}
}

[SM Ryan]

Re: Return of struct

"JR" <87325is@gmail. com> wrote:
#
# I need some help. I am trying to return a dirent struct location so i
# can access what the function found in main(). I dont understand
# pointers very well and think that is were i am getting it wrong. If i
# print everything from getdirlist everything is fine. I just cant pass
# along the namelist scandir creates. Any help would be great.
#
# JR
#
#
#
# #include <dirent.h>
#
#
# struct dirent getdirlist(char *dirstart)
# {
# struct dirent **namelist;
# int n;
#
# n = scandir(dirstar t, &namelist, 0, alphasort);
# if (n < 0) perror("scandir ");
# return **namelist;
# }
#
# int main()
#
# {
#
# struct dirent *dirlist;
#
# int c=0;
# char currentdir;
# currentdir='.';
# dirlist = getdirlist("/root");

getdirlist is (struct dirent) and dirlist is (struct dirent*).
You can't assign a struct to pointer and expect it to make
sense.


# while(c<sizeof( dirlist))
#
# {
#
# printf("%s\n",d irlist[c]->d_name);
# c=c+1;
#
# }
# }
#
#
#

--
SM Ryan http://www.rawbw.com/~wyrmwif/
I ASSURE YOU WE'RE OPEN!

[Artie Gold]

Re: Return of struct

JR wrote:[color=blue]
> I need some help. I am trying to return a dirent struct location so i
> can access what the function found in main(). I dont understand
> pointers very well and think that is were i am getting it wrong. If i
> print everything from getdirlist everything is fine. I just cant pass
> along the namelist scandir creates. Any help would be great.
>
> JR
>
>
>
> #include <dirent.h>[/color]

This is a non-standard header, hence off topic here. But see below...[color=blue]
>
>
> struct dirent getdirlist(char *dirstart)
> {
> struct dirent **namelist;
> int n;
>
> n = scandir(dirstar t, &namelist, 0, alphasort);
> if (n < 0) perror("scandir ");
> return **namelist;[/color]
[color=blue]
> }
>
> int main()
>
> {
>
> struct dirent *dirlist;
>
> int c=0;
> char currentdir;
> currentdir='.';
> dirlist = getdirlist("/root");
> while(c<sizeof( dirlist))[/color]

`sizeof(dirlist )' will give you the size of the size of a pointer to a
`sturct dirent', which is *not* what you want.[color=blue]
>
> {
>
> printf("%s\n",d irlist[c]->d_name);
> c=c+1;
>
> }
> }
>[/color]
I would advise you to post to news:comp.unix. programmer, but only
*after* you have spent some time trying to understand what a `struct
dirent' is and what it contains.

IOW, as of yet you don't have a clue. The good news is that getting one
should not be difficult.

HTH,
--ag

--
Artie Gold -- Austin, Texas

http://goldsays.blogspot.com

http://www.cafepress.com/goldsays
"If you have nothing to hide, you're not trying!"

[Barry Schwarz]

Re: Return of struct

On 26 Nov 2005 18:01:31 -0800, "JR" <87325is@gmail. com> wrote:
[color=blue]
>
>I need some help. I am trying to return a dirent struct location so i
>can access what the function found in main(). I dont understand
>pointers very well and think that is were i am getting it wrong. If i
>print everything from getdirlist everything is fine. I just cant pass
>along the namelist scandir creates. Any help would be great.[/color]

Why don't you[color=blue]
>
>JR
>
>
>
>#include <dirent.h>[/color]

Non-standard so many of us will not know how the types and functions
declared here work together.
[color=blue]
>
>
>struct dirent getdirlist(char *dirstart)[/color]

getdirlist returns a struct.
[color=blue]
>{
> struct dirent **namelist;
> int n;
>
> n = scandir(dirstar t, &namelist, 0, alphasort);[/color]

Does scandir really take a struct dirent*** as the second argument?
Assuming it does, namelist, *namelist, and **namelist must be
initialized within that function.
[color=blue]
> if (n < 0) perror("scandir ");
> return **namelist;[/color]

This is the struct to be returned.
[color=blue]
>}
>
>int main()
>
>{
>
> struct dirent *dirlist;
>
> int c=0;
> char currentdir;
> currentdir='.';
> dirlist = getdirlist("/root");[/color]

BZZT. Didn't your compiler give you a diagnostic here? getdirlist
returns a struct. dirlist is a pointer to struct. They are
incompatible types.
[color=blue]
> while(c<sizeof( dirlist))[/color]

dirlist is still a pointer. Its size is probably 4.
[color=blue]
>
> {
>
> printf("%s\n",d irlist[c]->d_name);[/color]

How about another diagnostic here? dirlist is a pointer to struct.
dirlist[c] is a struct. The -> operator cannot have a left operand of
type struct. It must have one of type pointer to struct.
[color=blue]
> c=c+1;
>
> }
>}[/color]

After you correct the obvious syntax errors, you need to ask in a
group where you system specific functions are on topic. My system
doesn't have a /root but then it doesn't have directories either.


<<Remove the del for email>>

[Mabden]

Re: Return of struct

"JR" <87325is@gmail. com> wrote in message
news:1133056891 .534216.39440@f 14g2000cwb.goog legroups.com...[color=blue]
>
> I need some help.[/color]

Type slower, and use all the letters.
[color=blue]
> I am trying to return a dirent struct location so i
> can access what the function found in main(). I dont understand
> pointers very well and think that is were i am getting it wrong. If i
> print everything from getdirlist everything is fine. I just cant pass
> along the namelist scandir creates. Any help would be great.
>[/color]

A lot of that is gibberish. Speak slowly, and explain the problem. Put
down the crack pipe, if necessary.

--
Mabden