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(dirstart, &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",dirlist[c]->d_name);
c=c+1;

}
}

 

[SM Ryan]

#
# 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(dirstart, &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",dirlist[c]->d_name);
# c=c+1;
#
# }
# }
#
#
#

 

[Artie Gold]

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>

This is a non-standard header, hence off topic here. But see below...

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

n = scandir(dirstart, &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))

`sizeof(dirlist)' will give you the size of the size of a pointer to a
`sturct dirent', which is *not* what you want.

{

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

}
}

I would advise you to post to 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

 

[Barry Schwarz]

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.

Why don't you

JR



#include <dirent.h>

Non-standard so many of us will not know how the types and functions
declared here work together.

struct dirent getdirlist(char *dirstart)

getdirlist returns a struct.

{
struct dirent **namelist;
int n;

n = scandir(dirstart, &namelist, 0, alphasort);

Does scandir really take a struct dirent*** as the second argument?
Assuming it does, namelist, *namelist, and **namelist must be
initialized within that function.

if (n < 0) perror("scandir");
return **namelist;

This is the struct to be returned.

}

int main()

{

struct dirent *dirlist;

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

BZZT. Didn't your compiler give you a diagnostic here? getdirlist
returns a struct. dirlist is a pointer to struct. They are
incompatible types.

while(c<sizeof(dirlist))

dirlist is still a pointer. Its size is probably 4.

{

printf("%s\n",dirlist[c]->d_name);

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.

c=c+1;

}
}

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]

I need some help.

Type slower, and use all the letters.

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.

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