Struct stat and stat function failure

Question

So, I'm trying to make a sort of ls function. Here's my code to the description of each file

struct stat fileStat;
struct dirent **files;

num_entries = scandir(filename, &files, file_select, alphasort);
stat(files[i-1]->d_name,fileStat);

for some reasons once it gets to stat it returns a -1. I was thinking it was because fileStat is not big enough to store the values, but I'm not sure how to solve that. Thanks for the help in advance!

ok it says no suchfile or directory ... I was able to fix it by just having a if loop that does nothing when it returns error. but yeah... how do I properly deal with this? — Jose A, May 18 '17 at 03:43
What is the value of `i`? See [**How to create a Minimal, Complete, and Verifiable example**](http://stackoverflow.com/help/mcve). Providing the necessary details, including your code, and associated errors, if any, will allow everyone here to help you with your question. — David C. Rankin, May 18 '17 at 04:17
I use i to run through the files in a for loop until position num_entries. — Jose A, May 18 '17 at 04:19
The scandir filenames are **not** *paths*. Perhaps you need to prepend the "`filename`" there. — Antti Haapala -- Слава Україні, May 18 '17 at 04:45
yeah, actually I'm trying this right now if(stat(files[i-1]->d_name,&fileStat) == 0){ } however, for some reason I can't print anything inside... — Jose A, May 18 '17 at 05:09
@JoseA people are asking for a [mcve] that _you_ need to provide by editing your question. Describing your code and posting bits of code in comments is not helpful. — Jabberwocky, May 18 '17 at 05:58

score 0 · Answer 1 · edited May 23 '17 at 12:34

Consider yourself to look at man pages. In short stat() returns:

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.

And the errno's list is:

EACCES
EBADF
EFAULT
ELOOP
ENAMETOOLONG
ENOENT
ENOMEM
ENOTDIR
EOVERFLOW

After calling stat, check it's return value with and if it equals -1, check errno (with switch).

Example:

if(stat(files[i-1]->d_name,fileStat)) {
   switch(errno) {
   case EACCES:
       // Add code or at least 
       perror("STAT ERROR:");
       break;

   case EBADF:
       // ...
       break;

   case EFAULT:
       // ...
       break;

       // ...
       // Do this to all possible errno's for the stat
       // ...
   case EOVERFLOW:
       // ...
       break;
   }
}

If you have troubles with storing path, try to declare array as this (if you using linux):

#include <linux/limits.h>
//...
char current_path[PATH_MAX];

If you using Windows:

#include <windows.h>
//...
char current_path[MAX_PATH];

P.S. Thanks for Jonathan Leffler for pointing out my switch typo :)

You can't have `case EFAULT:` twice in a single `switch` :) – Jonathan Leffler May 18 '17 at 06:15 — Jonathan Leffler, May 18 '17 at 06:15

Struct stat and stat function failure

1 Answers1