Sort files and folders in some path on ubuntu 12.04 (C coding)

dewin88 · 03-25-2015, 11:31 PM

Hello.

I make this scructure for save information which i get:

typedef struct _FILE_STAT
{
char* file_name;
struct stat st;
} FILE_STAT;

Allocate an array of pointers to this structure, for example 16 pieces.

Started on the array counter to know its size and not get out.

Pass on the folder cycle and gather information in this array. If the array has appeared small, the cycle is increased it twice through realloc. And read on.

If i find the file to allocate memory for structure FILE_STAT. The pointer is placed in the array and increments the counter.

Next allocate memory for the file name and I bring to the resulting structure.

Need some sort functions for the name, size, and other data. I want to expose a function qsort depending on the type of sorting.

At the end of the cycle is to sort an array, set on a qsort.

Well, and display information.

How to implement it in C for linux? Sorry, i know only bash scripting.

dewin88 · 03-26-2015, 04:31 AM

Code:

#include <stdio.h>
#include <dirent.h>
#include <sys/stat.h>

int main(int argc, char *argv[]) {
    struct stat file_stats;
    DIR *dirp;
    struct dirent* dent;

    dirp=opendir("."); // specify directory here: "." is the "current directory"
    do {
        dent = readdir(dirp);
        if (dent)
        {
            printf("%s  --  ", dent->d_name);
            if (!stat(dent->d_name, &file_stats))
            {
                printf("%u bytes\n", (unsigned int)file_stats.st_size);
                //how i can sort struct stat file_stats by bytes?
            }
            else
            {
                printf("(stat() failed for this file)\n");
            }
        }
    } while (dent);
    closedir(dirp);
}

find this code, but how i can sort by ascending and descending file size, which contain "bytes" ?

NevemTeve · 03-26-2015, 04:37 AM

Call 'qsort' after closedir. Read 'man qsort' for details.
http://www.tutorialspoint.com/c_stan...tion_qsort.htm

pan64 · 03-26-2015, 04:38 AM

first you need to read all of the entries into an array and/or in a list and next you can sort that.
you can find some tips on sorting here: http://stackoverflow.com/questions/7...ef-struct-in-c

dewin88 · 03-26-2015, 09:42 AM

my code:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/stat.h>

int QUICKsort_VALUE(const void *sortI, const void  *sortJ)
  {
int sortI, sortJ;

   int sortI1=((const struct st *) sortI)->value;
   int sortJ2=((const struct st *) sortJ)->value;

   if (sortI1<sortJ2) {return -1;} else if (sortI1==sortJ2){return 0;} else {return 1;}

  }

void main(int argc, char* argv[])
{
DIR* d;
struct dirent * entry;
struct stat st;
if (argc != 2)
{
printf("Usage: ./sizelist directory\n");
return;
}
d = opendir(argv[1]);
if (d == NULL) {
printf("Directory not found\n");
return;
}
while ((entry = readdir(d)) != NULL)
{
stat(entry->d_name, &st);
if (S_ISREG(st.st_mode))
{
  printf("%u bytes\n", (unsigned int)st.st_size);
qsort(st_size, un, sizeof(struct st), QUICKsort_VALUE);

printf("%20s\t%d", entry->d_name, st.st_size);
}}
closedir(d); 
}

Why its not compile? I add function qsort and set the struct for sorting . what am I doing wrong? What do I need to correct in the code?

pan64 · 03-26-2015, 09:52 AM

at least post the error message you got (or any other information related to your question)

rtmistler · 03-27-2015, 12:36 PM

Why your code didn't compile? A lot of reasons, which you should review in the errors and warnings. This is just from a cut/paste of your code, therefore the first line is Line 1 and so forth, I didn't edit or modify what you posted:

Code:

gcc -o quick_sort quick_sort.c 
quick_sort.c: In function ‘QUICKsort_VALUE’:
quick_sort.c:8:5: error: ‘sortI’ redeclared as different kind of symbol
quick_sort.c:6:33: note: previous definition of ‘sortI’ was here
quick_sort.c:8:12: error: ‘sortJ’ redeclared as different kind of symbol
quick_sort.c:6:53: note: previous definition of ‘sortJ’ was here
quick_sort.c:10:42: error: dereferencing pointer to incomplete type
quick_sort.c:11:42: error: dereferencing pointer to incomplete type
quick_sort.c: In function ‘main’:
quick_sort.c:38:7: error: ‘st_size’ undeclared (first use in this function)
quick_sort.c:38:7: note: each undeclared identifier is reported only once for each function it appears in
quick_sort.c:38:16: error: ‘un’ undeclared (first use in this function)
quick_sort.c:38:27: error: invalid application of ‘sizeof’ to incomplete type ‘struct st’ 
quick_sort.c:40:1: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘__off_t’ [-Wformat]

I go backwards because when you fix stuff it changes the line numberings so I usually start at the end and fix backwards when most plausible:

Line 40: You need to look up what the contents of a struct stat structure is, because st_size is not an integer, or you need to cast.

Line 38, column 7: You can't figure out what's wrong there? It's a typing mistake.
Line 38, column 16: Should be equally obvious
Line 38, column 27: Because it should be sizeof(struct stat) or sizeof(st)

Lines 6, 8, 10, and 11: The main issues here are that to take generic pointers and cast them to a structure, you should declare the local pointers to match what you wish to cast it too. You cannot take passing arguments of a function and reuse those names. The errors on line 8 are complaining that you're attempting to redefine the variable types of the function's passing arguments.

Suggestions for that section:

Code:

int QUICKsort_VALUE(void *sortI, void *sortJ)
{
    struct st *pSortI, *pSortJ;
    int sortIVal, sortJVal;

    pSortI = (struct st *)sortI;
    pSortJ = (struct st *)sortJ;

    sortIVal = pSortI->value;
    sortJVal = pSortJ->value;