Thread: How to access members of refered array?

Can you help to make this working?

files.c

Code:

#include "include/types.h"
#include "include/gaussian.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#include <dirent.h>
#include <string.h> // strcmp, strtok
#include <sys/types.h> // mkdir
#include <sys/stat.h> // mkdir

int makeConfig(char ** path)
{
    char configFile [12] = "kernels.cfg";
    DIR *dir; struct dirent *ent;
    int count = -1;

    if ( ( dir = opendir (*path) ) != NULL)
    {
    char ch;
    FILE* f;
    FILE* f2;
    f = fopen(configFile, "r");
    if( f != NULL ) // if config already exists, backup
        {
        f2 = fopen("kernels.bak", "w");
        while( ( ch = fgetc(f) ) != EOF )
            fputc(ch, f2);
        fclose(f);
        fclose(f2);
        }
    // write new file
    f = fopen(configFile, "w");
        if( f == NULL )
            perror("Cannot write to file kernels.cfg");


    int ckey = 0;
    size_t len;

    while ((ent = readdir (dir)) != NULL)
        {
            if ( ckey<2 && ( strcmp(".",ent->d_name) == 0 ||  strcmp("..",ent->d_name) == 0 )  )
                { ckey++; continue; }

            // backup ent->d_name because chTmp2 is changed by strtok
            len = strlen(ent->d_name);
            // char * dot = strchr( ent->d_name, '.' );
            if ( len >4 )
                {
                char name[64];
                char * pName = ent->d_name;
                char * ext;
                ext = pName + len - 3;
                memcpy( name, ent->d_name, len-3 );
                if ( 0 == strcmp( ".",  name) )
                    {
                    printf("Incorrect kernel source name. File name %s, must not contain dots, but must have .cl extension.\n",ent->d_name);
                    }
                    else
                    {
                    name[len-3]='\0';
                    fprintf(f, "%s\n", name);
                    printf (".'%s'\n", ent->d_name);
                    }
                }
                else
                {
                 printf("Incorrect kernel source name. File name %s too short.\n",ent->d_name);
                }
        }
        closedir (dir); fclose(f);
    }
    else
    {
        /* could not open directory */
        char error [255];
        sprintf(error, "Directory not found: %s", *path);
        perror (error);
        return -1;
    }
return count;
}


int readConfig(char ** path, FILES ** files )
{
    char configFile [12] = "kernels.cfg";
    DIR *dir;

    if ( ( dir = opendir (*path) ) == NULL)
        {
            perror("directory of binary kernels not found");
            return -2;
        }
        else
            closedir(dir);

    FILE* f;
    f = fopen(configFile, "r");
    if( f == NULL ) // if config already exists, backup
        {
        perror("Config file kernels.cfg not found. Run the program with -install argument.");
        return -3;
        }

    int ch; int c = 0; int prevc = 0; int count = 0;
    char name[64];
    while ((ch=fgetc(f)) != EOF )
    {
       name[c]=ch;
       c++;
       if (ch == '\n' && c-prevc>1 )
           {
           files[count]->name=malloc(64);
           files[count]->filename=malloc(64);
           // strncpy(files[count].name, name, 64);
           strcpy(files[count]->name,name);
           files[count]->name[c-prevc-1]='\0'; // remove linefeed \n
           strcpy(files[count]->filename,name);
         //  files[count].filename[c-prevc+1]='\0';
           files[count]->name[c-prevc+4]='\0';
           strcat(files[count]->filename,".bin");
           count++;
           prevc=c;
           }
    }
return count;
}

types.c

Code:

#include <stdbool.h>

typedef struct  {
  char * name;
  char * filename;
} FILES;

main.c

Code:

#include "include/types.h"
#include "include/gaussian.h"
#include "include/args.h"
#include "include/files.h"
#include "refu/Time/rfc_timer.h"
#include <stdio.h>

int main ( int argc, char *argv[] )
{
    char * path = "kernels";; // used as needed
    FILES files[256];
    int count;
count = readConfig(&path, &files));

After calling readConfig(&path, &files));
I need to access the members .name and .filename to allocate memory and copy strings in there.

Code:

files[count]->name=malloc(64);
files[count]->filename=malloc(64);

SIGSEGV error
How to make the reference working?

Thanks for links but I have fixed it.

Code:

char ch;
FILE* f;
FILE* f2;
f = fopen(configFile, "r");
if( f != NULL ) // if config already exists, backup
    {
    f2 = fopen("kernels.bak", "w");
    while( ( ch = fgetc(f) ) != EOF )

ch should be int not char since you are comparing against EOF. You do this correctly in your readConfig function but not here in the makeConfig function.

Thanks for notice. I have forget to correct it.

I have changed the function header to

Code:

int readConfig(char ** path, FILES ** files

to make call like this:
count = readConfig(&path, &files))
using dots to access members like this

Code:

files[count].name=...value...

Everything seems to be fine until I return count, than it crashes with error SIGSEGV. I cannot find out why. Yet I tried to make FILES * files and to access members with operator ->.

I have changed the function header to...

It doesn't look any different to me (except for missing the closing parenthesis).

to make call like this:
count = readConfig(&path, &files))

This doesn't look any different, either. (Note: You should be getting an error if your actual code has that extra closing parenthesis).

using dots to access members like this

So that's something different. Why did you think that would work?

This appears to have the same fundamental problem I described in my previous post.

Everything seems to be fine until I return count, than it crashes with error SIGSEGV. I cannot find out why.

Option 1: Heed my advice from above and start small, fixing warnings and testing as you go.
Option 2: Learn how to use a debugger to track down problems like these.
Option 3: Create the smallest compilable program that exhibits the problem, and post that.

---

[edit] Your claim that this program runs up to a point is at odds with at least one syntax error I see in the code you originally posted. I hope you're copy/pasting your actual code, and not a hastily typed "mock-up" that doesn't represent what you're really trying to compile. That would be wasting our time, debugging typos that wouldn't be in the original code.

Originally Posted by Matticus

I don't appreciate you wasting my time. I'm done with you.

What's your problem man? I did solve problems with strcpy there and allocating memory. Didn't you read the question? Here I asked how to access the members.
Approppos I started this topic after I solved the problems with strcpy.

Thanks for your reading of that topic and extracting the questions. I already forgot about them.

Sorry for wasting your time spend with analysis. I thought that the previous topic on strcpy is finished.

Originally Posted by Matticus

be sure to check the return value of "malloc()" for success, which your original code lacked

Do you mean to check if the returned pointer is not NULL?