my c

gistfile1.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <string.h>
#include <unistd.h>

#include "c_dbg.h"

#define MAX_PATH_LEN 1024
#define FILE_INFO_LEN 2048
// path to save file tree information of current directory
#define PLAYLIST_FILE_PATH "/mnt/sda1/playlist.local"


// build a file tree and write it to a text file
int build_files_tree(const char *path)
{
  DIR *dp;
  struct dirent *dir;
  char full_path[MAX_PATH_LEN];
  char file_infos[FILE_INFO_LEN];

  
  struct stat buf;
  FILE* fp = fopen(PLAYLIST_FILE_PATH, "w+");
  int ret;
  char size_str[20];
  int length_cnt = 0;  // record file info length

  if(path ==NULL || access(path, R_OK) )
  {
    perror("Read file failed.\n");
    return -1;
  }

  if( (dp = opendir(path)) == NULL)
  {
	fprintf(stderr,"%s: cannot open.\n",path);
    return -1;
  }


  while((dir = readdir(dp))!= NULL)
  {
    strncpy(full_path,path,strlen(path));
	full_path[strlen(path)]='\0';
    strcat(full_path,dir->d_name);
    
    if(lstat(full_path,&buf) < 0)
    {
      c_dbg_stmt("<%s.%d> lstat failed\n",__FUNCTION__,__LINE__);
	  continue;
	}

    // procedure for different file types , type 0 for regular file ; 1 for directory
    if( S_ISREG(buf.st_mode) )
    {
      // for transfer, send necessary information

	  if( strcmp(full_path,PLAYLIST_FILE_PATH)==0 )
	  {
		c_dbg_stmt("we filter %s\n",PLAYLIST_FILE_PATH);
		continue;
	  }
      
      
	  strncat(file_infos,dir->d_name,strlen(dir->d_name));
	  strncat(file_infos,"   ",3);
	  strncat(file_infos,full_path,strlen(full_path));
	  strncat(file_infos,"   ",3);
	  strncat(file_infos,"0",1);
	  strncat(file_infos,"   ",3);
	  
	  sprintf(size_str, "%llu",(unsigned long long)buf.st_size);
	  strncat(file_infos,size_str,strlen(size_str));
	  length_cnt = strlen(dir->d_name) + strlen(full_path)+ strlen(size_str) + 10;
	  if(length_cnt > FILE_INFO_LEN-1)
	  {
	  	printf("the memory size of file info is not enough\n");
		return -1;
	  }
	  file_infos[length_cnt] = '\0';
	  c_dbg_stmt("<%s> The file informations: %s\n",__FUNCTION__,file_infos);
	  
	  fwrite(file_infos, 1 , strlen(file_infos), fp);
	  
    }

    else if( S_ISDIR(buf.st_mode) )
    {
      #if 0
      if (ftw(full_path, &sum, 1))
      {
        perror("ftw");
        return 2;
      }
      #endif

	  // filter two special directories
	  if( strcmp(dir->d_name,".")==0 || strcmp(dir->d_name,"..")==0 )
	  	continue;
      
	  strncat(file_infos,dir->d_name,strlen(dir->d_name));
	  strncat(file_infos,"   ",3);
	  strncat(file_infos,full_path,strlen(full_path));
	  strncat(file_infos,"   ",3);
	  strncat(file_infos,"1",1);
	  length_cnt = strlen(dir->d_name) + strlen(full_path) + 7;
	  if(length_cnt > FILE_INFO_LEN-1)
	  {
	  	printf("the memory size of file info is not enough\n");
		return -1;
	  }

	  file_infos[length_cnt] = '\0';
	  c_dbg_stmt("<%s> The file informations: %s\n",__FUNCTION__,file_infos);
	  fwrite(file_infos, 1 , strlen(file_infos), fp);
	  

    }

	// add newline
	ret = fputs("\n",fp);
	if(ret == EOF)
	  return -1;

    memset(full_path,0,MAX_PATH_LEN);
	memset(file_infos,0,FILE_INFO_LEN);
  }

  closedir(dp);

  // write-through all data then close file
  ret = fflush(fp);
  if(ret == EOF)
  	perror("fflush failed.\n");
  fclose(fp);
  
  return 0;
}