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电梯直达

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发表于 2003-05-11 17:02 |只看该作者 |倒序浏览

$man scandir
显示
SunOS/BSD Compatibility Library Functions          scandir(3UCB)

NAME
   scandir, alphasort - scan a directory

SYNOPSIS
   /usr/ucb/cc [ flag... ] file...
   #include <sys/types.h>;
   #include <sys/dir.h>;

   int scandir(dirname, namelist, select, dcomp);
   char *dirname;
   struct direct *(*namelist[]);
   int (*select(.),(*dcomp)();

   int alphasort(d1, d2);
   struct direct **d1, **d2;

害得偶查半天，原来struct direct写错了，正确得应该是dirent

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发表于 2003-05-11 17:03 |只看该作者

sun的man手册好粗心呀

gcc怎么编译不通过，有大侠指点一下吗？
#include <stdio.h>;
#include <stdlib.h>;
#include <unistd.h>;
#include <errno.h>;
#include <sys/types.h>;
#include <dirent.h>;
#include <string.h>;

/*extern int scandir(const char *dirname, struct dirent ***namelist, \
int (*select)(struct dirent *), int (*compar)(const void *, const void *));
*/
extern int scandir(const char *dirname, struct dirent *(*namelist[]),int (*select)(struct dirent *), int (*compar)(struct dirent **, struct dirent **));

extern int alphasort(const void *d1, const void *d2);

/*
* Select only those direntory entries that start with
* 'h'to demonstrate the selection ability :
*/

static int my_select(struct dirent *dp)
{
  if ( dp->;d_name[0] != 'h')
return 0; /* Don't include this */
  return 1; /* else include this one*/
}

/*
* Sort entries in reverse order for demonstration
* purposes :
*/
static int my_compar(struct dirent **d1,struct dirent **d2)
{
  struct dirent *dir1 = *d1;
  struct dirent *dir2 = *d2;
  /*
* Reverse the comparison by reversing
* dir2 with dir1 in the strcmp(3) call:
*/
  return strcmp(dir2->;d_name,dir1->;d_name);
}

/*
* A good test is the direntory /etc :
*/
int main(int argc,char **argv)
{
  int x; /* Work index */
  int n; /* namelist[n] */
  struct dirent **namelist; /* List of names */

  if ( argc < 2 )
  {
fputs("A pathname argument is required.\n, Try /etc for the direntory.\n",stderr);
return 1;
  }

  /*
* Scan the direntory given :
*/
  n = scandir(argv[1],&namelist,my_select,my_compar);

  /*
* Report the direntory entries :
*/
  printf("%d entries for %s:\n",n,argv[1]);
  for ( x=0; x<n; ++x )
printf("%3d: %s\n",x,namelist[x]->;d_name);

  if ( n >; 0 )
  {
for ( x=0; x<n; ++x )
   free(namelist[x]); /* Release entry */
free(namelist); /* Release the array */
  }
  return 0;
}

编译
$g++ scandir.c
后返回下面的错误

未定义文件中的
符号在文件中
scandir(char const*, dirent***, int (*)(dirent*), int (*)(dirent**, dirent**))/var/tmp//ccdpIoK3.o
ld: 致命的: 符号参照错误. 没有输出被写入a.out
collect2: ld returned 1 exit status

是什么错误呀？请指教。