ack/lang/cem/libcc.ansi/misc/readdir.c

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1989-12-18 14:40:54 +00:00
/*
readdir -- read next entry from a directory stream
last edit: 25-Apr-1987 D A Gwyn
*/
#include <errno.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <dirent.h>
/* SVR3 system call, or emulation for getdents() */
extern int getdents(int fildes, char *buf, unsigned nbyte);
#ifndef NULL
#define NULL 0
#endif
struct dirent *
readdir(register DIR *dirp)
{
register struct dirent *dp; /* -> directory data */
if ( dirp == NULL || dirp->dd_buf == NULL )
{
errno = EFAULT;
return NULL; /* invalid pointer */
}
do {
if ( dirp->dd_loc >= dirp->dd_size ) /* empty or obsolete */
dirp->dd_loc = dirp->dd_size = 0;
if ( dirp->dd_size == 0 /* need to refill buffer */
&& (dirp->dd_size =
getdents( dirp->dd_fd, dirp->dd_buf, (unsigned)DIRBUF )
) <= 0
)
return NULL; /* EOF or error */
dp = (struct dirent *)&dirp->dd_buf[dirp->dd_loc];
dirp->dd_loc += dp->d_reclen;
}
while ( dp->d_ino == 0L ); /* don't rely on getdents() */
return dp;
}