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Sourcecode: tcl8.0 version File versions  Download package

opendir.c

/* 
 * opendir.c --
 *
 *    This file provides dirent-style directory-reading procedures
 *    for V7 Unix systems that don't have such procedures.  The
 *    origin of this code is unclear, but it seems to have come
 *    originally from Larry Wall.
 *
 *
 * RCS: @(#) $Id: opendir.c,v 1.2 1998/09/14 18:39:44 stanton Exp $
 */

#include "tclInt.h"
#include "tclPort.h"

#undef DIRSIZ
#define DIRSIZ(dp) \
    ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))

/*
 * open a directory.
 */
DIR *
opendir(name)
char *name;
{
      register DIR *dirp;
      register int fd;
      char *myname;

      myname = ((*name == '\0') ? "." : name);
      if ((fd = open(myname, 0, 0)) == -1)
            return NULL;
      if ((dirp = (DIR *)ckalloc(sizeof(DIR))) == NULL) {
            close (fd);
            return NULL;
      }
      dirp->dd_fd = fd;
      dirp->dd_loc = 0;
      return dirp;
}

/*
 * read an old style directory entry and present it as a new one
 */
#ifndef pyr
#define     ODIRSIZ     14

struct      olddirect {
      ino_t od_ino;
      char  od_name[ODIRSIZ];
};
#else /* a Pyramid in the ATT universe */
#define     ODIRSIZ     248

struct      olddirect {
      long  od_ino;
      short od_fill1, od_fill2;
      char  od_name[ODIRSIZ];
};
#endif

/*
 * get next entry in a directory.
 */
struct dirent *
readdir(dirp)
register DIR *dirp;
{
      register struct olddirect *dp;
      static struct dirent dir;

      for (;;) {
            if (dirp->dd_loc == 0) {
                  dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf,
                      DIRBLKSIZ);
                  if (dirp->dd_size <= 0)
                        return NULL;
            }
            if (dirp->dd_loc >= dirp->dd_size) {
                  dirp->dd_loc = 0;
                  continue;
            }
            dp = (struct olddirect *)(dirp->dd_buf + dirp->dd_loc);
            dirp->dd_loc += sizeof(struct olddirect);
            if (dp->od_ino == 0)
                  continue;
            dir.d_ino = dp->od_ino;
            strncpy(dir.d_name, dp->od_name, ODIRSIZ);
            dir.d_name[ODIRSIZ] = '\0'; /* insure null termination */
            dir.d_namlen = strlen(dir.d_name);
            dir.d_reclen = DIRSIZ(&dir);
            return (&dir);
      }
}

/*
 * close a directory.
 */
void
closedir(dirp)
register DIR *dirp;
{
      close(dirp->dd_fd);
      dirp->dd_fd = -1;
      dirp->dd_loc = 0;
      ckfree((char *) dirp);
}

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