isosize.c
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上传日期:2007-01-06
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文件大小:2k
- /* @(#)isosize.c 1.6 99/10/18 Copyright 1996 J. Schilling */
- #ifndef lint
- static char sccsid[] =
- "@(#)isosize.c 1.6 99/10/18 Copyright 1996 J. Schilling";
- #endif
- /*
- * Copyright (c) 1996 J. Schilling
- */
- /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; see the file COPYING. If not, write to
- * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
- */
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <statdefs.h>
- #include <unixstd.h>
- #include <standard.h>
- #include <utypes.h>
- #include <intcvt.h>
- #include "iso9660.h"
- long isosize __PR((int f));
- long
- isosize(f)
- int f;
- {
- struct iso9660_voldesc vd;
- struct iso9660_pr_voldesc *vp;
- long isize;
- struct stat sb;
- long mode;
- /*
- * First check if a bad guy tries to call isosize()
- * with an unappropriate file descriptor.
- * return -1 in this case.
- */
- if (isatty(f))
- return (-1L);
- if (fstat(f, &sb) < 0)
- return (-1L);
- mode = (long)(sb.st_mode & S_IFMT);
- if (!S_ISREG(mode) && !S_ISBLK(mode) && !S_ISCHR(mode))
- return (-1L);
- if (lseek(f, (off_t)(16L * 2048L), SEEK_SET) == -1)
- return (-1L);
- vp = (struct iso9660_pr_voldesc *) &vd;
- do {
- read(f, &vd, sizeof(vd));
- if (GET_UBYTE(vd.vd_type) == VD_PRIMARY)
- break;
- } while (GET_UBYTE(vd.vd_type) != VD_TERM);
- lseek(f, (off_t)0L, SEEK_SET);
- if (GET_UBYTE(vd.vd_type) != VD_PRIMARY)
- return (-1L);
- isize = GET_BINT(vp->vd_volume_space_size);
- isize *= GET_BSHORT(vp->vd_lbsize);
- return (isize);
- }