io/truncate.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2003-2005 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6
   7 #include "command.h"
   8 #include "input.h"
   9 #include "init.h"
  10 #include "io.h"
  11
  12 static cmdinfo_t truncate_cmd;
  13
  14 static int
  15 truncate_f(
  16         int             argc,
  17         char            **argv)
  18 {
  19         off64_t         offset;
  20         size_t          blocksize, sectsize;
  21
  22         init_cvtnum(&blocksize, &sectsize);
  23         offset = cvtnum(blocksize, sectsize, argv[1]);
  24         if (offset < 0) {
  25                 printf(_("non-numeric truncate argument -- %s\n"), argv[1]);
  26                 return 0;
  27         }
  28
  29         if (ftruncate(file->fd, offset) < 0) {
  30                 perror("ftruncate");
  31                 return 0;
  32         }
  33         return 0;
  34 }
  35
  36 void
  37 truncate_init(void)
  38 {
  39         truncate_cmd.name = "truncate";
  40         truncate_cmd.altname = "t";
  41         truncate_cmd.cfunc = truncate_f;
  42         truncate_cmd.argmin = 1;
  43         truncate_cmd.argmax = 1;
  44         truncate_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
  45         truncate_cmd.args = _("off");
  46         truncate_cmd.oneline =
  47                 _("truncates the current file at the given offset");
  48
  49         add_command(&truncate_cmd);
  50 }