libio/iopadn.c

   1 /* Copyright (C) 1993-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.
  17
  18    As a special exception, if you link the code in this file with
  19    files compiled with a GNU compiler to produce an executable,
  20    that does not cause the resulting executable to be covered by
  21    the GNU Lesser General Public License.  This exception does not
  22    however invalidate any other reasons why the executable file
  23    might be covered by the GNU Lesser General Public License.
  24    This exception applies to code released by its copyright holders
  25    in files containing the exception.  */
  26
  27 #include "libioP.h"
  28
  29 #define PADSIZE 16
  30 static char const blanks[PADSIZE] =
  31 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
  32 static char const zeroes[PADSIZE] =
  33 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
  34
  35 _IO_ssize_t
  36 _IO_padn (_IO_FILE *fp, int pad, _IO_ssize_t count)
  37 {
  38   char padbuf[PADSIZE];
  39   const char *padptr;
  40   int i;
  41   _IO_size_t written = 0;
  42   _IO_size_t w;
  43
  44   if (pad == ' ')
  45     padptr = blanks;
  46   else if (pad == '0')
  47     padptr = zeroes;
  48   else
  49     {
  50       for (i = PADSIZE; --i >= 0; )
  51         padbuf[i] = pad;
  52       padptr = padbuf;
  53     }
  54   for (i = count; i >= PADSIZE; i -= PADSIZE)
  55     {
  56       w = _IO_sputn (fp, padptr, PADSIZE);
  57       written += w;
  58       if (w != PADSIZE)
  59         return written;
  60     }
  61
  62   if (i > 0)
  63     {
  64       w = _IO_sputn (fp, padptr, i);
  65       written += w;
  66     }
  67   return written;
  68 }
  69 libc_hidden_def (_IO_padn)