libbb/copyfd.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <errno.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include "busybox.h"
  28 #include "libbb.h"
  29
  30
  31 #if BUFSIZ < 4096
  32 #undef BUFSIZ
  33 #define BUFSIZ 4096
  34 #endif
  35
  36
  37 static size_t bb_full_fd_action(int src_fd, int dst_fd, const size_t size2)
  38 {
  39         int status;
  40         size_t xread, wrote, total, size = size2;
  41
  42         if (src_fd < 0) {
  43                 return -1;
  44         }
  45
  46         if (size == 0) {
  47                 /* If size is 0 copy until EOF */
  48                 size = ULONG_MAX;
  49         }
  50
  51         {
  52                 RESERVE_CONFIG_BUFFER(buffer,BUFSIZ);
  53                 total = 0;
  54                 wrote = 0;
  55                 status = -1;
  56                 while (total < size)
  57                 {
  58                         xread = BUFSIZ;
  59                         if (size < (total + BUFSIZ))
  60                                 xread = size - total;
  61                         xread = bb_full_read(src_fd, buffer, xread);
  62                         if (xread > 0) {
  63                                 if (dst_fd < 0) {
  64                                         /* A -1 dst_fd means we need to fake it... */
  65                                         wrote = xread;
  66                                 } else {
  67                                         wrote = bb_full_write(dst_fd, buffer, xread);
  68                                 }
  69                                 if (wrote < xread) {
  70                                         bb_perror_msg(bb_msg_write_error);
  71                                         break;
  72                                 }
  73                                 total += wrote;
  74                         } else if (xread < 0) {
  75                                 bb_perror_msg(bb_msg_read_error);
  76                                 break;
  77                         } else if (xread == 0) {
  78                                 /* All done. */
  79                                 status = 0;
  80                                 break;
  81                         }
  82                 }
  83                 RELEASE_CONFIG_BUFFER(buffer);
  84         }
  85
  86         if (status == 0 || total)
  87                 return total;
  88         /* Some sortof error occured */
  89         return -1;
  90 }
  91
  92
  93 extern int bb_copyfd_size(int fd1, int fd2, const off_t size)
  94 {
  95         if (size) {
  96                 return(bb_full_fd_action(fd1, fd2, size));
  97         }
  98         return(0);
  99 }
 100
 101 extern int bb_copyfd_eof(int fd1, int fd2)
 102 {
 103         return(bb_full_fd_action(fd1, fd2, 0));
 104 }