Mercurial > hg > octave-nkf > gnulib-hg
annotate lib/safe-read.c @ 7292:17785d5bede0
Fix docstrings
| author | Sergey Poznyakoff <gray@gnu.org.ua> |
|---|---|
| date | Sun, 10 Sep 2006 11:52:44 +0000 |
| parents | fd0ccce602e4 |
| children | 8a1a9361108c |
| rev | line source |
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1 /* An interface to read and write that retries after interrupts. |
| 5159 | 2 |
| 6275 | 3 Copyright (C) 1993, 1994, 1998, 2002, 2003, 2004, 2005 Free Software |
| 5159 | 4 Foundation, Inc. |
| 182 | 5 |
| 6 This program is free software; you can redistribute it and/or modify | |
| 7 it under the terms of the GNU General Public License as published by | |
| 8 the Free Software Foundation; either version 2, or (at your option) | |
| 9 any later version. | |
| 10 | |
| 11 This program is distributed in the hope that it will be useful, | |
| 12 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 14 GNU General Public License for more details. | |
| 15 | |
| 16 You should have received a copy of the GNU General Public License | |
|
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17 along with this program; if not, write to the Free Software Foundation, |
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*** empty log message ***
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18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ |
| 182 | 19 |
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20 #ifdef HAVE_CONFIG_H |
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21 # include <config.h> |
| 182 | 22 #endif |
| 23 | |
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24 /* Specification. */ |
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25 #ifdef SAFE_WRITE |
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26 # include "safe-write.h" |
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27 #else |
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28 # include "safe-read.h" |
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29 #endif |
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30 |
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31 /* Get ssize_t. */ |
| 182 | 32 #include <sys/types.h> |
| 6275 | 33 #include <unistd.h> |
| 182 | 34 |
| 35 #include <errno.h> | |
| 36 | |
| 4050 | 37 #ifdef EINTR |
| 38 # define IS_EINTR(x) ((x) == EINTR) | |
| 39 #else | |
| 40 # define IS_EINTR(x) 0 | |
| 41 #endif | |
| 42 | |
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43 #include <limits.h> |
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44 |
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45 #ifdef SAFE_WRITE |
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46 # define safe_rw safe_write |
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47 # define rw write |
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48 #else |
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49 # define safe_rw safe_read |
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50 # define rw read |
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51 # undef const |
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52 # define const /* empty */ |
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53 #endif |
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54 |
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parents:
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55 /* Read(write) up to COUNT bytes at BUF from(to) descriptor FD, retrying if |
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56 interrupted. Return the actual number of bytes read(written), zero for EOF, |
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57 or SAFE_READ_ERROR(SAFE_WRITE_ERROR) upon error. */ |
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parents:
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58 size_t |
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59 safe_rw (int fd, void const *buf, size_t count) |
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60 { |
| 5159 | 61 /* Work around a bug in Tru64 5.1. Attempting to read more than |
| 62 INT_MAX bytes fails with errno == EINVAL. See | |
| 63 <http://lists.gnu.org/archive/html/bug-gnu-utils/2002-04/msg00010.html>. | |
| 64 When decreasing COUNT, keep it block-aligned. */ | |
| 65 enum { BUGGY_READ_MAXIMUM = INT_MAX & ~8191 }; | |
| 66 | |
| 67 for (;;) | |
| 68 { | |
| 69 ssize_t result = rw (fd, buf, count); | |
| 179 | 70 |
| 5159 | 71 if (0 <= result) |
| 72 return result; | |
| 73 else if (IS_EINTR (errno)) | |
| 74 continue; | |
| 75 else if (errno == EINVAL && BUGGY_READ_MAXIMUM < count) | |
| 76 count = BUGGY_READ_MAXIMUM; | |
| 77 else | |
| 78 return result; | |
| 371 | 79 } |
| 179 | 80 } |