Mercurial > hg > octave-nkf > gnulib-hg
annotate lib/fwriteerror.c @ 7292:17785d5bede0
Fix docstrings
| author | Sergey Poznyakoff <gray@gnu.org.ua> |
|---|---|
| date | Sun, 10 Sep 2006 11:52:44 +0000 |
| parents | bd5c81f4c585 |
| children | 1c4ed7637c24 |
| rev | line source |
|---|---|
| 4709 | 1 /* Detect write error on a stream. |
|
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Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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2 Copyright (C) 2003-2006 Free Software Foundation, Inc. |
| 4709 | 3 Written by Bruno Haible <bruno@clisp.org>, 2003. |
| 4 | |
| 5 This program is free software; you can redistribute it and/or modify | |
| 6 it under the terms of the GNU General Public License as published by | |
| 7 the Free Software Foundation; either version 2, or (at your option) | |
| 8 any later version. | |
| 9 | |
| 10 This program is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 13 GNU General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU General Public License | |
| 16 along with this program; if not, write to the Free Software Foundation, | |
|
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*** empty log message ***
Paul Eggert <eggert@cs.ucla.edu>
parents:
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17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ |
| 4709 | 18 |
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Use a consistent style for including <config.h>.
Paul Eggert <eggert@cs.ucla.edu>
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19 #ifdef HAVE_CONFIG_H |
| 4709 | 20 # include <config.h> |
| 21 #endif | |
| 22 | |
| 23 /* Specification. */ | |
| 24 #include "fwriteerror.h" | |
| 25 | |
| 26 #include <errno.h> | |
|
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The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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27 #include <stdbool.h> |
| 4709 | 28 |
| 29 int | |
| 30 fwriteerror (FILE *fp) | |
| 31 { | |
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The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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changeset
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32 /* State to allow multiple calls to fwriteerror (stdout). */ |
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c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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diff
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33 static bool stdout_closed = false; |
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c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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34 |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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35 if (fp == stdout && stdout_closed) |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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36 return 0; |
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c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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diff
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37 |
| 4709 | 38 /* Need to |
| 39 1. test the error indicator of the stream, | |
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The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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changeset
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40 2. flush the buffers both in userland and in the kernel, through fclose, |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
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41 testing for error again. */ |
| 4709 | 42 |
| 43 /* Clear errno, so that on non-POSIX systems the caller doesn't see a | |
| 44 wrong value of errno when we return -1. */ | |
| 45 errno = 0; | |
| 46 | |
| 47 if (ferror (fp)) | |
| 48 { | |
|
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The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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49 if (fflush (fp)) |
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6747
bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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50 goto close_preserving_errno; /* errno is set here */ |
| 4709 | 51 /* The stream had an error earlier, but its errno was lost. If the |
| 52 error was not temporary, we can get the same errno by writing and | |
| 53 flushing one more byte. We can do so because at this point the | |
| 54 stream's contents is garbage anyway. */ | |
| 55 if (fputc ('\0', fp) == EOF) | |
|
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Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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56 goto close_preserving_errno; /* errno is set here */ |
| 4709 | 57 if (fflush (fp)) |
|
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Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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58 goto close_preserving_errno; /* errno is set here */ |
| 4709 | 59 /* Give up on errno. */ |
| 60 errno = 0; | |
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Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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61 close_preserving_errno: |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
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diff
changeset
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62 /* There's an error. Nevertheless call fclose(fp), for consistency |
|
bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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63 with the other cases. */ |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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64 { |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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65 int saved_errno = errno; |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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66 fclose (fp); |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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67 errno = saved_errno; |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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68 return -1; |
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bd5c81f4c585
Call fclose() in all cases, even in the failure case.
Bruno Haible <bruno@clisp.org>
parents:
6259
diff
changeset
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69 } |
| 4709 | 70 } |
| 71 | |
|
5581
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
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72 /* If we are closing stdout, don't attempt to do it later again. */ |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
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73 if (fp == stdout) |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
|
74 stdout_closed = true; |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
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75 |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
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76 if (fclose (fp)) |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
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77 return -1; /* errno is set here */ |
|
c8676e66b5da
The fwriteerror() function now needs to fclose() the stream,
Bruno Haible <bruno@clisp.org>
parents:
4709
diff
changeset
|
78 |
| 4709 | 79 return 0; |
| 80 } | |
| 81 | |
| 82 | |
| 83 #if TEST | |
| 84 | |
| 85 /* Name of a file on which writing fails. On systems without /dev/full, | |
| 86 you can choose a filename on a full filesystem. */ | |
| 87 #define UNWRITABLE_FILE "/dev/full" | |
| 88 | |
| 89 int | |
| 90 main () | |
| 91 { | |
| 92 static int sizes[] = | |
| 93 { | |
| 94 511, 512, 513, | |
| 95 1023, 1024, 1025, | |
| 96 2047, 2048, 2049, | |
| 97 4095, 4096, 4097, | |
| 98 8191, 8192, 8193 | |
| 99 }; | |
| 100 static char dummy[8193]; | |
| 101 unsigned int i, j; | |
| 102 | |
| 103 for (i = 0; i < sizeof (sizes) / sizeof (sizes[0]); i++) | |
| 104 { | |
| 105 size_t size = sizes[i]; | |
| 106 | |
| 107 for (j = 0; j < 2; j++) | |
| 108 { | |
| 109 /* Run a test depending on i and j: | |
| 110 Write size bytes and then calls fflush if j==1. */ | |
| 111 FILE *stream = fopen (UNWRITABLE_FILE, "w"); | |
| 112 | |
| 113 if (stream == NULL) | |
| 114 { | |
| 115 fprintf (stderr, "Test %u:%u: could not open file\n", i, j); | |
| 116 continue; | |
| 117 } | |
| 118 | |
| 119 fwrite (dummy, 347, 1, stream); | |
| 120 fwrite (dummy, size - 347, 1, stream); | |
| 121 if (j) | |
| 122 fflush (stream); | |
| 123 | |
| 124 if (fwriteerror (stream) == -1) | |
| 125 { | |
| 126 if (errno != ENOSPC) | |
| 127 fprintf (stderr, "Test %u:%u: fwriteerror ok, errno = %d\n", | |
| 128 i, j, errno); | |
| 129 } | |
| 130 else | |
| 131 fprintf (stderr, "Test %u:%u: fwriteerror found no error!\n", | |
| 132 i, j); | |
| 133 } | |
| 134 } | |
| 135 | |
| 136 return 0; | |
| 137 } | |
| 138 | |
| 139 #endif |