Mercurial > hg > octave-kai > gnulib-hg
annotate lib/read-file.c @ 6848:2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
* read-file.c (fread_file): Start with buffer allocation of
0 bytes rather than 1 byte; this simplifies the code.
Don't invoke feof; it's not needed. Refactor to avoid duplicate
code to free buffer and save/restore errno.
(internal_read_file): Remove unused local.
| author | Simon Josefsson <simon@josefsson.org> |
|---|---|
| date | Wed, 21 Jun 2006 08:02:40 +0000 |
| parents | 19c37b3f23b1 |
| children | a88f85e4728f |
| rev | line source |
|---|---|
| 6829 | 1 /* read-file.c -- read file contents into a string |
| 2 Copyright (C) 2006 Free Software Foundation, Inc. | |
| 3 Written by Simon Josefsson and Bruno Haible. | |
| 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, | |
| 17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
| 18 | |
| 19 #ifdef HAVE_CONFIG_H | |
| 20 # include <config.h> | |
| 21 #endif | |
| 22 | |
| 23 #include "read-file.h" | |
| 24 | |
| 25 /* Get realloc, free. */ | |
| 26 #include <stdlib.h> | |
| 27 | |
| 28 /* Get errno. */ | |
| 29 #include <errno.h> | |
| 30 | |
| 31 /* Read a STREAM and return a newly allocated string with the content, | |
| 32 and set *LENGTH to the length of the string. The string is | |
| 33 zero-terminated, but the terminating zero byte is not counted in | |
| 34 *LENGTH. On errors, *LENGTH is undefined, errno preserves the | |
| 35 values set by system functions (if any), and NULL is returned. */ | |
| 36 char * | |
| 37 fread_file (FILE * stream, size_t * length) | |
| 38 { | |
|
6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
39 char *buf = NULL; |
|
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
40 size_t alloc = 0; |
| 6829 | 41 size_t size = 0; |
|
6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
42 int save_errno; |
| 6829 | 43 |
|
6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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44 for (;;) |
| 6829 | 45 { |
| 46 size_t count; | |
|
6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
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diff
changeset
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47 size_t requested; |
| 6829 | 48 |
| 49 if (size + BUFSIZ + 1 > alloc) | |
| 50 { | |
| 51 char *new_buf; | |
| 52 | |
| 53 alloc += alloc / 2; | |
| 54 if (alloc < size + BUFSIZ + 1) | |
| 55 alloc = size + BUFSIZ + 1; | |
| 56 | |
| 57 new_buf = realloc (buf, alloc); | |
| 58 if (!new_buf) | |
| 59 { | |
|
6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
60 save_errno = errno; |
|
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
61 break; |
| 6829 | 62 } |
| 63 | |
| 64 buf = new_buf; | |
| 65 } | |
| 66 | |
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6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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67 requested = alloc - size - 1; |
|
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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68 count = fread (buf + size, 1, requested, stream); |
| 6829 | 69 size += count; |
| 70 | |
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6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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71 if (count != requested) |
| 6829 | 72 { |
|
6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
73 save_errno = errno; |
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2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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74 if (ferror (stream)) |
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2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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75 break; |
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2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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76 buf[size] = '\0'; |
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2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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77 *length = size; |
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2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
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diff
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78 return buf; |
| 6829 | 79 } |
| 80 } | |
| 81 | |
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6848
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
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82 free (buf); |
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2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
83 errno = save_errno; |
|
2a11dd9faacd
2006-06-19 Paul Eggert <eggert@cs.ucla.edu>
Simon Josefsson <simon@josefsson.org>
parents:
6829
diff
changeset
|
84 return NULL; |
| 6829 | 85 } |
| 86 | |
| 87 static char * | |
| 88 internal_read_file (const char *filename, size_t * length, const char *mode) | |
| 89 { | |
| 90 FILE *stream = fopen (filename, mode); | |
| 91 char *out; | |
| 92 int save_errno; | |
| 93 | |
| 94 if (!stream) | |
| 95 return NULL; | |
| 96 | |
| 97 out = fread_file (stream, length); | |
| 98 | |
| 99 save_errno = errno; | |
| 100 | |
| 101 if (fclose (stream) != 0) | |
| 102 { | |
| 103 if (out) | |
| 104 { | |
| 105 save_errno = errno; | |
| 106 free (out); | |
| 107 } | |
| 108 errno = save_errno; | |
| 109 return NULL; | |
| 110 } | |
| 111 | |
| 112 return out; | |
| 113 } | |
| 114 | |
| 115 /* Open and read the contents of FILENAME, and return a newly | |
| 116 allocated string with the content, and set *LENGTH to the length of | |
| 117 the string. The string is zero-terminated, but the terminating | |
| 118 zero byte is not counted in *LENGTH. On errors, *LENGTH is | |
| 119 undefined, errno preserves the values set by system functions (if | |
| 120 any), and NULL is returned. */ | |
| 121 char * | |
| 122 read_file (const char *filename, size_t * length) | |
| 123 { | |
| 124 return internal_read_file (filename, length, "r"); | |
| 125 } | |
| 126 | |
| 127 /* Open (on non-POSIX systems, in binary mode) and read the contents | |
| 128 of FILENAME, and return a newly allocated string with the content, | |
| 129 and set LENGTH to the length of the string. The string is | |
| 130 zero-terminated, but the terminating zero byte is not counted in | |
| 131 the LENGTH variable. On errors, *LENGTH is undefined, errno | |
| 132 preserves the values set by system functions (if any), and NULL is | |
| 133 returned. */ | |
| 134 char * | |
| 135 read_binary_file (const char *filename, size_t * length) | |
| 136 { | |
| 137 return internal_read_file (filename, length, "rb"); | |
| 138 } |