/
fopen.xml
389 lines (379 loc) · 13.8 KB
/
fopen.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xmlns="http://docbook.org/ns/docbook" xml:id="function.fopen">
<refnamediv>
<refname>fopen</refname>
<refpurpose>Opens file or URL</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>resource</type><methodname>fopen</methodname>
<methodparam><type>string</type><parameter>filename</parameter></methodparam>
<methodparam><type>string</type><parameter>mode</parameter></methodparam>
<methodparam choice="opt"><type>bool</type><parameter>use_include_path</parameter><initializer>&false;</initializer></methodparam>
<methodparam choice="opt"><type>resource</type><parameter>context</parameter></methodparam>
</methodsynopsis>
<para>
<function>fopen</function> binds a named resource, specified by
<parameter>filename</parameter>, to a stream.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>filename</parameter></term>
<listitem>
<para>
If <parameter>filename</parameter> is of the form "scheme://...", it
is assumed to be a URL and PHP will search for a protocol handler
(also known as a wrapper) for that scheme. If no wrappers for that
protocol are registered, PHP will emit a notice to help you track
potential problems in your script and then continue as though
<parameter>filename</parameter> specifies a regular file.
</para>
<para>
If PHP has decided that <parameter>filename</parameter> specifies
a local file, then it will try to open a stream on that file.
The file must be accessible to PHP, so you need to ensure that
the file access permissions allow this access.
If you have enabled
<link linkend="ini.open-basedir">open_basedir</link> further
restrictions may apply.
</para>
<para>
If PHP has decided that <parameter>filename</parameter> specifies
a registered protocol, and that protocol is registered as a
network URL, PHP will check to make sure that
<link linkend="ini.allow-url-fopen">allow_url_fopen</link> is
enabled. If it is switched off, PHP will emit a warning and
the fopen call will fail.
</para>
<note>
<para>
The list of supported protocols can be found in <xref
linkend="wrappers"/>. Some protocols (also referred to as
<literal>wrappers</literal>) support <literal>context</literal>
and/or &php.ini; options. Refer to the specific page for the
protocol in use for a list of options which can be set. (e.g.
&php.ini; value <literal>user_agent</literal> used by the
<literal>http</literal> wrapper).
</para>
</note>
<para>
On the Windows platform, be careful to escape any backslashes
used in the path to the file, or use forward slashes.
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
$handle = fopen("c:\\folder\\resource.txt", "r");
?>
]]>
</programlisting>
</informalexample>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>mode</parameter></term>
<listitem>
<para>
The <parameter>mode</parameter> parameter specifies the type of access
you require to the stream. It may be any of the following:
<table>
<title>
A list of possible modes for <function>fopen</function>
using <parameter>mode</parameter>
</title>
<tgroup cols="2">
<thead>
<row>
<entry><parameter>mode</parameter></entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry><literal>'r'</literal></entry>
<entry>
Open for reading only; place the file pointer at the
beginning of the file.
</entry>
</row>
<row>
<entry><literal>'r+'</literal></entry>
<entry>
Open for reading and writing; place the file pointer at
the beginning of the file.
</entry>
</row>
<row>
<entry><literal>'w'</literal></entry>
<entry>
Open for writing only; place the file pointer at the
beginning of the file and truncate the file to zero length.
If the file does not exist, attempt to create it.
</entry>
</row>
<row>
<entry><literal>'w+'</literal></entry>
<entry>
Open for reading and writing; place the file pointer at
the beginning of the file and truncate the file to zero
length. If the file does not exist, attempt to create it.
</entry>
</row>
<row>
<entry><literal>'a'</literal></entry>
<entry>
Open for writing only; place the file pointer at the end of
the file. If the file does not exist, attempt to create it.
In this mode, <function>fseek</function> has no effect, writes are always appended.
</entry>
</row>
<row>
<entry><literal>'a+'</literal></entry>
<entry>
Open for reading and writing; place the file pointer at
the end of the file. If the file does not exist, attempt to
create it. In this mode, <function>fseek</function> only affects
the reading position, writes are always appended.
</entry>
</row>
<row>
<entry><literal>'x'</literal></entry>
<entry>
Create and open for writing only; place the file pointer at the
beginning of the file. If the file already exists, the
<function>fopen</function> call will fail by returning &false; and
generating an error of level <constant>E_WARNING</constant>. If
the file does not exist, attempt to create it. This is equivalent
to specifying <literal>O_EXCL|O_CREAT</literal> flags for the
underlying <literal>open(2)</literal> system call.
</entry>
</row>
<row>
<entry><literal>'x+'</literal></entry>
<entry>
Create and open for reading and writing; otherwise it has the
same behavior as <literal>'x'</literal>.
</entry>
</row>
<row>
<entry><literal>'c'</literal></entry>
<entry>
Open the file for writing only. If the file does not exist, it is
created. If it exists, it is neither truncated (as opposed to
<literal>'w'</literal>), nor the call to this function fails (as is
the case with <literal>'x'</literal>). The file pointer is
positioned on the beginning of the file. This may be useful if it's
desired to get an advisory lock (see <function>flock</function>)
before attempting to modify the file, as using
<literal>'w'</literal> could truncate the file before the lock
was obtained (if truncation is desired,
<function>ftruncate</function> can be used after the lock is
requested).
</entry>
</row>
<row>
<entry><literal>'c+'</literal></entry>
<entry>
Open the file for reading and writing; otherwise it has the same
behavior as <literal>'c'</literal>.
</entry>
</row>
<row>
<entry><literal>'e'</literal></entry>
<entry>
Set close-on-exec flag on the opened file descriptor. Only
available in PHP compiled on POSIX.1-2008 conform systems.
</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<note>
<para>
Different operating system families have different line-ending
conventions. When you write a text file and want to insert a line
break, you need to use the correct line-ending character(s) for your
operating system. Unix based systems use <literal>\n</literal> as the
line ending character, Windows based systems use <literal>\r\n</literal>
as the line ending characters and Macintosh based systems (Mac OS Classic) used
<literal>\r</literal> as the line ending character.
</para>
<para>
If you use the wrong line ending characters when writing your files, you
might find that other applications that open those files will "look
funny".
</para>
<para>
Windows offers a text-mode translation flag (<literal>'t'</literal>)
which will transparently translate <literal>\n</literal> to
<literal>\r\n</literal> when working with the file. In contrast, you
can also use <literal>'b'</literal> to force binary mode, which will not
translate your data. To use these flags, specify either
<literal>'b'</literal> or <literal>'t'</literal> as the last character
of the <parameter>mode</parameter> parameter.
</para>
<para>
The default translation mode is <literal>'b'</literal>.
You can use the <literal>'t'</literal>
mode if you are working with plain-text files and you use
<literal>\n</literal> to delimit your line endings in your script, but
expect your files to be readable with applications such as old versions of notepad. You
should use the <literal>'b'</literal> in all other cases.
</para>
<para>
If you specify the 't' flag when working with binary files, you
may experience strange problems with your data, including broken image
files and strange problems with <literal>\r\n</literal> characters.
</para>
</note>
<note>
<para>
For portability, it is also strongly recommended that
you re-write code that uses or relies upon the <literal>'t'</literal>
mode so that it uses the correct line endings and
<literal>'b'</literal> mode instead.
</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>use_include_path</parameter></term>
<listitem>
<para>
The optional third <parameter>use_include_path</parameter> parameter
can be set to '1' or &true; if you want to search for the file in the
<link linkend="ini.include-path">include_path</link>, too.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>context</parameter></term>
<listitem>
¬e.context-support;
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns a file pointer resource on success,
&return.falseforfailure;
</para>
</refsect1>
<refsect1 role="errors">
&reftitle.errors;
&fs.emits.warning.on.failure;
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<para>
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
<row>
<entry>7.0.16, 7.1.2</entry>
<entry>
The <literal>'e'</literal> option was added.
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>fopen</function> examples</title>
<programlisting role="php">
<![CDATA[
<?php
$handle = fopen("/home/rasmus/file.txt", "r");
$handle = fopen("/home/rasmus/file.gif", "wb");
$handle = fopen("http://www.example.com/", "r");
$handle = fopen("ftp://user:password@example.com/somefile.txt", "w");
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
&warn.ssl-non-standard;
<note>
<para>
If you are experiencing problems with reading and writing to files and
you're using the server module version of PHP, remember to make sure that
the files and directories you're using are accessible to the server
process.
</para>
</note>
<note>
<para>
This function may also succeed when <parameter>filename</parameter> is a
directory. If you are unsure whether <parameter>filename</parameter> is a
file or a directory, you may need to use the <function>is_dir</function>
function before calling <function>fopen</function>.
</para>
</note>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><xref linkend="wrappers"/></member>
<member><function>fclose</function></member>
<member><function>fgets</function></member>
<member><function>fread</function></member>
<member><function>fwrite</function></member>
<member><function>fsockopen</function></member>
<member><function>file</function></member>
<member><function>file_exists</function></member>
<member><function>is_readable</function></member>
<member><function>stream_set_timeout</function></member>
<member><function>popen</function></member>
<member><function>stream_context_create</function></member>
<member><function>umask</function></member>
<member><classname>SplFileObject</classname></member>
</simplelist>
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->