unistd.h.html

posix标准英文,html格式

<dt>_POSIX2_PBS_TRACK</dt>

<dd><sup>[<a href="javascript:open_code('BE')">BE</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation supports the Track Batch Job Request option. If this symbol is defined in <i>&lt;unistd.h&gt;</i>, it shall be
defined to be -1, 0, or 200112L. The value of this symbol reported by <a href="../functions/sysconf.html"><i>sysconf</i>()</a>
shall either be -1 or 200112L. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_POSIX2_SW_DEV</dt>

<dd><sup>[<a href="javascript:open_code('SD')">SD</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation supports the Software Development Utilities option. If this symbol is defined in <i>&lt;unistd.h&gt;</i>, it
shall be defined to be -1, 0, or 200112L. The value of this symbol reported by <a href=
"../functions/sysconf.html"><i>sysconf</i>()</a> shall either be -1 or 200112L. <img src="../images/opt-end.gif" alt="[Option End]"
border="0"></dd>

<dt>_POSIX2_UPE</dt>

<dd><sup>[<a href="javascript:open_code('UP')">UP</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation supports the User Portability Utilities option. If this symbol is defined in <i>&lt;unistd.h&gt;</i>, it shall
be defined to be -1, 0, or 200112L. The value of this symbol reported by <a href="../functions/sysconf.html"><i>sysconf</i>()</a>
shall either be -1 or 200112L. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_POSIX_V6_ILP32_OFF32</dt>

<dd>
The implementation provides a C-language compilation environment with 32-bit <b>int</b>, <b>long</b>, <b>pointer</b>, and
<b>off_t</b> types.</dd>

<dt>_POSIX_V6_ILP32_OFFBIG</dt>

<dd>
The implementation provides a C-language compilation environment with 32-bit <b>int</b>, <b>long</b>, and <b>pointer</b> types and
an <b>off_t</b> type using at least 64 bits.</dd>

<dt>_POSIX_V6_LP64_OFF64</dt>

<dd>
The implementation provides a C-language compilation environment with 32-bit <b>int</b> and 64-bit <b>long</b>, <b>pointer</b>, and
<b>off_t</b> types.</dd>

<dt>_POSIX_V6_LPBIG_OFFBIG</dt>

<dd>
The implementation provides a C-language compilation environment with an <b>int</b> type using at least 32 bits and <b>long</b>,
<b>pointer</b>, and <b>off_t</b> types using at least 64 bits.</dd>

<dt>_XBS5_ILP32_OFF32 (<b>LEGACY</b>)</dt>

<dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation provides a C-language compilation environment with 32-bit <b>int</b>, <b>long</b>, <b>pointer</b>, and
<b>off_t</b> types. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_XBS5_ILP32_OFFBIG (<b>LEGACY</b>)</dt>

<dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation provides a C-language compilation environment with 32-bit <b>int</b>, <b>long</b>, and <b>pointer</b> types and
an <b>off_t</b> type using at least 64 bits. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_XBS5_LP64_OFF64 (<b>LEGACY</b>)</dt>

<dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation provides a C-language compilation environment with 32-bit <b>int</b> and 64-bit <b>long</b>, <b>pointer</b>, and
<b>off_t</b> types. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_XBS5_LPBIG_OFFBIG (<b>LEGACY</b>)</dt>

<dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation provides a C-language compilation environment with an <b>int</b> type using at least 32 bits and <b>long</b>,
<b>pointer</b>, and <b>off_t</b> types using at least 64 bits. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_XOPEN_CRYPT</dt>

<dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation supports the X/Open Encryption Option Group.</dd>

<dt>_XOPEN_ENH_I18N</dt>

<dd>
The implementation supports the Issue 4, Version 2 Enhanced Internationalization Option Group. This symbol shall always be set to a
value other than -1.</dd>

<dt>_XOPEN_LEGACY</dt>

<dd>
The implementation supports the Legacy Option Group.</dd>

<dt>_XOPEN_REALTIME</dt>

<dd>
The implementation supports the X/Open Realtime Option Group.</dd>

<dt>_XOPEN_REALTIME_THREADS</dt>

<dd>
The implementation supports the X/Open Realtime Threads Option Group.</dd>

<dt>_XOPEN_SHM</dt>

<dd>
The implementation supports the Issue 4, Version 2 Shared Memory Option Group. This symbol shall always be set to a value other
than -1.</dd>

<dt>_XOPEN_STREAMS</dt>

<dd>
The implementation supports the XSI STREAMS Option Group. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>

<dt>_XOPEN_UNIX</dt>

<dd><sup>[<a href="javascript:open_code('XSI')">XSI</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]" border=
"0"><br>
The implementation supports the XSI extension. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></dd>
</dl>

<h5><a name="tag_13_80_03_03"></a>Execution-Time Symbolic Constants</h5>

<p>If any of the following constants are not defined in the <i>&lt;unistd.h&gt;</i> header, the value shall vary depending on the
file to which it is applied.</p>

<p>If any of the following constants are defined to have value -1 in the <i>&lt;unistd.h&gt;</i> header, the implementation shall
not provide the option on any file; if any are defined to have a value other than -1 in the <i>&lt;unistd.h&gt;</i> header, the
implementation shall provide the option on all applicable files.</p>

<p>All of the following constants, whether defined in <i>&lt;unistd.h&gt;</i> or not, may be queried with respect to a specific
file using the <a href="../functions/pathconf.html"><i>pathconf</i>()</a> or <a href=
"../functions/fpathconf.html"><i>fpathconf</i>()</a> functions:</p>

<dl compact>
<dt>_POSIX_ASYNC_IO</dt>

<dd>
Asynchronous input or output operations may be performed for the associated file.</dd>

<dt>_POSIX_PRIO_IO</dt>

<dd>
Prioritized input or output operations may be performed for the associated file.</dd>

<dt>_POSIX_SYNC_IO</dt>

<dd>
Synchronized input or output operations may be performed for the associated file.</dd>
</dl>

<h5><a name="tag_13_80_03_04"></a>Constants for Functions</h5>

<p>The following symbolic constant shall be defined:</p>

<dl compact>
<dt>NULL</dt>

<dd>Null pointer</dd>
</dl>

<p>The following symbolic constants shall be defined for the <a href="../functions/access.html"><i>access</i>()</a> function:</p>

<dl compact>
<dt>F_OK</dt>

<dd>Test for existence of file.</dd>

<dt>R_OK</dt>

<dd>Test for read permission.</dd>

<dt>W_OK</dt>

<dd>Test for write permission.</dd>

<dt>X_OK</dt>

<dd>Test for execute (search) permission.</dd>
</dl>

<p>The constants F_OK, R_OK, W_OK, and X_OK and the expressions <i>R_OK</i>|<i>W_OK</i>, <i>R_OK</i>|<i>X_OK</i>, and
<i>R_OK</i>|<i>W_OK</i>|<i>X_OK</i> shall all have distinct values.</p>

<p>The following symbolic constants shall be defined for the <a href="../functions/confstr.html"><i>confstr</i>()</a> function:</p>

<dl compact>
<dt>_CS_PATH</dt>

<dd>
This is the value for the <i>PATH</i> environment variable that finds all standard utilities.</dd>

<dt>_CS_POSIX_V6_ILP32_OFF32_CFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_ILP32_OFF32) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
initial options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a
programming model with 32-bit <b>int</b>, <b>long</b>, <b>pointer</b>, and <b>off_t</b> types.</dd>

<dt>_CS_POSIX_V6_ILP32_OFF32_LDFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_ILP32_OFF32) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
final options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with 32-bit <b>int</b>, <b>long</b>, <b>pointer</b>, and <b>off_t</b> types.</dd>

<dt>_CS_POSIX_V6_ILP32_OFF32_LIBS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_ILP32_OFF32) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
libraries to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with 32-bit <b>int</b>, <b>long</b>, <b>pointer</b>, and <b>off_t</b> types.</dd>

<dt>_CS_POSIX_V6_ILP32_OFFBIG_CFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_ILP32_OFFBIG) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
initial options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a
programming model with 32-bit <b>int</b>, <b>long</b>, and <b>pointer</b> types, and an <b>off_t</b> type using at least 64
bits.</dd>

<dt>_CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_ILP32_OFFBIG) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
final options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with 32-bit <b>int</b>, <b>long</b>, and <b>pointer</b> types, and an <b>off_t</b> type using at least 64 bits.</dd>

<dt>_CS_POSIX_V6_ILP32_OFFBIG_LIBS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_ILP32_OFFBIG) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
libraries to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with 32-bit <b>int</b>, <b>long</b>, and <b>pointer</b> types, and an <b>off_t</b> type using at least 64 bits.</dd>

<dt>_CS_POSIX_V6_LP64_OFF64_CFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_LP64_OFF64) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
initial options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a
programming model with 32-bit <b>int</b> and 64-bit <b>long</b>, <b>pointer</b>, and <b>off_t</b> types.</dd>

<dt>_CS_POSIX_V6_LP64_OFF64_LDFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_LP64_OFF64) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
final options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with 32-bit <b>int</b> and 64-bit <b>long</b>, <b>pointer</b>, and <b>off_t</b> types.</dd>

<dt>_CS_POSIX_V6_LP64_OFF64_LIBS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_LP64_OFF64) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
libraries to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with 32-bit <b>int</b> and 64-bit <b>long</b>, <b>pointer</b>, and <b>off_t</b> types.</dd>

<dt>_CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_LPBIG_OFFBIG) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
initial options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a
programming model with an <b>int</b> type using at least 32 bits and <b>long</b>, <b>pointer</b>, and <b>off_t</b> types using at
least 64 bits.</dd>

<dt>_CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS</dt>

<dd>
If <i>sysconf</i>(_SC_V6_LPBIG_OFFBIG) returns -1, the meaning of this value is unspecified. Otherwise, this value is the set of
final options to be given to the <a href="../utilities/c99.html"><i>c99</i></a> utility to build an application using a programming
model with an <b>int</b> type using at least 32 bits and <b>long</b>, <b>pointer</b>, and <b>off_t</b> types using at least 64
bits.</dd>

<dt>_CS_POSIX_V6_LPBIG_OFFBIG_LIBS</dt>