iolib.html

vxworks相关论文

<hr>
<a name="close"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>close</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>close</i>(&nbsp;)</strong> - close a file</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS close
    (
    int fd /* file descriptor to close */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine closes the specified file and frees the file descriptor.
It calls the device driver to do the work.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The status of the driver close routine, or ERROR if the file descriptor 
is invalid.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ioLib.html#top">ioLib</a></b>

<hr>
<a name="rename"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>rename</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>rename</i>(&nbsp;)</strong> - change the name of a file</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int rename
    (
    const char * oldname, /* name of file to rename */
    const char * newname  /* name with which to rename file */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine changes the name of a file from <i>oldfile</i> to <i>newfile</i>.
<p>
</blockquote><h4>NOTE</h4><blockquote><p>
Only certain devices support <b><i><a href="./ioLib.html#rename">rename</a></i>(&nbsp;)</b>.  To confirm that your device
supports it, consult the respective <b>xxDrv</b> or xxFs listings to verify that
ioctl FIORENAME exists.  For example, dosFs and rt11Fs support <b><i><a href="./ioLib.html#rename">rename</a></i>(&nbsp;)</b>,
but <b><a href="./netDrv.html#top">netDrv</a></b> and <b><a href="./nfsDrv.html#top">nfsDrv</a></b> do not.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK, or ERROR if the file could not be opened or renamed.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ioLib.html#top">ioLib</a></b>

<hr>
<a name="read"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>read</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>read</i>(&nbsp;)</strong> - read bytes from a file or device</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int read
    (
    int    fd,      /* file descriptor from which to read */
    char * buffer,  /* pointer to buffer to receive bytes */
    size_t maxbytes /* max no. of bytes to read into buffer */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine reads a number of bytes (less than or equal to <i>maxbytes</i>)
from a specified file descriptor and places them in <i>buffer</i>.  It calls
the device driver to do the work.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The number of bytes read (between 1 and <i>maxbytes</i>, 0 if end of file), or
ERROR if the file descriptor does not exist, the driver does not have
a read routines, or the driver returns ERROR. If the driver does not 
have a read routine, errno is set to ENOTSUP.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ioLib.html#top">ioLib</a></b>

<hr>
<a name="write"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>write</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>write</i>(&nbsp;)</strong> - write bytes to a file</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int write
    (
    int    fd,     /* file descriptor on which to write */
    char * buffer, /* buffer containing bytes to be written */
    size_t nbytes  /* number of bytes to write */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine writes <i>nbytes</i> bytes from <i>buffer</i> to a specified file
descriptor <i>fd</i>.  It calls the device driver to do the work.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The number of bytes written (if not equal to <i>nbytes</i>, an error has
occurred), or ERROR if the file descriptor does not exist, the driver
does not have a write routine, or the driver returns ERROR. If the driver
does not have a write routine, errno is set to ENOTSUP.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ioLib.html#top">ioLib</a></b>

<hr>
<a name="ioctl"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>ioctl</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>ioctl</i>(&nbsp;)</strong> - perform an I/O control function</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int ioctl
    (
    int fd,       /* file descriptor */
    int function, /* function code */
    int arg       /* arbitrary argument */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine performs an I/O control function on a device.  The control
functions used by VxWorks device drivers are defined in the header file
<b>ioLib.h</b>.  Most requests are passed on to the driver for handling.
Since the availability of <b><i><a href="./ioLib.html#ioctl">ioctl</a></i>(&nbsp;)</b> functions is driver-specific, these
functions are discussed separately in <b><a href="./tyLib.html#top">tyLib</a></b>, <b><a href="./pipeDrv.html#top">pipeDrv</a></b>, <b><a href="./nfsDrv.html#top">nfsDrv</a></b>, <b><a href="./dosFsLib.html#top">dosFsLib</a></b>,
<b><a href="./rt11FsLib.html#top">rt11FsLib</a></b>, and rawFsLib.
<p>
The following example renames the file or directory to the string "newname":
<p>
<pre>    ioctl (fd, FIORENAME, "newname");
</pre>

Note that the function FIOGETNAME is handled by the I/O interface level and
is not passed on to the device driver itself.  Thus this function code value
should not be used by customer-written drivers.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The return value of the driver, or ERROR if the file descriptor does 
not exist.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ioLib.html#top">ioLib</a></b>, <b><a href="./tyLib.html#top">tyLib</a></b>, <b><a href="./pipeDrv.html#top">pipeDrv</a></b>, <b><a href="./nfsDrv.html#top">nfsDrv</a></b>, <b><a href="./dosFsLib.html#top">dosFsLib</a></b>, <b><a href="./rt11FsLib.html#top">rt11FsLib</a></b>, <b><a href="./rawFsLib.html#top">rawFsLib</a></b>,  
<i>VxWorks Programmer's Guide: I/O System, Local File Systems</i>
<p>

VARARGS2
<hr>
<a name="lseek"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>lseek</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>lseek</i>(&nbsp;)</strong> - set a file read/write pointer</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int lseek
    (
    int  fd,     /* file descriptor */
    long offset, /* new byte offset to seek to */
    int  whence  /* relative file position */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine sets the file read/write pointer of file <i>fd</i> 
to <i>offset</i>.
The argument <i>whence</i>, which affects the file position pointer,
has three values:
<p>
<table>
<tr valign=top>
<td align=left><b>SEEK_SET</b>  (0) </td><td align=left>- set to <i>offset</i></tr>
<tr valign=top>
<td align=left><b>SEEK_CUR</b>  (1) </td><td align=left>- set to current position plus <i>offset</i></tr>
<tr valign=top>
<td align=left><b>SEEK_END</b>  (2) </td><td align=left>- set to the size of the file plus <i>offset</i></tr>
<tr valign=top>
<td align=left></tr>
</tr>

</table>

This routine calls <b><i><a href="./ioLib.html#ioctl">ioctl</a></i>(&nbsp;)</b> with functions FIOWHERE, FIONREAD, and FIOSEEK.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The new offset from the beginning of the file, or ERROR.
<p>
</blockquote><h4>ARGSUSED</h4><blockquote><p>
SEE ALSO
<b><a href="./ioLib.html#top">ioLib</a></b>

<hr>
<a name="ioDefPathSet"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>ioDefPathSet</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>ioDefPathSet</i>(&nbsp;)</strong> - set the current default path</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS ioDefPathSet
    (
    char * name /* name of the new default device and path */
    )</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine sets the default I/O path.  All relative pathnames specified
to the I/O system will be prepended with this pathname.  This pathname
must be an absolute pathname, i.e., <i>name</i> must begin with an existing
device name.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
OK, or ERROR if the first component of the pathname is not an existing
device.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ioLib.html#top">ioLib</a></b>, <b><i><a href="./ioLib.html#ioDefPathGet">ioDefPathGet</a></i>(&nbsp;)</b>, <b><i><a href="./ioLib.html#chdir">chdir</a></i>(&nbsp;)</b>, <b><i><a href="./ioLib.html#getcwd">getcwd</a></i>(&nbsp;)</b>

<hr>
<a name="ioDefPathGet"></a>
<p align=right>
<a href="rtnIndex.html"><i>Libraries :  Routines</i></a></p>

</blockquote><h1><i>ioDefPathGet</i>(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong><i>ioDefPathGet</i>(&nbsp;)</strong> - get the current default path</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void ioDefPathGet
    (