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>Managing procfs entries</H1
><P
> This chapter describes the functions that various kernel
components use to populate the procfs with files, symlinks,
device nodes, and directories.
</P
><P
> A minor note before we start: if you want to use any of the
procfs functions, be sure to include the correct header file!
This should be one of the first lines in your code:
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><PRE
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>#include <linux/proc_fs.h>
</PRE
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><A
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></A
>Creating a regular file</H1
><DIV
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><A
NAME="AEN67"
></A
><P
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>struct proc_dir_entry* <TT
CLASS="FUNCTION"
>create_proc_entry</TT
></CODE
>(const char* <TT
CLASS="PARAMETER"
><I
>name</I
></TT
>, mode_t <TT
CLASS="PARAMETER"
><I
>mode</I
></TT
>, struct proc_dir_entry* <TT
CLASS="PARAMETER"
><I
>parent</I
></TT
>);</CODE
></P
><P
></P
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><P
> This function creates a regular file with the name
<TT
CLASS="PARAMETER"
><I
>name</I
></TT
>, file mode
<TT
CLASS="PARAMETER"
><I
>mode</I
></TT
> in the directory
<TT
CLASS="PARAMETER"
><I
>parent</I
></TT
>. To create a file in the root of
the procfs, use <TT
CLASS="CONSTANT"
>NULL</TT
> as
<TT
CLASS="PARAMETER"
><I
>parent</I
></TT
> parameter. When successful, the
function will return a pointer to the freshly created
<SPAN
CLASS="STRUCTNAME"
>struct proc_dir_entry</SPAN
>; otherwise it
will return <TT
CLASS="CONSTANT"
>NULL</TT
>. <A
HREF="c177.html"
>the chapter called <I
>Communicating with userland</I
></A
> describes how to do something useful with
regular files.
</P
><P
> Note that it is specifically supported that you can pass a
path that spans multiple directories. For example
<TT
CLASS="FUNCTION"
>create_proc_entry</TT
>(<TT
CLASS="PARAMETER"
><I
>"drivers/via0/info"</I
></TT
>)
will create the <TT
CLASS="FILENAME"
>via0</TT
>
directory if necessary, with standard
<TT
CLASS="CONSTANT"
>0755</TT
> permissions.
</P
><P
> If you only want to be able to read the file, the function
<TT
CLASS="FUNCTION"
>create_proc_read_entry</TT
> described in <A
HREF="c275.html#CONVENIENCE"
>the Section called <I
>Convenience functions</I
> in the chapter called <I
>Tips and tricks</I
></A
> may be used to create and initialise
the procfs entry in one single call.
</P
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