<refentry id="chmod">
<refnamediv>
<refname>Chmod</refname>
<refpurpose>change access permissions of a file</refpurpose>
</refnamediv>

<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>
#include &lt;modes.h&gt;
</funcsynopsisinfo>
<funcprototype>
  <funcdef><function>chmod</function></funcdef>
  <paramdef>char *<parameter>fname</parameter></paramdef>
  <paramdef>int <parameter>perm</parameter></paramdef>
</funcprototype>
</funcsynopsis>

</refsynopsisdiv>

<refsect1><title>Description</title>
<para>
Chmod changes the permission bits associated with a file.
"Fname" must be a pointer to a file name, and "perm" should
contain the desired bit pattern,
</para>
<para>
The allowable bit patterns are defined in the include file as follows:
</para>
<programlisting>
/* permissions */
#define  S_IREAD   0x01     /* owner read */
#define  S_IWRITE  0x02     /* owner write */
#define  S_IEXEC   0x04     /* owner execute */
#define  S_IOREAD  0x08     /* public read */
#define  S_IOWRITE 0x10     /* public write */
#define  S_IOEXEC  0x20     /* public execute */
#define  S_ISHARE  0x40     /* sharable */
#define  S_IFDIR   0x80     /* directory */
</programlisting>
<para>
Only the owner or the super user may change the permissions of
a file.
</para>
</refsect1>

<refsect1><title>Diagnostics</title>
<para>
A successful call returns 0. A -1 is returned if the
caller is not entitled to change permissions of "fname" cannot
be found.
</para>
</refsect1>

<refsect1><title>See Also</title>
<para>
OS-9 command "attr"
</para>
</refsect1>

</refentry>