Linux / Unix Command: ioperm

Command Library

NAME

ioperm - set port input/output permissions  

SYNOPSIS

#include <unistd.h> /* for libc5 */
#include <sys/io.h> /* for glibc */

int ioperm(unsigned long from, unsigned long num, int turn_on);  

DESCRIPTION

Ioperm sets the port access permission bits for the process for num bytes starting from port address from to the value turn_on. The use of ioperm requires root privileges.

Only the first 0x3ff I/O ports can be specified in this manner. For more ports, the iopl function must be used. Permissions are not inherited on fork, but on exec they are. This is useful for giving port access permissions to non-privileged tasks.  

RETURN VALUE

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.  

CONFORMING TO

ioperm is Linux specific and should not be used in programs intended to be portable.  

SEE ALSO

iopl(2)

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