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i386_set_watch(3) [freebsd man page]

I386_SET_WATCH(3)					   BSD Library Functions Manual 					 I386_SET_WATCH(3)

NAME
i386_clr_watch, i386_set_watch -- manage i386 debug register values LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <machine/reg.h> #include <machine/sysarch.h> int i386_clr_watch(int watchnum, struct dbreg *d); int i386_set_watch(int watchnum, unsigned int watchaddr, int size, int access, struct dbreg *d); DESCRIPTION
The i386_clr_watch() function will disable the indicated watch point within the specified debug register set. The i386_set_watch() function will set up the specified debug registers as indicated by the arguments. The watchnum argument specifies which watch register is used, 0, 1, 2, 3, or -1. If watchnum is -1, a free watch register is found and used. If there are no free watch regis- ters, an error code of -1 is returned. The watchaddr argument specifies the watch address, size specifies the size in bytes of the area to be watched (1, 2, or 4 bytes), and access specifies the type of watch point: DBREG_DR7_EXEC An execution breakpoint. DBREG_DR7_WRONLY Break only when the watch area is written to. DBREG_DR7_RDWR Break when the watch area is read from or written to. Note that these functions do not actually set or clear breakpoints; they manipulate the indicated debug register set. You must use ptrace(2) to retrieve and install the debug register values for a process. RETURN VALUES
On success, the i386_clr_watch() function returns 0. On error, -1 returned which indicates that watchnum is invalid (not in the range of 0-3). If the specified watchnum was already disabled, no error is returned. On success, the i386_set_watch() function returns the watchnum argument, or the watchnum actually used in the case where the specified watchnum was -1. On error, the i386_set_watch() function returns -1 indicating that the watchpoint could not established because either no more watchpoints are available, or watchnum, size, or access is invalid. SEE ALSO
ptrace(2), procfs(5) AUTHORS
This man page was written by Brian S. Dean. BSD
August 24, 2000 BSD

Check Out this Related Man Page

INOTIFY_ADD_WATCH(2)					     Linux Programmer's Manual					      INOTIFY_ADD_WATCH(2)

NAME
inotify_add_watch - add a watch to an initialized inotify instance SYNOPSIS
#include <sys/inotify.h> int inotify_add_watch(int fd, const char *pathname, uint32_t mask); DESCRIPTION
inotify_add_watch() adds a new watch, or modifies an existing watch, for the file whose location is specified in pathname; the caller must have read permission for this file. The fd argument is a file descriptor referring to the inotify instance whose watch list is to be modi- fied. The events to be monitored for pathname are specified in the mask bit-mask argument. See inotify(7) for a description of the bits that can be set in mask. A successful call to inotify_add_watch() returns the unique watch descriptor associated with pathname for this inotify instance. If path- name was not previously being watched by this inotify instance, then the watch descriptor is newly allocated. If pathname was already being watched, then the descriptor for the existing watch is returned. The watch descriptor is returned by later read(2)s from the inotify file descriptor. These reads fetch inotify_event structures (see ino- tify(7)) indicating file system events; the watch descriptor inside this structure identifies the object for which the event occurred. RETURN VALUE
On success, inotify_add_watch() returns a nonnegative watch descriptor. On error -1 is returned and errno is set appropriately. ERRORS
EACCES Read access to the given file is not permitted. EBADF The given file descriptor is not valid. EFAULT pathname points outside of the process's accessible address space. EINVAL The given event mask contains no valid events; or fd is not an inotify file descriptor. ENOMEM Insufficient kernel memory was available. ENOSPC The user limit on the total number of inotify watches was reached or the kernel failed to allocate a needed resource. VERSIONS
Inotify was merged into the 2.6.13 Linux kernel. CONFORMING TO
This system call is Linux-specific. SEE ALSO
inotify_init(2), inotify_rm_watch(2), inotify(7) COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2006-02-07 INOTIFY_ADD_WATCH(2)

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