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KVM_GETPROCS(3)	       FreeBSD Library Functions Manual	       KVM_GETPROCS(3)

     kvm_getprocs, kvm_getargv,	kvm_getenvv -- access user process state

     Kernel Data Access	Library	(libkvm, -lkvm)

     #include <kvm.h>
     #include <sys/param.h>
     #include <sys/sysctl.h>
     #include <sys/user.h>

     struct kinfo_proc *
     kvm_getprocs(kvm_t	*kd, int op, int arg, int *cnt);

     char **
     kvm_getargv(kvm_t *kd, const struct kinfo_proc *p,	int nchr);

     char **
     kvm_getenvv(kvm_t *kd, const struct kinfo_proc *p,	int nchr);

     The kvm_getprocs()	function returns a (sub-)set of	active processes in
     the kernel	indicated by kd.  The op and arg arguments constitute a	predi-
     cate which	limits the set of processes returned.  The value of op
     describes the filtering predicate as follows:

	   KERN_PROC_ALL	 all processes and kernel visible threads
	   KERN_PROC_PROC	 all processes,	without	threads
	   KERN_PROC_PID	 processes with	process	ID arg
	   KERN_PROC_PGRP	 processes with	process	group arg
	   KERN_PROC_SESSION	 processes with	session	arg
	   KERN_PROC_TTY	 processes with	TTY arg
	   KERN_PROC_UID	 processes with	effective user ID arg
	   KERN_PROC_RUID	 processes with	real user ID arg
	   KERN_PROC_INC_THREAD	 modifier to return all	kernel visible threads
				 when filtering	by process ID, process group,
				 TTY, user ID, and real	user ID

     The number	of processes found is returned in the reference	parameter cnt.
     The processes are returned	as a contiguous	array of kinfo_proc struc-
     tures.  This memory is locally allocated, and subsequent calls to
     kvm_getprocs() and	kvm_close() will overwrite this	storage.

     The kvm_getargv() function	returns	a null-terminated argument vector that
     corresponds to the	command	line arguments passed to process indicated by
     p.	 Most likely, these arguments correspond to the	values passed to
     exec(3) on	process	creation.  This	information is,	however, deliberately
     under control of the process itself.  Note	that the original command name
     can be found, unaltered, in the p_comm field of the process structure
     returned by kvm_getprocs().

     The nchr argument indicates the maximum number of characters, including
     null bytes, to use	in building the	strings.  If this amount is exceeded,
     the string	causing	the overflow is	truncated and the partial result is
     returned.	This is	handy for programs like	ps(1) and w(1) that print only
     a one line	summary	of a command and should	not copy out large amounts of
     text only to ignore it.  If nchr is zero, no limit	is imposed and all
     argument strings are returned in their entirety.

     The memory	allocated to the argv pointers and string storage is owned by
     the kvm library.  Subsequent kvm_getprocs() and kvm_close(3) calls	will
     clobber this storage.

     The kvm_getenvv() function	is similar to kvm_getargv() but	returns	the
     vector of environment strings.  This data is also alterable by the

     The kvm_getprocs(), kvm_getargv(),	and kvm_getenvv() functions return
     NULL on failure.

     kvm(3), kvm_close(3), kvm_geterr(3), kvm_nlist(3),	kvm_open(3),
     kvm_openfiles(3), kvm_read(3), kvm_write(3)

     These routines do not belong in the kvm interface.

     In	order for kvm_getenvv(3) to function correctly,	procfs(5) must be
     mounted on	/proc.

FreeBSD	11.1		      September	27, 2003		  FreeBSD 11.1


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