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KVM_GETPROCS(3)       DragonFly Library Functions Manual       KVM_GETPROCS(3)


NAME

     kvm_getprocs, kvm_getargv, kvm_getenvv -- access user process state


LIBRARY

     Kernel Data Access Library (libkvm, -lkvm)


SYNOPSIS

     #include <sys/types.h>
     #include <kvm.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);


DESCRIPTION

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

           KERN_PROC_ALL      all processes
           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

     If the list of processes should contain all light weight processes, add
     the flag KERN_PROC_FLAG_LWP to op.

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

     kvm_getargv() 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
     process.


RETURN VALUES

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


SEE ALSO

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


BUGS

     These routines do not belong in the kvm interface.

DragonFly 4.3                    June 4, 1993                    DragonFly 4.3

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