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  man pages->OpenBSD man pages -> kvm_getargv (3)              



NAME    [Toc]    [Back]

     kvm_getprocs,   kvm_getargv,   kvm_getenvv,    kvm_getproc2,
     kvm_getenvv2 - access user process state

SYNOPSIS    [Toc]    [Back]

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

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

     struct kinfo_proc2 *
     kvm_getproc2(kvm_t  *kd,  int  op, int arg, size_t elemsize,
int *cnt);

     char **
     kvm_getargv2(kvm_t *kd, const  struct  kinfo_proc2  *p,  int

     char **
     kvm_getenvv2(kvm_t  *kd,  const  struct  kinfo_proc2 *p, int

DESCRIPTION    [Toc]    [Back]

     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_KTHREAD      all  processes (user-level plus
           KERN_PROC_ALL         all user-level 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(4) arg
           KERN_PROC_UID         processes with effective user ID
           KERN_PROC_RUID        processes with real user ID arg

     The number of processes found is returned in  the  reference
parameter cnt.
     The   processes  are  returned  as  a  contiguous  array  of
kinfo_proc structures,
  the   definition   for   which   is   available   in
<sys/sysctl.h>.  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
     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(3)   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.

     kvm_getproc2() is similar to kvm_getprocs() but  returns  an
array of
     kinfo_proc2   structures.    Additionally,  only  the  first
elemsize bytes of
     each  array  entry  are  returned.   If  the  size  of   the
kinfo_proc2 structure
     increases in size in a future release of OpenBSD, the kernel
will only
     return the requested amount of data for each array entry and
     that  use  kvm_getproc2()  will continue to function without
the need for

     The kvm_getargv2() and kvm_getenvv2() functions are  equivalents to the
     kvm_getargv()   and   kvm_getenvv()  functions  that  use  a
kinfo_proc2 structure
 to specify the process.

RETURN VALUES    [Toc]    [Back]

     kvm_getprocs(),        kvm_getargv(),         kvm_getenvv(),
     kvm_getargv2(),  and kvm_getenvv2() all return NULL on failure.

SEE ALSO    [Toc]    [Back]

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

BUGS    [Toc]    [Back]

     These routines do not belong in the kvm(3) interface.

OpenBSD      3.6                           June      4,      1993
[ Back ]
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