| KVM_GETPROCS(3) | Library Functions Manual | KVM_GETPROCS(3) | 
kvm_getprocs, kvm_getargv,
  kvm_getenvv, kvm_getproc2,
  kvm_getargv2, kvm_getenvv2
  —
#include <kvm.h>
#include <sys/param.h>
#include <sys/sysctl.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);
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
    nchr);
char **
  
  kvm_getenvv2(kvm_t
    *kd, const struct
    kinfo_proc2 *p, int
    nchr);
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:
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.
If the op argument for
    kvm_getprocs() is KERN_PROC_TTY,
    arg can also be KERN_PROC_TTY_NODEV
    to select processes with no controlling tty and
    KERN_PROC_TTY_REVOKE to select processes which have had
    their controlling tty revoked.
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.
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 NetBSD the kernel will only
    return the requested amount of data for each array entry and programs that
    use kvm_getproc2() will continue to function without
    the need for recompilation.
The kvm_getargv2() and
    kvm_getenvv2() are equivalents to the
    kvm_getargv() and
    kvm_getenvv() functions but use a
    kinfo_proc2 structure to specify the process.
If called against an active kernel, the
    kvm_getproc2(),
    kvm_getargv2(), and
    kvm_getenvv2() functions will use the
    sysctl(3) interface and do not
    require access to the kernel memory device file or swap device.
kvm_getprocs(), kvm_getargv(),
  kvm_getenvv(), kvm_getproc2(),
  kvm_getargv2(), and
  kvm_getenvv2() all return NULL
  on failure.
| January 9, 2018 | NetBSD 9.4 |