
README file for Solaris::Procfs 0.26 


NAME
    Solaris::Procfs - access Solaris process information from Perl

SYNOPSIS
    (See the EXAMPLES section below for more info.)

DESCRIPTION
    This module is an interface the /proc filesystem on Solaris
    systems.

    Each process on a Solaris system has a corresponding directory
    under /proc, named after the process id. In each of these
    directories are a series of files and subdirectories, which
    contain information about each process. The proc(4) manpage
    gives complete details about these files. Basically, the files
    contain one or more C structs with data about its corresponding
    process, maintained by the kernel.

    This module provides methods which access these files and
    convert the C structs contained in them into Perl data
    structures. A few utility functions are also included for
    manipulating these files.

STATUS
    This is pre-alpha software. It is far from finished. Parts of it
    need extensive rewriting and testing. However, the core
    functionality does seem to work properly.

    Contributions and critiques would be warmly welcomed.

EXAMPLES
    There are several different ways to invoke the functions in this
    module: as object methods, as functions, or as a tied hash.

    As functions:

            use Solaris::Procfs;

            my $psinfo = Solaris::Procfs::psinfo( $pid );

    As exported functions:

            use Solaris::Procfs (:procfiles);

            my $psinfo = psinfo( $pid );

    As process objects:

            use Solaris::Procfs;
            use Solaris::Procfs::Process;

            my $p = new Solaris::Procfs::Process $pid;
            my $psinfo = $p->psinfo;

    As process objects with tied hashes:

            use Solaris::Procfs;
            use Solaris::Procfs::Process;

            my $p = new Solaris::Procfs::Process $pid;
            my $psinfo = $p->{psinfo};

    As a filesystem object with tied hashes:

            use Solaris::Procfs;
            use Solaris::Procfs::Filesystem;

            my $fs = new Solaris::Procfs::Filesystem;
            my $psinfo = $fs->{$pid}->{psinfo};

    By default the module will fill the hash
    %Solaris::Procfs::TTYDEVS with a mapping of TTY device ids to
    the name of the TTY (it examines each file under /dev/pts). The
    module uses this mapping to populate fields in other hashes. If
    your system has a very large list of these TTYs, and you want to
    suppress this preloading behavior, then use the following
    pragma:

            use Solaris::Procfs qw(:dont_preload_tty_list);

    The module will then use the string '??' to populate fields
    which normally contain TTY names.

FUNCTIONS
    This module defines functions which each correspond to the files
    available under the directories in /proc. Complete descriptions
    of these files are available in the proc(4) manpage.

    Unless otherwise noted, the corresponding function in the
    Solaris::Procfs module simply returns the contents of the file
    in the form of a set of nested hashrefs. Exceptions to this are
    listed below.

    These functions can also be accessed implcitly as elements in a
    tied hash. When used this way, each process can be accessed as
    if it were one giant Perl structure, containing all the data
    related to that process id in the files under /proc/{pid}. To do
    this, you must use either the Solaris::Procfs::Process or the
    Solaris::Procfs::Filesystem modules. If you only use the
    Solaris::Procfs module, then you can only use the function-
    oriented interface.

    Additional functions are also available.

  as

    Not yet implemented. The 'as' file contains the address-space
    image of the process.

  auxv

    The 'auxv' file contains the initial values of the process's aux
    vector in an array of auxv_t structures (see <sys/auxv.h>).

  ctl

    Not implemented as a function. The 'ctl' file is a write-only
    file to which structured messages are written directing the
    system to change some aspect of the process's state or control
    its behavior in some way. This file somewhat like a device file.
    See the examples directory 'examples' included in this package
    for some simple examples showing how to write to this file.

  cwd or pcwd

    Returns a string containing the absolute path to the process'
    current working directory. The 'cwd' file is a symbolic link to
    the process's current working directory.

  fd

    Returns a hash whose keys are the process' open file
    descriptors, and whose values are the absolute paths to the open
    files, as far as can be determined. The 'fd' directory contains
    references to the open files of the process. Each entry is a
    decimal number corresponding to an open file descriptor in the
    process.

  ldt

    Not yet implemented. The 'ldt' file exists only on x86 based
    machines. It is non-empty only if the process has established a
    local descriptor table (LDT). If non-empty, the file contains
    the array of currently active LDT entries in an array of
    elements of type struct ssd, defined in <sys/sysi86.h>, one
    element for each active LDT entry.

  lpsinfo

    The 'lpsinfo' file contains a prheader structure followed by an
    array of lwpsinfo structures, one for each lwp in the process.

  lstatus

    The 'lstatus' file contains a prheader structure followed by an
    array of lwpstatus structures, one for each lwp in the process.

  lusage

    The 'lusage' file contains a prheader structure followed by an
    array of prusage structures, one for each lwp in the process
    plus an additional element at the beginning that contains the
    summation over all defunct lwps.

  lwp

    The 'lwp' directory contains entries each of which names an lwp
    within the process. These entries are themselves directories
    containing additional files. This function returns the contents
    of the files 'lwpstatus', 'lwpsinfo', and 'lwpusage', translated
    into a set of nested hashes. Interfaces to the files 'asrs',
    'gwindoes', 'lwpctl' and 'xregs' have not been implemented.

  map

    The 'map' file contains information about the virtual address
    map of the process. The file contains an array of prmap
    structures, each of which describes a contiguous virtual address
    region in the address space of the traced process.

  object

    Not yet implemented. The 'object' directory containing read-only
    files with names corresponding to the entries in the map and
    pagedata files. Opening such a file yields a file descriptor for
    the underlying mapped file associated with an address-space
    mapping in the process.

  pagedata

    Not yet implemented. Opening the 'pagedata' file enables
    tracking of address space references and modifications on a per-
    page basis.

  prcred

    The 'prcred' file contains a description of the credentials
    associated with the process (UID, GID, etc.).

  psinfo

    The 'psinfo' file ontains miscellaneous information about the
    process and the representative lwp needed by the ps(1) command.

  rmap

    The 'rmap' file contains information about the reserved address
    ranges of the process. Examples of such reservations include the
    address ranges reserved for the process stack and the individual
    thread stacks of a multi-threaded process.

  root or proot

    Returns a string containing the absolute path to the process'
    root directory. The 'root' file is a symbolic link to the
    process' current working directory.

  sigact

    The 'sigact' file contains an array of sigaction structures
    describing the current dispositions of all signals associated
    with the traced process (see sigaction(2)).

  status

    The 'status' file ontains state information about the process
    and the representative lwp.

  usage

    The 'usage' file contains process usage information described by
    a prusage structure.

  watch

    Not yet implemented. The 'watch' file contains an array of
    prwatch structures, one for each watched area established by the
    PCWATCH control operation.

  xmap

    The 'xmap' file contains information about the virtual address
    map of the process. This file is not documented in the proc
    manpage.

OTHER FUNCTIONS
  writectl

    Write control directives to a process control file
    (/proc/<pid>/ctl). For example, the following code will turn on
    microstate accounting for a given process ($pid):

            use Solaris::Procfs qw(writectl);
            writectl($pid,PCSET,PR_MSACCT); 

ERROR HANDLING
    Most of these functions are essentially wrappers around the
    system calls open(), read() and write(). Basically, we are
    reading and writing to the files under `/proc'. If any of these
    system calls fail, they will set the system errno variable, and
    the function calling them will just return.

    When using these functions, you should check the return value
    just like you would check the return value of a system call.
    Make sure that that the return value is defined before using it.
    If the value is not defined, print out the variable `$!' for a
    verbose description of the error. The most likely error message
    will be "No such file or directory" if the process you are
    accessing does not exist, or "Permission denied" or "Bad file
    number" if you do not have permission to access the file.

    Here is an example from the file examples/ptree:

            my $psinfo = psinfo($pid);

            unless (defined $psinfo and ref $psinfo eq 'HASH') {

                    warn "Cannot get psinfo on process $pid: $!\n";
            }

    Here is an example from the file examples/pstop:

            writectl($pid,PCSTOP) or warn "Can't control process $pid: $!\n";

CHANGES
    * Version 0.26
                Made some changes to the macros.
                Also applied a small patch to the lwp() function, 
                provided by Stephen Youndt. Thanks!

    * Version 0.25
                Plugged a memory leak in the _psinfo2hash() function.
                Thanks to Dmitry Frolov for catching this and sending a patch. 

    * Version 0.23
                Fixed one bug in the basic.t and process.t test scripts. 
                Added more notes to the usage instructions. 

    * Version 0.22
                Fixed a bug in the _prcred function, reported by
                David Landgren and Chris Lamb.  Also fixed a bug 
                in the _lwp function, which prevented the module 
                from building properly on multi-threaded perls.   
                Thanks to Marek Rouchal for assisting with this bug.  
                Also fixed a problem with the get_tty_devs program, 
                thanks to Norbert Klasen for reporting this.   
                Thanks also to the CPAN testers,
                whose reports are very useful.  

    * Version 0.21
                Brian Farrell sent a very useful patch which handles
                inspection of argv and environment of processes 
                other than the currently running process. 

    * Version 0.20
                Thomas Whateley sent a patch with functions for
                accessing the /proc/<pid>/xmap file.
                Dominic Dunlop submitted a small patch to the XS function
                which accesses the map file.

    * Version 0.19
                Kenneth Skaar sent a patch which fixed some memory leaks.
                Updated the documentation.
                Expanded the regression tests. 

    * Version 0.18
                Cleaned up the error handling.
                Created regression tests. 
                Added several more example scripts. 
                Reorganized files in the install package. 

    * Version 0.16
                Added a writectl() function for sending signals to processes.
                Defined a set of constants which correspond to the #define's
                in the sys/procfs.h header.  Added a few example scripts. 

    * Version 0.14
                Separated the Filesystem and Process modules from the 
                main Procfs module.  The module Procfs.pm itself now contains 
                no object-oriented code.  All OO code is in Filesystem.pm
                and Process.pm. 

    * Version 0.10
                Initial release on CPAN

TO DO
    *   Improve the documentation, test scripts and sample scripts.
        Create examples of the use of the writectl() functions. Add
        and test a writelwp() function similar to writectl().

    *   Add functions which can read the 'as' file.

    *   Finish implementing Perl scripts which correspond to each of the
        procutils binaries (under /usr/proc/bin). These are
        described in the proc(1) manpage.

THANKS
    Much of this code is modeled after code written by Alan
    Burlison, and I received some helpful and timely advice from Tye
    McQueen.

    Thanks to Daniel J. Urist for writing Proc::ProcessTable. I used
    his method for keeping track of TTY numbers.

    Thanks to Kennth Skaar (kenneths@regina.uio.no) for fixing some
    memory leaks and teaching me to count (references).

    Thanks to Thomas Whateley for sending a patch with functions for
    accessing the /proc/<pid>/xmap file.

    Thanks to Dominic Dunlop for submitting a patch to the functions
    which access the map file.

    Thanks to Brian Farrell, for sending a very useful patch which
    allows Solaris::Procfs to inspect the argv and environment of
    processes other than the currently running process.

AUTHOR
    John Nolan jpnolan@sonic.net 1999-2003. A copyright statment is
    contained in the source code itself.

