#!/bin/bash
#
# Copyright (c) 2000 Alexander V. Konstantinou <akonstan@acm.org>
#
# Permission to use, copy, modify, distribute and sell this software
# and its documentation for any purpose is hereby granted without fee,
# provided that the above copyright notice appear in all copies and
# that both that copyright notice and this permission notice appear
# in supporting documentation.  Alexander V. Konstantinou makes no
# representations about the suitability of this software for any
# purpose.  It is provided "as is" without express or implied warranty.
# 
# Description: prints out the java processes running on a Linux host.
#              Optional "-noflags" argument controls verbosity
#
# Requirements: Linux host with a /proc filesystem
#
# Updates: http://www.cs.columbia.edu/~akonstan/javaps
#
# $Id: javaps,v 1.3 2002/01/21 02:32:12 akonstan Exp $

PATH=/bin:/usr/bin

SYSNAME=`uname -s`

if [ "$SYSNAME" != "Linux" ]; then
  echo "$0: must be executed on Linux system (found $SYSNAME)" >&2
  exit 1
fi

if [ ! -d "/proc" ]; then
  echo "$0: Linux host does not appear to have a /proc filesystem" >&2
  exit 1
fi

NOFLAGS=0
if [ -n "$1" ]; then
  if [ "$1" = "-noflags" ]; then
    NOFLAGS=1
  else
    echo "Usage: $0 { -noflags }" >&2
    exit 1
  fi
fi

echo "PID	Process"

# For every file in the /proc file system

FILES=`/bin/ls -1 /proc`

for FILE in $FILES; do
  PROCESS_ID=$FILE
  STATUS_FILE=/proc/$FILE/status
  CMDLINE_FILE=/proc/$FILE/cmdline

  # Check if it is a process directory and that we have read access
  if [ -d "/proc/$FILE" -a -r $STATUS_FILE -a -r $CMDLINE_FILE -a "$FILE" != "/proc/self" ]; then
    
    PROCESS_NAME=`grep 'Name:' $STATUS_FILE | awk '{print $2}'`

    # Only interested in java processes
    if [ "$PROCESS_NAME" = "java" ]; then
      PARENT_PID=`grep 'PPid' $STATUS_FILE | awk '{print $2}'`

      # Figure out if process has a parent that is a java process
      ISROOT=0
      if [ $PARENT_PID -eq 1 ]; then
        ISROOT=1
      else
        PARENT_NAME=`grep 'Name:' /proc/$PARENT_PID/status | awk '{print $2}'`
        if [ "$PARENT_NAME" != "java" ]; then
          ISROOT=1
        fi
      fi

      # If root java process print out
      if [ $ISROOT -ne 0 ]; then
        PROCESS_CMDLINE="`cat $CMDLINE_FILE | tr '\000' ' '`"

        IGNORE_ARG=0
        DESCR=
        for ARG in $PROCESS_CMDLINE; do
          if [ $NOFLAGS -eq 0 ]; then
             DESCR="$DESCR $ARG"
          else
            if [ $IGNORE_ARG -eq 0 ]; then
              if [ $ARG = "-classpath" -o $ARG = "-cp" ]; then
                IGNORE_ARG=1
              elif [ -z "`echo $ARG | grep '^-D'`" -a -z "`echo $ARG | grep '^-X'`" ]; then
                DESCR="$DESCR $ARG"
              fi
            else 
             IGNORE_ARG=0
            fi
          fi
        done
        echo "$PROCESS_ID	$DESCR"
      fi
    fi
  fi
done