#!/bin/sh

#   Copyright (C) 2003-2013 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

#
# Script to generate a core file of a running program.
# It starts up gdb, attaches to the given PID and invokes the gcore command.
#

# Need to check for -o option, but set default basename to "core".
name=core

# When the -a option is present, this may hold additional commands
# to ensure gdb dumps all mappings (OS dependent).
dump_all_cmds=()

while getopts :ao: opt; do
    case $opt in
        a)
            case $OSTYPE in
                linux*)
                    dump_all_cmds=("-ex" "set use-coredump-filter off")
                    dump_all_cmds+=("-ex" "set dump-excluded-mappings on")
                    ;;
            esac
            ;;
        o)
            name=$OPTARG
            ;;
        *)
            echo "usage:  gcore [-a] [-o filename] pid"
            exit 2
            ;;
    esac
done

shift $((OPTIND-1))

if [ "$#" -eq "0" ]
then
    echo "usage:  gcore [-a] [-o filename] pid"
    exit 2
fi

# Initialise return code.
rc=0

# Loop through pids
for pid in $*
do
	# `</dev/null' to avoid touching interactive terminal if it is
	# available but not accessible as GDB would get stopped on SIGTTIN.
	gdb </dev/null --nx --batch \
	    -ex "set pagination off" -ex "set height 0" -ex "set width 0" \
	    "${dump_all_cmds[@]}" \
	    -ex "attach $pid" -ex "gcore $name.$pid" -ex detach -ex quit

	if [ -r $name.$pid ] ; then 
	    rc=0
	else
	    echo "gcore: failed to create $name.$pid"
	    rc=1
	    break
	fi


done

exit $rc