#!/bin/bash

# Near-misses fail with SIGILL or SIGSEGV, we don't want core dumps.
ulimit -c 0

HELPERS=/usr/lib/arch-test/

case "$1" in
  --version)
    printf 'arch-test %s\n' "v0.20"
    exit 0
    ;;
  -n|--native)
    export QEMU_VERSION=meow WINEPREFIX=/dev/null
    shift
    ;;
  -c|--chroot)
    shift
    CHROOT="$1"
    shift
    if [ -z "$CHROOT" ]
      then
        echo >&2 "$0: -c requires path to the chroot (possibly '.')."; exit 2
    fi
    if [ ! -d "$CHROOT" ]
      then
        echo >&2 "$0: chroot '$CHROOT' is not a directory."; exit 2
    fi
    if [ "x$(id -u)" != "x0" ]
      then
        echo >&2 "$0: chrooting requires root."; exit 2
    fi
    if [ -z "$1" ]
      then
        echo >&2 "$0: -c works only with a single-arch query."; exit 2
    fi
    ;;
  -*)
    echo >&2 "$0: unknown option '$1'."; exit 2
    ;;
esac

if [ $# -gt 1 ]
  then echo >&2 'Usage: "arch-test [-n]" or "arch-test [-n|-c <chroot>] <arch>".'; exit 1
fi

if [ $# -eq 1 ]
  then
    if [ ! -x "$HELPERS$1" ]
      then echo "I don't know how to detect arch '$1', sorry."; exit 2
    fi

    if [ -n "$CHROOT" ]
      then
        HELPER_F="$(basename $HELPERS$1)"
        cp -p "$HELPERS$1" "$CHROOT/$HELPER_F"
        trap "rm '$CHROOT/$HELPER_F'" 0
        MSG=`chroot "$CHROOT" /"$HELPER_F" 2>/dev/null`
      else
        MSG=`$HELPERS$1 2>/dev/null`
    fi
    if [ $? -eq 0 -a "x$MSG" = "xok" ]
      then echo "$1: ok"; exit 0
      else echo "$1: not supported on this machine/kernel"; exit 1
    fi
fi

for x in $HELPERS*
  do
    ARCH="$(basename "$x")"
    ARCH="${ARCH##arch-test-}"
    MSG=`"$x" 2>/dev/null|tr -d '\r'`
    if [ $? -eq 0 -a "x$MSG" = "xok" ]
      then echo "$ARCH"
    fi
  done