/usr/bin/xml2-config is in libxml2-dev 2.9.4+dfsg1-6.1ubuntu1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 | #! /bin/sh
prefix=/usr
exec_prefix=${prefix}
includedir=${prefix}/include
libdir=${prefix}/lib
usage()
{
    cat <<EOF
Usage: xml2-config [OPTION]
Known values for OPTION are:
  --prefix=DIR		change libxml prefix [default $prefix]
  --exec-prefix=DIR	change libxml exec prefix [default $exec_prefix]
  --libs		print library linking information
                        add --static to print static library linking
                        information
  --cflags		print pre-processor and compiler flags
  --modules		module support enabled
  --help		display this help and exit
  --version		output version information
EOF
    exit $1
}
if test $# -eq 0; then
    usage 1
fi
cflags=false
libs=false
while test $# -gt 0; do
    case "$1" in
    -*=*) optarg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
    *) optarg= ;;
    esac
    case "$1" in
    --prefix=*)
	prefix=$optarg
	includedir=$prefix/include
	libdir=$prefix/lib
	;;
    --prefix)
	echo $prefix
	;;
    --exec-prefix=*)
      exec_prefix=$optarg
      libdir=$exec_prefix/lib
      ;;
    --exec-prefix)
      echo $exec_prefix
      ;;
    --version)
	echo 2.9.4
	exit 0
	;;
    --help)
	usage 0
	;;
    --cflags)
       	echo -I${includedir}/libxml2 
       	;;
    --libtool-libs)
	if [ -r ${libdir}/libxml2.la ]
	then
	    echo ${libdir}/libxml2.la
	fi
        ;;
    --modules)
       	echo 1
       	;;
    --libs)
        LIBS="-lxml2 "
        if [ "$2" = "--static" ]
        then
                shift
                LIBS="${LIBS} -lz -lpthread  -lm "
        fi
        echo ${LIBS}
        ;;
    *)
	usage
	exit 1
	;;
    esac
    shift
done
exit 0
 |