configure - third_party/github.com/madler/zlib - Git at Google

 #!/bin/sh
 # configure script for zlib.
 #
 # Normally configure builds both a static and a shared library.
 # If you want to build just a static library, use: ./configure --static
 #
 # To impose specific compiler or flags or install directory, use for example:
 #    prefix=$HOME CC=cc CFLAGS="-O4" ./configure
 # or for csh/tcsh users:
 #    (setenv prefix $HOME; setenv CC cc; setenv CFLAGS "-O4"; ./configure)

 # Incorrect settings of CC or CFLAGS may prevent creating a shared library.
 # If you have problems, try without defining CC and CFLAGS before reporting
 # an error.

 # make sure we are running under a compatible shell (stolen from ffmpeg and libnfo,
 # except their's wasn't portable enough due to ! usage, so this is better)
 if test "0$ZLIB_CONFIGURE_EXEC" -lt 1; then
   unset foo
   try=0
   (: ${foo%%bar}) 2>/dev/null
   if test "$?" -ne 0; then
     try=1
   else
     (: ${foo?}) 2>/dev/null
     if test "$?" -eq 0; then
       try=1
     fi
   fi
   if test "$try" -eq 1; then
     ZLIB_CONFIGURE_EXEC=1
     export ZLIB_CONFIGURE_EXEC
     type "bash" > /dev/null 2>&1 && exec bash "$0" "$@"
     type "ksh" > /dev/null 2>&1 && exec ksh "$0" "$@"
     if test -x /usr/xpg4/bin/sh; then
       exec /usr/xpg4/bin/sh "$0" "$@"
     fi
 #    echo "No compatible shell script interpreter found."
 #    exit 1
 # we could give up here, but go ahead and give their old sh a try
   fi
   unset try
 fi

 if [ -n "${CHOST}" ]; then
     uname="$(echo "${CHOST}" | sed 's/.*-.*-\(.*\)-.*/\1/')"
     CROSS_PREFIX="${CHOST}-"
 fi

 STATICLIB=libz.a
 LDFLAGS="${LDFLAGS} -L. ${STATICLIB}"
 VER=`sed -n -e '/VERSION "/s/.*"\(.*\)".*/\1/p' < zlib.h`
 VER3=`sed -n -e '/VERSION "/s/.*"\([0-9]*\\.[0-9]*\\.[0-9]*\).*/\1/p' < zlib.h`
 VER2=`sed -n -e '/VERSION "/s/.*"\([0-9]*\\.[0-9]*\)\\..*/\1/p' < zlib.h`
 VER1=`sed -n -e '/VERSION "/s/.*"\([0-9]*\)\\..*/\1/p' < zlib.h`
 if [ -x "${CROSS_PREFIX}ar" ]; then
     AR=${AR-"${CROSS_PREFIX}ar"}
 else
     AR=${AR-"ar"}
 fi
 AR_RC="${AR} rc"
 if [ -x "${CROSS_PREFIX}ranlib" ]; then
     RANLIB=${RANLIB-"${CROSS_PREFIX}ranlib"}
 else
     RANLIB=${RANLIB-"ranlib"}
 fi
 if [ -x "${CROSS_PREFIX}nm" ]; then
     NM=${NM-"${CROSS_PREFIX}nm"}
 else
     NM=${NM-"nm"}
 fi
 LDCONFIG=${LDCONFIG-"ldconfig"}
 LDSHAREDLIBC="${LDSHAREDLIBC-"-lc"}"
 prefix=${prefix-/usr/local}
 exec_prefix=${exec_prefix-'${prefix}'}
 libdir=${libdir-'${exec_prefix}/lib'}
 includedir=${includedir-'${prefix}/include'}
 mandir=${mandir-'${prefix}/share/man'}
 shared_ext='.so'
 shared=1
 zprefix=0
 build64=0
 gcc=0
 old_cc="$CC"
 old_cflags="$CFLAGS"

 while test $# -ge 1
 do
 case "$1" in
     -h* | --help)
       echo 'usage:'
       echo '  configure [--zprefix] [--prefix=PREFIX]  [--eprefix=EXPREFIX]'
       echo '    [--static] [--64] [--libdir=LIBDIR] [--includedir=INCLUDEDIR]'
         exit 0 ;;
     -p*=* | --prefix=*) prefix=`echo $1 | sed 's/.*=//'`; shift ;;
     -e*=* | --eprefix=*) exec_prefix=`echo $1 | sed 's/.*=//'`; shift ;;
     -l*=* | --libdir=*) libdir=`echo $1 | sed 's/.*=//'`; shift ;;
     -i*=* | --includedir=*) includedir=`echo $1 | sed 's/.*=//'`;shift ;;
     -u*=* | --uname=*) uname=`echo $1 | sed 's/.*=//'`;shift ;;
     -p* | --prefix) prefix="$2"; shift; shift ;;
     -e* | --eprefix) exec_prefix="$2"; shift; shift ;;
     -l* | --libdir) libdir="$2"; shift; shift ;;
     -i* | --includedir) includedir="$2"; shift; shift ;;
     -s* | --shared | --enable-shared) shared=1; shift ;;
     -t | --static) shared=0; shift ;;
     -z* | --zprefix) zprefix=1; shift ;;
     -6* | --64) build64=1; shift ;;
     --sysconfdir=*) echo "ignored option: --sysconfdir"; shift ;;
     --localstatedir=*) echo "ignored option: --localstatedir"; shift ;;
     *) echo "unknown option: $1"; echo "$0 --help for help"; exit 1 ;;
     esac
 done

 test=ztest$$
 cat > $test.c <<EOF
 extern int getchar();
 int hello() {return getchar();}
 EOF

 test -z "$CC" && echo Checking for gcc...
 cc=${CC-${CROSS_PREFIX}gcc}
 cflags=${CFLAGS-"-O3"}
 # to force the asm version use: CFLAGS="-O3 -DASMV" ./configure
 case "$cc" in
   *gcc*) gcc=1 ;;
 esac

 if test "$gcc" -eq 1 && ($cc -c $cflags $test.c) 2>/dev/null; then
   CC="$cc"
   SFLAGS="${CFLAGS-"-O3"} -fPIC"
   CFLAGS="${CFLAGS-"-O3"}"
   if test $build64 -eq 1; then
     CFLAGS="${CFLAGS} -m64"
     SFLAGS="${SFLAGS} -m64"
   fi
   if test "${ZLIBGCCWARN}" = "YES"; then
     CFLAGS="${CFLAGS} -Wall -Wextra -pedantic"
   fi
   if test -z "$uname"; then
     uname=`(uname -s || echo unknown) 2>/dev/null`
   fi
   case "$uname" in
   Linux* | linux* | GNU | GNU/* | *BSD | DragonFly) LDSHARED=${LDSHARED-"$cc -shared -Wl,-soname,libz.so.1,--version-script,zlib.map"} ;;
   CYGWIN* | Cygwin* | cygwin* | OS/2*)
         EXE='.exe' ;;
   MINGW*)
         LDSHARED=${LDSHARED-"$cc -shared"}
         LDSHAREDLIBC=""
         EXE='.exe' ;;
   QNX*)  # This is for QNX6. I suppose that the QNX rule below is for QNX2,QNX4
          # (alain.bonnefoy@icbt.com)
                  LDSHARED=${LDSHARED-"$cc -shared -Wl,-hlibz.so.1"} ;;
   HP-UX*)
          LDSHARED=${LDSHARED-"$cc -shared $SFLAGS"}
          case `(uname -m || echo unknown) 2>/dev/null` in
          ia64)
                  shared_ext='.so'
                  SHAREDLIB='libz.so' ;;
          *)
                  shared_ext='.sl'
                  SHAREDLIB='libz.sl' ;;
          esac ;;
   Darwin*)   shared_ext='.dylib'
              SHAREDLIB=libz$shared_ext
              SHAREDLIBV=libz.$VER$shared_ext
              SHAREDLIBM=libz.$VER1$shared_ext
              LDSHARED=${LDSHARED-"$cc -dynamiclib -install_name $libdir/$SHAREDLIBM -compatibility_version $VER1 -current_version $VER3"} ;;
   *)             LDSHARED=${LDSHARED-"$cc -shared"} ;;
   esac
 else
   # find system name and corresponding cc options
   CC=${CC-cc}
   if test -z "$uname"; then
     uname=`(uname -sr || echo unknown) 2>/dev/null`
   fi
   case "$uname" in
   HP-UX*)    SFLAGS=${CFLAGS-"-O +z"}
              CFLAGS=${CFLAGS-"-O"}
 #            LDSHARED=${LDSHARED-"ld -b +vnocompatwarnings"}
              LDSHARED=${LDSHARED-"ld -b"}
          case `(uname -m || echo unknown) 2>/dev/null` in
          ia64)
              shared_ext='.so'
              SHAREDLIB='libz.so' ;;
          *)
              shared_ext='.sl'
              SHAREDLIB='libz.sl' ;;
          esac ;;
   IRIX*)     SFLAGS=${CFLAGS-"-ansi -O2 -rpath ."}
              CFLAGS=${CFLAGS-"-ansi -O2"}
              LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so.1"} ;;
   OSF1\ V4*) SFLAGS=${CFLAGS-"-O -std1"}
              CFLAGS=${CFLAGS-"-O -std1"}
              LDFLAGS="${LDFLAGS} -Wl,-rpath,."
              LDSHARED=${LDSHARED-"cc -shared  -Wl,-soname,libz.so -Wl,-msym -Wl,-rpath,$(libdir) -Wl,-set_version,${VER}:1.0"} ;;
   OSF1*)     SFLAGS=${CFLAGS-"-O -std1"}
              CFLAGS=${CFLAGS-"-O -std1"}
              LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so.1"} ;;
   QNX*)      SFLAGS=${CFLAGS-"-4 -O"}
              CFLAGS=${CFLAGS-"-4 -O"}
              LDSHARED=${LDSHARED-"cc"}
              RANLIB=${RANLIB-"true"}
              AR_RC="cc -A" ;;
   SCO_SV\ 3.2*) SFLAGS=${CFLAGS-"-O3 -dy -KPIC "}
              CFLAGS=${CFLAGS-"-O3"}
              LDSHARED=${LDSHARED-"cc -dy -KPIC -G"} ;;
   SunOS\ 5*) LDSHARED=${LDSHARED-"cc -G"}
          case `(uname -m || echo unknown) 2>/dev/null` in
          i86*)
              SFLAGS=${CFLAGS-"-xpentium -fast -KPIC -R."}
              CFLAGS=${CFLAGS-"-xpentium -fast"} ;;
          *)
              SFLAGS=${CFLAGS-"-fast -xcg92 -KPIC -R."}
              CFLAGS=${CFLAGS-"-fast -xcg92"} ;;
          esac ;;
   SunOS\ 4*) SFLAGS=${CFLAGS-"-O2 -PIC"}
              CFLAGS=${CFLAGS-"-O2"}
              LDSHARED=${LDSHARED-"ld"} ;;
   SunStudio\ 9*) SFLAGS=${CFLAGS-"-fast -xcode=pic32 -xtarget=ultra3 -xarch=v9b"}
              CFLAGS=${CFLAGS-"-fast -xtarget=ultra3 -xarch=v9b"}
              LDSHARED=${LDSHARED-"cc -xarch=v9b"} ;;
   UNIX_System_V\ 4.2.0)
              SFLAGS=${CFLAGS-"-KPIC -O"}
              CFLAGS=${CFLAGS-"-O"}
              LDSHARED=${LDSHARED-"cc -G"} ;;
   UNIX_SV\ 4.2MP)
              SFLAGS=${CFLAGS-"-Kconform_pic -O"}
              CFLAGS=${CFLAGS-"-O"}
              LDSHARED=${LDSHARED-"cc -G"} ;;
   OpenUNIX\ 5)
              SFLAGS=${CFLAGS-"-KPIC -O"}
              CFLAGS=${CFLAGS-"-O"}
              LDSHARED=${LDSHARED-"cc -G"} ;;
   AIX*)  # Courtesy of dbakker@arrayasolutions.com
              SFLAGS=${CFLAGS-"-O -qmaxmem=8192"}
              CFLAGS=${CFLAGS-"-O -qmaxmem=8192"}
              LDSHARED=${LDSHARED-"xlc -G"} ;;
   # send working options for other systems to zlib@gzip.org
   *)         SFLAGS=${CFLAGS-"-O"}
              CFLAGS=${CFLAGS-"-O"}
              LDSHARED=${LDSHARED-"cc -shared"} ;;
   esac
 fi

 SHAREDLIB=${SHAREDLIB-"libz$shared_ext"}
 SHAREDLIBV=${SHAREDLIBV-"libz$shared_ext.$VER"}
 SHAREDLIBM=${SHAREDLIBM-"libz$shared_ext.$VER1"}

 if test $shared -eq 1; then
   echo Checking for shared library support...
   # we must test in two steps (cc then ld), required at least on SunOS 4.x
   if test "`($CC -w -c $SFLAGS $test.c) 2>&1`" = "" &&
      test "`($LDSHARED $SFLAGS -o $test$shared_ext $test.o) 2>&1`" = ""; then
     echo Building shared library $SHAREDLIBV with $CC.
   elif test -z "$old_cc" -a -z "$old_cflags"; then
     echo No shared library support.
     shared=0;
   else
     echo Tested $CC -w -c $SFLAGS $test.c
     $CC -w -c $SFLAGS $test.c
     echo Tested $LDSHARED $SFLAGS -o $test$shared_ext $test.o
     $LDSHARED $SFLAGS -o $test$shared_ext $test.o
     echo 'No shared library support; try without defining CC and CFLAGS'
     shared=0;
   fi
 fi
 if test $shared -eq 0; then
   LDSHARED="$CC"
   ALL="static"
   TEST="all teststatic"
   SHAREDLIB=""
   SHAREDLIBV=""
   SHAREDLIBM=""
   echo Building static library $STATICLIB version $VER with $CC.
 else
   ALL="static shared"
   TEST="all teststatic testshared"
 fi

 cat > $test.c <<EOF
 #include <sys/types.h>
 off64_t dummy = 0;
 EOF
 if test "`($CC -c $CFLAGS -D_LARGEFILE64_SOURCE=1 $test.c) 2>&1`" = ""; then
   CFLAGS="${CFLAGS} -D_LARGEFILE64_SOURCE=1"
   SFLAGS="${SFLAGS} -D_LARGEFILE64_SOURCE=1"
   ALL="${ALL} all64"
   TEST="${TEST} test64"
   echo "Checking for off64_t... Yes."
   echo "Checking for fseeko... Yes."
 else
   echo "Checking for off64_t... No."
   cat > $test.c <<EOF
 #include <stdio.h>
 int main(void) {
   fseeko(NULL, 0, 0);
   return 0;
 }
 EOF
   if test "`($CC $CFLAGS -o $test $test.c) 2>&1`" = ""; then
     echo "Checking for fseeko... Yes."
   else
     CFLAGS="${CFLAGS} -DNO_FSEEKO"
     SFLAGS="${SFLAGS} -DNO_FSEEKO"
     echo "Checking for fseeko... No."
   fi
 fi

 cp -p zconf.h.in zconf.h

 cat > $test.c <<EOF
 #include <unistd.h>
 int main() { return 0; }
 EOF
 if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
   sed < zconf.h "/^#ifdef HAVE_UNISTD_H.* may be/s/def HAVE_UNISTD_H\(.*\) may be/ 1\1 was/" > zconf.temp.h
   mv zconf.temp.h zconf.h
   echo "Checking for unistd.h... Yes."
 else
   echo "Checking for unistd.h... No."
 fi

 if test $zprefix -eq 1; then
   sed < zconf.h "/#ifdef Z_PREFIX.* may be/s/def Z_PREFIX\(.*\) may be/ 1\1 was/" > zconf.temp.h
   mv zconf.temp.h zconf.h
   echo "Using z_ prefix on all symbols."
 fi

 cat > $test.c <<EOF
 #include <stdio.h>
 #include <stdarg.h>
 #include "zconf.h"

 int main()
 {
 #ifndef STDC
   choke me
 #endif

   return 0;
 }
 EOF

 if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
   echo "Checking whether to use vs[n]printf() or s[n]printf()... using vs[n]printf()."

   cat > $test.c <<EOF
 #include <stdio.h>
 #include <stdarg.h>

 int mytest(const char *fmt, ...)
 {
   char buf[20];
   va_list ap;

   va_start(ap, fmt);
   vsnprintf(buf, sizeof(buf), fmt, ap);
   va_end(ap);
   return 0;
 }

 int main()
 {
   return (mytest("Hello%d\n", 1));
 }
 EOF

   if test "`($CC $CFLAGS -o $test $test.c) 2>&1`" = ""; then
     echo "Checking for vsnprintf() in stdio.h... Yes."

     cat >$test.c <<EOF
 #include <stdio.h>
 #include <stdarg.h>

 int mytest(const char *fmt, ...)
 {
   int n;
   char buf[20];
   va_list ap;

   va_start(ap, fmt);
   n = vsnprintf(buf, sizeof(buf), fmt, ap);
   va_end(ap);
   return n;
 }

 int main()
 {
   return (mytest("Hello%d\n", 1));
 }
 EOF

     if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
       echo "Checking for return value of vsnprintf()... Yes."
     else
       CFLAGS="$CFLAGS -DHAS_vsnprintf_void"
       SFLAGS="$SFLAGS -DHAS_vsnprintf_void"
       echo "Checking for return value of vsnprintf()... No."
       echo "  WARNING: apparently vsnprintf() does not return a value. zlib"
       echo "  can build but will be open to possible string-format security"
       echo "  vulnerabilities."
     fi
   else
     CFLAGS="$CFLAGS -DNO_vsnprintf"
     SFLAGS="$SFLAGS -DNO_vsnprintf"
     echo "Checking for vsnprintf() in stdio.h... No."
     echo "  WARNING: vsnprintf() not found, falling back to vsprintf(). zlib"
     echo "  can build but will be open to possible buffer-overflow security"
     echo "  vulnerabilities."

     cat >$test.c <<EOF
 #include <stdio.h>
 #include <stdarg.h>

 int mytest(const char *fmt, ...)
 {
   int n;
   char buf[20];
   va_list ap;

   va_start(ap, fmt);
   n = vsprintf(buf, fmt, ap);
   va_end(ap);
   return n;
 }

 int main()
 {
   return (mytest("Hello%d\n", 1));
 }
 EOF

     if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
       echo "Checking for return value of vsprintf()... Yes."
     else
       CFLAGS="$CFLAGS -DHAS_vsprintf_void"
       SFLAGS="$SFLAGS -DHAS_vsprintf_void"
       echo "Checking for return value of vsprintf()... No."
       echo "  WARNING: apparently vsprintf() does not return a value. zlib"
       echo "  can build but will be open to possible string-format security"
       echo "  vulnerabilities."
     fi
   fi
 else
   echo "Checking whether to use vs[n]printf() or s[n]printf()... using s[n]printf()."

   cat >$test.c <<EOF
 #include <stdio.h>

 int mytest()
 {
   char buf[20];

   snprintf(buf, sizeof(buf), "%s", "foo");
   return 0;
 }

 int main()
 {
   return (mytest());
 }
 EOF

   if test "`($CC $CFLAGS -o $test $test.c) 2>&1`" = ""; then
     echo "Checking for snprintf() in stdio.h... Yes."

     cat >$test.c <<EOF
 #include <stdio.h>

 int mytest()
 {
   char buf[20];

   return snprintf(buf, sizeof(buf), "%s", "foo");
 }

 int main()
 {
   return (mytest());
 }
 EOF

     if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
       echo "Checking for return value of snprintf()... Yes."
     else
       CFLAGS="$CFLAGS -DHAS_snprintf_void"
       SFLAGS="$SFLAGS -DHAS_snprintf_void"
       echo "Checking for return value of snprintf()... No."
       echo "  WARNING: apparently snprintf() does not return a value. zlib"
       echo "  can build but will be open to possible string-format security"
       echo "  vulnerabilities."
     fi
   else
     CFLAGS="$CFLAGS -DNO_snprintf"
     SFLAGS="$SFLAGS -DNO_snprintf"
     echo "Checking for snprintf() in stdio.h... No."
     echo "  WARNING: snprintf() not found, falling back to sprintf(). zlib"
     echo "  can build but will be open to possible buffer-overflow security"
     echo "  vulnerabilities."

     cat >$test.c <<EOF
 #include <stdio.h>

 int mytest()
 {
   char buf[20];

   return sprintf(buf, "%s", "foo");
 }

 int main()
 {
   return (mytest());
 }
 EOF

     if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
       echo "Checking for return value of sprintf()... Yes."
     else
       CFLAGS="$CFLAGS -DHAS_sprintf_void"
       SFLAGS="$SFLAGS -DHAS_sprintf_void"
       echo "Checking for return value of sprintf()... No."
       echo "  WARNING: apparently sprintf() does not return a value. zlib"
       echo "  can build but will be open to possible string-format security"
       echo "  vulnerabilities."
     fi
   fi
 fi

 CPP=${CPP-"$CC -E"}
 case $CFLAGS in
   *ASMV*)
     if test "`$NM $test.o | grep _hello`" = ""; then
       CPP="$CPP -DNO_UNDERLINE"
       echo Checking for underline in external names... No.
     else
       echo Checking for underline in external names... Yes.
     fi ;;
 esac

 rm -f $test.[co] $test $test$shared_ext

 # udpate Makefile
 sed < Makefile.in "
 /^CC *=/s#=.*#=$CC#
 /^CFLAGS *=/s#=.*#=$CFLAGS#
 /^SFLAGS *=/s#=.*#=$SFLAGS#
 /^LDFLAGS *=/s#=.*#=$LDFLAGS#
 /^LDSHARED *=/s#=.*#=$LDSHARED#
 /^CPP *=/s#=.*#=$CPP#
 /^STATICLIB *=/s#=.*#=$STATICLIB#
 /^SHAREDLIB *=/s#=.*#=$SHAREDLIB#
 /^SHAREDLIBV *=/s#=.*#=$SHAREDLIBV#
 /^SHAREDLIBM *=/s#=.*#=$SHAREDLIBM#
 /^AR *=/s#=.*#=$AR_RC#
 /^RANLIB *=/s#=.*#=$RANLIB#
 /^LDCONFIG *=/s#=.*#=$LDCONFIG#
 /^LDSHAREDLIBC *=/s#=.*#=$LDSHAREDLIBC#
 /^EXE *=/s#=.*#=$EXE#
 /^prefix *=/s#=.*#=$prefix#
 /^exec_prefix *=/s#=.*#=$exec_prefix#
 /^libdir *=/s#=.*#=$libdir#
 /^includedir *=/s#=.*#=$includedir#
 /^mandir *=/s#=.*#=$mandir#
 /^all: */s#:.*#: $ALL#
 /^test: */s#:.*#: $TEST#
 " > Makefile

 sed < zlib.pc.in "
 /^CC *=/s#=.*#=$CC#
 /^CFLAGS *=/s#=.*#=$CFLAGS#
 /^CPP *=/s#=.*#=$CPP#
 /^LDSHARED *=/s#=.*#=$LDSHARED#
 /^STATICLIB *=/s#=.*#=$STATICLIB#
 /^SHAREDLIB *=/s#=.*#=$SHAREDLIB#
 /^SHAREDLIBV *=/s#=.*#=$SHAREDLIBV#
 /^SHAREDLIBM *=/s#=.*#=$SHAREDLIBM#
 /^AR *=/s#=.*#=$AR_RC#
 /^RANLIB *=/s#=.*#=$RANLIB#
 /^EXE *=/s#=.*#=$EXE#
 /^prefix *=/s#=.*#=$prefix#
 /^exec_prefix *=/s#=.*#=$exec_prefix#
 /^libdir *=/s#=.*#=$libdir#
 /^includedir *=/s#=.*#=$includedir#
 /^mandir *=/s#=.*#=$mandir#
 /^LDFLAGS *=/s#=.*#=$LDFLAGS#
 " | sed -e "
 s/\@VERSION\@/$VER/g;
 " > zlib.pc
	#!/bin/sh
	# configure script for zlib.
	#
	# Normally configure builds both a static and a shared library.
	# If you want to build just a static library, use: ./configure --static
	#
	# To impose specific compiler or flags or install directory, use for example:
	# prefix=$HOME CC=cc CFLAGS="-O4" ./configure
	# or for csh/tcsh users:
	# (setenv prefix $HOME; setenv CC cc; setenv CFLAGS "-O4"; ./configure)

	# Incorrect settings of CC or CFLAGS may prevent creating a shared library.
	# If you have problems, try without defining CC and CFLAGS before reporting
	# an error.

	# make sure we are running under a compatible shell (stolen from ffmpeg and libnfo,
	# except their's wasn't portable enough due to ! usage, so this is better)
	if test "0$ZLIB_CONFIGURE_EXEC" -lt 1; then
	unset foo
	try=0
	(: ${foo%%bar}) 2>/dev/null
	if test "$?" -ne 0; then
	try=1
	else
	(: ${foo?}) 2>/dev/null
	if test "$?" -eq 0; then
	try=1
	fi
	fi
	if test "$try" -eq 1; then
	ZLIB_CONFIGURE_EXEC=1
	export ZLIB_CONFIGURE_EXEC
	type "bash" > /dev/null 2>&1 && exec bash "$0" "$@"
	type "ksh" > /dev/null 2>&1 && exec ksh "$0" "$@"
	if test -x /usr/xpg4/bin/sh; then
	exec /usr/xpg4/bin/sh "$0" "$@"
	fi
	# echo "No compatible shell script interpreter found."
	# exit 1
	# we could give up here, but go ahead and give their old sh a try
	fi
	unset try
	fi

	if [ -n "${CHOST}" ]; then
	uname="$(echo "${CHOST}" \| sed 's/.-.-\(.\)-./\1/')"
	CROSS_PREFIX="${CHOST}-"
	fi

	STATICLIB=libz.a
	LDFLAGS="${LDFLAGS} -L. ${STATICLIB}"
	VER=`sed -n -e '/VERSION "/s/."\(.\)".*/\1/p' < zlib.h`
	VER3=`sed -n -e '/VERSION "/s/."\([0-9]\\.[0-9]\\.[0-9]\).*/\1/p' < zlib.h`
	VER2=`sed -n -e '/VERSION "/s/."\([0-9]\\.[0-9]\)\\../\1/p' < zlib.h`
	VER1=`sed -n -e '/VERSION "/s/."\([0-9]\)\\..*/\1/p' < zlib.h`
	if [ -x "${CROSS_PREFIX}ar" ]; then
	AR=${AR-"${CROSS_PREFIX}ar"}
	else
	AR=${AR-"ar"}
	fi
	AR_RC="${AR} rc"
	if [ -x "${CROSS_PREFIX}ranlib" ]; then
	RANLIB=${RANLIB-"${CROSS_PREFIX}ranlib"}
	else
	RANLIB=${RANLIB-"ranlib"}
	fi
	if [ -x "${CROSS_PREFIX}nm" ]; then
	NM=${NM-"${CROSS_PREFIX}nm"}
	else
	NM=${NM-"nm"}
	fi
	LDCONFIG=${LDCONFIG-"ldconfig"}
	LDSHAREDLIBC="${LDSHAREDLIBC-"-lc"}"
	prefix=${prefix-/usr/local}
	exec_prefix=${exec_prefix-'${prefix}'}
	libdir=${libdir-'${exec_prefix}/lib'}
	includedir=${includedir-'${prefix}/include'}
	mandir=${mandir-'${prefix}/share/man'}
	shared_ext='.so'
	shared=1
	zprefix=0
	build64=0
	gcc=0
	old_cc="$CC"
	old_cflags="$CFLAGS"

	while test $# -ge 1
	do
	case "$1" in
	-h* \| --help)
	echo 'usage:'
	echo ' configure [--zprefix] [--prefix=PREFIX] [--eprefix=EXPREFIX]'
	echo ' [--static] [--64] [--libdir=LIBDIR] [--includedir=INCLUDEDIR]'
	exit 0 ;;
	-p= \| --prefix=) prefix=`echo $1 \| sed 's/.=//'`; shift ;;
	-e= \| --eprefix=) exec_prefix=`echo $1 \| sed 's/.=//'`; shift ;;
	-l= \| --libdir=) libdir=`echo $1 \| sed 's/.=//'`; shift ;;
	-i= \| --includedir=) includedir=`echo $1 \| sed 's/.=//'`;shift ;;
	-u= \| --uname=) uname=`echo $1 \| sed 's/.=//'`;shift ;;
	-p* \| --prefix) prefix="$2"; shift; shift ;;
	-e* \| --eprefix) exec_prefix="$2"; shift; shift ;;
	-l* \| --libdir) libdir="$2"; shift; shift ;;
	-i* \| --includedir) includedir="$2"; shift; shift ;;
	-s* \| --shared \| --enable-shared) shared=1; shift ;;
	-t \| --static) shared=0; shift ;;
	-z* \| --zprefix) zprefix=1; shift ;;
	-6* \| --64) build64=1; shift ;;
	--sysconfdir=*) echo "ignored option: --sysconfdir"; shift ;;
	--localstatedir=*) echo "ignored option: --localstatedir"; shift ;;
	*) echo "unknown option: $1"; echo "$0 --help for help"; exit 1 ;;
	esac
	done

	test=ztest$$
	cat > $test.c <<EOF
	extern int getchar();
	int hello() {return getchar();}
	EOF

	test -z "$CC" && echo Checking for gcc...
	cc=${CC-${CROSS_PREFIX}gcc}
	cflags=${CFLAGS-"-O3"}
	# to force the asm version use: CFLAGS="-O3 -DASMV" ./configure
	case "$cc" in
	gcc) gcc=1 ;;
	esac

	if test "$gcc" -eq 1 && ($cc -c $cflags $test.c) 2>/dev/null; then
	CC="$cc"
	SFLAGS="${CFLAGS-"-O3"} -fPIC"
	CFLAGS="${CFLAGS-"-O3"}"
	if test $build64 -eq 1; then
	CFLAGS="${CFLAGS} -m64"
	SFLAGS="${SFLAGS} -m64"
	fi
	if test "${ZLIBGCCWARN}" = "YES"; then
	CFLAGS="${CFLAGS} -Wall -Wextra -pedantic"
	fi
	if test -z "$uname"; then
	uname=`(uname -s \|\| echo unknown) 2>/dev/null`
	fi
	case "$uname" in
	Linux* \| linux* \| GNU \| GNU/* \| *BSD \| DragonFly) LDSHARED=${LDSHARED-"$cc -shared -Wl,-soname,libz.so.1,--version-script,zlib.map"} ;;
	CYGWIN* \| Cygwin* \| cygwin* \| OS/2*)
	EXE='.exe' ;;
	MINGW*)
	LDSHARED=${LDSHARED-"$cc -shared"}
	LDSHAREDLIBC=""
	EXE='.exe' ;;
	QNX*) # This is for QNX6. I suppose that the QNX rule below is for QNX2,QNX4
	# (alain.bonnefoy@icbt.com)
	LDSHARED=${LDSHARED-"$cc -shared -Wl,-hlibz.so.1"} ;;
	HP-UX*)
	LDSHARED=${LDSHARED-"$cc -shared $SFLAGS"}
	case `(uname -m \|\| echo unknown) 2>/dev/null` in
	ia64)
	shared_ext='.so'
	SHAREDLIB='libz.so' ;;
	*)
	shared_ext='.sl'
	SHAREDLIB='libz.sl' ;;
	esac ;;
	Darwin*) shared_ext='.dylib'
	SHAREDLIB=libz$shared_ext
	SHAREDLIBV=libz.$VER$shared_ext
	SHAREDLIBM=libz.$VER1$shared_ext
	LDSHARED=${LDSHARED-"$cc -dynamiclib -install_name $libdir/$SHAREDLIBM -compatibility_version $VER1 -current_version $VER3"} ;;
	*) LDSHARED=${LDSHARED-"$cc -shared"} ;;
	esac
	else
	# find system name and corresponding cc options
	CC=${CC-cc}
	if test -z "$uname"; then
	uname=`(uname -sr \|\| echo unknown) 2>/dev/null`
	fi
	case "$uname" in
	HP-UX*) SFLAGS=${CFLAGS-"-O +z"}
	CFLAGS=${CFLAGS-"-O"}
	# LDSHARED=${LDSHARED-"ld -b +vnocompatwarnings"}
	LDSHARED=${LDSHARED-"ld -b"}
	case `(uname -m \|\| echo unknown) 2>/dev/null` in
	ia64)
	shared_ext='.so'
	SHAREDLIB='libz.so' ;;
	*)
	shared_ext='.sl'
	SHAREDLIB='libz.sl' ;;
	esac ;;
	IRIX*) SFLAGS=${CFLAGS-"-ansi -O2 -rpath ."}
	CFLAGS=${CFLAGS-"-ansi -O2"}
	LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so.1"} ;;
	OSF1\ V4*) SFLAGS=${CFLAGS-"-O -std1"}
	CFLAGS=${CFLAGS-"-O -std1"}
	LDFLAGS="${LDFLAGS} -Wl,-rpath,."
	LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so -Wl,-msym -Wl,-rpath,$(libdir) -Wl,-set_version,${VER}:1.0"} ;;
	OSF1*) SFLAGS=${CFLAGS-"-O -std1"}
	CFLAGS=${CFLAGS-"-O -std1"}
	LDSHARED=${LDSHARED-"cc -shared -Wl,-soname,libz.so.1"} ;;
	QNX*) SFLAGS=${CFLAGS-"-4 -O"}
	CFLAGS=${CFLAGS-"-4 -O"}
	LDSHARED=${LDSHARED-"cc"}
	RANLIB=${RANLIB-"true"}
	AR_RC="cc -A" ;;
	SCO_SV\ 3.2*) SFLAGS=${CFLAGS-"-O3 -dy -KPIC "}
	CFLAGS=${CFLAGS-"-O3"}
	LDSHARED=${LDSHARED-"cc -dy -KPIC -G"} ;;
	SunOS\ 5*) LDSHARED=${LDSHARED-"cc -G"}
	case `(uname -m \|\| echo unknown) 2>/dev/null` in
	i86*)
	SFLAGS=${CFLAGS-"-xpentium -fast -KPIC -R."}
	CFLAGS=${CFLAGS-"-xpentium -fast"} ;;
	*)
	SFLAGS=${CFLAGS-"-fast -xcg92 -KPIC -R."}
	CFLAGS=${CFLAGS-"-fast -xcg92"} ;;
	esac ;;
	SunOS\ 4*) SFLAGS=${CFLAGS-"-O2 -PIC"}
	CFLAGS=${CFLAGS-"-O2"}
	LDSHARED=${LDSHARED-"ld"} ;;
	SunStudio\ 9*) SFLAGS=${CFLAGS-"-fast -xcode=pic32 -xtarget=ultra3 -xarch=v9b"}
	CFLAGS=${CFLAGS-"-fast -xtarget=ultra3 -xarch=v9b"}
	LDSHARED=${LDSHARED-"cc -xarch=v9b"} ;;
	UNIX_System_V\ 4.2.0)
	SFLAGS=${CFLAGS-"-KPIC -O"}
	CFLAGS=${CFLAGS-"-O"}
	LDSHARED=${LDSHARED-"cc -G"} ;;
	UNIX_SV\ 4.2MP)
	SFLAGS=${CFLAGS-"-Kconform_pic -O"}
	CFLAGS=${CFLAGS-"-O"}
	LDSHARED=${LDSHARED-"cc -G"} ;;
	OpenUNIX\ 5)
	SFLAGS=${CFLAGS-"-KPIC -O"}
	CFLAGS=${CFLAGS-"-O"}
	LDSHARED=${LDSHARED-"cc -G"} ;;
	AIX*) # Courtesy of dbakker@arrayasolutions.com
	SFLAGS=${CFLAGS-"-O -qmaxmem=8192"}
	CFLAGS=${CFLAGS-"-O -qmaxmem=8192"}
	LDSHARED=${LDSHARED-"xlc -G"} ;;
	# send working options for other systems to zlib@gzip.org
	*) SFLAGS=${CFLAGS-"-O"}
	CFLAGS=${CFLAGS-"-O"}
	LDSHARED=${LDSHARED-"cc -shared"} ;;
	esac
	fi

	SHAREDLIB=${SHAREDLIB-"libz$shared_ext"}
	SHAREDLIBV=${SHAREDLIBV-"libz$shared_ext.$VER"}
	SHAREDLIBM=${SHAREDLIBM-"libz$shared_ext.$VER1"}

	if test $shared -eq 1; then
	echo Checking for shared library support...
	# we must test in two steps (cc then ld), required at least on SunOS 4.x
	if test "`($CC -w -c $SFLAGS $test.c) 2>&1`" = "" &&
	test "`($LDSHARED $SFLAGS -o $test$shared_ext $test.o) 2>&1`" = ""; then
	echo Building shared library $SHAREDLIBV with $CC.
	elif test -z "$old_cc" -a -z "$old_cflags"; then
	echo No shared library support.
	shared=0;
	else
	echo Tested $CC -w -c $SFLAGS $test.c
	$CC -w -c $SFLAGS $test.c
	echo Tested $LDSHARED $SFLAGS -o $test$shared_ext $test.o
	$LDSHARED $SFLAGS -o $test$shared_ext $test.o
	echo 'No shared library support; try without defining CC and CFLAGS'
	shared=0;
	fi
	fi
	if test $shared -eq 0; then
	LDSHARED="$CC"
	ALL="static"
	TEST="all teststatic"
	SHAREDLIB=""
	SHAREDLIBV=""
	SHAREDLIBM=""
	echo Building static library $STATICLIB version $VER with $CC.
	else
	ALL="static shared"
	TEST="all teststatic testshared"
	fi

	cat > $test.c <<EOF
	#include <sys/types.h>
	off64_t dummy = 0;
	EOF
	if test "`($CC -c $CFLAGS -D_LARGEFILE64_SOURCE=1 $test.c) 2>&1`" = ""; then
	CFLAGS="${CFLAGS} -D_LARGEFILE64_SOURCE=1"
	SFLAGS="${SFLAGS} -D_LARGEFILE64_SOURCE=1"
	ALL="${ALL} all64"
	TEST="${TEST} test64"
	echo "Checking for off64_t... Yes."
	echo "Checking for fseeko... Yes."
	else
	echo "Checking for off64_t... No."
	cat > $test.c <<EOF
	#include <stdio.h>
	int main(void) {
	fseeko(NULL, 0, 0);
	return 0;
	}
	EOF
	if test "`($CC $CFLAGS -o $test $test.c) 2>&1`" = ""; then
	echo "Checking for fseeko... Yes."
	else
	CFLAGS="${CFLAGS} -DNO_FSEEKO"
	SFLAGS="${SFLAGS} -DNO_FSEEKO"
	echo "Checking for fseeko... No."
	fi
	fi

	cp -p zconf.h.in zconf.h

	cat > $test.c <<EOF
	#include <unistd.h>
	int main() { return 0; }
	EOF
	if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
	sed < zconf.h "/^#ifdef HAVE_UNISTD_H.* may be/s/def HAVE_UNISTD_H\(.*\) may be/ 1\1 was/" > zconf.temp.h
	mv zconf.temp.h zconf.h
	echo "Checking for unistd.h... Yes."
	else
	echo "Checking for unistd.h... No."
	fi

	if test $zprefix -eq 1; then
	sed < zconf.h "/#ifdef Z_PREFIX.* may be/s/def Z_PREFIX\(.*\) may be/ 1\1 was/" > zconf.temp.h
	mv zconf.temp.h zconf.h
	echo "Using z_ prefix on all symbols."
	fi

	cat > $test.c <<EOF
	#include <stdio.h>
	#include <stdarg.h>
	#include "zconf.h"

	int main()
	{
	#ifndef STDC
	choke me
	#endif

	return 0;
	}
	EOF

	if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
	echo "Checking whether to use vs[n]printf() or s[n]printf()... using vs[n]printf()."

	cat > $test.c <<EOF
	#include <stdio.h>
	#include <stdarg.h>

	int mytest(const char *fmt, ...)
	{
	char buf[20];
	va_list ap;

	va_start(ap, fmt);
	vsnprintf(buf, sizeof(buf), fmt, ap);
	va_end(ap);
	return 0;
	}

	int main()
	{
	return (mytest("Hello%d\n", 1));
	}
	EOF

	if test "`($CC $CFLAGS -o $test $test.c) 2>&1`" = ""; then
	echo "Checking for vsnprintf() in stdio.h... Yes."

	cat >$test.c <<EOF
	#include <stdio.h>
	#include <stdarg.h>

	int mytest(const char *fmt, ...)
	{
	int n;
	char buf[20];
	va_list ap;

	va_start(ap, fmt);
	n = vsnprintf(buf, sizeof(buf), fmt, ap);
	va_end(ap);
	return n;
	}

	int main()
	{
	return (mytest("Hello%d\n", 1));
	}
	EOF

	if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
	echo "Checking for return value of vsnprintf()... Yes."
	else
	CFLAGS="$CFLAGS -DHAS_vsnprintf_void"
	SFLAGS="$SFLAGS -DHAS_vsnprintf_void"
	echo "Checking for return value of vsnprintf()... No."
	echo " WARNING: apparently vsnprintf() does not return a value. zlib"
	echo " can build but will be open to possible string-format security"
	echo " vulnerabilities."
	fi
	else
	CFLAGS="$CFLAGS -DNO_vsnprintf"
	SFLAGS="$SFLAGS -DNO_vsnprintf"
	echo "Checking for vsnprintf() in stdio.h... No."
	echo " WARNING: vsnprintf() not found, falling back to vsprintf(). zlib"
	echo " can build but will be open to possible buffer-overflow security"
	echo " vulnerabilities."

	cat >$test.c <<EOF
	#include <stdio.h>
	#include <stdarg.h>

	int mytest(const char *fmt, ...)
	{
	int n;
	char buf[20];
	va_list ap;

	va_start(ap, fmt);
	n = vsprintf(buf, fmt, ap);
	va_end(ap);
	return n;
	}

	int main()
	{
	return (mytest("Hello%d\n", 1));
	}
	EOF

	if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
	echo "Checking for return value of vsprintf()... Yes."
	else
	CFLAGS="$CFLAGS -DHAS_vsprintf_void"
	SFLAGS="$SFLAGS -DHAS_vsprintf_void"
	echo "Checking for return value of vsprintf()... No."
	echo " WARNING: apparently vsprintf() does not return a value. zlib"
	echo " can build but will be open to possible string-format security"
	echo " vulnerabilities."
	fi
	fi
	else
	echo "Checking whether to use vs[n]printf() or s[n]printf()... using s[n]printf()."

	cat >$test.c <<EOF
	#include <stdio.h>

	int mytest()
	{
	char buf[20];

	snprintf(buf, sizeof(buf), "%s", "foo");
	return 0;
	}

	int main()
	{
	return (mytest());
	}
	EOF

	if test "`($CC $CFLAGS -o $test $test.c) 2>&1`" = ""; then
	echo "Checking for snprintf() in stdio.h... Yes."

	cat >$test.c <<EOF
	#include <stdio.h>

	int mytest()
	{
	char buf[20];

	return snprintf(buf, sizeof(buf), "%s", "foo");
	}

	int main()
	{
	return (mytest());
	}
	EOF

	if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
	echo "Checking for return value of snprintf()... Yes."
	else
	CFLAGS="$CFLAGS -DHAS_snprintf_void"
	SFLAGS="$SFLAGS -DHAS_snprintf_void"
	echo "Checking for return value of snprintf()... No."
	echo " WARNING: apparently snprintf() does not return a value. zlib"
	echo " can build but will be open to possible string-format security"
	echo " vulnerabilities."
	fi
	else
	CFLAGS="$CFLAGS -DNO_snprintf"
	SFLAGS="$SFLAGS -DNO_snprintf"
	echo "Checking for snprintf() in stdio.h... No."
	echo " WARNING: snprintf() not found, falling back to sprintf(). zlib"
	echo " can build but will be open to possible buffer-overflow security"
	echo " vulnerabilities."

	cat >$test.c <<EOF
	#include <stdio.h>

	int mytest()
	{
	char buf[20];

	return sprintf(buf, "%s", "foo");
	}

	int main()
	{
	return (mytest());
	}
	EOF

	if test "`($CC -c $CFLAGS $test.c) 2>&1`" = ""; then
	echo "Checking for return value of sprintf()... Yes."
	else
	CFLAGS="$CFLAGS -DHAS_sprintf_void"
	SFLAGS="$SFLAGS -DHAS_sprintf_void"
	echo "Checking for return value of sprintf()... No."
	echo " WARNING: apparently sprintf() does not return a value. zlib"
	echo " can build but will be open to possible string-format security"
	echo " vulnerabilities."
	fi
	fi
	fi

	CPP=${CPP-"$CC -E"}
	case $CFLAGS in
	ASMV)
	if test "`$NM $test.o \| grep _hello`" = ""; then
	CPP="$CPP -DNO_UNDERLINE"
	echo Checking for underline in external names... No.
	else
	echo Checking for underline in external names... Yes.
	fi ;;
	esac

	rm -f $test.[co] $test $test$shared_ext

	# udpate Makefile
	sed < Makefile.in "
	/^CC =/s#=.#=$CC#
	/^CFLAGS =/s#=.#=$CFLAGS#
	/^SFLAGS =/s#=.#=$SFLAGS#
	/^LDFLAGS =/s#=.#=$LDFLAGS#
	/^LDSHARED =/s#=.#=$LDSHARED#
	/^CPP =/s#=.#=$CPP#
	/^STATICLIB =/s#=.#=$STATICLIB#
	/^SHAREDLIB =/s#=.#=$SHAREDLIB#
	/^SHAREDLIBV =/s#=.#=$SHAREDLIBV#
	/^SHAREDLIBM =/s#=.#=$SHAREDLIBM#
	/^AR =/s#=.#=$AR_RC#
	/^RANLIB =/s#=.#=$RANLIB#
	/^LDCONFIG =/s#=.#=$LDCONFIG#
	/^LDSHAREDLIBC =/s#=.#=$LDSHAREDLIBC#
	/^EXE =/s#=.#=$EXE#
	/^prefix =/s#=.#=$prefix#
	/^exec_prefix =/s#=.#=$exec_prefix#
	/^libdir =/s#=.#=$libdir#
	/^includedir =/s#=.#=$includedir#
	/^mandir =/s#=.#=$mandir#
	/^all: /s#:.#: $ALL#
	/^test: /s#:.#: $TEST#
	" > Makefile

	sed < zlib.pc.in "
	/^CC =/s#=.#=$CC#
	/^CFLAGS =/s#=.#=$CFLAGS#
	/^CPP =/s#=.#=$CPP#
	/^LDSHARED =/s#=.#=$LDSHARED#
	/^STATICLIB =/s#=.#=$STATICLIB#
	/^SHAREDLIB =/s#=.#=$SHAREDLIB#
	/^SHAREDLIBV =/s#=.#=$SHAREDLIBV#
	/^SHAREDLIBM =/s#=.#=$SHAREDLIBM#
	/^AR =/s#=.#=$AR_RC#
	/^RANLIB =/s#=.#=$RANLIB#
	/^EXE =/s#=.#=$EXE#
	/^prefix =/s#=.#=$prefix#
	/^exec_prefix =/s#=.#=$exec_prefix#
	/^libdir =/s#=.#=$libdir#
	/^includedir =/s#=.#=$includedir#
	/^mandir =/s#=.#=$mandir#
	/^LDFLAGS =/s#=.#=$LDFLAGS#
	" \| sed -e "
	s/\@VERSION\@/$VER/g;
	" > zlib.pc