Index: configure
@@ -1,11 +1,11 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 CONFIG="config.mk"
 PREFIX="/usr/local"
 
 DEBUG=
 LIQSRCDIR=./lib
-LIQCONFIGURE=(--quiet)
+LIQCONFIGURE=--quiet
 SSE=auto
 OPENMP=
 LIBPNG_DIR=.
@@ -35,7 +35,7 @@
         help "--with-libimagequant=<dir>    external libimagequant (lib/ default)"
         help "--with-openmp=static          compile with multicore support"
         help "--with-lcms2/--without-lcms2  compile with color profile support"
-if [[ "$OSTYPE" =~ "darwin" ]]; then
+if echo "$OSTYPE" | grep -q "darwin"; then
         help "--with-cocoa/--without-cocoa  use Cocoa framework to read images"
 fi
         help "--with-libpng=<dir>           search for libpng in directory"
@@ -50,35 +50,35 @@
     CC=*)
         CC=${i#*=}
         SKIP_CC_CHECK=1
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     CFLAGS=*)
         CFLAGS=${i#*=}
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     LDFLAGS=*)
         LDFLAGS=${i#*=}
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --enable-debug)
         DEBUG=1
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --enable-sse)
         SSE=1
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --disable-sse)
         SSE=0
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --with-openmp)
         OPENMP=1
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --with-openmp=static)
         OPENMP=static
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --with-lcms2)
         LCMS2=1
@@ -103,16 +103,16 @@
         ;;
     --prefix=*)
         PREFIX=${i#*=}
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     # can be used multiple times or in quotes to set multiple flags
     --extra-cflags=*)
         EXTRA_CFLAGS="$EXTRA_CFLAGS ${i#*=}"
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     --extra-ldflags=*)
         EXTRA_LDFLAGS="$EXTRA_LDFLAGS ${i#*=}"
-        LIQCONFIGURE+=("$i")
+        LIQCONFIGURE="$LIQCONFIGURE $i"
         ;;
     *)
         echo "warning: unknown switch ${i%%=*} (see $0 --help for the list)"
@@ -122,7 +122,7 @@
 
 # If someone runs sudo make install as very first command, and configure later,
 # $CONFIG cannot be overwritten, and must be deleted before continuing.
-if [[ -f "$CONFIG" && ! -w "$CONFIG" ]]; then
+if [ -f "$CONFIG" -a ! -w "$CONFIG" ]; then
     echo "Cannot overwrite file $CONFIG! Please delete it."
     exit 1
 fi
@@ -160,7 +160,7 @@
 find_pkgconfig() {
     local LIBNAME=$1
     PKG_CONFIG=${PKG_CONFIG:-pkg-config}
-    if $PKG_CONFIG --exists "$LIBNAME" &> /dev/null; then
+    if $PKG_CONFIG --exists "$LIBNAME" > /dev/null; then
         cflags "$($PKG_CONFIG --cflags "$LIBNAME")"
         lflags "$($PKG_CONFIG --libs "$LIBNAME")"
         LIBRARY_FOUND_VERSION=$($PKG_CONFIG --modversion "$LIBNAME")
@@ -244,9 +244,13 @@
         return 0
     fi
 
-    for i in "${DIRS[@]}"; do
-        DIR=($i)
-        if find_dynamic "$LIBNAME" "$HEADERPATTERN" "$DYNAMICPATTERN" "${DIR[0]}" "${DIR[1]}"; then
+    # destroys positional parameters
+    set -- ${DIRS}
+    while [ -n "$1" -a -n "$2" ]; do
+        DIRS_h="$1"
+        DIRS_l="$2"
+        shift 2
+        if find_dynamic "$LIBNAME" "$HEADERPATTERN" "$DYNAMICPATTERN" "${DIRS_h}" "${DIRS_l}"; then
             return 0
         fi
     done
@@ -303,12 +307,8 @@
 # SSE
 if [ "$SSE" = 'auto' ]; then
     SSE=0
-    if type uname > /dev/null; then
-        if [[ "$(uname -m)" =~ "amd64" || "$(uname -m)" =~ "x86_64" ||
-              "$(grep -E -m1 "^flags" /proc/cpuinfo)" =~ "sse" ]]; then
-            SSE=1
-        fi
-    fi
+    echo $(uname -m) | grep -E -q '(amd|x86_)64' && SSE=1
+    grep -E -m1 -q '^flags.*sse' /proc/cpuinfo 2>/dev/null && SSE=1
 fi
 
 if [ "$SSE" -eq 1 ]; then
@@ -331,9 +331,8 @@
     else
         OPENMPFLAGS="-fopenmp"
     fi
-    if [[ "$("$CC" -xc -E $OPENMPFLAGS <(echo "#ifdef _OPENMP
-           #include <omp.h>
-           #endif") 2>&1)" =~ "omp_get_thread_num" ]]; then
+    if echo "$(printf '#ifdef _OPENMP\n#include <omp.h>\n#endif\n' | \
+        "$CC" -xc -E $OPENMPFLAGS - 2>&1)" | grep -q omp_get_thread_num; then
         cflags "$OPENMPFLAGS"
         lflags "$OPENMPFLAGS"
         status "OpenMP" "yes"
@@ -348,7 +347,7 @@
 fi
 
 # Cocoa
-if [[ "$OSTYPE" =~ "darwin" ]]; then
+if echo "$OSTYPE" | grep -q "darwin"; then
     if [ -z "${MACOSX_DEPLOYMENT_TARGET+isset}" ]; then
         cflags "-mmacosx-version-min=10.9"
         lflags "-mmacosx-version-min=10.9"
@@ -356,32 +355,29 @@
 fi
 
 # pairs of possible *.h and lib*.so locations
-DIRS=()
+DIRS=
 
 if command -v >/dev/null libpng-config; then
-    DIRS+=("$(libpng-config --prefix) $(libpng-config --libdir)")
+    DIRS="$(libpng-config --prefix) $(libpng-config --libdir)"
 fi
 
-if [ -n $"LIQSRCDIR" ]; then
-    DIRS+=("$LIQSRCDIR" "$LIQSRCDIR") # local libimagequant
+if [ -n "$LIQSRCDIR" ]; then
+    DIRS="$DIRS $LIQSRCDIR $LIQSRCDIR" # local libimagequant
 fi
 
-DIRS+=(
-      "/usr/local/include /usr/local/lib"
-      "/usr/include /usr/lib64"
-      "/usr/include /usr/lib"
-      "/opt/local/include /opt/local/lib" # macports
-      )
+DIRS="$DIRS /usr/local/include /usr/local/lib \
+      /usr/include /usr/lib \
+      /opt/local/include /opt/local/lib" # macports
 
-if [[ "$OSTYPE" =~ "darwin" ]]; then
+if echo "$OSTYPE" | grep -q "darwin" ; then
     SOLIBSUFFIX=dylib
 
     # Search Developer SDK paths, since Apple seems to have dropped the standard Unixy ones
     XCODE_CMD="xcode-select"
     XCODE_PATH=$($XCODE_CMD -p)
-    DIRS+=("$XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include $XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib")
-    DIRS+=("$XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include $XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib")
-elif [[ "$OSTYPE" =~ "msys" ]]; then
+    DIRS="$DIRS $XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include $XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib"
+    DIRS="$DIRS $XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include $XCODE_PATH/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib"
+elif echo "$OSTYPE" | grep -q "msys" ; then
     SOLIBSUFFIX=dll
 else
     SOLIBSUFFIX=so
@@ -422,7 +418,7 @@
 if echo "#include \"png.h\"
     int main(){
     return !png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-}" | "$CC" -xc -std=c99 -o /dev/null $CFLAGS $LDFLAGS - &> /dev/null; then
+}" | "$CC" -xc -std=c99 -o /dev/null $CFLAGS $LDFLAGS - >/dev/null 2>&1; then
     status "libpng" "custom flags"
     HAS_LIBPNG=1
 fi
@@ -433,7 +429,7 @@
     if [ -n "$PNGH" ]; then
         PNGH_STRING=$(pngh_string "$PNGH")
         PNGH_MAJMIN=$(pngh_majmin "$PNGH")
-        if [[ -n "$PNGH_STRING" && -n "$PNGH_MAJMIN" ]]; then
+        if [ -n "$PNGH_STRING" -a -n "$PNGH_MAJMIN" ]; then
             LIBPNGA=$(find_f "$LIBPNG_DIR" "libpng${PNGH_MAJMIN}.a")
             if [ -z "$LIBPNGA" ]; then
                 LIBPNGA=$(find_f "$LIBPNG_DIR" "libpng.a")
@@ -452,14 +448,19 @@
     if find_pkgconfig libpng; then
         HAS_LIBPNG=1
     else
-        for i in "${DIRS[@]}"; do
-            DIR=($i)
-            PNGH=$(find_h "${DIR[0]}" "png.h")
+        # destroys positional parameters
+        set -- ${DIRS}
+        while [ -n "$1" -a -n "$2" ]; do
+            DIRS_h="$1"
+            DIRS_l="$2"
+            shift 2
+
+            PNGH=$(find_h "${DIRS_h}" "png.h")
             if [ -n "$PNGH" ]; then
                 PNGH_STRING=$(pngh_string "$PNGH")
                 PNGH_MAJMIN=$(pngh_majmin "$PNGH")
-                if [[ -n "$PNGH_STRING" && -n "$PNGH_MAJMIN" ]]; then
-                    LIBPNGSO=$(find_f "${DIR[1]}" "libpng${PNGH_MAJMIN}.$SOLIBSUFFIX*")
+                if [ -n "$PNGH_STRING" -a -n "$PNGH_MAJMIN" ]; then
+                    LIBPNGSO=$(find_f "${DIRS_l}" "libpng${PNGH_MAJMIN}.$SOLIBSUFFIX*")
                     if [ -n "$LIBPNGSO" ]; then
                         cflags "-I${PNGH%/*}"
                         lflags "-L${LIBPNGSO%/*} -lpng${PNGH_MAJMIN}"
@@ -473,7 +474,7 @@
     fi
 fi
 if [ "$HAS_LIBPNG" -eq 0 ]; then
-    if [[ "$OSTYPE" =~ "darwin" ]]; then
+    if echo "$OSTYPE" | grep -q "darwin"; then
         LIBPNG_CMD='`brew install libpng`'
     else
         LIBPNG_CMD='`apt-get install libpng16-dev` or `apt-get install libpng-dev` or `yum install libpng-devel`'
@@ -542,6 +543,6 @@
 SOLIBSUFFIX = $SOLIBSUFFIX
 STATICLIBDEPS = $STATICLIBDEPS
 LIQSRCDIR = $LIQSRCDIR
-LIQCONFIGUREFLAGS = $(printf "'%s' " "${LIQCONFIGURE[@]}")
+LIQCONFIGUREFLAGS = "$LIQCONFIGURE"
 " > "$CONFIG"