Add the libcurl check to the m4 archive.

svn path=/trunk/m4/; revision=5149

m4/xiph_curl.m4

@@ -0,0 +1,63 @@
+dnl XIPH_PATH_CURL([ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
+dnl Test for libcurl, and define CURL_CFLAGS and CURL_LIBS
+dnl
+AC_DEFUN(XIPH_PATH_CURL,
+[dnl 
+dnl Get the cflags and libraries
+dnl
+AC_ARG_WITH(curl,
+    AC_HELP_STRING([--with-curl=PFX],[Prefix where libcurl is installed (optional)]),
+    curl_prefix="$withval", curl_prefix="")
+AC_ARG_WITH(curl-config,
+    AC_HELP_STRING([--with-curl-config=curl-config],[Use curl-config to find libcurl]),
+    CURL_CONFIG="$withval", [AC_PATH_PROGS(CURL_CONFIG, [curl-config], "")])
+
+if test "x$curl_prefix" != "x"; then
+    CURL_LIBS="-L$curl_prefix/lib -lcurl"
+    CURL_CFLAGS="-I$curl_prefix/include"
+elif test "x$CURL_CONFIG" != "x"; then
+    if ! test -x "$CURL_CONFIG"; then
+        AC_MSG_ERROR([$CURL_CONFIG cannot be executed])
+    fi
+    CURL_LIBS="$($CURL_CONFIG --libs)"
+    CURL_CFLAGS="$($CURL_CONFIG --cflags)"
+else
+    if test "x$prefix" != "xNONE"; then
+        CURL_LIBS="-L$prefix/lib"
+        CURL_CFLAGS="-I$prefix/include"
+    fi
+    CURL_LIBS="$CURL_LIBS -lcurl"
+fi
+
+curl_ok="yes"
+
+ac_curl_CFLAGS="$CFLAGS"
+ac_curl_LIBS="$LIBS"
+CFLAGS="$CFLAGS $CURL_CFLAGS"
+LIBS="$LIBS $CURL_LIBS"
+dnl
+dnl Now check if the installed libcurl is sufficiently new.
+dnl
+AC_CHECK_HEADERS([curl/curl.h],, curl_ok="no") 
+AC_MSG_CHECKING(for libcurl)
+if test "$curl_ok" = "yes"; then
+    AC_TRY_RUN([
+#include <curl/curl.h>
+int main()
+{
+    return 0;
+}
+],,[curl_ok="no"])
+fi
+CFLAGS="$ac_curl_CFLAGS"
+LIBS="$ac_curl_LIBS"
+
+if test "$curl_ok" = "yes"; then
+    AC_MSG_RESULT(yes)
+    AC_DEFINE(HAVE_CURL, 1, [Define if you have libcurl.])
+    ifelse([$1], , :, [$1])     
+else
+    AC_MSG_RESULT(no)
+    ifelse([$2], , :, [$2])
+fi
+])