Fixed ftp behavior on Linux.

Author: rouson

install_prerequisites/build

@@ -129,7 +129,7 @@ set_default_version()
 check_prerequisites()
 {
   if [[ "$package_to_build" == "gcc" && "$version_to_build" != "trunk" ]]; then
-    gcc_fetch="ftp"
+    gcc_fetch="ftp-url"
   else
     gcc_fetch="svn"
   fi
@@ -138,14 +138,14 @@ check_prerequisites()
   # See http://stackoverflow.com/questions/1494178/how-to-define-hash-tables-in-bash
   package_download_mechanism=(
     "gcc:$gcc_fetch"
-    "wget:ftp"
+    "wget:ftp-url"
     "cmake:wget"
     "mpich:wget"
     "flex:wget"
-    "bison:wget"
+    "bison:ftp-url"
     "pkg-config:wget"
-    "make:ftp"
-    "m4:ftp"
+    "make:ftp-url"
+    "m4:ftp-url"
     "subversion:wget"
     "_unknown:0"
   )
@@ -184,7 +184,7 @@ set_url()
   if [[ $package_to_build == 'cmake' ]]; then
     major_minor="${version_to_build%.*}"
   elif [[ "$package_to_build" == "gcc" && "$version_to_build" != "trunk" ]]; then
-    gcc_url_head="http://ftpmirror.gnu.org/gcc/gcc-$version_to_build/"
+    gcc_url_head="ftp.gnu.org:/gnu/gcc/gcc-$version_to_build"
   else
     gcc_url_head="svn://gcc.gnu.org/svn/gcc/"
   fi
@@ -196,7 +196,7 @@ set_url()
     "mpich;http://www.mpich.org/static/downloads/$version_to_build/"
     "flex;http://sourceforge.net/projects/flex/files/"
     "make;ftp://ftp.gnu.org/gnu/make/"
-    "bison;http://ftp.gnu.org/gnu/bison/"
+    "bison;ftp.gnu.org:/gnu/bison/"
     "cmake;http://www.cmake.org/files/v$major_minor/"
     "subversion;http://www.eu.apache.org/dist/subversion/"
     "_unknown;0"
@@ -257,6 +257,37 @@ set_url()
 
 }
 
+ftp-url()
+{
+  ftp_mode=$1
+  url=$2
+
+  text_before_colon="${url%%:*}"
+  FTP_SERVER=$text_before_colon
+
+  text_after_colon="${url##*:}"
+  text_after_final_slash="${text_after_colon##*/}"
+  FILE_NAME=$text_after_final_slash
+
+  text_before_final_slash="${text_after_colon%/*}"
+  FILE_PATH="$text_before_final_slash"
+
+  USERNAME=anonymous
+  PASSWORD=""
+  echo "$this_script: starting anonymous download: ftp $ftp_mode $FTP_SERVER... cd $FILE_PATH... get $FILE_NAME"
+
+ftp $ftp_mode $FTP_SERVER <<Done-ftp
+user $USERNAME $PASSWORD
+cd $FILE_PATH
+passive
+binary
+get "$FILE_NAME"
+bye
+Done-ftp
+
+  echo "$this_script: finished anonymous ftp"
+}
+
 # Download pkg-config if the tar ball is not already in the present working directory
 download_if_necessary()
 {
@@ -307,7 +338,7 @@ download_if_necessary()
       fi
     elif [[ "$fetch" == "wget" ]]; then
       args=--no-check-certificate
-    elif [[ "$fetch" == "ftp" ]]; then
+    elif [[ "$fetch" == "ftp-url" ]]; then
       args=-n
     elif [[ "$fetch" == "git" ]]; then
       args=clone