replace $() with backticks

$() does not work with heredoc's in bash 4.0

docs/examples/core/ipython-completion.bash

@@ -1,106 +1,106 b''
 # load with: . ipython-completion.bash
 
 _ipython_get_flags()
 {
     local url=$1
     local var=$2
     local dash=$3
     if [[ "$url $var" == $__ipython_complete_last ]]; then
         opts=$__ipython_complete_last_res
         return
     fi
     # pylab and profile don't need the = and the
     # version without simplifies the special cased completion
     opts=$(ipython ${url} --help-all | grep -E "^-{1,2}[^-]" | sed -e "s/<.*//" -e "s/[^=]$/& /" -e "s/^--pylab=$//" -e "s/^--profile=$/--profile /")
     __ipython_complete_last="$url $var"
     __ipython_complete_last_res="$opts"
 }
 
 _ipython()
 {
     local cur=${COMP_WORDS[COMP_CWORD]}
     local prev=${COMP_WORDS[COMP_CWORD - 1]}
     local subcommands="notebook qtconsole console kernel profile locate"
     local opts=""
     if [ -z "$__ipython_complete_baseopts" ]; then
         _ipython_get_flags baseopts
         __ipython_complete_baseopts="${opts}"
     fi
     local baseopts="$__ipython_complete_baseopts"
     local mode=""
     for i in "${COMP_WORDS[@]}"; do
         [ "$cur" = "$i" ] && break
         if [[ ${subcommands} == *${i}* ]]; then
             mode="$i"
             break
         elif [[ ${i} == "--"* ]]; then
             mode="nosubcommand"
             break
         fi
     done
 
     if [[ $mode == "profile" ]]; then
         opts="list create"
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
     elif [[ ${cur} == -* ]]; then
         if [[ $mode == "notebook" ]]; then
             _ipython_get_flags notebook
             opts=$"${opts} ${baseopts}"
         elif [[ $mode == "qtconsole" ]]; then
             _ipython_get_flags qtconsole
             opts="${opts} ${baseopts}"
         elif [[ $mode == "console" ]]; then
             _ipython_get_flags console
         elif [[ $mode == "kernel" ]]; then
             _ipython_get_flags kernel
             opts="${opts} ${baseopts}"
         elif [[ $mode == "locate" ]]; then
             opts=""
         else
             opts=$baseopts
         fi
         # don't drop the trailing space
         local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
         return 0
     elif [[ ${prev} == "--pylab"* ]] || [[ ${prev} == "--gui"* ]]; then
         if [ -z "$__ipython_complete_pylab" ]; then
-            __ipython_complete_pylab=$(cat <<EOF | python -
+            __ipython_complete_pylab=`cat <<EOF | python -
 try:
     import IPython.core.shellapp as mod;
     for k in mod.InteractiveShellApp.pylab.values:
         print "%s " % k
 except:
     pass
 EOF
-        )
+        `
         fi
         local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${__ipython_complete_pylab}" -- ${cur}) )
     elif [[ ${prev} == "--profile"* ]]; then
         if [ -z  "$__ipython_complete_profiles" ]; then
-        __ipython_complete_profiles=$(cat <<EOF | python -
+        __ipython_complete_profiles=`cat <<EOF | python -
 try:
     import IPython.core.profileapp
     for k in IPython.core.profileapp.list_bundled_profiles():
         print "%s " % k
     p = IPython.core.profileapp.ProfileList()
     for k in IPython.core.profileapp.list_profiles_in(p.ipython_dir):
         print "%s " % k
 except:
     pass
 EOF
-        )
+        `
         fi
         local IFS=$'\t\n'
         COMPREPLY=( $(compgen -W "${__ipython_complete_profiles}" -- ${cur}) )
     else
         if [ -z "$mode" ]; then
             COMPREPLY=( $(compgen -f -W "${subcommands}" -- ${cur}) )
         else
             COMPREPLY=( $(compgen -f -- ${cur}) )
         fi
     fi
 
 }
 complete -o default -o nospace -F _ipython ipython