[bash] Silence error output if programs are missing

bash_aliases

@@ -49,7 +49,7 @@ alias gsr="git svn rebase"
 alias gsp="git svn dcommit"
 alias gsu="git submodule update --init --recursive"
 alias gi="git config branch.master.remote 'origin'; git config branch.master.merge 'refs/heads/master'"
-if [ `which hub` ]; then
+if [ `which hub 2> /dev/null` ]; then
   alias git="hub"
 fi
 

bashrc

@@ -90,7 +90,7 @@ function parse_git_branch {
   git branch --no-color 2> /dev/null | sed -e '/^[^*]/d' -e "s/* \(.*\)/\(\1$(parse_git_dirty)\)/"
 }
 
-if [ `which git` ]; then
+if [ `which git 2> /dev/null` ]; then
   function git_prompt {
     parse_git_branch
   }
@@ -100,7 +100,7 @@ else
   }
 fi
 
-if [ `which rvm-prompt` ]; then
+if [ `which rvm-prompt 2> /dev/null` ]; then
   function rvm_prompt {
     echo "($(rvm-prompt v g))"
   }