bash: restructured bashrc and bash_profile so they won't cause problems with scp

.bash_profile

@@ -14,13 +14,16 @@ for file in ~/.environment.d/*.env; do
 done
 set +a
 
-# Source the .bashrc if the Filedescriptor for stdin is opened. This is a very
+unset -v file
+
+# Source the .bashrc if the file descriptor for stdin is opened. This is a very
 # simple test to determine if the .bash_profile was sourced from VT or SSH-login
 # where the .bashrc has to be sourced to provide a similar environment to a
 # terminal emulator. Found here:
 # https://eklitzke.org/effectively-using-bash-profile
-if [[ -t 0 && -r ~/.bashrc ]]; then
+# I had to move the actual test '-t 0' over to the bashrc. More information as
+# to why can be found there.
+if [[ -r ~/.bashrc ]]; then
   . ~/.bashrc
 fi
 
-unset -v file

.bashrc

@@ -1,4 +1,14 @@
 # .bashrc
+# Don't load the bashrc if the terminal is not interactive. More information
+# on how this test works can be found at the end of the bash_profile. I had to
+# move this test here, because in remote shells the bashrc is sourced directly,
+# wether the shell is really interactive or not. A brief explanation of this
+# behaviour can be found here:
+# https://unix.stackexchange.com/questions/257571
+if ! [[ -t 0 ]]; then
+  return 0
+fi
+
 # Source global definitions
 if [[ -r /etc/bashrc ]]; then
   . /etc/bashrc
@@ -6,52 +16,53 @@ fi
 
 # Bash 4 or bust
 if (( BASH_VERSINFO[0] < 4 )); then
-  echo "Please get a newer version of Bash."
-  echo "Your bashrc won't work otherwise."
-else
-
-  # Basic safe boolean evaluation. See this Gist for details:
-  # https://gist.github.com/gliech/184dc7566821442202f21dfe15e2b7ff
-  function truthy {
-    if [[ "${1,,}" == @(y|yes|on|true|1) ]]; then
-      return 0
-    fi
-    return 1
-  }
-
-  function falsy {
-    if [[ "${1,,}" == @(n|no|off|false|0) ]]; then
-      return 0
-    fi
-    return 1
-  }
-
-  function true_false_default {
-    case "${1,,}" in
-      y | yes | on | true | 1)
-        return 0 ;;
-      n | no | off | false | 0)
-        return 1 ;;
-    esac
-    shift
-    eval "$@"
-    return 1
-  }
-
-  export -f truthy falsy true_false_default
-
-  if truthy $DOTFILES_ACTIVE; then
-
-    # Source .bashrc.d
-    for file in ~/.bashrc.d/*.sh; do
-      . "$file"
-    done
-
-    unset -v file
-
-  elif [[ ! -v DOTFILES_ACTIVE ]]; then
-    echo "Dotfiles environment not found."
-    echo "You should probably reload your login session before proceeding."
-  fi
+  echo "Please get a newer version of Bash." >&2
+  echo "Your bashrc won't work otherwise." >&2
+  return 1
+fi
+
+# Basic safe boolean evaluation. See this Gist for details:
+# https://gist.github.com/gliech/184dc7566821442202f21dfe15e2b7ff
+function truthy {
+  if [[ "${1,,}" == @(y|yes|on|true|1) ]]; then
+    return 0
+  fi
+  return 1
+}
+
+function falsy {
+  if [[ "${1,,}" == @(n|no|off|false|0) ]]; then
+    return 0
+  fi
+  return 1
+}
+
+function true_false_default {
+  case "${1,,}" in
+    y | yes | on | true | 1)
+      return 0 ;;
+    n | no | off | false | 0)
+      return 1 ;;
+  esac
+  shift
+  eval "$@"
+  return 1
+}
+
+export -f truthy falsy true_false_default
+
+if truthy $DOTFILES_ACTIVE; then
+
+  # Source .bashrc.d
+  for file in ~/.bashrc.d/*.sh; do
+    . "$file"
+  done
+
+  unset -v file
+
+elif [[ ! -v DOTFILES_ACTIVE ]]; then
+  echo "Dotfiles environment not found." >&2
+  echo "You should probably reload your login session before proceeding." >&2
+  return 1
 fi