From 936cca97dc46219cca23e91ea9411eec359432cf Mon Sep 17 00:00:00 2001
From: Iain Patterson <me@iain.cx>
Date: Tue, 2 Feb 2016 10:59:11 +0000
Subject: [PATCH] Set PROMPT_DIRTRIM dynamically.

Unless PROMPT_DIRTRIM is explicitly set to 0, force trimming if the
length of the prompt is guesstimated to be more than 2/3 of the
available terminal width.
---
 .profile.d/ps1.bashrc | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/.profile.d/ps1.bashrc b/.profile.d/ps1.bashrc
index 0283611..0667d0f 100644
--- a/.profile.d/ps1.bashrc
+++ b/.profile.d/ps1.bashrc
@@ -201,11 +201,24 @@ function __ps1_colon() {
 
 function __ps1_short() {
   local dirtrim=${PROMPT_DIRTRIM//[^0-9]/}
-  dirtrim=${dirtrim##0}
-  if [ -z "$dirtrim" ]; then
+
+  if [ "${dirtrim:0:1}" = "0" ]; then
     echo "$PWD"
     return $1
   fi
+
+  dirtrim=${dirtrim##0}
+  if [ -z "$dirtrim" ]; then
+    local prompt="$USER$HOSTNAME$PWD"
+    local width=$(((COLUMNS*2)/3))
+    if [ ${#prompt} -le ${width:-53} ]; then
+      echo "$PWD"
+      return $1
+    else
+      dirtrim=1
+    fi
+  fi
+
   local dirname=${PWD##*/}
   local basename=${PWD%/$dirname}
   local reversed=
@@ -223,6 +236,7 @@ function __ps1_short() {
     fi
     n=$((n+1))
   done
+
   echo "$short/$dirname"
   return $1
 }
-- 
2.20.1