abs_dirname is similar to dirname but prints the directory name in the absolute path.

abs_dirname.sh

#! /bin/sh

# Prints the absolute path to the directory containing the given path.
# The directory must exist.
abs_dirname() {(
  cd "`dirname \"$1\"`" && pwd
)}

# Examples

mkdir tmp_ABC

dirname /usr/bin/
abs_dirname /usr/bin/

dirname .
abs_dirname .

dirname ../1
abs_dirname ../1

dirname ./tmp_ABC/1
abs_dirname ./tmp_ABC/1

rmdir tmp_ABC