Along with Grails we are seeing a resurgence of the shell and the command line. And if there is anything experienced unix users hate, it’s asking a newbie how their environment is configured and getting a blank stare in return. Well I solved this problem years ago with a simple shell script — it’s time to resurrect printconfig. A call to printconfig shows the path and a subset of the shell’s environment variables. For example:

yaal.local[525]> printconfig
HOME		/Users/amiller
ANT_HOME	/Users/amiller/devtools/ant/current -> ant-1.7.1
CATALINA_HOME	/Users/amiller/devtools/tomcat/current -> tomcat-6.0.16
EMACS_HOME	/Users/amiller/devtools/emacs/carbon-emacs-22.3.1_2009.07.25.app
GRAILS_HOME	/Users/amiller/devtools/grails/current -> grails-1.2.0
GROOVY_HOME	/Users/amiller/devtools/groovy/current -> groovy-1.6.7
IVY_HOME	/Users/amiller/devtools/ivy/current -> ivy-2.1.0
JAVA_HOME	/Users/amiller/devtools/jdk/current -> jdk-1.6.0
JBOSS_HOME	/Users/amiller/devtools/jboss-4.0.5
MAVEN_HOME	/Users/amiller/devtools/maven/current -> maven-2.0.9
TOMCAT_HOME	/Users/amiller/devtools/tomcat/current -> tomcat-6.0.16
ANT_OPTS	-Xmx128m
JAVA_OPTS	-Xmx512m
MAVEN_OPTS	-Xmx2100m -Xms512m
PATH=.
     /Users/amiller/bin
     /Users/amiller/devtools/ant/current/bin
     /Users/amiller/devtools/emacs/carbon-emacs-22.3.1_2009.07.25.app/bin
     /Users/amiller/devtools/grails/current/bin
     /Users/amiller/devtools/groovy/current/bin
     /Users/amiller/devtools/jdk/current/bin
  ...

(See my post on Fast path switching between projects for an explanation of the “current” path elements.)

Call printconfig from the last line in your .profile and your new user shells will always show the environment as it is configured. Try it next time you’re debugging a shell’s environment and let me know what you think.

The printconfig script:

#!/bin/sh
#
# Echo some config info at shell startup time
# (useful when debugging the shell environment.)
#
# Preserve the intentionally HARD_TABS when editing!
#
echo "HOME		$HOME"

for home_var in `printenv | grep _HOME | sort`; do
    home_var_name=`echo $home_var | awk -F= '{ print $1 }'`
    home_var_value=`echo $home_var | awk -F= '{ print $2 }'`
    if [ -h $home_var_value ]; then
        # echo out what symbolic links are pointing to...
        echo "$home_var_name	`ls -l $home_var_value | awk '{ printf "%s -> %sn", $9, $11 }'`"
        #                   ^ hard tab
    else
        echo "$home_var_name	$home_var_value"
        #                   ^ hard tab
    fi
done

printenv | grep _OPTS | sort | sed 's/=/	/'
#                                       ^ hard tab

echo "PATH=$PATH" | sed 's/:/
     /g'