verGo

Introduction

verGo.sh provides a much more sophisticated method to find preferred versions of various applications than trying to manage PATH variables or shell aliases. verGo.sh is driven by a configuration file with each application being individually configured:

• Each application has it’s own search path. This allows one to use the same configuration file across systems with the applications installed in different locations.
• Configuration lines can be selected based on logical conditions. For example, a line might only be active on a particular version of an operating system or when being run from a particular terminal.
• Applications may be wrapped in ”rlwrap” or ”winpty” if desired.
• Each application can have runtime shell environment variables defined.

Common Useage Patterns

verGo.sh is normally used in one of four ways:

1. Create a link to verGo.sh. The name of the link will be used as the “application” name This allows us to create a personal “bin” directory containing links to verGo.sh specifying various applications we use.
2. Run verGo.sh with the -app argument to specify the application name.
3. Run verGo.sh with the application name after any verGo.sh options. On Linux, this mode can be used for SHBANG lines:
   #!/home/richmit/bin/verGo.sh ruby
4. On some platforms (BSDs for example) SHBANG lines require a binary, so you can use verGo.sh this way:
   #!/bin/bash /home/richmit/bin/ruby

Command Line Options

-noRun ................... Don't actually run the application
-app APP_NAME ............ Name of the application to run
-noWrap .................. Enable or disable rlwrap & winpty
-prtCmd .................. Print the command we find
-prtVar .................. Print the variables for the command we find
                           Each variable is printed on a separate line
                           If -prtCmd & -prtVar are both provided, the command is printed first
-prtFmt <UNIX|WIN|DOS> ... Print format for -prtCmd
-noErrors ................ Don't print errors -- still, exit, just don't print anything
-rcfile <FILE> ........... Use this RC file instead of ~/.verGoRC
-debug ................... Enable debugging

Exit Codes

• 7 ERROR: Invalid value for -prtFmt
• 6 ERROR: No application name provided!
• 5 ERROR: rcfile not found!
• 4 ERROR: Duplicate app found in rcfile
• 3 ERROR: Application not supported
• 2 ERROR: Application supported, but no executable found
• 1 ERROR: Application supported, executable found, failed to exec
• 0 Application found in -noRun mode

Recipies

• To just see if verGo.sh knows about an application: Use the -app and -noRun options.
• To just print the command binary that would be executed: Use the -app, -noRun, and -prtCmd options.

Configuration file

The default configuration file is ~/.verGoRC. This may be overridden via the -rcfile option. A simple line oriented format is used with each line looking like:
[BOOLEAN_EXPR ::: ] APP_NAME [-r HIST_NAME|-w] [VARIABLES] == ALTERNATIVES= Syntax rules:

• The APP_NAME is the name of the application and may not contain whitespace
• When present, the HIST_NAME, must not contain whitespace
• VARIABLES is a space separated list of variable definitions of the form FOO=BAR – may be single quoted
  • Example: PATH=/usr/bin 'HOMER_RANGE=/a/path with/spaces in it/'
• ALTERNATIVES is a space separated list of fully qualified path component or APP_NAME values – may be single quoted
  • Example: /a/path '/path/with spaces/foo.exe' anAppName /another/path
• Note the whitespace in front of and after both operators (”:::” and ”===”)!
• BOOLEAN_EXPR is a shell boolean expression – something that can be placed between square brackets
  • Variables available for use in this expression include:
    • HOSTNAME ........... Hostname
    • OSTYPE ............. OS family name (msys for MSYS2,
    • MACHTYPE ........... Bash built-in for machine hardware type
    • HOME ............... Usually set to the user home directory (some systems don’t set this)
    • PATH ............... The system path
    • MJR_LOC ............ Location of system as defined by the existence of a file like ~/mjrLOC-NAME
  • Examples
    • "$HOSTNAME" == 'foobar'
    • "$OSTYPE" == 'msys' -a "$MACHTYPE" == 'x86_64'
    • "$TERM" != 'dumb'