Ranger v0.1

Run commands in nested directory structures.

ranger lets you define a directory structure using a path-like string, using placeholders to indicate variables, e.g. ./data/@department/@expenses. Ranger will visit the subdirectories, associate appropriate values to @department and @expenses and run a command replacing variable names with values. You can define filters on variables or transform them in the command.

Build

To build, just run go build ranger.go. Then move the ranger executable somewhere in your PATH.

Usage

ranger [-root path] [-structure path] \
       [-filter filter] [-filter filter] \
       [-unique] [-debug] [-log] [-echo] \
       command

-help
  Show help.
-debug
  Output debug info.
-echo
  Only show commands, do not execute them.
-filter structure
  Filters acting on variables defined in structure.
  A filter is given as variable_name:glob_pattern,
  e.g. -filter @filename:*.txt. (default map[]).
-log
  Show commands while executing.
-root structure
  Path relative to which structure is evaluated.
-structure string
  Path-like string describing the directory structure being visited.
  Variables can be defined by prepending @ to a name, 
  e.g. /some/directory/@subdir/@filename.
-unique command
  Only call command once for a unique combination of arguments.

Example

Starting from /home/joe/data, visit every entry in */*, associating the name of the subdirectory to @department and the files therein to @expenses. Only visit departments ending with ENG and expense files starting with 2016 and having a .tab extension. For each file in each subdirectory matching the criteria, replace tabs with commas (using sed -e 's/\t/, /g) and save the result in /home/joe/out/, changing the extension from .tab to .csv:

ranger -root /home/joe/data \
       -structure @department/@expenses \
       -filter @department:*ENG \
       -filter @expenses:2016*.tab \
       sed -e 's/\t/, /g' @@expenses > \
       /home/joe/out/@{expenses/tab/csv}

Limitations

• Currently ranger collects all entries and then runs all commands. It should do that lazily instead.
• Variable substitution @{foo/txt/csv} currently doesn't accept regex's.
• Commands are executed serially. They could be run in parallel with a defined maximum number of processes.

##License

MIT license http://www.opensource.org/licenses/mit-license.php/

Copyright (C) 2016 Luca Antiga, Orobix Srl (www.orobix.com)