Pipewrench

General purpose command line pipe processing tool.

Installation

$ gem install pipewrench

Usage

Usage: pipewrench [options] expression [file ...]
    -c, --compact                    Remove nil lines from output
    -m, --map                        Run each line through the expression
    -r, --rails                      Load Active Support Core Extensions
    -s, --strip                      Strip trailing whitespace from each line before running
    -h, --help                       Show this message
        --version                    Show version

Pipewrench evaluates the given expression against the specified files (or standard input if no files are given). This allows you to write powerful ruby expressions as part of your pipeline.

Here are some examples:

# Given a list of integers, add them up
$ seq 1 10 | pipewrench 'map(&:to_i).inject(:+)'
55

# Extract regex from matching lines
$ echo "My Cat" >> pipewrench.txt
$ echo "His Dog" >> pipewrench.txt
$ echo "Her Fish" >> pipewrench.txt
$ echo "My Frog" >> pipewrench.txt
$ pipewrench 'grep(/^My (\w+)/) {$1}' pipewrench.txt
Cat
Frog

# Or, from standard in
$ cat pipewrench.txt | pipewrench 'grep(/^My (\w+)/) {$1}'
Cat
Frog

-m, --map

Evaluate the expression for each line of input.

# Convert input to upper case
$ pipewrench -m upcase pipewrench.txt
MY CAT
HIS DOG
HER FISH
MY FROG

-c, --compact

Remove nils from the output. This is primarily useful in conjunction with --map but can be used on its own as well.

# Only show lines less than 5
$ seq 1 10 | pipewrench -c -m 'self if to_i < 5'
1
2
3
4

-r, --rails

Load Active Support Core Extensions. This gives you access to rails helper methods.

# Convert numbers to human readable sizes
$ echo 100000000 | pipewrench -mr 'to_i.to_s(:human_size)'
95.4 MB

-s, --strip

Remove trailing whitespace from each line before evaluating the expression.

# Join a list of numbers as a comma separated list
$ seq 1 10 | pipewrench -s 'join(", ")'
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Development

After checking out the repo, run rake rspec to run the tests.

To install this gem onto your local machine, run bundle exec rake install.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/sionide21/pipewrench.