Grepping lines with multiple matches

I want to filter log files by matching lines that contains all of  set of matches (I don’t want to alternate them).

For example lines like:

RawURL /1.2/user/authorize?ip=10.254.142.175&method=GET

I want to match lines that contain the terms “RawURL” and “/1.2/user/authorize?” without resorting to piping multiple greps:

$ grep RawURL | grep /1.2/user/authorize? *.txt

This means I want a regexp like:

RawURL.+\/1.2\/user\/authorize

Translating to grep extended regex, this becomes:

$ grep -E RawURL.+/1.2/user/authorize *.txt

Note: There is no need to enforce non-greedy matching.

Regular expressions, character classes and special characters

The expression:

RawURL.+\/1.2\/user\/authorize

Is not equivalent to:

RawURL[.]+\/1.2\/user\/authorize

Because in the second one, the special character ‘.’ is no longer special. Character classes have all special characters turned off.

Rake — shell task failure

For my current project, we’re running cucumber as one of our tasks. Our report generation runs afterwards — which we need to happen regardless of cucumber’s exit code (cucumber exits with code 1 when any tests fail).

Handling shell task failure

We noticed that if cucumber fails, rake exits immediately — without running our subsequent report tasks.

We’re running cucumber with rake’s ruby function — which runs the ruby interpreter in its own process by invoking a shell command.

Pseudo-stacktrace (irrelevant source lines omitted):

Shell::CommandProcessor.system(command, *opts)
Rake::Win32.rake_system(*cmd)
FileUtils.sh(*args, &block)
FileUtils.ruby(*args, &block)

The key to this is the behaviour of rake’s FileUtils.sh. Examining the source shows:

If it is not supplied a block, and the shell command fails, and rake exits with error status.

Aside: For some reason, Kernel.system echoes errors.

Example

This task will cause rake to exit immediately with status 1:

task 'this-one-fails' do
    ruby("xxx")
end

while the following task does not cause rake to terminate  normally, any subsequent task will still run:

path = File.expand_path(File.dirname(__FILE__) + ‘/output/cucumber-manual.txt’)

cuke_path = ‘C:/ruby/lib/ruby/gems/1.8/gems/cucumber-0.3.3/bin/cucumber’

ruby(“#{cuke_path} -h > ‘#{path}’”) do |success, exit_code|

puts “Exited with code: #{exit_code}” if !success

end

task 'this-one-succeeds' do
    ruby("xxx") do |success, exit_code|
        puts "Exited with code: #{exit_code.exitstatus}" unless success
    end
end

Getting the last exit status

The $? variable contains the status of the last child process to terminate. This may be useful if steps subsequent to the failed one require this information.