How deeply does The Well-Grounded Rubyist, Fourth Edition cover Dir.glob?

Explains syntax, aliases, wildcard and recursive matching, hidden-entry behavior, and a compact aggregation example.

Dir.glob

As explained in The Well-Grounded Rubyist, Fourth Edition

Dir.[] is Ruby's index-style directory globbing method for returning pathnames matching a glob pattern.

Dir.glob returns pathnames matching a glob pattern. Its index-style spelling, Dir[pattern], is equivalent to calling Dir.glob(pattern). section 12.4.1

Match header files

Dir["/Users/dblack/Devel/ruby-4.0.1/include/ruby/r*.h"] returns the matching header pathnames, such as ractor.h, random.h, and ruby.h. section 12.4.1

Use directory globbing when you need:

Wildcard matching, such as Dir["*info*"], rather than every directory entry. section 12.4.1
Recursive matching in subdirectories. section 12.4.1
A compact replacement for collecting entries, joining full paths, filtering regular files, and summing their sizes. section 12.4.1

Sum matching regular files

dir = "/Users/dblack/Devel/ruby-4.0.1/lib/net" entries = Dir["#{dir}/*"].select { |entry| File.file?(entry) } puts entries.inject(0) { |total, entry| total + File.size(entry) } section 12.4.1

Unlike Dir.entries, globbing omits hidden entries by default, including names beginning with a period on UNIX-like systems. A matching flag can include them: my_directory.glob("*info*", File::FNM_DOTMATCH). section 12.4.1

How The Well-Grounded Rubyist, Fourth Edition covers it

Cover of The Well-Grounded Rubyist, Fourth Edition

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Related concepts

classkind of · A class is a programming-language construct that defines a type’s structure or behavior and provides a basis for creating or representing objects.
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file pathuses · A file path is a textual or structured identifier specifying the location of a file or directory in a filesystem.
continuous improvementuses · Continuous improvement is an ongoing process of evaluating outcomes and making successive changes to improve a system, process, or result.

This explainer was generated by Manning's knowledge graph from the text of The Well-Grounded Rubyist, Fourth Edition. The section links point to the parts of the book it draws on.