msgextract

README

Email Message Header Extractor

Parse through gzipped tar archive and output the desired header information to file. Email header fields collected: Subject, From, Date.

Program Walk-Through

msgextract first unpacks the gzip-compressed file into a tar archive in a temporary directory. The MSG files in the archive are iterated through, reading the header (ignoring the potentially large body), and passing the header lines through a channel to a consumer. The consumer parses the lines into a map (key: header field name, value: header field content). This holistic map allows for arbitrary field selection, which are currently set to Subject, From, and Date. The selected fields are filtered from the map and output to file, in json or tsv format. See Suggested Improvements below for feature ideas and bugs.

Installation

• Install Go
• go get -u github.com/asgaines/msgextract/...

Usage

• msgextract [--format=(json|tsv)] gzipped-archive.tar.gz output.(json|tsv)
• If -format not specified, default is json output (note: optional args must precede positional args)

Examples

• msgextract gzipped-archive.tar.gz output.json
• msgextract --format=tsv gzipped-archive.tar.gz output.tsv

Suggested Improvements

• Concurrency in mapping of header lines returned by unpack.Tar
• Standardize formatting of Date header information
• Remove data duplication in output.WriteFields
• Move header field filtering to new procedure
• Specify which header fields to collect as optional args
• Allow for multiple values for same header fields (e.g. multiple Receiveds)
• Add csv format capability
• Will require addressing , in header field values

Testing

• cd path/to/msgextract
• go test ./...