bsd-from

bsd-from [file]

file
    The input file to process. If no file is specified, bsd-from reads from standard input.

The bsd-from command extracts mail addresses from a mailbox file formatted according to BSD conventions. It scans the input file (typically a system mailbox) looking for 'From ' lines which mark the beginning of mail messages. It then parses these lines to extract the sender's email address. The command is primarily used for older mailbox formats and might not handle all modern email address variations flawlessly. The main use case is automated processing of legacy mail spools for statistical analysis or user extraction.

bsd-from is designed for BSD-style mailboxes. It might not function correctly with other mailbox formats, such as Maildir or mboxo. Its address parsing capabilities might be limited compared to modern email parsers. Also, it's reliance on 'From ' lines makes it susceptible to false positives if the line appears within message bodies.

The bsd-from command exits with a status of 0 on success and a non-zero value on error.

Each extracted email address is printed to standard output, one address per line.

When processing user-controlled mailbox files, ensure proper sanitization and validation to prevent malicious input from causing unexpected behavior or security vulnerabilities. The command relies on pattern matching so carefully control how the file will be accessed.

bsd-from is a relatively old utility, originating from BSD systems, where it was used to process system mail spools. Its presence on Linux systems is largely due to its inclusion in packages providing compatibility with BSD utilities. It sees less use in modern Linux environments, where more sophisticated email processing tools are common.

mail(1), sendmail(8)