refret

A regular expression file rename tool and library written in Go.

Usage

Usage: refret.exe --name="migration" --root=STRING [<pattern> ...] [flags]

Searches for and optionally renames files according to regular expression
patterns. It matches file and directory names as it traverses a file system from
a given root. Successive patterns match successive traversal depths.

Proposed rename actions, omitted (non-matching) files and the results of actions
taken are logged for inspection and review.

During evaluation, files are scanned concurrently for speed. Rename operations
happen in series for safety.

Arguments:
  [<pattern> ...]    Regular expression patterns to match, with optional
                     substitution delimited by a forward slash (exp/sub)
                     ($PATTERN).

Flags:
  -h, --help                Show context-sensitive help.
      --name="migration"    Output file name prefix ($NAME).
      --root=STRING         Root path of the file directory structure ($ROOT).
  -v, --verbose             Provide verbose output ($VERBOSE).
  -m, --matched             Show matching files and directories ($MATCHED).
  -u, --unmatched           Show non-matching files and directories
                            ($UNMATCHED).
  -c, --concurrency=32      Maximum number of concurrent read operations during
                            scanning ($CONCURRENCY).
      --proceed             Proceed with renaming operations ($PROCEED).

Patterns

Regular expressions are interpreted according to Go's regular expression engine. Go has excellent documentation for the regular expression syntax that it supports, which can be found here:

https://pkg.go.dev/regexp/syntax

The sole exception to these parsing rules is the special interpretation of the first / character within a pattern, which is used by refret to distinguish between the matching expression and the substitution expression.

Substitutions can refer to capture groups by their numbered order, like $1 and $2. In the following example pattern, the first two words in each file name would be reversed:

^(\w+) (\w+)/$2 $1

Examples

Change PDF document year suffix to prefix

Linux:

refret --name "prefix-with-year" --root "~/justin.case/Documents/Test" "(.*) (\\d{4}-\\d{2}-\\d{2})\\.pdf/$2 $1.pdf"

Windows:

refret.exe --name "prefix-with-year" --root "C:\Users\justin.case\Documents\Test" "(.*) (\d{4}-\d{2}-\d{2})\.pdf/$2 $1.pdf"

• Document A 2009-09-10.pdf → 2009-09-10 Document A.pdf
• Document B 2011-12-01.pdf → 2011-12-01 Document B.pdf