A Go language library for parsing file sequence strings commonly used in VFX and animation applications.

Ported from the original fileseq Python library: https://github.com/justinfx/fileseq

For C++, see C++ Support

Frame Range Shorthand

Support for:

• Standard: 1-10
• Comma Delimted: 1-10,10-20
• Chunked: 1-100x5
• Filled: 1-100y5
• Staggered: 1-100:3 (1-100x3, 1-100x2, 1-100)
• Negative frame numbers: -10-100
• Padding: #=4 padded, @=single pad
• Printf Syntax Padding: %04d=4 padded, %01d=1 padded
• Houdini Syntax Padding: $F4=4 padding, $F=1 padded
• Udim Syntax Padding: or %(UDIM)d, always 4 padded

Sequence Formats

Sequences of files are expected to follow a pattern similar to:

• /path/to/some/file_foo.0100.exr
• /path/to/some/file_foo.1-100#.jpg
• /path/to/some/file_foo.1-100@@@.tif
• /path/to/some/file_foo.1-100%03d.tif
• /path/to/some/file_foo.1-100$F3.tif
• /path/to/some/file_foo.1-100.tif
• /path/to/some/file_foo.1-100%(UDIM)d.tif

Install

go get github.com/justinfx/gofileseq/v3

Also included is a seqls tool, which uses gofileseq to produce an executable, used for listing sequences on the filesystem:

And seqinfo tool, which can print plain-text or json parsed information about one or more sequence strings.

Download the latest binary release

Or install from source:

go get github.com/justinfx/gofileseq/v3/cmd/seqls
seql some/images
# some/images/file_foo.1-100@@@.tif

Development

The file sequence parser is built using an ANTLR4 grammar defined in grammar/fileseq.g4.

When the grammar file is modified, the parser must be regenerated and committed:

# Regenerate parser from grammar
go generate ./...

# Or directly via make
cd grammar && make generate-go

Requirements: Java runtime (for ANTLR code generation)

If Java is not in a default system location, specify the path:

# Using go generate
JAVA=/path/to/java go generate ./...

# Using make directly
cd grammar && make JAVA=/path/to/java generate-go

Alternative: Use Docker (no Java required):

cd grammar && make generate-go-docker

C++ Support

A C++ pure port of gofileseq is also available in the cpp dir