gofile

README

gorepotemplate

Tricky and fun utilities for Go programs.

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Getting Started

Prerequisites

• Go
• Git
• GitHub CLI

Developed with $( go version; ). Go is extremely backwards compatible and semver stable. Nearly any v1.x should work fine.

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Installation

To use this repo as a template for your own project:

gh repo create -y --public --template "https://github.com/skeptycal/gorepotemplate"

Clone this repo to test and contribute:

# add repo to $GOPATH (xxxxxx is your computer login username)
go get github.com/xxxxxx/gorepotemplate

cd ${GOPATH}/src/github.com/xxxxxx/gorepotemplate

# test results and coverage info
./go.test.sh

# install as a utility package
go install

Use the Issues and PR templates on the GitHub repo page to contribute.

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Basic Usage

This is a copy of the example script available in the cmd/example/gorepotemplate folder:

package main

import "github.com/skeptycal/gorepotemplate"

func main() {
    gorepotemplate.Example()
}

To try it out:

# change to the sample folder
cd cmd/example/gorepotemplate

# run the main.go program
go run ./main.go

# to compile as an executable
go build

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Code of Conduct and Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us. Please read the Code of Conduct for details before submitting anything.

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Versioning

We use SemVer for versioning. For the versions available, see the tags on this repository.

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Contributors and Inspiration

• Michael Treanor (GitHub / Twitter) - Initial work, updates, maintainer
• Francesc Campoy - Inspiration and great YouTube videos!

See also the list of contributors who participated in this project.

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License

Licensed under the MIT https://opensource.org/licenses/MIT - see the LICENSE file for details.

Documentation

Overview

Package gofile provides support for file operations.

Index

• Variables
• func Copy(src, dest string) (int64, error)
• func Create(name string) (io.ReadWriteCloser, error)
• func CreateSafe(name string) (io.ReadWriteCloser, error)
• func InitialCapacity(capacity int64) int
• func IsDir(name string) bool
• func IsRegular(name string) bool
• func Mode(file string) os.FileMode
• func PWD() string
• func Stat(file string) (os.FileInfo, error)
• func StatCheck(filename string) (os.FileInfo, error)
• type DIR
  • func NewDIR(name string) (DIR, error)
• type DataFile
  • func NewDataFile(filename string) (DataFile, error)
• type DirEntry
• type ErrorLogger
• type File
  • func Open(name string) (File, error)
• type FileInfo
• type FileMode
• type PathError
  • func NewPathError(op, path string, err error) *PathError
• type ReadDirFile
• type SortType
  • func (s SortType) String() string
• type TextFile
• type TimeZone
  • func (tz TimeZone) String() string

Variables

var (
	EL  = errorlogger.EL
	Err = errorlogger.Err
)

Package errorlogger implements error logging to a logrus log by default. It is completely compatible with the standard library 'log' logger API. It provides an efficient and convenient way to log errors with minimal overhead and to temporarily disable or enable logging.

A global EL and Err with default behaviors are supplied that may be aliased if you wish:

EL = errorlogger.EL // implements the ErrorLogger interface
Err = errorlogger.Err // trigger function

ErrorLogger is:

 type ErrorLogger interface {
	 Disable()
	 Enable()
	 Err(err error) error
	 SetLoggerFunc(fn func(args ...interface{}))

	// SetErrorType allows ErrorLogger to wrap errors in a
	// specified custom type. For example, if you want all errors
 // returned to be of type *os.PathError
	 SetErrorType(errType error)
}

var (
	ErrBadCount   = errors.New("datafile: bad read count")
	ErrNotRegular = errors.New("datafile: not regular file")
)

var SameFile = os.SameFile

SameFile reports whether fi1 and fi2 describe the same file. For example, on Unix this means that the device and inode fields of the two underlying structures are identical; on other systems the decision may be based on the path names. SameFile only applies to results returned by this package's Stat. It returns false in other cases.

Functions

func Copy

func Copy(src, dest string) (int64, error)

func Create

func Create(name string) (io.ReadWriteCloser, error)

Create creates or truncates the named file and returns an opened file as io.ReadWriteCloser.

If the file already exists, it is truncated. If the file does not exist, it is created with mode 0644 (before umask). If successful, methods on the returned File can be used for I/O; the associated file descriptor has mode O_RDWR.

If there is an error, it will be of type *PathError.

func CreateSafe

func CreateSafe(name string) (io.ReadWriteCloser, error)

CreateSafe creates the named file and returns an opened file as io.ReadWriteCloser.

If the file already exists, an error is returned. If the file does not exist, it is created with mode 0644 (before umask). If successful, methods on the returned File can be used for I/O; the associated file descriptor has mode O_RDWR.

If there is an error, it will be of type *PathError.

func InitialCapacity

func InitialCapacity(capacity int64) int

InitialCapacity returns the multiple of 'chunk' one more than needed to accomodate the given capacity.

func IsDir

func IsDir(name string) bool

func IsRegular

func IsRegular(name string) bool

func Mode

func Mode(file string) os.FileMode

Mode returns the filemode of file.

func PWD

func PWD() string

PWD returns a rooted path name corresponding to the current directory. If the current directory can be reached via multiple paths (due to symbolic links), PWD may return any one of them.

If an error occurs, the empty string is returned and the error is logged.

func Stat

func Stat(file string) (os.FileInfo, error)

Stat returns the os.FileInfo for file if it exists. If the file does not exist, nil is returned. Errors are logged if Err is active.

func StatCheck

func StatCheck(filename string) (os.FileInfo, error)

StatCheck returns file information (after symlink evaluation) using os.Stat(). If the file does not exist, is not a regular file, or if the user lacks adequate permissions, an error is returned.

Types

type DIR

type DIR interface {
	Len() int
	Path() string
	List() ([]DataFile, error)
	SetOpts(opts dirOpts)
}

func NewDIR

func NewDIR(name string) (DIR, error)

type DataFile

type DataFile interface {
	File
	Data() ([]byte, error)
}

func NewDataFile

func NewDataFile(filename string) (DataFile, error)

type DirEntry

type DirEntry interface {
	// Name returns the name of the file (or subdirectory) described by the entry.
	// This name is only the final element of the path (the base name), not the entire path.
	// For example, Name would return "hello.go" not "/home/gopher/hello.go".
	Name() string

	// IsDir reports whether the entry describes a directory.
	IsDir() bool

	// Type returns the type bits for the entry.
	// The type bits are a subset of the usual FileMode bits, those returned by the FileMode.Type method.
	Type() FileMode

	// Info returns the FileInfo for the file or subdirectory described by the entry.
	// The returned FileInfo may be from the time of the original directory read
	// or from the time of the call to Info. If the file has been removed or renamed
	// since the directory read, Info may return an error satisfying errors.Is(err, ErrNotExist).
	// If the entry denotes a symbolic link, Info reports the information about the link itself,
	// not the link's target.
	Info() (FileInfo, error)
}

A DirEntry is an entry read from a directory (using the ReadDir function or a ReadDirFile's ReadDir method).

type ErrorLogger

type ErrorLogger interface {

	// Disable disables logging and sets a no-op function for
	// Err() to prevent slowdowns while logging is disabled.
	Disable()

	// Enable enables logging and restores the Err() logging functionality.
	Enable()

	// Err logs an error to the provided logger, if it is enabled,
	// and returns the error unchanged.
	Err(err error) error

	// SetLoggerFunc allows setting of the logger function.
	// The default is log.Error(), which is compatible with
	// the standard library log package and logrus.
	SetLoggerFunc(fn func(args ...interface{}))

	Wrap(err error, message string) error
}

type File

type File interface {
	Stat() (FileInfo, error)
	Read([]byte) (int, error)
	Close() error
}

A File provides access to a single file. The File interface is the minimum implementation required of the file. A file may implement additional interfaces, such as ReadDirFile, ReaderAt, or Seeker, to provide additional or optimized functionality.

Reference: standard library fs.go

func Open

func Open(name string) (File, error)

Open opens the named file for reading. If successful, methods on the returned file can be used for reading; the associated file descriptor has mode O_RDONLY. If there is an error, it will be of type *os.PathError.

type FileInfo

type FileInfo interface {
	Name() string       // base name of the file
	Size() int64        // length in bytes for regular files; system-dependent for others
	Mode() FileMode     // file mode bits
	ModTime() time.Time // modification time
	IsDir() bool        // abbreviation for Mode().IsDir()
	Sys() interface{}   // underlying data source (can return nil)
}

A FileInfo describes a file and is returned by Stat and Lstat.

type FileMode

type FileMode = os.FileMode

A FileMode represents a file's mode and permission bits. The bits have the same definition on all systems, so that information about files can be moved from one system to another portably. Not all bits apply to all systems. The only required bit is ModeDir for directories.

type PathError

type PathError = os.PathError

func NewPathError

func NewPathError(op, path string, err error) *PathError

NewPathError records an error and the operation and file path that caused it.

type PathError struct {
	Op   string
	Path string
	Err  error
}

type ReadDirFile

type ReadDirFile interface {
	File

	// ReadDir reads the contents of the directory and returns
	// a slice of up to n DirEntry values in directory order.
	// Subsequent calls on the same file will yield further DirEntry values.
	//
	// If n > 0, ReadDir returns at most n DirEntry structures.
	// In this case, if ReadDir returns an empty slice, it will return
	// a non-nil error explaining why.
	// At the end of a directory, the error is io.EOF.
	//
	// If n <= 0, ReadDir returns all the DirEntry values from the directory
	// in a single slice. In this case, if ReadDir succeeds (reads all the way
	// to the end of the directory), it returns the slice and a nil error.
	// If it encounters an error before the end of the directory,
	// ReadDir returns the DirEntry list read until that point and a non-nil error.
	ReadDir(n int) ([]DirEntry, error)
}

A ReadDirFile is a directory file whose entries can be read with the ReadDir method. Every directory file should implement this interface. (It is permissible for any file to implement this interface, but if so ReadDir should return an error for non-directories.)

type SortType

type SortType int

SortType is a list of constants representing sort methods for directory listings.

const (
	Alpha SortType = iota + 1
	Size
	Version
	Extension
	Atime
	Ctime
)

func (SortType) String

func (s SortType) String() string

type TextFile

type TextFile interface {
	File
	Text() string
	Lines() (retval []string, err error)
}

type TimeZone

type TimeZone int

const (
	EST TimeZone = -(5 + iota)
	CST
	MST
	PST
)

American Time Zones

func (TimeZone) String

func (tz TimeZone) String() string