README
¶
Filters
Filters Package for Golang
The Filters package is designed to allow the chaining of cli commands using stdin and stdout.
The command allows setting the commands explicitly or loading from a yaml file.
Filter
A Filter is any cli command, but primarily focused on the idea of unix cli commands being used as byte filters used to mangle and transform text and piping commands together.
Chain
A Chain is a sequential list of Filters with each piping its output into the next.
Exec
From either a chain or filter an Exec can be generated.
Input for an Exec is provided as a io.Reader and output is assigned as an io.Writer.
On an Exec from a chain, input is assigned to the first process and output assigned to the last. Everything in between is automatically piped to the next Filter.
Chains
Chains allow the application to load multiple chains in one yaml file and retrive them by title.
Yaml file definitions
Filter YAML Example
Name: 'cat'
Domain: 'bash'
Version: '1.0'
Command: 'cat'
Arguments:
Chain YAML Example
Chain:
- Name: 'cat'
Domain: 'bash'
Version: '1.0'
Command: 'cat'
Arguments:
- Name: 'grep'
Domain: 'bash'
Version: '1.0'
Command: 'grep'
Arguments:
- 'wrong'
- Name: 'xargs'
Domain: 'bash'
Version: '1.0'
Command: 'xargs'
Arguments:
- '-n'
- '3'
Chains YAML Example
FirstChain:
Chain:
- Name: 'ls'
Domain: 'bash'
Version: '1.0'
Command: 'ls'
Arguments:
VCS:
Type: 'git'
Location: 'github.com'
- Name: 'grep'
Domain: 'bash'
Version: '1.0'
Command: 'grep'
Arguments:
- 'filters'
VCS:
Type: 'git'
Location: 'github.com'
- Name: 'xargs'
Domain: 'bash'
Version: '1.0'
Command: 'xargs'
Arguments:
- '-n'
- '4'
VCS:
Type: 'git'
Location: 'github.com'
SecondChain:
Chain:
- Name: 'ls'
Domain: 'bash'
Version: '1.0'
Command: 'ls'
Arguments:
VCS:
Type: 'git'
Location: 'github.com'
- Name: 'grep'
Domain: 'bash'
Version: '1.0'
Command: 'grep'
Arguments:
- 'filters'
VCS:
Type: 'git'
Location: 'github.com'
- Name: 'xargs'
Domain: 'bash'
Version: '1.0'
Command: 'xargs'
Arguments:
- '-n'
- '4'
VCS:
Type: 'git'
Location: 'github.com'
See the godocs for more information and examples.
Documentation
¶
Overview ¶
Example (Chain) ¶
text := "Alphabet city is haunted\n"
text += "Constantina feels right at home\n"
text += "She probably wont say youre wrong\n"
text += "Youre already wrong\nYoure already wrong\n"
filtercat := New()
filtercat.Command = "cat"
filtergrep := New()
filtergrep.Command = "grep"
filtergrep.Argument("wrong")
filterxargs := New()
filterxargs.Command = "xargs"
filterxargs.Argument("-n")
filterxargs.Argument("3")
c := Chain{
Filters: []Filter{
filtercat,
filtergrep,
filterxargs,
},
}
exec, err := c.Exec()
if err != nil {
log.Print(err)
}
exec.SetInput(bytes.NewReader([]byte(text)))
var buf bytes.Buffer
exec.SetOutput(&buf)
err = exec.Run()
if err != nil {
log.Print(err)
}
fmt.Print(buf.String())
Output: She probably wont say youre wrong Youre already wrong Youre already wrong
Example (Chainfile) ¶
text := "Alphabet city is haunted\n"
text += "Constantina feels right at home\n"
text += "She probably wont say youre wrong\n"
text += "Youre already wrong\nYoure already wrong\n"
c, err := ChainFile("chain.yml")
if err != nil {
log.Print(err)
}
exec, err := c.Exec()
if err != nil {
log.Print(err)
}
exec.SetInput(bytes.NewReader([]byte(text)))
var buf bytes.Buffer
exec.SetOutput(&buf)
err = exec.Run()
if err != nil {
log.Print(err)
}
fmt.Print(buf.String())
Output: She probably wont say youre wrong Youre already wrong Youre already wrong
Example (Input) ¶
text := []byte("hello world\ngoodbye world")
filter := New()
filter.Command = "grep"
filter.Argument("goodbye")
var buf bytes.Buffer
exec := filter.Exec()
exec.SetInput(bytes.NewReader(text))
exec.SetOutput(&buf)
err := exec.Run()
if err != nil {
log.Print(err)
}
fmt.Println(buf.String())
Output: goodbye world
Example (Simple) ¶
text := "hello world"
filter := New()
filter.Command = "echo"
filter.Argument(text)
var buf bytes.Buffer
exec := filter.Exec()
exec.SetOutput(&buf)
err := exec.Run()
if err != nil {
log.Print(err)
}
fmt.Println(buf.String())
Output: hello world
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrNotPointer the passed in vvariable was not a pointer ErrNotPointer = errors.New("Unmarshal requires pointer") // ErrChainDoesNotExist the chain was not found in the list of chains ErrChainDoesNotExist = errors.New("Chain does not exist") )
Functions ¶
This section is empty.
Types ¶
type Chain ¶
type Chain struct {
Filters []Filter `yaml:"Chain"`
}
Chain of commands where each feeds into stdin of the next
type Chains ¶
Chains is a map of chains that can be retrieved by name
func ChainsFile ¶
ChainsFile returns Chains loaded with data from a file
type Error ¶
type Error struct {
// contains filtered or unexported fields
}
Error is a filter error
type Exec ¶
type Exec struct {
// contains filtered or unexported fields
}
Exec is a command and with input and output attached
type Filter ¶
type Filter struct {
// Program name
Name string `yaml:"Name"`
// Domain of program
Domain string `yaml:"Domain"`
// Version number
Version string `yaml:"Version"`
// Command to execute
Command string `yaml:"Command"`
// Arguments to command
Arguments []string `yaml:"Arguments"`
// VCS where filter can be found
VCS `yaml:"VCS"`
}
Filter is one command to be used as a filter
func FilterFile ¶
FilterFile returns a new Filter from a file definitions
Source Files
Directories