open
open
Open a file with a preferred handler
Description
open
is a smart tool for reading files:
- It will read a file from disk or a HTTP(S) endpoints
- Detect the file type via file extension or HTTP header
Content-Type
- It intelligently writes to stdout
- If stdout is a TTY it will perform any transformations to render to the terminal (eg using inlining images)
- If stdout is a pipe then it will write a byte stream with the relevant data-type
- If there are no open handlers then it will fallback to the systems default. eg
open
(on macOS, Linux),open-xdg
(X11), etc.
Usage
open filename[.gz]|uri -> <stdout>
Examples
» open https://api.github.com/repos/lmorg/murex/issues -> foreach issue { out "$issue[number]: $issue[title]" }
Detail
File Extensions
Supported file extensions are listed in config
under the app and key names of shell, extensions.
Unsupported file extensions are defaulted to generic, *
.
Files with a .gz
extension are assumed to be gzipped and thus are are automatically expanded.
MIME Types
The Content-Type
HTTP header is compared against a list of MIME types, which are stored in config
under the app and key names of shell, mime-types.
There is a little bit of additional logic to determine the Murex data-type to use should the MIME type not appear in config
, as seen in the following code:
package lang
import (
"regexp"
"strings"
"github.com/lmorg/murex/lang/types"
)
var rxMimePrefix = regexp.MustCompile(`^([-0-9a-zA-Z]+)/.*$`)
// MimeToMurex gets the murex data type for a corresponding MIME
func MimeToMurex(mimeType string) string {
mime := strings.Split(mimeType, ";")[0]
mime = strings.TrimSpace(mime)
mime = strings.ToLower(mime)
// Find a direct match. This is only used to pick up edge cases, eg text files used as images.
dt := mimes[mime]
if dt != "" {
return dt
}
// No direct match found. Fall back to prefix.
prefix := rxMimePrefix.FindStringSubmatch(mime)
if len(prefix) != 2 {
return types.Generic
}
switch prefix[1] {
case "text", "i-world", "message":
return types.String
case "audio", "music", "video", "image", "model":
return types.Binary
case "application":
if strings.HasSuffix(mime, "+json") {
return types.Json
}
return types.Generic
default:
// Mime type not recognized so lets just make it a generic.
return types.Generic
}
}
// MurexToMime returns the default MIME for a given Murex data type.
// The intended use case for this is for GET and POST requests where the body
// is STDIN.
func MurexToMime(dataType string) string {
return defaultMimes[dataType]
}
HTTP User Agent
open
's user agent is the same as get
and post
and is configurable via config
under they app http
» config -> [http]
{
"cookies": {
"Data-Type": "json",
"Default": {
"example.com": {
"name": "value"
},
"www.example.com": {
"name": "value"
}
},
"Description": "Defined cookies to send, ordered by domain.",
"Dynamic": false,
"Global": false,
"Value": {
"example.com": {
"name": "value"
},
"www.example.com": {
"name": "value"
}
}
},
"default-https": {
"Data-Type": "bool",
"Default": false,
"Description": "If true then when no protocol is specified (`http://` nor `https://`) then default to `https://`.",
"Dynamic": false,
"Global": false,
"Value": false
},
"headers": {
"Data-Type": "json",
"Default": {
"example.com": {
"name": "value"
},
"www.example.com": {
"name": "value"
}
},
"Description": "Defined HTTP request headers to send, ordered by domain.",
"Dynamic": false,
"Global": false,
"Value": {
"example.com": {
"name": "value"
},
"www.example.com": {
"name": "value"
}
}
},
"insecure": {
"Data-Type": "bool",
"Default": false,
"Description": "Ignore certificate errors.",
"Dynamic": false,
"Global": false,
"Value": false
},
"redirect": {
"Data-Type": "bool",
"Default": true,
"Description": "Automatically follow redirects.",
"Dynamic": false,
"Global": false,
"Value": true
},
"timeout": {
"Data-Type": "int",
"Default": 10,
"Description": "Timeout in seconds for `get` and `getfile`.",
"Dynamic": false,
"Global": false,
"Value": 10
},
"user-agent": {
"Data-Type": "str",
"Default": "murex/1.7.0000 BETA",
"Description": "User agent string for `get` and `getfile`.",
"Dynamic": false,
"Global": false,
"Value": "murex/1.7.0000 BETA"
}
}
Open Flags
If the open
builtin falls back to using the systems default (like open-xdg
) then the only thing that gets passed is the path being opened. If the path is stdin then a temporary file will be created. If you want to pass command line flags to open-xdg
(for example), then you need to call that command directly. In the case of macOS and some Linux systems, that might look like:
exec open --flags filename
See Also
*
(generic): generic (primitive)config
: Query or define Murex runtime settingsexec
: Runs an executablefexec
: Execute a command or function, bypassing the usual order of precedence.foreach
: Iterate through an arrayget
: Makes a standard HTTP request and returns the result as a JSON objectgetfile
: Makes a standard HTTP request and return the contents as Murex-aware data type for passing along Murex pipelines.openagent
: Creates a handler function foropen
out
: Print a string to the stdout with a trailing new line characterpost
: HTTP POST request with a JSON-parsable return
This document was generated from builtins/core/open/open_doc.yaml.