Merge pull request #1 from gliderlabs/master

v0.2.0

.gitignore

@@ -1 +1,2 @@
 build
+site

Makefile

@@ -1,7 +1,7 @@
 NAME=sigil
 ARCH=$(shell uname -m)
 ORG=gliderlabs
-VERSION=0.1.0
+VERSION=0.2.0
 
 build:
 	mkdir -p build/Linux  && GOOS=linux  go build -ldflags "-X main.Version $(VERSION)" -o build/Linux/$(NAME) ./cmd
@@ -22,10 +22,10 @@ release:
 
 circleci:
 	rm ~/.gitconfig
-	test -d /home/ubuntu/.go_workspace/src/github.com/$(ORG)/$(NAME) || { cd .. \
+	rm -rf /home/ubuntu/.go_workspace/src/github.com/$(ORG)/$(NAME) && cd .. \
 		&& mkdir -p /home/ubuntu/.go_workspace/src/github.com/$(ORG) \
 		&& mv $(NAME) /home/ubuntu/.go_workspace/src/github.com/$(ORG)/$(NAME) \
-		&& ln -s /home/ubuntu/.go_workspace/src/github.com/$(ORG)/$(NAME) $(NAME); }
+		&& ln -s /home/ubuntu/.go_workspace/src/github.com/$(ORG)/$(NAME) $(NAME)
 
 clean:
 	rm -rf build release

README.md

@@ -1,3 +1,93 @@
-# sigil
+# Sigil
 
 Standalone string interpolator and template processor
+
+```
+$ echo '${name} is{{ range seq ${count:-3} }} cool{{ end }}!' | sigil name=Sigil
+Sigil is cool cool cool!
+```
+
+Sigil is a command line tool for template processing and POSIX-compliant
+variable expansion. It was created for configuration templating, but can be used
+for any text processing.
+
+## Getting Sigil
+
+```
+$ curl https://dl.gliderlabs.com/sigil/latest/$(uname -sm|tr \  _).tgz \
+    | tar -zxC /usr/local/bin
+```
+
+Other releases can be downloaded from [Github Releases](https://github.com/gliderlabs/sigil/releases).
+
+## Using Sigil
+
+Template text can be provided via STDIN or from a file if provided with the `-f`
+flag. Any other arguments are key-values in the form `<key>=<value>`. They are
+used as variables.
+
+ * `echo 'Hello, $name' | sigil name=Jeff`
+ * `sigil -f config.tmpl var1=foo "var2=Hello world"`
+
+### Variables
+
+#### POSIX style
+
+There are two forms of variable syntax in Sigil. The first is POSIX style, which
+among other features allows default values or enforces required values:
+
+ * `$variable` - normal POSIX style
+ * `${variable:-"default"}` - expansion with default value
+ * `${variable:?}` - fails when not set
+
+Environment variables are also available as POSIX style variables. This makes
+Sigil great for quick and simple string interpolation.
+
+#### Template style
+
+The other syntax to use variables is consistent with the rest of the templating
+syntax. It uses `{{` and `}}` to define template expressions. Variable expansion
+in this form is simply used as:
+
+ * `{{ $variable }}`
+
+You can do much more with this syntax, such as modifier pipelines. All of which
+is explained below.
+
+### Functions
+
+There are a number of builtin functions that can be used as modifiers,
+conditional tests, expansion data sources, and more. There are two references
+for functions available:
+
+ * [Sigil builtins](http://godoc.org/github.com/gliderlabs/sigil/builtin)
+ * [Go template builtins](http://golang.org/pkg/text/template/#hdr-Functions)
+
+Here are a few examples:
+
+ * `{{ $variable | capitalize }}`
+ * `{{ include "file.tmpl" "var1=foo" "var2=bar" }}`
+ * `{{ file "example.txt" | replace "old" "new" }}`
+ * `{{ json "file.json" | pointer "/Widgets/0/Name" }}`
+
+### Conditionals
+
+ * `{{ if expr }} true {{ end }}`
+ * `{{ if expr }} true {{ else }} false {{ end }}`
+ * `{{ if expr }} true {{ else if expr }} also true {{ end }}`
+
+### Loops / Iteration
+
+ * `{{ range expr }} element: {{.}} {{ end }}`
+ * `{{ range expr }} elements {{ else }} no elements {{ end }}`
+
+### Full Syntax
+
+Lots more is possible with this template syntax. Sigil is based on Go's
+[text/template package](http://golang.org/pkg/text/template/). You can read full
+documentation there.
+
+
+## License
+
+BSD

cmd/sigil.go

@@ -16,6 +16,7 @@ var Version string
 
 var (
 	filename = flag.String("f", "", "use template file instead of STDIN")
+	posix    = flag.Bool("p", true, "preprocess with POSIX variable expansion")
 	version  = flag.Bool("v", false, "prints version")
 )
 
@@ -41,8 +42,14 @@ func main() {
 		fmt.Println(Version)
 		os.Exit(0)
 	}
+	if *posix {
+		sigil.PosixPreprocess = true
+	}
 	vars := make(map[string]string)
 	for _, arg := range os.Args {
+		if strings.HasPrefix(arg, "-") {
+			continue
+		}
 		parts := strings.SplitN(arg, "=", 2)
 		if len(parts) == 2 {
 			vars[parts[0]] = parts[1]

sigil.go

@@ -11,7 +11,8 @@ import (
 )
 
 var (
-	TemplateDir string
+	TemplateDir     string
+	PosixPreprocess bool
 )
 
 var fnMap = template.FuncMap{}
@@ -24,6 +25,7 @@ func Register(fm template.FuncMap) {
 
 func Execute(input string, vars map[string]string) (string, error) {
 	var tmplVars string
+	var err error
 	for k, v := range vars {
 		err := os.Setenv(k, v)
 		if err != nil {
@@ -32,6 +34,12 @@ func Execute(input string, vars map[string]string) (string, error) {
 		escaped := strings.Replace(v, "\"", "\\\"", -1)
 		tmplVars = tmplVars + fmt.Sprintf("{{ $%s := \"%s\" }}", k, escaped)
 	}
+	if PosixPreprocess {
+		input, err = posix.ExpandEnv(input)
+		if err != nil {
+			return "", err
+		}
+	}
 	tmpl, err := template.New("template").Funcs(fnMap).Parse(tmplVars + input)
 	if err != nil {
 		return "", err
@@ -41,9 +49,5 @@ func Execute(input string, vars map[string]string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	postprocessed, err := posix.ExpandEnv(buf.String())
-	if err != nil {
-		return "", err
-	}
-	return postprocessed, nil
+	return buf.String(), nil
 }