Adds .RUN and .RUNFILE attributes (#21)

TekWizely · Jan 5, 2020 · 4cd9fd0 · 4cd9fd0
1 parent 584e19b
commit 4cd9fd0
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Showing 4 changed files with 54 additions and 2 deletions.
diff --git a/README.md b/README.md
@@ -72,6 +72,8 @@ In run, the entire script is executed within a single sub-shell.
    - [Referencing Other Variables](#referencing-other-variables)
    - [Shell Substitution](#shell-substitution)
    - [Conditional Assignment](#conditional-assignment)
+   - [Invoking Other Commands & Runfiles](#invoking-other-commands--runfiles)
+     - [.RUN & .RUNFILE Attributes](#run--runfile-attributes)
  - [Script Shells](#script-shells)
    - [Per-Command Shell Config](#per-command-shell-config)
    - [Global Default Shell Config](#global-default-shell-config)
@@ -706,6 +708,37 @@ NAME="Newman" run hello
 Hello, Newman
 ```
 
+#### Invoking Other Commands & Runfiles
+
+##### .RUN / .RUNFILE Attributes
+Run exposes the following attributes:
+
+* `.RUN` - Absolute path of the run binary currently in use
+* `.RUNFILE` - Absolute path of the current Runfile
+
+Your command script can use these to invoke other commands:
+
+_Runfile_
+```
+##
+# Invokes hello
+# EXPORT RUN := ${.RUN}
+# EXPORT RUNFILE := ${.RUNFILE}
+test:
+    "${RUN}" -r "${RUNFILE}" hello
+
+hello:
+    echo "Hello, World"
+```
+
+_output_
+```
+$ run test
+
+Hello, World
+```
+
+
 -----------------
 ### Script Shells
 

diff --git a/internal/ast/ast.go b/internal/ast/ast.go
@@ -16,6 +16,8 @@ func ProcessAST(ast *Ast) *runfile.Runfile {
 	// Seed defaults
 	//
 	rf.Scope.PutAttr(".SHELL", config.DefaultShell)
+	rf.Scope.PutAttr(".RUN", config.RunBin)
+	rf.Scope.PutAttr(".RUNFILE", config.RunFile)
 	for _, n := range ast.nodes {
 		n.Apply(rf)
 	}

diff --git a/internal/config/config.go b/internal/config/config.go
@@ -50,6 +50,13 @@ var CommandList []*Command
 //
 var CommandMap = make(map[string]*Command)
 
+// RunBin holds the absolute path to the run command in use.
+//
+var RunBin string
+
+// RunFile holds the absolute path to the current Runfile.
+var RunFile string
+
 // EnableFnTrace shows parser/lexer fn call/stack
 //
 var EnableFnTrace = false

diff --git a/main.go b/main.go
@@ -7,6 +7,7 @@ import (
 	"log"
 	"os"
 	"path"
+	"path/filepath"
 	"strings"
 
 	"github.com/tekwizely/run/internal/ast"
@@ -71,7 +72,12 @@ func showVersion() {
 //
 func main() {
 	config.ErrOut = os.Stderr
-	config.Me = path.Base(os.Args[0])
+	if exec, err := os.Executable(); err != nil { // Returns abs path on success
+		config.RunBin = exec
+	} else {
+		config.RunBin = os.Args[0] // Punt to arg[0]
+	}
+	config.Me = path.Base(config.RunBin)
 	// Configure logging
 	//
 	log.SetFlags(0)
@@ -116,13 +122,17 @@ func main() {
 			log.Printf("Error reading file '%s': File not considered 'regular'\n", inputFile)
 			showUsage() // exits
 		}
+		if config.RunFile, err = filepath.Abs(inputFile); err != nil {
+			log.Printf("Error reading file '%s': Cannot determine absolute path\n", inputFile)
+			showUsage() // exits
+		}
 	} else {
 		log.Printf("Input file not found: '%s' : Please create the file or specify an alternative", inputFile)
 		showUsage() // exits
 	}
 	// Read file into memory
 	//
-	fileBytes, err := readFile(inputFile)
+	fileBytes, err := readFile(config.RunFile)
 	if err != nil {
 		log.Printf("Error reading file '%s': %s\n", inputFile, err.Error())
 		showUsage() // exits