4 files changed, 69 insertions, 39 deletions

diff --git a/cmd/cat.go b/cmd/cat.go
index 186f7da..f3ea2bf 100644
--- a/cmd/cat.go
+++ b/cmd/cat.go
@@ -2,7 +2,7 @@ package cmd
 
 import (
 	"fmt"
-	"golang.flu0r1ne.net/zfdiff/snap"
+	"golang.flu0r1ne.net/zsu/snap"
 	"os"
 	"io"
 )
@@ -14,34 +14,32 @@ func Cat(params []string) {
 		die.Fatal("Reference file is required")
 	}
 
-	if(n_params > 3) {
+	if(n_params > 2) {
 		die.Fatal("Too many arguments provided")
 	}
 
-	var reference string
-	snapish := ""
+	reference := params[0]
 
-	if(n_params == 1) {
-		reference = params[0]
-	} else {
-		snapish, reference = params[0], params[1]
+	snapish := "@"
+	if(n_params > 1) {
+		snapish = params[1]
 	}
 
 	snapRef := snap.ToRelative(snapish)
 
 	oracle := snap.GetOracle(reference)
 
-	path := oracle.ResolveRelative(snapRef)
+	path := oracle.PathTo(snapRef)
 
 	file, err := os.Open(path)
 
 	if err != nil {
-		die.Fatal("Could not open snapshot %s\nError: %v", path, err)
+		die.Fatalf("Could not open snapshot %s\nError: %v", path, err)
 	}
 
 	defer func() {
         if err = file.Close(); err != nil {
-            die.Fatal("Could not close file %s\nError: %v", path, err)
+            die.Fatalf("Could not close file %s\nError: %v", path, err)
         }
     }()
 
@@ -59,7 +57,7 @@ func Cat(params []string) {
         }
 
         if err != nil {
-            die.Fatal("Encountered error while reading file: %v", err)
+            die.Fatalf("Encountered error while reading file: %v", err)
         }
     }
-}
\ No newline at end of file
+}
diff --git a/cmd/diff.go b/cmd/diff.go
index 46327b3..8d6a85f 100644
--- a/cmd/diff.go
+++ b/cmd/diff.go
@@ -1,8 +1,13 @@
 package cmd
 
 import (
+	"golang.flu0r1ne.net/zsu/snap"
+	"os/exec"
+	"os"
+	"io"
+	"log"
 	"fmt"
-	"golang.flu0r1ne.net/zfdiff/snap"
+	"errors"
 )
 
 func Diff(params []string) {
@@ -15,9 +20,57 @@ func Diff(params []string) {
 		die.Fatal("Too many arguments provided")
 	}
 
-	from, to := snap.ParseDiff(params[0])
+	reference := params[0]
 
-	reference := params[1]
+	from, to := snap.ToRelative("@-"), snap.ToRelative("@")
+	if len(params) > 1 {
+		from, to = snap.ParseDiff(params[1])
+	}
+
+	oracle := snap.GetOracle(reference)
+
+	fromPath := oracle.PathTo(from)
+	toPath := oracle.PathTo(to)
+
+	_, noColor := os.LookupEnv("NO_COLOR")
+
+	colorOpt := "--color=always"
+	if noColor {
+		colorOpt = "--color=never"
+	}
+
+	diff := exec.Command("diff", colorOpt, fromPath, toPath)
+	diff.Env = os.Environ()
+	
+	stderr, err := diff.StderrPipe()
+	if err != nil {
+		log.Fatal(err);
+	}
 
-	fmt.Println(from, to, reference);
+	stdout, err := diff.StdoutPipe()
+	if err != nil {
+		log.Fatal(err);
+	}
+
+	if err := diff.Start(); err != nil {
+		log.Fatal(err)
+	}
+
+	outtext, _ := io.ReadAll(stdout)
+	errtext, _ := io.ReadAll(stderr)
+	
+	fmt.Fprintf(os.Stderr, "%s", errtext)
+	fmt.Fprintf(os.Stdout, "%s", outtext)
+
+	if err := diff.Wait(); err != nil {
+		var exiterr *exec.ExitError
+
+		// GNU Diff exits 1 if the files differ
+		if errors.As(err, &exiterr) && exiterr.ExitCode() == 1 {
+			os.Exit(exiterr.ExitCode())
+		}
+
+		die.Fatalf("Error encountered while executing diff.")
+		os.Exit(2)
+	}
 }
diff --git a/cmd/list.go b/cmd/list.go
index 5849975..94c18b8 100644
--- a/cmd/list.go
+++ b/cmd/list.go
@@ -3,7 +3,7 @@ package cmd
 import (
 	"fmt"
 	"flag"
-	"golang.flu0r1ne.net/zfdiff/snap"
+	"golang.flu0r1ne.net/zsu/snap"
 )
 
 func List(params []string) {
diff --git a/cmd/overwrite.go b/cmd/overwrite.go
deleted file mode 100644
index 324dfb4..0000000
--- a/cmd/overwrite.go
+++ /dev/null
@@ -1,21 +0,0 @@
-package cmd
-
-import (
-	"fmt"
-	"golang.flu0r1ne.net/zfdiff/snap"
-)
-
-func Overwrite(params [] string) {
-	if(len(params) == 0) {
-		die.Fatal("Reference file is required")
-	}
-
-	if(len(params) > 3) {
-		die.Fatal("Too many arguments provided")
-	}
-
-	snapRef := snap.ToRelative(params[0])
-	reference := params[1]
-
-	fmt.Print(snapRef, reference)
-}
\ No newline at end of file