List command, diff command, and snapshot search infrastructure

1 files changed, 49 insertions, 5 deletions

diff --git a/cmd/cat.go b/cmd/cat.go
index d5a275d..186f7da 100644
--- a/cmd/cat.go
+++ b/cmd/cat.go
@@ -3,19 +3,63 @@ package cmd
 import (
 	"fmt"
 	"golang.flu0r1ne.net/zfdiff/snap"
+	"os"
+	"io"
 )
 
 func Cat(params []string) {
-	if(len(params) == 0) {
+	n_params := len(params)
+
+	if(n_params == 0) {
 		die.Fatal("Reference file is required")
 	}
 
-	if(len(params) > 3) {
+	if(n_params > 3) {
 		die.Fatal("Too many arguments provided")
 	}
 
-	snapRef := snap.ToRelative(params[0])
-	reference := params[1]
+	var reference string
+	snapish := ""
+
+	if(n_params == 1) {
+		reference = params[0]
+	} else {
+		snapish, reference = params[0], params[1]
+	}
+
+	snapRef := snap.ToRelative(snapish)
+
+	oracle := snap.GetOracle(reference)
+
+	path := oracle.ResolveRelative(snapRef)
+
+	file, err := os.Open(path)
+
+	if err != nil {
+		die.Fatal("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)
+        }
+    }()
+
+	buf := make([]byte, 10*1024*1024) //10Ki
+
+    for {
+        n, err := file.Read(buf)
+
+        if n > 0 {
+            fmt.Printf("%s", buf[:n])
+        }
+
+        if err == io.EOF {
+            break
+        }
 
-	fmt.Println(snapRef, reference);
+        if err != nil {
+            die.Fatal("Encountered error while reading file: %v", err)
+        }
+    }
 }
\ No newline at end of file