debug/cmd/viewcore: add a simple read command
Add a simple command that prints the contents of a range of memory in hex.
Change-Id: I3426002e08018acfadfdd6be2c7fe89ffb2d48c2
Reviewed-on: https://go-review.googlesource.com/102736
Reviewed-by: Peter Weinberger <pjw@google.com>
diff --git a/cmd/viewcore/main.go b/cmd/viewcore/main.go
index 0f38d2d..22b4eeb 100644
--- a/cmd/viewcore/main.go
+++ b/cmd/viewcore/main.go
@@ -38,9 +38,9 @@
objgraph: dump object graph to the file tmp.dot
reachable: find path from root to an object
html: start an http server on :8080 for browsing core file data
+ read: read a chunk of memory
-Flags applicable to all commands:
-`)
+Flags applicable to all commands:\n`)
flag.PrintDefaults()
}
@@ -92,6 +92,7 @@
flags = gocore.FlagTypes | gocore.FlagReverse
case "html":
flags = gocore.FlagTypes | gocore.FlagReverse
+ case "read":
}
// All commands other than "help" need a core file.
@@ -385,6 +386,42 @@
}
case "html":
serveHTML(c)
+ case "read":
+ if len(args) < 3 {
+ fmt.Fprintf(os.Stderr, "no address provided\n")
+ os.Exit(1)
+ }
+ n, err := strconv.ParseInt(args[2], 16, 64)
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "can't parse %s as an object address\n", args[2])
+ os.Exit(1)
+ }
+ a := core.Address(n)
+ if len(args) < 4 {
+ n = 256
+ } else {
+ n, err = strconv.ParseInt(args[3], 10, 64)
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "can't parse %s as a byte count\n", args[3])
+ os.Exit(1)
+ }
+ }
+ if !p.ReadableN(a, n) {
+ fmt.Fprintf(os.Stderr, "address range [%x,%x] not readable\n", a, a.Add(n))
+ os.Exit(1)
+ }
+ b := make([]byte, n)
+ p.ReadAt(b, a)
+ for i, x := range b {
+ if i%16 == 0 {
+ if i > 0 {
+ fmt.Println()
+ }
+ fmt.Printf("%x:", a.Add(int64(i)))
+ }
+ fmt.Printf(" %02x", x)
+ }
+ fmt.Println()
}
}
