krino: release 0.0.1 — man pages, install, examples, cross and release, README, changelogv0.0.1

Also: undo removes the directories its run created; a hardlink is never a
duplicate of its own other name; a flag written before "undo" is honoured;
--version prints no leading v. Duplicate conditions with different scopes
not sharing an original is documented as a known limitation.

1 files changed, 21 insertions, 1 deletions

diff --git a/cmd/krino/main.go b/cmd/krino/main.go
index e204b5f..f5fdfea 100644
--- a/cmd/krino/main.go
+++ b/cmd/krino/main.go
@@ -9,12 +9,32 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"runtime/debug"
 	"strings"
 )
 
 // version is stamped by the Makefile with -ldflags "-X main.version=...".
 var version = "dev"
 
+// displayVersion returns the version to print for --version. The Makefile
+// stamps a git tag, which carries a leading "v" (required for
+// go install ...@v0.0.1, per design.md §14); that "v" belongs on the tag,
+// not in the output, so it is stripped here. A "go install" build carries no
+// ldflags, leaving version at its built-in "dev"; in that case fall back to
+// the build info Go embeds automatically.
+func displayVersion() string {
+	v := version
+	if v == "dev" {
+		if info, ok := debug.ReadBuildInfo(); ok && info.Main.Version != "" && info.Main.Version != "(devel)" {
+			v = info.Main.Version
+		}
+	}
+	if len(v) > 1 && v[0] == 'v' && v[1] >= '0' && v[1] <= '9' {
+		v = v[1:]
+	}
+	return v
+}
+
 const usage = `usage: krino [-y | -n] [-v] [--json] [-c FILE] [NAME...]
        krino init
        krino new NAME PATH
@@ -63,7 +83,7 @@ func run(args []string, stdout, stderr io.Writer) int {
 		return code
 	}
 	if *showVersion {
-		fmt.Fprintf(stdout, "krino %s\n", version)
+		fmt.Fprintf(stdout, "krino %s\n", displayVersion())
 		return 0
 	}
 	rest := fs.Args()