From: Rafael Sadowski <rafael@sizeofvoid.org>
Subject: Re: btrace(1): fix -e and filename args
To: tech@openbsd.org
Date: Sat, 17 May 2025 13:12:38 +0200

On Sat May 17, 2025 at 06:44:53AM +0100, Jason McIntyre wrote:
> On Sat, May 17, 2025 at 05:00:50AM +0200, Rafael Sadowski wrote:
> > btrace(1) does not accept "-e file" Instead, it depends on filename as
> > the last parameter if no -b inline-script is specified. I also improved
> > the definition of "program".
> > 
> 
> hi!
> 
> - is there a reason for changing "file" to "filename"? "file" is
>   probably more common - if you keep it you can simply do "Op Ar".

No special reason. It was so named in the source code. "file" is fine. Thanks.
"Op Ar" translates to "[file ...]". The current implantation expects
only one file.

> 
> - you need to sync usage()
> 

Thanks.

> - what does "argument ..." represent? i mean, what arguments can be
>   passed? i know its not part of your diff, but i want to make sure that
>   it's not also meant to represent "file".

I have no clue what "argument ..." expects and what it does. I haven't
look to deeply in bt_parse.c.


diff --git a/usr.sbin/btrace/btrace.8 b/usr.sbin/btrace/btrace.8
index b233465185a..8a6532ba682 100644
--- a/usr.sbin/btrace/btrace.8
+++ b/usr.sbin/btrace/btrace.8
@@ -23,8 +23,9 @@
 .Sh SYNOPSIS
 .Nm btrace
 .Op Fl lnv
-.Op Fl e Ar program | Ar file
+.Op Fl e Ar program
 .Op Fl p Ar file
+.Op Ar file
 .Op Ar argument ...
 .Sh DESCRIPTION
 The
@@ -33,7 +34,8 @@ utility provides an interface to inspect the internals of the system and
 programs.
 It interprets the
 .Xr bt 5
-program in
+.Ar program
+or
 .Ar file
 and communicates with the dynamic tracer device using the interface described in
 .Xr dt 4 .
@@ -41,7 +43,8 @@ and communicates with the dynamic tracer device using the interface described in
 The options are as follows:
 .Bl -tag -width Ds
 .It Fl e Ar program
-Execute
+Execute inline
+.Xr bt 5
 .Ar program .
 .It Fl l
 List all available probes.
diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c
index 977c9ed5162..f8556ca26aa 100644
--- a/usr.sbin/btrace/btrace.c
+++ b/usr.sbin/btrace/btrace.c
@@ -231,7 +231,7 @@ main(int argc, char *argv[])
 __dead void
 usage(void)
 {
-	fprintf(stderr, "usage: %s [-lnv] [-e program | file] [-p file] "
+	fprintf(stderr, "usage: %s [-lnv] [-e program] [-p file] [ file ] "
 	    "[argument ...]\n", getprogname());
 	exit(1);
 }