[PATCH] checkpatch: Print some info if no filenames are given

[PATCH] checkpatch: Print some info if no filenames are given

[Tiezhu Yang]

After commit 45107ff6d526 ("checkpatch: if no filenames then read stdin"),
if no filenames are given, it will read patch from stdin rather than exit
directly, it is better to print some info about what to do next, otherwise
it is a bit confusing whether the script hangs.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 scripts/checkpatch.pl | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 23697a6..d84d4fb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -361,6 +361,8 @@ if ($^V && $^V lt $minimum_perl_version) {
 
 #if no filenames are given, push '-' to read patch from stdin
 if ($#ARGV < 0) {
+	print "$P: missing patchfile or -f file\n";
+	print "Use --help if necessary or read patch from stdin\n";
 	push(@ARGV, '-');
 }
 
-- 
2.1.0

Re: [PATCH] checkpatch: Print some info if no filenames are given

[Joe Perches]

On Sat, 2021-05-15 at 12:15 +0800, Tiezhu Yang wrote:
> After commit 45107ff6d526 ("checkpatch: if no filenames then read stdin"),
> if no filenames are given, it will read patch from stdin rather than exit
> directly, it is better to print some info about what to do next, otherwise
> it is a bit confusing whether the script hangs.

I think this is unnecessary.
It's like trying to make cat without command line arguments emit something.

> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -361,6 +361,8 @@ if ($^V && $^V lt $minimum_perl_version) {
>  
> 
>  #if no filenames are given, push '-' to read patch from stdin
>  if ($#ARGV < 0) {
> +	print "$P: missing patchfile or -f file\n";
> +	print "Use --help if necessary or read patch from stdin\n";
>  	push(@ARGV, '-');
>  }
>  
> 

Re: [PATCH] checkpatch: Print some info if no filenames are given

[Lukas Bulwahn]

On Sat, May 15, 2021 at 6:26 AM Joe Perches <joe@perches.com> wrote:
>
> On Sat, 2021-05-15 at 12:15 +0800, Tiezhu Yang wrote:
> > After commit 45107ff6d526 ("checkpatch: if no filenames then read stdin"),
> > if no filenames are given, it will read patch from stdin rather than exit
> > directly, it is better to print some info about what to do next, otherwise
> > it is a bit confusing whether the script hangs.
>
> I think this is unnecessary.
> It's like trying to make cat without command line arguments emit something.
>

Tiezhu, if you think this behaviour of checkpatch needs a description
and explanation that the informed users* of checkpatch would value,
you may submit a patch to the kernel's checkpatch documentation,
./Documentation/dev-tools/checkpatch.rst (or to see a rendered
version, e.g., https://www.kernel.org/doc/html/latest/dev-tools/checkpatch.html).
You might want to add a few example invocations of checkpatch and then
explain with an example that checkpatch consumes stdin, if no patch
file is given as argument.

Looking forward to your patch to the documentation...

*informed user = "somebody that actually reads the available kernel
documentation on checkpatch"

Lukas