Re: [PATCH v2 4/6] log: Add _perror() logging function variants

On Wed, 19 Jun 2024 12:21:56 +1000 David Gibson wrote:

On Tue, Jun 18, 2024 at 09:14:25AM +0200, Stefano Brivio wrote:

...

In many places, we have direct perror() calls, which completely bypass logging functions and log files.

They are definitely convenient: offer similar convenience with _perror() logging variants, so that we can drop those direct perror() calls.

Signed-off-by: Stefano Brivio --- log.c | 21 +++++++++++++++++++++ log.h | 21 +++++++++++++++++---- 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/log.c b/log.c index 5853496..9ddc58c 100644 --- a/log.c +++ b/log.c @@ -79,6 +79,11 @@ void vlogmsg(int pri, const char *format, va_list ap) } }

+/** + * logmsg() - vlogmsg() wrapper for variable argument lists + * @pri: Facility and level map, same as priority for vsyslog() + * @format: Message + */ void logmsg(int pri, const char *format, ...) { va_list ap; @@ -88,6 +93,22 @@ void logmsg(int pri, const char *format, ...) va_end(ap); }

+/** + * logmsg_perror() - vlogmsg() wrapper with perror()-like functionality + * @pri: Facility and level map, same as priority for vsyslog() + * @format: Message + */ +void logmsg_perror(int pri, const char *format, ...) +{ + va_list ap; + + va_start(ap, format); + vlogmsg(pri, format, ap); + va_end(ap); + + logmsg(pri, ": %s", strerror(errno));

The vlogmsg() above could invoke syscalls which clobber errno, so you need to save it beforehand.

Oops, nice catch. -- Stefano