[libcamera-devel] [PATCH] libcamera: log: add colors to log levels

[Laurent Pinchart]

Hi Marco,

On Wed, May 05, 2021 at 05:44:44PM +0200, Marco Felsch wrote:
> On 21-05-05 18:37, Laurent Pinchart wrote:
> > On Wed, May 05, 2021 at 05:33:18PM +0200, Marco Felsch wrote:
> > > Add colored logs if the output belongs to a terminal. This makes it easier
> > > to identitify warnings and/or errors.
> > > 
> > > Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
> > > ---
> > > Hi all,
> > > 
> > > this is an reworked version of [1]. I used by sob and auther since I did
> > > more changes than I kept from [1].
> > > 
> > > [1] 20210203181746.22028-1-m.cichy at pengutronix.de
> > > 
> > >  src/libcamera/log.cpp | 28 ++++++++++++++++++++++++++++
> > >  1 file changed, 28 insertions(+)
> > > 
> > > diff --git a/src/libcamera/log.cpp b/src/libcamera/log.cpp
> > > index 94175ab3..3dffd004 100644
> > > --- a/src/libcamera/log.cpp
> > > +++ b/src/libcamera/log.cpp
> > > @@ -19,6 +19,7 @@
> > >  #include <string.h>
> > >  #include <syslog.h>
> > >  #include <time.h>
> > > +#include <unistd.h>
> > >  #include <unordered_set>
> > >  
> > >  #include <libcamera/logging.h>
> > > @@ -98,6 +99,26 @@ static const char *log_severity_name(LogSeverity severity)
> > >  		return "UNKWN";
> > >  }
> > >  
> > > +static const char *log_severity_color_name(LogSeverity severity)
> > > +{
> > > +	static const char *const names[] = {
> > > +		"\033[1m\033[37mDEBUG\033[0m",
> > > +		"\033[1m\033[32m INFO\033[0m",
> > > +		"\033[1m\033[33m WARN\033[0m",
> > > +		"\033[1m\033[31mERROR\033[0m",
> > > +		"\033[1m\033[35mFATAL\033[0m",
> > > +	};
> > > +
> > > +	/* Only print colored output if output really belongs to a terminal */
> > > +	if (!isatty(fileno(stderr)))
> > 
> > What is the stream that the logger logs to isn't stderr ?
> 
> Hi Laurent,
> 
> According Logger::parseLogFile this can't be the case.

But we also have Logger::logSetStream(), which can be used by
applications to redirect the log output to a custom stream. It gets
called by the global logSetStream() function (declared in the public
include/libcamera/logging.h header).

> > > +		return log_severity_name(severity);
> > > +
> > > +	if (static_cast<unsigned int>(severity) < std::size(names))
> > > +		return names[severity];
> > > +	else
> > > +		return "\033[1m\033[32mUNKWN\033[0m";
> > > +}
> > > +
> > >  /**
> > >   * \brief Log output
> > >   *
> > > @@ -197,6 +218,13 @@ void LogOutput::write(const LogMessage &msg)
> > >  		writeSyslog(msg.severity(), str);
> > >  		break;
> > >  	case LoggingTargetStream:
> > > +		str = "[" + utils::time_point_to_string(msg.timestamp()) + "] ["
> > > +		    + std::to_string(Thread::currentId()) + "] "
> > > +		    + log_severity_color_name(msg.severity()) + " "
> > > +		    + msg.category().name() + " " + msg.fileInfo() + " "
> > > +		    + msg.msg();
> > > +		writeStream(str);
> > > +		break;
> > >  	case LoggingTargetFile:
> > >  		str = "[" + utils::time_point_to_string(msg.timestamp()) + "] ["
> > >  		    + std::to_string(Thread::currentId()) + "] "

-- 
Regards,

Laurent Pinchart