[PATCH v32 11/12] log: colorize log output

[David Marchand <david.marchand@redhat.com>]

From: Stephen Hemminger <stephen@networkplumber.org>

Like dmesg, colorize the log output (unless redirected to file).
Timestamp is green, the subsystem is in yellow and the message is red
if urgent, boldface if an error, and normal for info and debug messages.

The default is to not use color since it may disturb automatic tests
and other embedded usage.

Note: add fileno() and isatty() to the Windows wrapper.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>
---
 app/test/test_eal_flags.c              |  24 +++
 doc/guides/prog_guide/log_lib.rst      |  24 +++
 doc/guides/rel_notes/release_24_11.rst |   2 +
 lib/eal/common/eal_common_options.c    |  11 ++
 lib/eal/common/eal_options.h           |   2 +
 lib/eal/windows/include/rte_os_shim.h  |   2 +
 lib/log/log.c                          |  23 ++-
 lib/log/log_color.c                    | 214 +++++++++++++++++++++++++
 lib/log/log_internal.h                 |   5 +
 lib/log/log_private.h                  |   8 +
 lib/log/meson.build                    |   1 +
 lib/log/version.map                    |   1 +
 12 files changed, 312 insertions(+), 5 deletions(-)
 create mode 100644 lib/log/log_color.c

diff --git a/app/test/test_eal_flags.c b/app/test/test_eal_flags.c
index 1a062fe0e8..d37d6b8627 100644
--- a/app/test/test_eal_flags.c
+++ b/app/test/test_eal_flags.c
@@ -1067,6 +1067,18 @@ test_misc_flags(void)
 	const char * const argv25[] = {prgname, prefix, mp_flag,
 				       "--log-timestamp=invalid" };
 
+	/* Try running with --log-color */
+	const char * const argv26[] = {prgname, prefix, mp_flag,
+				       "--log-color" };
+
+	/* Try running with --log-color=never */
+	const char * const argv27[] = {prgname, prefix, mp_flag,
+				       "--log-color=never" };
+
+	/* Try running with --log-color=invalid */
+	const char * const argv28[] = {prgname, prefix, mp_flag,
+				       "--log-color=invalid" };
+
 	/* run all tests also applicable to FreeBSD first */
 
 	if (launch_proc(argv0) == 0) {
@@ -1186,6 +1198,18 @@ test_misc_flags(void)
 		printf("Error - process did run ok with --log-timestamp=invalid parameter\n");
 		goto fail;
 	}
+	if (launch_proc(argv26) != 0) {
+		printf("Error - process did not run ok with --log-color parameter\n");
+		goto fail;
+	}
+	if (launch_proc(argv27) != 0) {
+		printf("Error - process did not run ok with --log-color=never parameter\n");
+		goto fail;
+	}
+	if (launch_proc(argv28) == 0) {
+		printf("Error - process did run ok with --log-timestamp=invalid parameter\n");
+		goto fail;
+	}
 
 	rmdir(hugepath_dir3);
 	rmdir(hugepath_dir2);
diff --git a/doc/guides/prog_guide/log_lib.rst b/doc/guides/prog_guide/log_lib.rst
index a2e95317f5..3e888b8965 100644
--- a/doc/guides/prog_guide/log_lib.rst
+++ b/doc/guides/prog_guide/log_lib.rst
@@ -59,6 +59,7 @@ For example::
 
 Within an application, the same result can be got using the ``rte_log_set_level_pattern()`` or ``rte_log_set_level_regex()`` APIs.
 
+
 Using Logging APIs to Generate Log Messages
 -------------------------------------------
 
@@ -138,3 +139,26 @@ To prefix all console messages with ISO format time the syntax is::
 
    Timestamp option has no effect if using syslog
    because the ``syslog()`` service already does timestamping internally.
+
+
+Color output
+~~~~~~~~~~~~
+
+The log library will highlight important messages.
+This is controlled by the ``--log-color`` option.
+The optional argument describes when color is enabled:
+
+:never: Do not enable color. This is the default behavior.
+
+:auto: Enable color only when printing to a terminal.
+       This is the same as ``--log-color`` with no argument.
+
+:always: Always print color.
+
+For example to enable color in logs if using terminal::
+
+	/path/to/app --log-color
+
+.. note::
+
+   Color output is never used for syslog or systemd journal logging.
diff --git a/doc/guides/rel_notes/release_24_11.rst b/doc/guides/rel_notes/release_24_11.rst
index 341606f541..543becba28 100644
--- a/doc/guides/rel_notes/release_24_11.rst
+++ b/doc/guides/rel_notes/release_24_11.rst
@@ -128,6 +128,8 @@ New Features
 
   * Log messages can be timestamped with ``--log-timestamp`` option.
 
+  * Log messages can be colorized with the ``--log-color`` option.
+
 * **Updated Marvell cnxk mempool driver.**
 
   * Added mempool driver support for CN20K SoC.
diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
index 7de6a25e62..79db9a47dd 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -73,6 +73,7 @@ eal_long_options[] = {
 	{OPT_HUGE_UNLINK,       2, NULL, OPT_HUGE_UNLINK_NUM      },
 	{OPT_IOVA_MODE,	        1, NULL, OPT_IOVA_MODE_NUM        },
 	{OPT_LCORES,            1, NULL, OPT_LCORES_NUM           },
+	{OPT_LOG_COLOR,		2, NULL, OPT_LOG_COLOR_NUM	  },
 	{OPT_LOG_LEVEL,         1, NULL, OPT_LOG_LEVEL_NUM        },
 	{OPT_LOG_TIMESTAMP,     2, NULL, OPT_LOG_TIMESTAMP_NUM    },
 	{OPT_TRACE,             1, NULL, OPT_TRACE_NUM            },
@@ -1599,6 +1600,7 @@ bool
 eal_option_is_log(int opt)
 {
 	switch (opt) {
+	case OPT_LOG_COLOR_NUM:
 	case OPT_LOG_LEVEL_NUM:
 	case OPT_LOG_TIMESTAMP_NUM:
 	case OPT_SYSLOG_NUM:
@@ -1869,6 +1871,14 @@ eal_parse_common_option(int opt, const char *optarg,
 		}
 		break;
 
+	case OPT_LOG_COLOR_NUM:
+		if (eal_log_color(optarg) < 0) {
+			EAL_LOG(ERR, "invalid parameters for --"
+				OPT_LOG_COLOR);
+			return -1;
+		}
+		break;
+
 #ifndef RTE_EXEC_ENV_WINDOWS
 	case OPT_TRACE_NUM: {
 		if (eal_trace_args_save(optarg) < 0) {
@@ -2235,6 +2245,7 @@ eal_common_usage(void)
 	       "                      Set specific log level\n"
 	       "  --"OPT_LOG_LEVEL"=help    Show log types and levels\n"
 	       "  --"OPT_LOG_TIMESTAMP"[=<format>]  Timestamp log output\n"
+	       "  --"OPT_LOG_COLOR"[=<when>] Colorize log messages\n"
 #ifndef RTE_EXEC_ENV_WINDOWS
 	       "  --"OPT_TRACE"=<regex-match>\n"
 	       "                      Enable trace based on regular expression trace name.\n"
diff --git a/lib/eal/common/eal_options.h b/lib/eal/common/eal_options.h
index a1b52ae694..95fb4f6108 100644
--- a/lib/eal/common/eal_options.h
+++ b/lib/eal/common/eal_options.h
@@ -33,6 +33,8 @@ enum {
 	OPT_HUGE_UNLINK_NUM,
 #define OPT_LCORES            "lcores"
 	OPT_LCORES_NUM,
+#define OPT_LOG_COLOR	      "log-color"
+	OPT_LOG_COLOR_NUM,
 #define OPT_LOG_LEVEL         "log-level"
 	OPT_LOG_LEVEL_NUM,
 #define OPT_LOG_TIMESTAMP     "log-timestamp"
diff --git a/lib/eal/windows/include/rte_os_shim.h b/lib/eal/windows/include/rte_os_shim.h
index 665c9ac93b..0e74eb19c7 100644
--- a/lib/eal/windows/include/rte_os_shim.h
+++ b/lib/eal/windows/include/rte_os_shim.h
@@ -30,6 +30,8 @@
 #define write(fd, buf, n) _write(fd, buf, n)
 #define close(fd) _close(fd)
 #define unlink(path) _unlink(path)
+#define fileno(f) _fileno(f)
+#define isatty(fd) _isatty(fd)
 
 #define IPVERSION	4
 
diff --git a/lib/log/log.c b/lib/log/log.c
index 0974adc81f..eb087d601e 100644
--- a/lib/log/log.c
+++ b/lib/log/log.c
@@ -12,6 +12,7 @@
 #include <regex.h>
 #include <fnmatch.h>
 #include <sys/queue.h>
+#include <unistd.h>
 
 #include <rte_common.h>
 #include <rte_log.h>
@@ -517,12 +518,24 @@ eal_log_init(const char *id)
 			logf = log_syslog_open(id);
 
 		/* if either syslog or journal is used, then no special handling */
-		if (logf)
+		if (logf) {
 			rte_openlog_stream(logf);
-		else if (log_timestamp_enabled())
-			rte_logs.print_func = log_print_with_timestamp;
-		else
-			rte_logs.print_func = vfprintf;
+		} else {
+			bool is_terminal = isatty(fileno(stderr));
+			bool use_color = log_color_enabled(is_terminal);
+
+			if (log_timestamp_enabled()) {
+				if (use_color)
+					rte_logs.print_func = color_print_with_timestamp;
+				else
+					rte_logs.print_func = log_print_with_timestamp;
+			} else {
+				if (use_color)
+					rte_logs.print_func = color_print;
+				else
+					rte_logs.print_func = vfprintf;
+			}
+		}
 	}
 
 #if RTE_LOG_DP_LEVEL >= RTE_LOG_DEBUG
diff --git a/lib/log/log_color.c b/lib/log/log_color.c
new file mode 100644
index 0000000000..04eb5aa485
--- /dev/null
+++ b/lib/log/log_color.c
@@ -0,0 +1,214 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <rte_common.h>
+#include <rte_log.h>
+
+#ifdef RTE_EXEC_ENV_WINDOWS
+#include <rte_os_shim.h>
+#endif
+
+#include "log_internal.h"
+#include "log_private.h"
+
+enum  {
+	LOG_COLOR_AUTO = 0,
+	LOG_COLOR_NEVER,
+	LOG_COLOR_ALWAYS,
+} log_color_mode = LOG_COLOR_NEVER;
+
+enum color {
+	COLOR_NONE,
+	COLOR_RED,
+	COLOR_GREEN,
+	COLOR_YELLOW,
+	COLOR_BLUE,
+	COLOR_MAGENTA,
+	COLOR_CYAN,
+	COLOR_WHITE,
+	COLOR_BOLD,
+	COLOR_CLEAR,
+};
+
+enum log_field {
+	LOG_FIELD_SUBSYS,
+	LOG_FIELD_TIME,
+	LOG_FIELD_ALERT,
+	LOG_FIELD_ERROR,
+	LOG_FIELD_INFO,
+};
+
+static const enum color field_colors[] = {
+	[LOG_FIELD_SUBSYS] = COLOR_YELLOW,
+	[LOG_FIELD_TIME]   = COLOR_GREEN,
+	[LOG_FIELD_ALERT]  = COLOR_RED,
+	[LOG_FIELD_ERROR]  = COLOR_BOLD,
+	[LOG_FIELD_INFO]   = COLOR_NONE,
+};
+
+/* If set all colors are bolder */
+static bool dark_mode;
+
+/* Standard terminal escape codes for colors and bold */
+static const uint8_t color_esc_code[] = {
+	[COLOR_RED]	= 31,
+	[COLOR_GREEN]	= 32,
+	[COLOR_YELLOW]	= 33,
+	[COLOR_BLUE]	= 34,
+	[COLOR_MAGENTA] = 35,
+	[COLOR_CYAN]    = 36,
+	[COLOR_WHITE]	= 37,
+	[COLOR_BOLD]	= 1,
+};
+
+__rte_format_printf(4, 5)
+static int
+color_snprintf(char *buf, size_t len, enum log_field field,
+	       const char *fmt, ...)
+{
+	enum color color = field_colors[field];
+	uint8_t esc = color_esc_code[color];
+	va_list args;
+	int ret = 0;
+
+	va_start(args, fmt);
+	if (esc == 0) {
+		ret = vsnprintf(buf, len, fmt, args);
+	} else {
+		ret = snprintf(buf, len,
+			       dark_mode ? "\033[1;%um" : "\033[%um", esc);
+		ret += vsnprintf(buf + ret, len - ret, fmt, args);
+		ret += snprintf(buf + ret,  len - ret, "%s", "\033[0m");
+	}
+	va_end(args);
+
+	return ret;
+}
+
+/*
+ * Controls whether color is enabled:
+ * modes are:
+ *   always - enable color output regardless
+ *   auto - enable if stderr is a terminal
+ *   never - color output is disabled.
+ */
+int
+eal_log_color(const char *mode)
+{
+	if (mode == NULL || strcmp(mode, "always") == 0)
+		log_color_mode = LOG_COLOR_ALWAYS;
+	else if (strcmp(mode, "never") == 0)
+		log_color_mode = LOG_COLOR_NEVER;
+	else if (strcmp(mode, "auto") == 0)
+		log_color_mode = LOG_COLOR_AUTO;
+	else
+		return -1;
+
+	return 0;
+}
+
+bool
+log_color_enabled(bool is_terminal)
+{
+	char *env, *sep;
+
+	/* Set dark mode using the defacto heuristics used by other programs */
+	env = getenv("COLORFGBG");
+	if (env) {
+		sep = strrchr(env, ';');
+		if (sep &&
+		    ((sep[1] >= '0' && sep[1] <= '6') || sep[1] == '8') &&
+		    sep[2] == '\0')
+			dark_mode = true;
+	}
+
+	if (log_color_mode == LOG_COLOR_ALWAYS)
+		return true;
+	else if (log_color_mode == LOG_COLOR_AUTO)
+		return is_terminal;
+	else
+		return false;
+}
+
+/* Look ast the current message level to determine color of field */
+static enum log_field
+color_msg_field(void)
+{
+	const int level = rte_log_cur_msg_loglevel();
+
+	if (level <= 0 || level >= (int)RTE_LOG_INFO)
+		return LOG_FIELD_INFO;
+	else if (level >= (int)RTE_LOG_ERR)
+		return LOG_FIELD_ERROR;
+	else
+		return LOG_FIELD_ALERT;
+}
+
+__rte_format_printf(3, 0)
+static int
+color_fmt_msg(char *out, size_t len, const char *format, va_list ap)
+{
+	enum log_field field = color_msg_field();
+	char buf[LINE_MAX];
+	int ret = 0;
+
+	/* format raw message */
+	vsnprintf(buf, sizeof(buf), format, ap);
+	const char *msg = buf;
+
+	/*
+	 * use convention that first part of message (up to the ':' character)
+	 * is the subsystem id and should be highlighted.
+	 */
+	const char *cp = strchr(msg, ':');
+	if (cp) {
+		/* print first part in yellow */
+		ret = color_snprintf(out, len, LOG_FIELD_SUBSYS,
+				     "%.*s", (int)(cp - msg + 1), msg);
+		/* skip the first part */
+		msg = cp + 1;
+	}
+
+	ret += color_snprintf(out + ret, len - ret, field, "%s", msg);
+	return ret;
+}
+
+__rte_format_printf(2, 0)
+int
+color_print(FILE *f, const char *format, va_list ap)
+{
+	char out[LINE_MAX];
+
+	/* format raw message */
+	int ret = color_fmt_msg(out, sizeof(out), format, ap);
+	if (fputs(out, f) < 0)
+		return -1;
+
+	return ret;
+}
+
+__rte_format_printf(2, 0)
+int
+color_print_with_timestamp(FILE *f, const char *format, va_list ap)
+{
+	char out[LINE_MAX];
+	char tsbuf[128];
+	int ret = 0;
+
+	if (log_timestamp(tsbuf, sizeof(tsbuf)) > 0)
+		ret = color_snprintf(out, sizeof(out),
+				     LOG_FIELD_TIME, "[%s] ", tsbuf);
+
+	ret += color_fmt_msg(out + ret, sizeof(out) - ret, format, ap);
+	if (fputs(out, f) < 0)
+		return -1;
+
+	return ret;
+}
diff --git a/lib/log/log_internal.h b/lib/log/log_internal.h
index 82fdc21ac2..bba7041ea3 100644
--- a/lib/log/log_internal.h
+++ b/lib/log/log_internal.h
@@ -50,5 +50,10 @@ void rte_eal_log_cleanup(void);
 __rte_internal
 int eal_log_timestamp(const char *fmt);
 
+/*
+ * Enable or disable color in log messages
+ */
+__rte_internal
+int eal_log_color(const char *mode);
 
 #endif /* LOG_INTERNAL_H */
diff --git a/lib/log/log_private.h b/lib/log/log_private.h
index 1b66057fd6..f275346c7b 100644
--- a/lib/log/log_private.h
+++ b/lib/log/log_private.h
@@ -46,4 +46,12 @@ ssize_t log_timestamp(char *tsbuf, size_t tsbuflen);
 __rte_format_printf(2, 0)
 int log_print_with_timestamp(FILE *f, const char *format, va_list ap);
 
+bool log_color_enabled(bool is_tty);
+
+__rte_format_printf(2, 0)
+int color_print(FILE *f, const char *format, va_list ap);
+
+__rte_format_printf(2, 0)
+int color_print_with_timestamp(FILE *f, const char *format, va_list ap);
+
 #endif /* LOG_PRIVATE_H */
diff --git a/lib/log/meson.build b/lib/log/meson.build
index 86e4452b19..b3de57b9c7 100644
--- a/lib/log/meson.build
+++ b/lib/log/meson.build
@@ -4,6 +4,7 @@
 includes += global_inc
 sources = files(
         'log.c',
+        'log_color.c',
         'log_timestamp.c',
 )
 
diff --git a/lib/log/version.map b/lib/log/version.map
index 800d3943bc..09d8a4289b 100644
--- a/lib/log/version.map
+++ b/lib/log/version.map
@@ -25,6 +25,7 @@ DPDK_25 {
 INTERNAL {
 	global:
 
+	eal_log_color;
 	eal_log_init;
 	eal_log_journal; # WINDOWS_NO_EXPORT
 	eal_log_level2str;
-- 
2.47.0