From 01936218a441986666f4e0fcfb4ae8d22f7be891 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 14 Mar 2020 20:30:02 -0400
Subject: [PATCH 01/16] Update usage message

---
 x5/khatus.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/x5/khatus.c b/x5/khatus.c
index ea63fa1..b835ad8 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -133,6 +133,7 @@ print_usage()
 		"  DATA_TTL   = int  (* (positive) number of seconds *)\n"
 		"  OPTION     = -i INTERVAL\n"
 		"             | -s SEPARATOR\n"
+		"             | -x (* Output to X root window *)\n"
 		"  SEPARATOR  = string\n"
 		"  INTERVAL   = int  (* (positive) number of seconds *)\n"
 		"\n",
-- 
2.20.1


From b6316e94783d975f109c9901e4061ba041f0cb3f Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 14 Mar 2020 21:14:30 -0400
Subject: [PATCH 02/16] Implement log levels

---
 x5/khatus.c | 81 ++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 62 insertions(+), 19 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index b835ad8..37cbccc 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -15,9 +15,9 @@
 
 #include "bsdtimespec.h"
 
-#define debug(args...) {fprintf(stderr, "[debug] " args); fflush(stderr);}
-#define info( args...) {fprintf(stderr, "[info] "  args); fflush(stderr);}
-#define error(args...) {fprintf(stderr, "[error] " args); fflush(stderr);}
+#define debug(args...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " args); fflush(stderr);}
+#define info( args...) if (cfg->log_level >= Info ) {fprintf(stderr, "[info] "  args); fflush(stderr);}
+#define error(args...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " args); fflush(stderr);}
 #define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
 #define usage(args...) {print_usage(); fatal("[usage] " args);}
 
@@ -28,6 +28,13 @@ static const int  errlen   = sizeof(ERRMSG) - 1;
 
 char *argv0;
 
+typedef enum LogLevel {
+	Nothing,
+	Error,
+	Info,
+	Debug
+} LogLevel;
+
 /* TODO: Convert fifo list to fifo array. */
 typedef struct Fifo Fifo;
 struct Fifo {
@@ -48,6 +55,7 @@ struct Config {
 	int    fifo_count;
 	int    total_width;
 	int    output_to_x_root_window;
+	LogLevel log_level;
 } defaults = {
 	.interval    = 1,
 	.separator   = "|",
@@ -55,12 +63,13 @@ struct Config {
 	.fifo_count  = 0,
 	.total_width = 0,
 	.output_to_x_root_window = 0,
+	.log_level   = Info,
 };
 
 void
-fifo_print_one(Fifo *f)
+fifo_print_one(Fifo *f, Config *cfg)
 {
-	debug(
+	info(
 		"Fifo "
 		"{"
 			" name = %s,"
@@ -82,31 +91,33 @@ fifo_print_one(Fifo *f)
 }
 
 void
-fifo_print_all(Fifo *head)
+fifo_print_all(Fifo *head, Config *cfg)
 {
 	for (Fifo *f = head; f; f = f->next) {
-		fifo_print_one(f);
+		fifo_print_one(f, cfg);
 	}
 }
 
 void
-config_print(Config *c)
+config_print(Config *cfg)
 {
-	debug(
+	info(
 		"Config "
 		"{"
 			" interval = %d,"
 			" separator = %s,"
 			" fifo_count = %d,"
 			" total_width = %d,"
+			" log_level = %d,"
 			" fifos = ..."
 		" }\n",
-		c->interval,
-		c->separator,
-		c->fifo_count,
-		c->total_width
+		cfg->interval,
+		cfg->separator,
+		cfg->fifo_count,
+		cfg->total_width,
+		cfg->log_level
 	);
-	fifo_print_all(c->fifos);
+	fifo_print_all(cfg->fifos, cfg);
 }
 
 int
@@ -134,10 +145,14 @@ print_usage()
 		"  OPTION     = -i INTERVAL\n"
 		"             | -s SEPARATOR\n"
 		"             | -x (* Output to X root window *)\n"
+		"             | -l LOG_LEVEL\n"
 		"  SEPARATOR  = string\n"
 		"  INTERVAL   = int  (* (positive) number of seconds *)\n"
+		"  LOG_LEVEL  = int  (* %d through %d *)\n"
 		"\n",
-		argv0
+		argv0,
+		Nothing,
+		Debug
 	);
 	fprintf(
 		stderr,
@@ -178,6 +193,30 @@ parse_opts_opt_s(Config *cfg, int argc, char *argv[], int i)
 	}
 }
 
+void
+parse_opts_opt_l(Config *cfg, int argc, char *argv[], int i)
+{
+	int log_level;
+
+	if (i < argc) {
+		char *param = argv[i++];
+
+		if (is_pos_num(param)) {
+			log_level = atoi(param);
+			if (log_level <= Debug) {
+				cfg->log_level = log_level;
+				opts_parse_any(cfg, argc, argv, i);
+			} else {
+				usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
+			}
+		} else {
+			usage("Option -l parameter is invalid: \"%s\"\n", param);
+		}
+	} else {
+		usage("Option -l parameter is missing.\n");
+	}
+}
+
 void
 parse_opts_opt(Config *cfg, int argc, char *argv[], int i)
 {
@@ -194,6 +233,10 @@ parse_opts_opt(Config *cfg, int argc, char *argv[], int i)
 			cfg->output_to_x_root_window = 1;
 			opts_parse_any(cfg, argc, argv, ++i);
 			break;
+		case 'l':
+			/* TODO: Generic set_int */
+			parse_opts_opt_l(cfg, argc, argv, ++i);
+			break;
 		default :
 			usage("Option \"%s\" is invalid\n", argv[i]);
 	}
@@ -278,7 +321,7 @@ fifo_read_error(Fifo *f, char *buf)
 }
 
 void
-fifo_read_one(Fifo *f, char *buf)
+fifo_read_one(Fifo *f, char *buf, Config *cfg)
 {
 	ssize_t current;
 	ssize_t total;
@@ -345,13 +388,13 @@ fifo_read_all(Config *cfg, char *buf)
 	for (Fifo *f = cfg->fifos; f; f = f->next) {
 		if (FD_ISSET(f->fd, &fds)) {
 			debug("reading: %s\n", f->name);
-			fifo_read_one(f, buf);
+			fifo_read_one(f, buf, cfg);
 		}
 	}
 }
 
 void
-snooze(struct timespec *t)
+snooze(struct timespec *t, Config *cfg)
 {
 	struct timespec remainder;
 	int result;
@@ -474,7 +517,7 @@ main(int argc, char *argv[])
 			 */
 			timespecsub(&ti, &td, &tc);
 			debug("snooze YES\n");
-			snooze(&tc);
+			snooze(&tc, cfg);
 		} else
 			debug("snooze NO\n");
 	}
-- 
2.20.1


From 64bb32bdd2a5cf0624b34036cfca7d8006f7537f Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 14 Mar 2020 21:26:55 -0400
Subject: [PATCH 03/16] Update README

---
 README.md | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index ca1fcf1..4fa29a2 100644
--- a/README.md
+++ b/README.md
@@ -12,10 +12,10 @@ Experiments
 The approaches experimented-with so far (later versions do not _necessarily_
 obsolete earlier ones, they're just different):
 
-| Name   | Status    | Language  | Tested-on    | Description |
-|--------|-----------|-----------|--------------|-------------|
-| __x1__ | Archived  | Bash, AWK | Ubuntu 16.04 | Single, synchronous script, saving state in text files |
-| __x2__ | In-use    | Bash, AWK | Debian 10    | Parallel processes: collectors, cache and reporters; passing messages over pipes |
-| __x3__ | Scratched | OCaml     | Debian 10    | Re-write and refinement of __x2__ |
-| __x4__ | Prototype | Dash, AWK | Debian 10    | Sensors are completely decoupled daemons, cache is a file tree |
-| __x5__ | In-dev    | C         | Debian 10    | Re-implementation of __x4__ in C |
+| Name   | Status    | Language  | Tested-on               | Description |
+|--------|-----------|-----------|-------------------------|-------------|
+| __x1__ | Archived  | Bash, AWK |            Ubuntu 16.04 | Single, synchronous script, saving state in text files |
+| __x2__ | In-use    | Bash, AWK | Debian 10, Ubuntu 18.04 | Parallel processes: collectors, cache and reporters; passing messages through a single named pipe |
+| __x3__ | Scratched | OCaml     | Debian 10               | Re-write and refinement of __x2__ |
+| __x4__ | Prototype | Dash, AWK | Debian 10               | Sensors are completely decoupled daemons, cache is a file tree |
+| __x5__ | In-dev    | C         |            Ubuntu 18.04 | Sensors are completely decoupled daemons, writing to dedicated named pipes, bar repeatedly `select`s and reads the pipes. |
-- 
2.20.1


From dbdf0f7b374e9fdde3804fc11f25f5f60ccb5c88 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 14 Mar 2020 21:39:22 -0400
Subject: [PATCH 04/16] Revise status nomenclature

---
 README.md | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 4fa29a2..6b87dad 100644
--- a/README.md
+++ b/README.md
@@ -12,10 +12,10 @@ Experiments
 The approaches experimented-with so far (later versions do not _necessarily_
 obsolete earlier ones, they're just different):
 
-| Name   | Status    | Language  | Tested-on               | Description |
-|--------|-----------|-----------|-------------------------|-------------|
-| __x1__ | Archived  | Bash, AWK |            Ubuntu 16.04 | Single, synchronous script, saving state in text files |
-| __x2__ | In-use    | Bash, AWK | Debian 10, Ubuntu 18.04 | Parallel processes: collectors, cache and reporters; passing messages through a single named pipe |
-| __x3__ | Scratched | OCaml     | Debian 10               | Re-write and refinement of __x2__ |
-| __x4__ | Prototype | Dash, AWK | Debian 10               | Sensors are completely decoupled daemons, cache is a file tree |
-| __x5__ | In-dev    | C         |            Ubuntu 18.04 | Sensors are completely decoupled daemons, writing to dedicated named pipes, bar repeatedly `select`s and reads the pipes. |
+| Name   | Status              | Language  | Tested-on               | Description |
+|--------|---------------------|-----------|-------------------------|-------------|
+| __x1__ | Archive,   complete | Bash, AWK |            Ubuntu 16.04 | Single, synchronous script, saving state in text files |
+| __x2__ | Legacy ,   complete | Bash, AWK | Debian 10, Ubuntu 18.04 | Parallel processes: collectors, cache and reporters; passing messages through a single named pipe |
+| __x3__ | Archive, incomplete | OCaml     | Debian 10               | Re-write and refinement of __x2__ |
+| __x4__ | Archive, incomplete | Dash, AWK | Debian 10               | Sensors are completely decoupled daemons, cache is a file tree |
+| __x5__ | Current, incomplete | C         |            Ubuntu 18.04 | Sensors are completely decoupled daemons, writing to dedicated named pipes, bar repeatedly `select`s and reads the pipes. |
-- 
2.20.1


From 4c438cef6b69db82d2835d2c32d41fae12c93016 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 14 Mar 2020 22:07:59 -0400
Subject: [PATCH 05/16] Invert nesting of error checking

which reduces nesting levels.
---
 x5/khatus.c | 53 +++++++++++++++++++++--------------------------------
 1 file changed, 21 insertions(+), 32 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index 37cbccc..3d81cad 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -167,54 +167,43 @@ void opts_parse_any(Config *, int, char *[], int);  /* For mutually-recursive ca
 void
 parse_opts_opt_i(Config *cfg, int argc, char *argv[], int i)
 {
-	if (i < argc) {
-		char *param = argv[i++];
+	char *param;
 
-		if (is_pos_num(param)) {
-			cfg->interval = atoi(param);
-			opts_parse_any(cfg, argc, argv, i);
-		} else {
-			usage("Option -i parameter is invalid: \"%s\"\n", param);
-		}
-	} else {
+	if (i >= argc)
 		usage("Option -i parameter is missing.\n");
-	}
+	param = argv[i++];
+	if (!is_pos_num(param))
+		usage("Option -i parameter is invalid: \"%s\"\n", param);
+	cfg->interval = atoi(param);
+	opts_parse_any(cfg, argc, argv, i);
 }
 
 void
 parse_opts_opt_s(Config *cfg, int argc, char *argv[], int i)
 {
-	if (i < argc) {
-		cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
-		strcpy(cfg->separator, argv[i]);
-		opts_parse_any(cfg, argc, argv, ++i);
-	} else {
+	if (i >= argc)
 		usage("Option -s parameter is missing.\n");
-	}
+	cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
+	strcpy(cfg->separator, argv[i]);
+	opts_parse_any(cfg, argc, argv, ++i);
 }
 
 void
 parse_opts_opt_l(Config *cfg, int argc, char *argv[], int i)
 {
+	char *param;
 	int log_level;
 
-	if (i < argc) {
-		char *param = argv[i++];
-
-		if (is_pos_num(param)) {
-			log_level = atoi(param);
-			if (log_level <= Debug) {
-				cfg->log_level = log_level;
-				opts_parse_any(cfg, argc, argv, i);
-			} else {
-				usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
-			}
-		} else {
-			usage("Option -l parameter is invalid: \"%s\"\n", param);
-		}
-	} else {
+	if (i >= argc)
 		usage("Option -l parameter is missing.\n");
-	}
+	param = argv[i++];
+	if (!is_pos_num(param))
+		usage("Option -l parameter is invalid: \"%s\"\n", param);
+	log_level = atoi(param);
+	if (log_level > Debug)
+		usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
+	cfg->log_level = log_level;
+	opts_parse_any(cfg, argc, argv, i);
 }
 
 void
-- 
2.20.1


From ce552549378d618f5915f06217626fcdc2b1fc8c Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 14 Mar 2020 22:19:47 -0400
Subject: [PATCH 06/16] Reduce switch case nesting

---
 x5/khatus.c | 46 +++++++++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index 3d81cad..d95390a 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -210,24 +210,24 @@ void
 parse_opts_opt(Config *cfg, int argc, char *argv[], int i)
 {
 	switch (argv[i][1]) {
-		case 'i':
-			/* TODO: Generic set_int */
-			parse_opts_opt_i(cfg, argc, argv, ++i);
-			break;
-		case 's':
-			/* TODO: Generic set_str */
-			parse_opts_opt_s(cfg, argc, argv, ++i);
-			break;
-		case 'x':
-			cfg->output_to_x_root_window = 1;
-			opts_parse_any(cfg, argc, argv, ++i);
-			break;
-		case 'l':
-			/* TODO: Generic set_int */
-			parse_opts_opt_l(cfg, argc, argv, ++i);
-			break;
-		default :
-			usage("Option \"%s\" is invalid\n", argv[i]);
+	case 'i':
+		/* TODO: Generic set_int */
+		parse_opts_opt_i(cfg, argc, argv, ++i);
+		break;
+	case 's':
+		/* TODO: Generic set_str */
+		parse_opts_opt_s(cfg, argc, argv, ++i);
+		break;
+	case 'x':
+		cfg->output_to_x_root_window = 1;
+		opts_parse_any(cfg, argc, argv, ++i);
+		break;
+	case 'l':
+		/* TODO: Generic set_int */
+		parse_opts_opt_l(cfg, argc, argv, ++i);
+		break;
+	default :
+		usage("Option \"%s\" is invalid\n", argv[i]);
 	}
 }
 
@@ -269,11 +269,11 @@ opts_parse_any(Config *cfg, int argc, char *argv[], int i)
 {
 	if (i < argc) {
 		switch (argv[i][0]) {
-			case '-':
-				parse_opts_opt(cfg, argc, argv, i);
-				break;
-			default :
-				parse_opts_spec(cfg, argc, argv, i);
+		case '-':
+			parse_opts_opt(cfg, argc, argv, i);
+			break;
+		default :
+			parse_opts_spec(cfg, argc, argv, i);
 		}
 	}
 }
-- 
2.20.1


From a6b13fa2d61136a971b2ebbf6eadb943002fa9d5 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sun, 15 Mar 2020 01:50:43 -0400
Subject: [PATCH 07/16] Fix second level indent - should be four spaces

---
 x5/khatus.c | 115 ++++++++++++++++++++++++++--------------------------
 1 file changed, 57 insertions(+), 58 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index d95390a..ee96d60 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -69,24 +69,23 @@ struct Config {
 void
 fifo_print_one(Fifo *f, Config *cfg)
 {
-	info(
-		"Fifo "
-		"{"
-			" name = %s,"
-			" fd = %d,"
-			" width = %d,"
-			" last_read = %d,"
-			" ttl = %d,"
-			" pos = %d,"
-			" next = %p,"
-		" }\n",
-		f->name,
-		f->fd,
-		f->width,
-		f->last_read,
-		f->ttl,
-		f->pos,
-		f->next
+	info("Fifo "
+	    "{"
+	    " name = %s,"
+	    " fd = %d,"
+	    " width = %d,"
+	    " last_read = %d,"
+	    " ttl = %d,"
+	    " pos = %d,"
+	    " next = %p,"
+	    " }\n",
+	    f->name,
+	    f->fd,
+	    f->width,
+	    f->last_read,
+	    f->ttl,
+	    f->pos,
+	    f->next
 	);
 }
 
@@ -102,20 +101,20 @@ void
 config_print(Config *cfg)
 {
 	info(
-		"Config "
-		"{"
-			" interval = %d,"
-			" separator = %s,"
-			" fifo_count = %d,"
-			" total_width = %d,"
-			" log_level = %d,"
-			" fifos = ..."
-		" }\n",
-		cfg->interval,
-		cfg->separator,
-		cfg->fifo_count,
-		cfg->total_width,
-		cfg->log_level
+	    "Config "
+	    "{"
+	    " interval = %d,"
+	    " separator = %s,"
+	    " fifo_count = %d,"
+	    " total_width = %d,"
+	    " log_level = %d,"
+	    " fifos = ..."
+	    " }\n",
+	    cfg->interval,
+	    cfg->separator,
+	    cfg->fifo_count,
+	    cfg->total_width,
+	    cfg->log_level
 	);
 	fifo_print_all(cfg->fifos, cfg);
 }
@@ -134,31 +133,31 @@ print_usage()
 {
 	assert(argv0);
 	fprintf(
-		stderr,
-		"\n"
-		"Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
-		"\n"
-		"  SPEC       = FILE_PATH DATA_WIDTH DATA_TTL\n"
-		"  FILE_PATH  = string\n"
-		"  DATA_WIDTH = int  (* (positive) number of characters *)\n"
-		"  DATA_TTL   = int  (* (positive) number of seconds *)\n"
-		"  OPTION     = -i INTERVAL\n"
-		"             | -s SEPARATOR\n"
-		"             | -x (* Output to X root window *)\n"
-		"             | -l LOG_LEVEL\n"
-		"  SEPARATOR  = string\n"
-		"  INTERVAL   = int  (* (positive) number of seconds *)\n"
-		"  LOG_LEVEL  = int  (* %d through %d *)\n"
-		"\n",
-		argv0,
-		Nothing,
-		Debug
+	    stderr,
+	    "\n"
+	    "Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
+	    "\n"
+	    "  SPEC       = FILE_PATH DATA_WIDTH DATA_TTL\n"
+	    "  FILE_PATH  = string\n"
+	    "  DATA_WIDTH = int  (* (positive) number of characters *)\n"
+	    "  DATA_TTL   = int  (* (positive) number of seconds *)\n"
+	    "  OPTION     = -i INTERVAL\n"
+	    "             | -s SEPARATOR\n"
+	    "             | -x (* Output to X root window *)\n"
+	    "             | -l LOG_LEVEL\n"
+	    "  SEPARATOR  = string\n"
+	    "  INTERVAL   = int  (* (positive) number of seconds *)\n"
+	    "  LOG_LEVEL  = int  (* %d through %d *)\n"
+	    "\n",
+	    argv0,
+	    Nothing,
+	    Debug
 	);
 	fprintf(
-		stderr,
-		"Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
-		"\n",
-		argv0
+	    stderr,
+	    "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
+	    "\n",
+	    argv0
 	);
 }
 
@@ -393,9 +392,9 @@ snooze(struct timespec *t, Config *cfg)
 	if (result < 0) {
 		if (errno == EINTR) {
 			info(
-				"nanosleep interrupted. Remainder: "
-				"{ tv_sec = %ld, tv_nsec = %ld }",
-				remainder.tv_sec, remainder.tv_nsec);
+			    "nanosleep interrupted. Remainder: "
+			    "{ tv_sec = %ld, tv_nsec = %ld }",
+			    remainder.tv_sec, remainder.tv_nsec);
 			/* No big deal if we occasionally sleep less,
 			 * so not attempting to correct after an interruption.
 			 */
-- 
2.20.1


From 574a4bff980c2e56c603c81e8c2773e42b4baf71 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sun, 15 Mar 2020 02:26:12 -0400
Subject: [PATCH 08/16] Use braces in elses which follow multi-statement ifs

---
 x5/khatus.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index ee96d60..db800ea 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -325,9 +325,10 @@ fifo_read_one(Fifo *f, char *buf, Config *cfg)
 	if (current == -1) {
 		error("Failed to read: \"%s\". Error: %s\n", f->name, strerror(errno));
 		fifo_read_error(f, buf);
-	} else
+	} else {
 		while (total++ < f->width)
 			*b++ = ' ';
+	}
 	/* TODO Record timestamp read */
 	close(f->fd);
 	f->fd = -1;
@@ -506,8 +507,9 @@ main(int argc, char *argv[])
 			timespecsub(&ti, &td, &tc);
 			debug("snooze YES\n");
 			snooze(&tc, cfg);
-		} else
+		} else {
 			debug("snooze NO\n");
+		}
 	}
 
 	return EXIT_SUCCESS;
-- 
2.20.1


From 7911aa98ea23b71ca4249621bcf861d9f6ca34f4 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 16 Mar 2020 14:42:07 -0400
Subject: [PATCH 09/16] Add warn log level

---
 x5/khatus.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index db800ea..bb76507 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -17,6 +17,7 @@
 
 #define debug(args...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " args); fflush(stderr);}
 #define info( args...) if (cfg->log_level >= Info ) {fprintf(stderr, "[info] "  args); fflush(stderr);}
+#define warn( args...) if (cfg->log_level >= Warn ) {fprintf(stderr, "[warn] "  args); fflush(stderr);}
 #define error(args...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " args); fflush(stderr);}
 #define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
 #define usage(args...) {print_usage(); fatal("[usage] " args);}
@@ -31,6 +32,7 @@ char *argv0;
 typedef enum LogLevel {
 	Nothing,
 	Error,
+	Warn,
 	Info,
 	Debug
 } LogLevel;
@@ -392,7 +394,7 @@ snooze(struct timespec *t, Config *cfg)
 
 	if (result < 0) {
 		if (errno == EINTR) {
-			info(
+			warn(
 			    "nanosleep interrupted. Remainder: "
 			    "{ tv_sec = %ld, tv_nsec = %ld }",
 			    remainder.tv_sec, remainder.tv_nsec);
-- 
2.20.1


From 61e033f5d4e3e6080b194cc3a0ede0ae40976464 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 16 Mar 2020 15:55:45 -0400
Subject: [PATCH 10/16] Use __VA_ARGS__ instead of named param

---
 x5/khatus.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index bb76507..16c9a56 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -15,12 +15,12 @@
 
 #include "bsdtimespec.h"
 
-#define debug(args...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " args); fflush(stderr);}
-#define info( args...) if (cfg->log_level >= Info ) {fprintf(stderr, "[info] "  args); fflush(stderr);}
-#define warn( args...) if (cfg->log_level >= Warn ) {fprintf(stderr, "[warn] "  args); fflush(stderr);}
-#define error(args...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " args); fflush(stderr);}
-#define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
-#define usage(args...) {print_usage(); fatal("[usage] " args);}
+#define debug(...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " __VA_ARGS__); fflush(stderr);}
+#define info(...)  if (cfg->log_level >= Info ) {fprintf(stderr, "[info] "  __VA_ARGS__); fflush(stderr);}
+#define warn(...)  if (cfg->log_level >= Warn ) {fprintf(stderr, "[warn] "  __VA_ARGS__); fflush(stderr);}
+#define error(...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " __VA_ARGS__); fflush(stderr);}
+#define fatal(...) {fprintf(stderr, "[fatal] " __VA_ARGS__); exit(EXIT_FAILURE);}
+#define usage(...) {print_usage(); fatal("[usage] " __VA_ARGS__);}
 
 #define ERRMSG "ERROR"
 
-- 
2.20.1


From 4dc09422dcd8b69ad8095bf664a7346291eb95b8 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 16 Mar 2020 16:25:47 -0400
Subject: [PATCH 11/16] Build as C99

---
 x5/Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/x5/Makefile b/x5/Makefile
index 59d115b..585ca12 100644
--- a/x5/Makefile
+++ b/x5/Makefile
@@ -1,5 +1,6 @@
-CFLAGS := -Wall -Wextra
-LDLIBS := -lX11
+CPPFLAGS := -D_POSIX_C_SOURCE=200809L
+CFLAGS   := -std=c99 -Wall -Wextra
+LDLIBS   := -lX11
 
 .PHONY: build clean rebuild
 
-- 
2.20.1


From 17a27e4866eb3e245e17dc211b4469f1c5aa3f1e Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 16 Mar 2020 18:45:26 -0400
Subject: [PATCH 12/16] Break-out logging and time-related functions into lib
 modules

---
 x5/Makefile          | 12 +++++++--
 x5/khatus.c          | 63 +++++++++-----------------------------------
 x5/khatus_lib_log.c  | 17 ++++++++++++
 x5/khatus_lib_log.h  | 17 ++++++++++++
 x5/khatus_lib_time.c | 31 ++++++++++++++++++++++
 x5/khatus_lib_time.h |  1 +
 6 files changed, 88 insertions(+), 53 deletions(-)
 create mode 100644 x5/khatus_lib_log.c
 create mode 100644 x5/khatus_lib_log.h
 create mode 100644 x5/khatus_lib_time.c
 create mode 100644 x5/khatus_lib_time.h

diff --git a/x5/Makefile b/x5/Makefile
index 585ca12..1a356f5 100644
--- a/x5/Makefile
+++ b/x5/Makefile
@@ -4,10 +4,18 @@ LDLIBS   := -lX11
 
 .PHONY: build clean rebuild
 
-build: khatus
+build: \
+    khatus
+
+khatus: \
+	khatus_lib_log.o \
+	khatus_lib_time.o
+
+khatus_lib_time.o: khatus_lib_log.o
 
 clean:
-	@ find . -type f -executable -delete
+	@find . -type f -executable -delete
+	@find . -type f -name '*.o' -delete
 
 rebuild:
 	@$(MAKE) -s clean
diff --git a/x5/khatus.c b/x5/khatus.c
index 16c9a56..e0b71cd 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -14,14 +14,10 @@
 #include <X11/Xlib.h>
 
 #include "bsdtimespec.h"
+#include "khatus_lib_log.h"
+#include "khatus_lib_time.h"
 
-#define debug(...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " __VA_ARGS__); fflush(stderr);}
-#define info(...)  if (cfg->log_level >= Info ) {fprintf(stderr, "[info] "  __VA_ARGS__); fflush(stderr);}
-#define warn(...)  if (cfg->log_level >= Warn ) {fprintf(stderr, "[warn] "  __VA_ARGS__); fflush(stderr);}
-#define error(...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " __VA_ARGS__); fflush(stderr);}
-#define fatal(...) {fprintf(stderr, "[fatal] " __VA_ARGS__); exit(EXIT_FAILURE);}
-#define usage(...) {print_usage(); fatal("[usage] " __VA_ARGS__);}
-
+#define usage(...) {print_usage(); fprintf(stderr, "Error:\n    " __VA_ARGS__); exit(EXIT_FAILURE);}
 #define ERRMSG "ERROR"
 
 static const char errmsg[] = ERRMSG;
@@ -29,14 +25,6 @@ static const int  errlen   = sizeof(ERRMSG) - 1;
 
 char *argv0;
 
-typedef enum LogLevel {
-	Nothing,
-	Error,
-	Warn,
-	Info,
-	Debug
-} LogLevel;
-
 /* TODO: Convert fifo list to fifo array. */
 typedef struct Fifo Fifo;
 struct Fifo {
@@ -57,7 +45,6 @@ struct Config {
 	int    fifo_count;
 	int    total_width;
 	int    output_to_x_root_window;
-	LogLevel log_level;
 } defaults = {
 	.interval    = 1,
 	.separator   = "|",
@@ -65,11 +52,10 @@ struct Config {
 	.fifo_count  = 0,
 	.total_width = 0,
 	.output_to_x_root_window = 0,
-	.log_level   = Info,
 };
 
 void
-fifo_print_one(Fifo *f, Config *cfg)
+fifo_print_one(Fifo *f)
 {
 	info("Fifo "
 	    "{"
@@ -92,10 +78,10 @@ fifo_print_one(Fifo *f, Config *cfg)
 }
 
 void
-fifo_print_all(Fifo *head, Config *cfg)
+fifo_print_all(Fifo *head)
 {
 	for (Fifo *f = head; f; f = f->next) {
-		fifo_print_one(f, cfg);
+		fifo_print_one(f);
 	}
 }
 
@@ -109,16 +95,14 @@ config_print(Config *cfg)
 	    " separator = %s,"
 	    " fifo_count = %d,"
 	    " total_width = %d,"
-	    " log_level = %d,"
 	    " fifos = ..."
 	    " }\n",
 	    cfg->interval,
 	    cfg->separator,
 	    cfg->fifo_count,
-	    cfg->total_width,
-	    cfg->log_level
+	    cfg->total_width
 	);
-	fifo_print_all(cfg->fifos, cfg);
+	fifo_print_all(cfg->fifos);
 }
 
 int
@@ -203,7 +187,7 @@ parse_opts_opt_l(Config *cfg, int argc, char *argv[], int i)
 	log_level = atoi(param);
 	if (log_level > Debug)
 		usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
-	cfg->log_level = log_level;
+	_khatus_lib_log_level = log_level;
 	opts_parse_any(cfg, argc, argv, i);
 }
 
@@ -311,7 +295,7 @@ fifo_read_error(Fifo *f, char *buf)
 }
 
 void
-fifo_read_one(Fifo *f, char *buf, Config *cfg)
+fifo_read_one(Fifo *f, char *buf)
 {
 	ssize_t current;
 	ssize_t total;
@@ -379,30 +363,7 @@ fifo_read_all(Config *cfg, char *buf)
 	for (Fifo *f = cfg->fifos; f; f = f->next) {
 		if (FD_ISSET(f->fd, &fds)) {
 			debug("reading: %s\n", f->name);
-			fifo_read_one(f, buf, cfg);
-		}
-	}
-}
-
-void
-snooze(struct timespec *t, Config *cfg)
-{
-	struct timespec remainder;
-	int result;
-
-	result = nanosleep(t, &remainder);
-
-	if (result < 0) {
-		if (errno == EINTR) {
-			warn(
-			    "nanosleep interrupted. Remainder: "
-			    "{ tv_sec = %ld, tv_nsec = %ld }",
-			    remainder.tv_sec, remainder.tv_nsec);
-			/* No big deal if we occasionally sleep less,
-			 * so not attempting to correct after an interruption.
-			 */
-		} else {
-			fatal("nanosleep: %s\n", strerror(errno));
+			fifo_read_one(f, buf);
 		}
 	}
 }
@@ -508,7 +469,7 @@ main(int argc, char *argv[])
 			 */
 			timespecsub(&ti, &td, &tc);
 			debug("snooze YES\n");
-			snooze(&tc, cfg);
+			snooze(&tc);
 		} else {
 			debug("snooze NO\n");
 		}
diff --git a/x5/khatus_lib_log.c b/x5/khatus_lib_log.c
new file mode 100644
index 0000000..16a5509
--- /dev/null
+++ b/x5/khatus_lib_log.c
@@ -0,0 +1,17 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "khatus_lib_log.h"
+
+LogLevel _khatus_lib_log_level = Debug;
+
+void
+_fatal(char *fmt, ...) {
+	va_list ap;
+
+	va_start(ap, fmt);
+	fprintf(stderr, fmt, ap);
+	va_end(ap);
+	exit(EXIT_FAILURE);
+}
diff --git a/x5/khatus_lib_log.h b/x5/khatus_lib_log.h
new file mode 100644
index 0000000..ca93ddd
--- /dev/null
+++ b/x5/khatus_lib_log.h
@@ -0,0 +1,17 @@
+#define debug(...) if (_khatus_lib_log_level >= Debug) {fprintf(stderr, "[debug] " __VA_ARGS__); fflush(stderr);}
+#define info(...)  if (_khatus_lib_log_level >= Info ) {fprintf(stderr, "[info] "  __VA_ARGS__); fflush(stderr);}
+#define warn(...)  if (_khatus_lib_log_level >= Warn ) {fprintf(stderr, "[warn] "  __VA_ARGS__); fflush(stderr);}
+#define error(...) if (_khatus_lib_log_level >= Error) {fprintf(stderr, "[error] " __VA_ARGS__); fflush(stderr);}
+#define fatal(...) _fatal("[fatal] " __VA_ARGS__)
+
+typedef enum LogLevel {
+	Nothing,
+	Error,
+	Warn,
+	Info,
+	Debug
+} LogLevel;
+
+void _fatal(char *, ...);
+
+LogLevel _khatus_lib_log_level;
diff --git a/x5/khatus_lib_time.c b/x5/khatus_lib_time.c
new file mode 100644
index 0000000..ba74226
--- /dev/null
+++ b/x5/khatus_lib_time.c
@@ -0,0 +1,31 @@
+#include <errno.h>
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include "khatus_lib_log.h"
+#include "khatus_lib_time.h"
+
+void
+snooze(struct timespec *t)
+{
+	struct timespec remainder;
+	int result;
+
+	result = nanosleep(t, &remainder);
+
+	if (result < 0) {
+		if (errno == EINTR) {
+			warn(
+			    "nanosleep interrupted. Remainder: "
+			    "{ tv_sec = %ld, tv_nsec = %ld }",
+			    remainder.tv_sec, remainder.tv_nsec);
+			/* No big deal if we occasionally sleep less,
+			 * so not attempting to correct after an interruption.
+			 */
+		} else {
+			fatal("nanosleep: %s\n", strerror(errno));
+		}
+	}
+}
diff --git a/x5/khatus_lib_time.h b/x5/khatus_lib_time.h
new file mode 100644
index 0000000..2d16d65
--- /dev/null
+++ b/x5/khatus_lib_time.h
@@ -0,0 +1 @@
+void snooze(struct timespec *);
-- 
2.20.1


From 8345f2b388e0986829ceeae50ecf186d5d540a9c Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 16 Mar 2020 18:48:38 -0400
Subject: [PATCH 13/16] Implement time sensor

---
 x5/.gitignore           |  1 +
 x5/Makefile             |  7 ++++-
 x5/khatus_lib_time.c    | 14 +++++++++
 x5/khatus_lib_time.h    |  2 ++
 x5/khatus_sensor_time.c | 65 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 x5/khatus_sensor_time.c

diff --git a/x5/.gitignore b/x5/.gitignore
index fa71cac..09901ba 100644
--- a/x5/.gitignore
+++ b/x5/.gitignore
@@ -1,2 +1,3 @@
 *.o
 khatus
+khatus_sensor_time
diff --git a/x5/Makefile b/x5/Makefile
index 1a356f5..c6a0576 100644
--- a/x5/Makefile
+++ b/x5/Makefile
@@ -5,12 +5,17 @@ LDLIBS   := -lX11
 .PHONY: build clean rebuild
 
 build: \
-    khatus
+    khatus \
+    khatus_sensor_time
 
 khatus: \
 	khatus_lib_log.o \
 	khatus_lib_time.o
 
+khatus_sensor_time: \
+	khatus_lib_log.o \
+	khatus_lib_time.o
+
 khatus_lib_time.o: khatus_lib_log.o
 
 clean:
diff --git a/x5/khatus_lib_time.c b/x5/khatus_lib_time.c
index ba74226..a169471 100644
--- a/x5/khatus_lib_time.c
+++ b/x5/khatus_lib_time.c
@@ -7,6 +7,20 @@
 #include "khatus_lib_log.h"
 #include "khatus_lib_time.h"
 
+struct timespec
+timespec_of_float(double n)
+{
+	double integral;
+	double fractional;
+	struct timespec t;
+
+	fractional = modf(n, &integral);
+	t.tv_sec = (int) integral;
+	t.tv_nsec = (int) (1E9 * fractional);
+
+	return t;
+}
+
 void
 snooze(struct timespec *t)
 {
diff --git a/x5/khatus_lib_time.h b/x5/khatus_lib_time.h
index 2d16d65..1d4bb44 100644
--- a/x5/khatus_lib_time.h
+++ b/x5/khatus_lib_time.h
@@ -1 +1,3 @@
+struct timespec timespec_of_float(double);
+
 void snooze(struct timespec *);
diff --git a/x5/khatus_sensor_time.c b/x5/khatus_sensor_time.c
new file mode 100644
index 0000000..f156f45
--- /dev/null
+++ b/x5/khatus_sensor_time.c
@@ -0,0 +1,65 @@
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "khatus_lib_log.h"
+#include "khatus_lib_time.h"
+
+char *argv0;
+
+void
+usage()
+{
+	printf(
+	    "%s: [OPT ...]\n"
+	    "\n"
+	    "OPT = -i int     # interval\n"
+	    "    | -f string  # format string\n"
+	    "    | -h         # help message (i.e. what you're reading now :) )\n",
+	    argv0);
+	fatal("usage\n");
+}
+
+int
+main(int argc, char **argv)
+{
+	argv0 = argv[0];
+
+	double opt_interval = 1.0;
+	char *opt_fmt = "%a %b %d %H:%M:%S";
+
+	time_t t;
+	struct timespec ti;
+	char buf[128];
+	char c;
+
+	memset(buf, '\0', 128);
+	while ((c = getopt(argc, argv, "f:i:h")) != -1)
+		switch (c) {
+		case 'f':
+			opt_fmt = calloc(strlen(optarg), sizeof(char));
+			strcpy(opt_fmt, optarg);
+			break;
+		case 'i':
+			opt_interval = atof(optarg);
+			break;
+		case 'h':
+			usage();
+			break;
+		default:
+			usage();
+		}
+	ti = timespec_of_float(opt_interval);
+	for (;;) {
+		t = time(NULL);
+		strftime(buf, sizeof(buf), opt_fmt, localtime(&t));
+		puts(buf);
+		fflush(stdout);
+		snooze(&ti);
+	}
+	return EXIT_SUCCESS;
+}
-- 
2.20.1


From 348d5f367c12e60de79ac4647417aa7184996d06 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 16 Mar 2020 19:07:16 -0400
Subject: [PATCH 14/16] Support sub-second intervals

---
 x5/khatus.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index e0b71cd..b6f66f7 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -39,14 +39,14 @@ struct Fifo {
 
 typedef struct Config Config;
 struct Config {
-	int    interval;
+	double interval;
 	char * separator;
 	Fifo * fifos;
 	int    fifo_count;
 	int    total_width;
 	int    output_to_x_root_window;
 } defaults = {
-	.interval    = 1,
+	.interval    = 1.0,
 	.separator   = "|",
 	.fifos       = NULL,
 	.fifo_count  = 0,
@@ -91,7 +91,7 @@ config_print(Config *cfg)
 	info(
 	    "Config "
 	    "{"
-	    " interval = %d,"
+	    " interval = %f,"
 	    " separator = %s,"
 	    " fifo_count = %d,"
 	    " total_width = %d,"
@@ -114,6 +114,22 @@ is_pos_num(char *s)
 	return 1;
 }
 
+int
+is_decimal(char *s)
+{
+	char c;
+	int seen = 0;
+
+	while ((c = *(s++)) != '\0')
+		if (!isdigit(c)) {
+			if (c == '.' && !seen++)
+				continue;
+			else
+				return 0;
+		}
+	return 1;
+}
+
 void
 print_usage()
 {
@@ -157,9 +173,9 @@ parse_opts_opt_i(Config *cfg, int argc, char *argv[], int i)
 	if (i >= argc)
 		usage("Option -i parameter is missing.\n");
 	param = argv[i++];
-	if (!is_pos_num(param))
+	if (!is_decimal(param))
 		usage("Option -i parameter is invalid: \"%s\"\n", param);
-	cfg->interval = atoi(param);
+	cfg->interval = atof(param);
 	opts_parse_any(cfg, argc, argv, i);
 }
 
@@ -394,9 +410,7 @@ main(int argc, char *argv[])
 	debug("argv0 = %s\n", argv0);
 	config_print(cfg);
 
-	/* TODO: Support interval < 1. i.e. implement timespec_of_float */
-	ti.tv_sec  = cfg->interval;
-	ti.tv_nsec = 0;
+	ti = timespec_of_float(cfg->interval);
 
 	if (cfg->fifos == NULL)
 		usage("No fifo specs were given!\n");
-- 
2.20.1


From c7262f37a3abbd4931eefb8cd2c9f9408b76750c Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 21 Mar 2020 16:54:16 -0400
Subject: [PATCH 15/16] Fix fatality trigger

---
 x5/khatus_lib_log.c  | 10 ----------
 x5/khatus_lib_log.h  |  4 +---
 x5/khatus_lib_time.c |  1 +
 3 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/x5/khatus_lib_log.c b/x5/khatus_lib_log.c
index 16a5509..ce172e4 100644
--- a/x5/khatus_lib_log.c
+++ b/x5/khatus_lib_log.c
@@ -5,13 +5,3 @@
 #include "khatus_lib_log.h"
 
 LogLevel _khatus_lib_log_level = Debug;
-
-void
-_fatal(char *fmt, ...) {
-	va_list ap;
-
-	va_start(ap, fmt);
-	fprintf(stderr, fmt, ap);
-	va_end(ap);
-	exit(EXIT_FAILURE);
-}
diff --git a/x5/khatus_lib_log.h b/x5/khatus_lib_log.h
index ca93ddd..f2cf46b 100644
--- a/x5/khatus_lib_log.h
+++ b/x5/khatus_lib_log.h
@@ -2,7 +2,7 @@
 #define info(...)  if (_khatus_lib_log_level >= Info ) {fprintf(stderr, "[info] "  __VA_ARGS__); fflush(stderr);}
 #define warn(...)  if (_khatus_lib_log_level >= Warn ) {fprintf(stderr, "[warn] "  __VA_ARGS__); fflush(stderr);}
 #define error(...) if (_khatus_lib_log_level >= Error) {fprintf(stderr, "[error] " __VA_ARGS__); fflush(stderr);}
-#define fatal(...) _fatal("[fatal] " __VA_ARGS__)
+#define fatal(...)                                     {fprintf(stderr, "[fatal] " __VA_ARGS__); exit(EXIT_FAILURE);}
 
 typedef enum LogLevel {
 	Nothing,
@@ -12,6 +12,4 @@ typedef enum LogLevel {
 	Debug
 } LogLevel;
 
-void _fatal(char *, ...);
-
 LogLevel _khatus_lib_log_level;
diff --git a/x5/khatus_lib_time.c b/x5/khatus_lib_time.c
index a169471..d13f689 100644
--- a/x5/khatus_lib_time.c
+++ b/x5/khatus_lib_time.c
@@ -1,6 +1,7 @@
 #include <errno.h>
 #include <math.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 
-- 
2.20.1


From efa97b71295ad84d9660c392100369f99d533fa7 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Sat, 21 Mar 2020 16:56:13 -0400
Subject: [PATCH 16/16] Handle fifo read errors and ends of messages

---
 x5/khatus.c | 110 ++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 80 insertions(+), 30 deletions(-)

diff --git a/x5/khatus.c b/x5/khatus.c
index b6f66f7..93550a9 100644
--- a/x5/khatus.c
+++ b/x5/khatus.c
@@ -33,7 +33,9 @@ struct Fifo {
 	int     width;
 	int     last_read;
 	int     ttl;
-	int     pos;  /* Position on the output buffer. */
+	int     pos_init;  /* Initial position on the output buffer. */
+	int     pos_curr;  /* Current position on the output buffer. */
+	int     pos_final; /* Final   position on the output buffer. */
 	Fifo   *next;
 };
 
@@ -54,6 +56,13 @@ struct Config {
 	.output_to_x_root_window = 0,
 };
 
+enum read_status {
+	FAIL_FINAL     = -2,
+	FAIL_TMP       = -1,
+	END_OF_FILE    =  0,
+	END_OF_MESSAGE =  1
+};
+
 void
 fifo_print_one(Fifo *f)
 {
@@ -64,7 +73,9 @@ fifo_print_one(Fifo *f)
 	    " width = %d,"
 	    " last_read = %d,"
 	    " ttl = %d,"
-	    " pos = %d,"
+	    " pos_init = %d,"
+	    " pos_curr = %d,"
+	    " pos_final = %d,"
 	    " next = %p,"
 	    " }\n",
 	    f->name,
@@ -72,7 +83,9 @@ fifo_print_one(Fifo *f)
 	    f->width,
 	    f->last_read,
 	    f->ttl,
-	    f->pos,
+	    f->pos_init,
+	    f->pos_curr,
+	    f->pos_final,
 	    f->next
 	);
 }
@@ -253,7 +266,9 @@ parse_opts_spec(Config *cfg, int argc, char *argv[], int i)
 		f->width     = atoi(w);
 		f->ttl       = atoi(t);
 		f->last_read = 0;
-		f->pos       = cfg->total_width;
+		f->pos_init  = cfg->total_width;
+		f->pos_curr  = f->pos_init;
+		f->pos_final = f->pos_init + f->width - 1;
 		f->next      = cfg->fifos;
 
 		cfg->fifos        = f;
@@ -300,7 +315,7 @@ fifo_read_error(Fifo *f, char *buf)
 	char *b;
 	int i;
 
-	b = buf + f->pos;
+	b = buf + f->pos_init;
 	/* Copy as much of the error message as possible.
 	 * EXCLUDING the reminating \0. */
 	for (i = 0; i < errlen && i < f->width; i++)
@@ -310,30 +325,48 @@ fifo_read_error(Fifo *f, char *buf)
 		b[i] = '_';
 }
 
-void
+enum read_status
 fifo_read_one(Fifo *f, char *buf)
 {
-	ssize_t current;
-	ssize_t total;
-	char *b;
-	char c;
+	/* Initialize all to an impossible value: */
+	ssize_t n = -5;  /* Number of bytes read. */
+	char    c = -1;  /* Character read. */
+	int     r = -1;  /* Remaining unused slots in buffer range. */
 
-	current = 0;
-	total = 0;
-	c = '\0';
-	b = buf + f->pos;
-	while ((current = read(f->fd, &c, 1)) && c != '\n' && c != '\0' && total++ < f->width)
-		*b++ = c;
-	if (current == -1) {
-		error("Failed to read: \"%s\". Error: %s\n", f->name, strerror(errno));
-		fifo_read_error(f, buf);
-	} else {
-		while (total++ < f->width)
-			*b++ = ' ';
+	for (;;) {
+		n = read(f->fd, &c, 1);
+		assert(n >= -1 && n <= 1);
+		switch (n) {
+		case -1:
+			error("Failed to read: \"%s\". errno: %d, msg: %s\n",
+			    f->name, errno, strerror(errno));
+			if (errno == 11)
+				return FAIL_TMP;
+			else
+				return FAIL_FINAL;
+		case  0:
+			debug("%s: End of FILE\n", f->name);
+			f->pos_curr = f->pos_init;
+			return END_OF_FILE;
+		case  1:
+			/* TODO: Consider making msg term char a CLI option */
+			if (c == '\n' || c == '\0') {
+				r = f->pos_final - f->pos_curr;
+				if (r > 0)
+					memset(buf + f->pos_curr, ' ', r);
+				f->pos_curr = f->pos_init;
+				return END_OF_MESSAGE;
+			} else {
+				if (f->pos_curr <= f->pos_final)
+					buf[f->pos_curr++] = c;
+				/* Drop beyond available range. */
+			}
+			break;
+		default:
+			assert(0);
+		}
 	}
 	/* TODO Record timestamp read */
-	close(f->fd);
-	f->fd = -1;
 }
 
 void
@@ -357,15 +390,19 @@ fifo_read_all(Config *cfg, char *buf)
 			fifo_read_error(f, buf);
 			continue;
 		}
-		debug("opening: %s\n", f->name);
-		if (f->fd < 0)
+		if (f->fd < 0) {
+			debug("%s: closed. opening. fd: %d\n", f->name, f->fd);
 			f->fd = open(f->name, O_RDONLY | O_NONBLOCK);
+		} else {
+			debug("%s: already openned. fd: %d\n", f->name, f->fd);
+		}
 		if (f->fd == -1) {
 			/* TODO: Consider backing off retries for failed fifos. */
 			error("Failed to open \"%s\"\n", f->name);
 			fifo_read_error(f, buf);
 			continue;
 		}
+		debug("%s: open. fd: %d\n", f->name, f->fd);
 		if (f->fd > maxfd)
 			maxfd = f->fd;
 		FD_SET(f->fd, &fds);
@@ -379,7 +416,18 @@ fifo_read_all(Config *cfg, char *buf)
 	for (Fifo *f = cfg->fifos; f; f = f->next) {
 		if (FD_ISSET(f->fd, &fds)) {
 			debug("reading: %s\n", f->name);
-			fifo_read_one(f, buf);
+			switch (fifo_read_one(f, buf)) {
+			case END_OF_FILE:
+			case FAIL_FINAL:
+				close(f->fd);
+				f->fd = -1;
+				break;
+			case END_OF_MESSAGE:
+			case FAIL_TMP:
+				break;
+			default:
+				assert(0);
+			}
 		}
 	}
 }
@@ -436,7 +484,9 @@ main(int argc, char *argv[])
 
 	/* 2nd pass to make space for separators */
 	for (Fifo *f = cfg->fifos; f; f = f->next) {
-		f->pos += prefix;
+		f->pos_init  += prefix;
+		f->pos_final += prefix;
+		f->pos_curr = f->pos_init;
 		prefix += seplen;
 		nfifos++;
 	}
@@ -448,9 +498,9 @@ main(int argc, char *argv[])
 	buf[width] = '\0';
 	/* 3rd pass to set the separators */
 	for (Fifo *f = cfg->fifos; f; f = f->next) {
-		if (f->pos) {  /* Skip the first, left-most */
+		if (f->pos_init) {  /* Skip the first, left-most */
 			/* Copying only seplen ensures we omit the '\0' byte. */
-			strncpy(buf + (f->pos - seplen), cfg->separator, seplen);
+			strncpy(buf + (f->pos_init - seplen), cfg->separator, seplen);
 		}
 	}
 
-- 
2.20.1