statbar

commit 5eac48609cc8d2c2959bb1aff21a07d624863e14
Author: Mikołaj Lenczewski <mblenczewski@gmail.com>
Date:   Tue, 13 Aug 2024 20:04:37 +0000

Initial commit

Diffstat:
A
Makefile
 | 
26
++++++++++++++++++++++++++
A
README.txt
 | 
3
+++
A
statbar-wl.c
 | 
245
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 274 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -0,0 +1,26 @@
+.PHONY: all build clean install uninstall
+
+CFLAGS	:= -std=c17 -Wall -Wextra -Wpedantic -Og -ggdb
+CPPFLAGS:= -D_XOPEN_SOURCE=700
+LDFLAGS	:=
+
+CC	?= cc
+
+PREFIX	?= /usr/local
+
+all: build
+
+build: statbar-wl
+
+clean:
+	rm -rf statbar-wl $(OBJ)
+
+install: build
+	mkdir -p $(DESTDIR)$(PREFIX)/bin
+	install -m 0755 statbar-wl $(DESTDIR)$(PREFIX)/bin/statbar-wl
+
+uninstall:
+	rm -f $(DESTDIR)$(PREFIX)/bin/statbar-wl
+
+statbar-wl: statbar-wl.c
+	$(CC) -o $@ $^ $(CFLAGS) $(CPPFLAGS) $(LDFLAGS)
diff --git a/README.txt b/README.txt
@@ -0,0 +1,3 @@
+statbar
+-------------------------------------------------------------------------------
+A status tracker for somebar.
diff --git a/statbar-wl.c b/statbar-wl.c
@@ -0,0 +1,245 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
+
+#define ARRLEN(arr) (sizeof (arr) / sizeof (arr)[0])
+
+#define NSECS 1000000000UL
+
+#define BUFSZ 8192
+static char statbuf[BUFSZ];
+
+#define BLOCKSEP " | "
+
+struct block { u64 (*fn)(char *buf, u64 len); };
+
+u64 cpuinfo(char *buf, u64 len);
+u64 meminfo(char *buf, u64 len);
+u64 batinfo(char *buf, u64 len);
+u64 datetime(char *buf, u64 len);
+
+static struct block blocks[] = {
+	{ .fn = cpuinfo, },
+	{ .fn = meminfo, },
+//	{ .fn = batinfo, },
+	{ .fn = datetime, },
+};
+
+static inline void
+difftimespec(struct timespec const *restrict lhs, struct timespec const *restrict rhs,
+	     struct timespec *restrict out) {
+	out->tv_sec = lhs->tv_sec - rhs->tv_sec - (lhs->tv_nsec < rhs->tv_nsec);
+	out->tv_nsec = lhs->tv_nsec - rhs->tv_nsec + (lhs->tv_nsec < rhs->tv_nsec) * NSECS;
+}
+
+static char *somebar_path = NULL;
+
+void
+read_env_vars(void) {
+	somebar_path = strcat(getenv("XDG_RUNTIME_DIR"), "/somebar-0");
+}
+
+void
+exec_blocks(void) {
+	u64 written = 0, limit = BUFSZ - 1;
+	for (u64 i = 0; i < ARRLEN(blocks) && written < limit; i++) {
+		written += blocks[i].fn(statbuf + written, limit - written);
+	}
+
+	statbuf[written] = '\0';
+}
+
+void
+output_status(void) {
+	static int somebarfd = -1;
+
+	if (somebarfd < 0) {
+		if ((somebarfd = open(somebar_path, O_WRONLY|O_CLOEXEC)) < 0 && errno == ENOENT) {
+			sleep(1); // TODO: wait for somebar path to appear
+			somebarfd = open(somebar_path, O_WRONLY|O_CLOEXEC);
+		}
+
+		if (somebarfd < 0) {
+			perror("open");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	dprintf(somebarfd, "status %s\n", statbuf);
+}
+
+int
+main(void) {
+	read_env_vars();
+
+	struct timespec start, end, diff, wait, interval = { .tv_sec = 1, };
+	while (true) {
+		if (clock_gettime(CLOCK_MONOTONIC, &start) < 0) {
+			perror("clock_gettime");
+			exit(EXIT_FAILURE);
+		}
+
+		exec_blocks();
+		output_status();
+
+		if (clock_gettime(CLOCK_MONOTONIC, &end) < 0) {
+			perror("clock_gettime");
+			exit(EXIT_FAILURE);
+		}
+
+		difftimespec(&end, &start, &diff);
+		difftimespec(&interval, &diff, &wait);
+
+		if (wait.tv_sec >= 0 && nanosleep(&wait, NULL) < 0 && errno != EINTR) {
+			perror("nanosleep");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	return 0;
+}
+
+/* ===========================================================================
+ * status bar blocks
+ * ===========================================================================
+ */
+
+static int
+pscanf(const char *path, const char *fmt, ...) {
+	FILE *fp;
+	va_list ap;
+	int n;
+
+	if (!(fp = fopen(path, "r"))) {
+		fprintf(stderr, "fopen '%s':", path);
+		return -1;
+	}
+	va_start(ap, fmt);
+	n = vfscanf(fp, fmt, ap);
+	va_end(ap);
+	fclose(fp);
+
+	return (n == EOF) ? -1 : n;
+}
+
+u64
+cpuinfo(char *buf, u64 len) {
+	static long double a[7];
+	long double b[7], sum;
+	s32 usage;
+
+	memcpy(b, a, sizeof(b));
+
+	/* cpu user nice system idle iowait irq softirq */
+	if (pscanf("/proc/stat", "%*s %LF %LF %LF %LF %LF %LF %LF",
+	           &a[0], &a[1], &a[2], &a[3], &a[4], &a[5], &a[6]) != 7) {
+		perror("vfscanf");
+		exit(EXIT_FAILURE);
+	}
+
+	sum = (b[0] + b[1] + b[2] + b[3] + b[4] + b[5] + b[6]) -
+	      (a[0] + a[1] + a[2] + a[3] + a[4] + a[5] + a[6]);
+
+	if (sum == 0) {
+		usage = 0;
+	} else {
+		usage = (s32)(100 * 
+			     ((b[0] + b[1] + b[2] + b[5] + b[6]) -
+			      (a[0] + a[1] + a[2] + a[5] + a[6])) / sum);
+	}
+
+	u64 written;
+	if (!(written = snprintf(buf, len, "CPU: %" PRIi32 "%%" BLOCKSEP, usage))) {
+		perror("snprintf");
+		exit(EXIT_FAILURE);
+	}
+
+	return written;
+}
+
+u64
+meminfo(char *buf, u64 len) {
+	uintmax_t total, free, buffers, cached;
+	int percent;
+
+	if (pscanf("/proc/meminfo",
+	           "MemTotal: %ju kB\n"
+	           "MemFree: %ju kB\n"
+	           "MemAvailable: %ju kB\n"
+	           "Buffers: %ju kB\n"
+	           "Cached: %ju kB\n",
+	           &total, &free, &buffers, &buffers, &cached) != 5) {
+		perror("vfscanf");
+		exit(EXIT_FAILURE);
+	}
+
+	if (total == 0) {
+		percent = 0;
+	} else {
+		percent = 100 * ((total - free) - (buffers + cached)) / total;
+	}
+
+	u64 written;
+	if (!(written = snprintf(buf, len, "MEM: %" PRIi32 "%%" BLOCKSEP, percent))) {
+		perror("snprintf");
+		exit(EXIT_FAILURE);
+	}
+
+	return written;
+}
+
+u64
+batinfo(char *buf, u64 len) {
+	s32 capacity;
+	char status[13]; // "Charging" | "Discharging" | "Full" | "Not Charging"
+
+	if (pscanf("/sys/class/power_supply/BAT0/capacity", "%" SCNi32 "", &capacity) != 1) {
+		perror("vfscanf");
+		exit(EXIT_FAILURE);
+	}
+
+	if (pscanf("/sys/class/power_supply/BAT0/status", "%12[a-zA-Z ]", &status) != 1) {
+		perror("vfscanf");
+		exit(EXIT_FAILURE);
+	}
+
+	u64 written;
+	if (!(written = snprintf(buf, len, "BAT: %" PRIi32 "%% %12s" BLOCKSEP, capacity, status))) {
+		perror("snprintf");
+		exit(EXIT_FAILURE);
+	}
+
+	return written;
+}
+
+u64
+datetime(char *buf, u64 len) {
+	char const *timefmt = "%F %T";
+	time_t t = time(NULL);
+
+	u64 written;
+	if (!(written = strftime(buf, len, timefmt, localtime(&t)))) {
+		perror("strftime");
+		exit(EXIT_FAILURE);
+	}
+
+	return written;
+}