slb

commit 77c9da3a1909c0d3e870957fb2247ca6a3ab73c8
Author: zerous Naveen Narayanan <zerous@nocebo.space>
Date:   Wed, 30 Oct 2019 18:54:42 +0100

Initial commit

Diffstat:
A
Makefile
 | 
8
++++++++
A
README
 | 
25
+++++++++++++++++++++++++
A
config.h
 | 
17
+++++++++++++++++
A
slb.c
 | 
66
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

4 files changed, 116 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -0,0 +1,8 @@
+all: slb
+
+slb: config.h
+
+.PHONY: clean
+
+clean:
+	rm -f slb 2>/dev/null
diff --git a/README b/README
@@ -0,0 +1,25 @@
+     _ _     
+ ___| | |__  
+/ __| | '_ \ 
+\__ \ | |_) |
+|___/_|_.__/ 
+             -- zerous
+=============
+
+What is it?
+===========
+
+slb (acroynm for sleep on low battery) is a daemon which hibernates
+your machine when your battery is below a certain threshold.
+
+Building
+========
+
+   Customize config.h
+   make
+
+Contact
+=======
+
+To report bugs and/or submit patches, you can reach us through
+irc.2f30.org at #2f30
diff --git a/config.h b/config.h
@@ -0,0 +1,17 @@
+int delay = 10;
+
+/* threshold below which system should hibernate */
+int threshold = 10;
+
+const char bat[][64] = {
+	"/sys/class/power_supply/BAT0/capacity",
+	"/sys/class/power_supply/BAT1/capacity"
+};
+
+const char ac[64] = {
+	"/sys/class/power_supply/AC/online"
+};
+
+const char cmd[64] = {
+	"/bin/ZZZ"
+};
diff --git a/slb.c b/slb.c
@@ -0,0 +1,66 @@
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "config.h"
+
+int
+pwread(const char *bat)
+{
+	char buf[4];
+	int fd;
+	int t;
+	
+	if ((fd = open(bat, O_RDONLY)) == -1) {
+		err(1, "open failed");
+	}
+
+	if ((t = read(fd,buf,3)) == -1) {
+		err(1, "read failed");
+	}
+
+	buf[t]=0;
+	
+	return atoi(buf);
+}
+
+int
+main(int argc, char **argv)
+{
+	(void) argc;
+	(void) argv;
+
+	int tpow;
+	int t;
+	pid_t p;
+
+	
+	for (;;) {
+		tpow = 0;
+
+		for (int i = 0; i < sizeof(bat)/64; i++) {
+			tpow += pwread(bat[i]);
+		}
+
+		if (!pwread(ac) && (tpow < threshold)) {
+			if ((p = fork()) == -1)
+				err(1, "fork failed");
+			else if (p > 0) {
+				wait(NULL);
+			}
+			else if (p == 0) {
+				if ((t = execve(cmd,NULL,NULL)) == -1)
+					err(1, "execve failed");
+			}
+		}
+
+		sleep(delay);
+	}
+
+	return 0;
+}