# HG changeset patch
# User Eleni Maria Stea <eleni@mutantstargoat.com>
# Date 1463162586 -10800
# Node ID 50af08b83a1f28f921b515229862289e48da6af3

a program that shouts "Don't touch my screen, bro" whenever someone
touches the screen

diff -r 000000000000 -r 50af08b83a1f .hgignore
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.hgignore	Fri May 13 21:03:06 2016 +0300
@@ -0,0 +1,7 @@
+syntax: glob
+*.au
+*.o
+*.d
+*.aup
+*.swp
+dtms
diff -r 000000000000 -r 50af08b83a1f Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Makefile	Fri May 13 21:03:06 2016 +0300
@@ -0,0 +1,24 @@
+src = $(wildcard src/*.c)
+obj = $(src:.c=.o)
+dep = $(obj:.o=.d)
+bin = dtms
+
+dbg = -g
+opt = -O0
+
+CC = gcc
+INCLUDE = -I/usr/include
+CFLAGS = -pedantic -Wall -std=c99 -D_XOPEN_SOURCE=600 $(dbg) $(INCLUDE)
+LDFLAGS = -L/usr/lib $(libs)
+
+$(bin): $(obj)
+	$(CC) -o $@ $(obj) $(LDFLAGS)
+
+-include $(dep)
+
+%.d: %.c
+	@$(CPP) $(CFLAGS) $< -MM -MT $(@:.d=.o) >$@
+
+.PHONY: clean
+clean:
+	rm -f $(obj) $(bin) $(dep)
diff -r 000000000000 -r 50af08b83a1f data/dtms.mp3
Binary file data/dtms.mp3 has changed
diff -r 000000000000 -r 50af08b83a1f src/main.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main.c	Fri May 13 21:03:06 2016 +0300
@@ -0,0 +1,156 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+static int parse_args(int argc, char **argv);
+static void print_help();
+static void check_device(char *device_path);
+static char* concatenate(char *mp_path, char *data_path);
+
+static int uid;
+static char *path;
+static char *dev_path;
+
+int main(int argc, char **argv)
+{
+    time_t last_touch_time = 0;
+    int fd;
+
+    if(parse_args(argc, argv))
+	return 1;
+
+    check_device(dev_path);
+
+    if((fd = open(dev_path, O_RDONLY | O_NONBLOCK)) == -1) {
+	fprintf(stderr, "Failed to open device: %s, error: %s\n", dev_path, strerror(errno));
+	return 1;
+    }
+
+    if(seteuid(uid) == -1) {
+	perror("Set uid failed");
+	uid = 0;
+    }
+
+    if(!uid) {
+	const char *st = "/";
+	if(strncmp(path, st, 1) != 0) {
+	    fprintf(stderr, "If you run this program as root you should pass the absolute path to a valid mp3 player.\n");
+	    return 1;
+	}
+    }
+
+    while(1) {
+	fd_set read_set;
+	FD_ZERO(&read_set);
+	FD_SET(fd, &read_set);
+
+	int res;
+	while((res = select(fd + 1, &read_set, 0, 0, 0)) == -1 && errno == EINTR);
+	if(res < 0) {
+	    perror("Select failed");
+	    break;
+	}
+	if(res == 0) //nothing to read
+	    continue;
+
+	if(FD_ISSET(fd, &read_set)) {
+	    char buf[1024];
+	    time_t now = time(0);
+	    while(read(fd, buf, sizeof buf) > 0);
+	    if (now - last_touch_time > 2) {
+		char *cmd = concatenate(path, "data/dtms.mp3");
+		system(cmd);
+		last_touch_time = now;
+	    }
+	}
+    }
+    close(fd);
+}
+
+static int parse_args(int argc, char **argv)
+{
+    for(int i=1; i<argc; i++) {
+	if((strcmp(argv[i], "-h") == 0)) {
+	    print_help();
+	    exit(0);
+	}
+	if((strcmp(argv[i], "-p") == 0)) {
+	    if(argv[i+1]) {
+		path = argv[i+1];
+	    }
+	    else {
+		fprintf(stderr, "Invalid path. Please give the absolute path to an mp3 player.\n");
+		exit(1);
+	    }
+	}
+
+	if((strcmp(argv[i], "-u") == 0)) {
+	    if(argv[i+1]) {
+		struct passwd *passwd = getpwnam(argv[i+1]);
+		if(!passwd) {
+		    fprintf(stderr, "Failed to get uid for: %s : %s.\n", argv[i+1], strerror(errno));
+		    exit(1);
+		}
+		uid = passwd->pw_uid;
+	    }
+	    else {
+		fprintf(stderr, "Invalid username. Type -u `whoami`.\n");
+		exit(1);
+	    }
+	}
+	if((strcmp(argv[i], "-d") == 0)) {
+	    if(argv[i+1]) {
+		dev_path = argv[i+1];
+	    }
+	    else {
+		fprintf(stderr, "Invalid device file.\n");
+		exit(1);
+	    }
+	}
+    }
+    return 0;
+}
+
+static void print_help()
+{
+    printf("Options:\n");
+    printf("-h, prints this help\n");
+    printf("-d, path to the device\n");
+    printf("-p, path to the mp3 player\n");
+    printf("-u. username of the user that runs the program\n");
+    printf("--------\n");
+    printf("Examples:\n");
+    printf("--------\n");
+    printf("./dtms -d /dev/usb/hiddev0 -u eleni -p /usr/bin/mpv\n");
+}
+
+static void check_device(char *device_path)
+{
+    struct stat sb;
+    if(stat(dev_path, &sb) == -1) {
+	perror("stat");
+	exit(0);
+    }
+    if(((sb.st_mode & S_IFMT) != S_IFBLK) && ((sb.st_mode & S_IFMT) != S_IFCHR)) {
+	fprintf(stderr, "Invalid device file.\n");
+	exit(0);
+    }
+}
+
+static char *concatenate(char *mp_path, char *data_path)
+{
+    char *res = malloc(strlen(mp_path) + 1 + strlen(data_path) + 1);
+    strcpy(res, mp_path);
+    strcat(res, " ");
+    strcat(res, data_path);
+
+    return res;
+}