slstatus.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <X11/Xlib.h>

#include "arg.h"
#include "slstatus.h"
#include "util.h"

struct arg {
	const char *(*func)();
	const char *fmt;
	const char *args;
};

char buf[1024];
static int done;
static Display *dpy;

#include "config.h"

static void
terminate(const int signo)
{
	(void)signo;

	done = 1;
}

static void
difftimespec(struct timespec *res, struct timespec *a, struct timespec *b)
{
	res->tv_sec = a->tv_sec - b->tv_sec - (a->tv_nsec < b->tv_nsec);
	res->tv_nsec = a->tv_nsec - b->tv_nsec +
	               (a->tv_nsec < b->tv_nsec) * 1000000000;
}

static void
usage(void)
{
	die("usage: %s [-so]", argv0);
}

int
main(int argc, char *argv[])
{
	struct sigaction act;
	struct timespec start, current, diff, intspec, wait;
	size_t i, len;
	int sflag, oflag, ret;
	char status[MAXLEN];
	const char *res;

	sflag = oflag = 0;
	ARGBEGIN {
		case 's':
			sflag = 1;
			break;
		case 'o':
			oflag = 1;
			break;
		default:
			usage();
	} ARGEND

	if (argc) {
		usage();
	}

	memset(&act, 0, sizeof(act));
	act.sa_handler = terminate;
	sigaction(SIGINT,  &act, NULL);
	sigaction(SIGTERM, &act, NULL);

	if (sflag) {
		setbuf(stdout, NULL);
	}

	if (!sflag && !(dpy = XOpenDisplay(NULL))) {
		die("XOpenDisplay: Failed to open display");
	}

	while (!done) {
		if (clock_gettime(CLOCK_MONOTONIC, &start) < 0) {
			die("clock_gettime:");
		}

		status[0] = '\0';
		for (i = len = 0; i < LEN(args); i++) {
			if (!(res = args[i].func(args[i].args))) {
				res = unknown_str;
			}
			if ((ret = esnprintf(status + len, sizeof(status) - len,
			                    args[i].fmt, res)) < 0) {
				break;
			}
			len += ret;
		}

		if (sflag) {
			printf("%s\n", status);
		} else {
			if (XStoreName(dpy, DefaultRootWindow(dpy), status) < 0) {
				die("XStoreName: Allocation failed");
			}
			XFlush(dpy);
		}

		if (oflag) {
			done = 1;
		}

		if (!done) {
			if (clock_gettime(CLOCK_MONOTONIC, &current) < 0) {
				die("clock_gettime:");
			}
			difftimespec(&diff, &current, &start);

			intspec.tv_sec = interval / 1000;
			intspec.tv_nsec = (interval % 1000) * 1000000;
			difftimespec(&wait, &intspec, &diff);

			if (wait.tv_sec >= 0) {
				if (nanosleep(&wait, NULL) < 0 &&
				    errno != EINTR) {
					die("nanosleep:");
				}
			}
		}
	}

	if (!sflag) {
		XStoreName(dpy, DefaultRootWindow(dpy), NULL);
		if (XCloseDisplay(dpy) < 0) {
			die("XCloseDisplay: Failed to close display");
		}
	}

	return 0;
}