summaryrefslogtreecommitdiffstats
path: root/lib/ttyutils.c
blob: 70645650391b1864d5b24444a7330bfcf7703b08 (plain)
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
145
146
147
148
149
150
151
152
/*
 * No copyright is claimed.  This code is in the public domain; do with
 * it what you wish.
 *
 * Written by Karel Zak <kzak@redhat.com>
 */
#include <ctype.h>
#include <unistd.h>

#include "c.h"
#include "ttyutils.h"


static int get_env_int(const char *name)
{
	const char *cp = getenv(name);

	if (cp) {
		char *end = NULL;
		long x;

		errno = 0;
		x = strtol(cp, &end, 10);

		if (errno == 0 && end && *end == '\0' && end > cp &&
		    x > 0 && x <= INT_MAX)
			return x;
	}

	return -1;
}

int get_terminal_dimension(int *cols, int *lines)
{
	int c = 0, l = 0;

#if defined(TIOCGWINSZ)
	struct winsize	w_win;
	if (ioctl (STDOUT_FILENO, TIOCGWINSZ, &w_win) == 0) {
		c = w_win.ws_col;
		l = w_win.ws_row;
	}
#elif defined(TIOCGSIZE)
	struct ttysize	t_win;
	if (ioctl (STDOUT_FILENO, TIOCGSIZE, &t_win) == 0) {
		c = t_win.ts_cols;
		l = t_win.ts_lines;
	}
#endif
	if (cols) {
		if (c <= 0)
			c = get_env_int("COLUMNS");
		*cols = c;
	}
	if (lines) {
		if (l <= 0)
			l = get_env_int("LINES");
		*lines = l;
	}
	return 0;
}

int get_terminal_width(int default_width)
{
	int width = 0;

	get_terminal_dimension(&width, NULL);

	return width > 0 ? width : default_width;
}

int get_terminal_stdfd(void)
{
	if (isatty(STDIN_FILENO))
		return STDIN_FILENO;
	if (isatty(STDOUT_FILENO))
		return STDOUT_FILENO;
	if (isatty(STDERR_FILENO))
		return STDERR_FILENO;

	return -EINVAL;
}

int get_terminal_name(const char **path,
		      const char **name,
		      const char **number)
{
	const char *tty;
	const char *p;
	int fd;


	if (name)
		*name = NULL;
	if (path)
		*path = NULL;
	if (number)
		*number = NULL;

	fd = get_terminal_stdfd();
	if (fd < 0)
		return fd;	/* error */

	tty = ttyname(fd);
	if (!tty)
		return -1;

	if (path)
		*path = tty;
	if (name || number)
		tty = strncmp(tty, "/dev/", 5) == 0 ? tty + 5 : tty;
	if (name)
		*name = tty;
	if (number) {
		for (p = tty; p && *p; p++) {
			if (isdigit(*p)) {
				*number = p;
				break;
			}
		}
	}
	return 0;
}

int get_terminal_type(const char **type)
{
	*type = getenv("TERM");
	if (*type)
		return -EINVAL;
	return 0;
}

#ifdef TEST_PROGRAM_TTYUTILS
# include <stdlib.h>
int main(void)
{
	const char *path, *name, *num;
	int c, l;

	if (get_terminal_name(&path, &name, &num) == 0) {
		fprintf(stderr, "tty path:   %s\n", path);
		fprintf(stderr, "tty name:   %s\n", name);
		fprintf(stderr, "tty number: %s\n", num);
	}
	get_terminal_dimension(&c, &l);
	fprintf(stderr,         "tty cols:   %d\n", c);
	fprintf(stderr,         "tty lines:  %d\n", l);


	return EXIT_SUCCESS;
}
#endif /* TEST_PROGRAM_TTYUTILS */