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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
// Copyright © Tavian Barnes <tavianator@tavianator.com>
// SPDX-License-Identifier: 0BSD
#include "prelude.h"
#include "bar.h"
#include "alloc.h"
#include "atomic.h"
#include "bfstd.h"
#include "bit.h"
#include "dstring.h"
#include "sighook.h"
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <termios.h>
struct bfs_bar {
int fd;
atomic unsigned int width;
atomic unsigned int height;
struct sighook *exit_hook;
struct sighook *winch_hook;
};
/** Get the terminal size, if possible. */
static int bfs_bar_getsize(struct bfs_bar *bar) {
#if BFS_HAS_TCGETWINSIZE || defined(TIOCGWINSZ)
struct winsize ws;
# if BFS_HAS_TCGETWINSIZE
int ret = tcgetwinsize(bar->fd, &ws);
# else
int ret = ioctl(bar->fd, TIOCGWINSZ, &ws);
# endif
if (ret != 0) {
return ret;
}
store(&bar->width, ws.ws_col, relaxed);
store(&bar->height, ws.ws_row, relaxed);
return 0;
#else
errno = ENOTSUP;
return -1;
#endif
}
/** Write a string to the status bar (async-signal-safe). */
static int bfs_bar_write(struct bfs_bar *bar, const char *str, size_t len) {
return xwrite(bar->fd, str, len) == len ? 0 : -1;
}
/** Write a string to the status bar (async-signal-safe). */
static int bfs_bar_puts(struct bfs_bar *bar, const char *str) {
return bfs_bar_write(bar, str, strlen(str));
}
/** Number of decimal digits needed for terminal sizes. */
#define ITOA_DIGITS ((USHRT_WIDTH + 2) / 3)
/** Async Signal Safe itoa(). */
static char *ass_itoa(char *str, unsigned int n) {
char *end = str + ITOA_DIGITS;
*end = '\0';
char *c = end;
do {
*--c = '0' + (n % 10);
n /= 10;
} while (n);
size_t len = end - c;
memmove(str, c, len + 1);
return str + len;
}
/** Update the size of the scrollable region. */
static int bfs_bar_resize(struct bfs_bar *bar) {
static const char PREFIX[] =
"\033D" // IND: Line feed, possibly scrolling
"\033[1A" // CUU: Move cursor up 1 row
"\0337" // DECSC: Save cursor
"\033[;"; // DECSTBM: Set scrollable region
static const char SUFFIX[] =
"r" // (end of DECSTBM)
"\0338" // DECRC: Restore the cursor
"\033[J"; // ED: Erase display from cursor to end
char esc_seq[sizeof(PREFIX) + ITOA_DIGITS + sizeof(SUFFIX)];
// DECSTBM takes the height as the second argument
unsigned int height = load(&bar->height, relaxed) - 1;
char *cur = stpcpy(esc_seq, PREFIX);
cur = ass_itoa(cur, height);
cur = stpcpy(cur, SUFFIX);
return bfs_bar_write(bar, esc_seq, cur - esc_seq);
}
#ifdef SIGWINCH
/** SIGWINCH handler. */
static void bfs_bar_sigwinch(int sig, siginfo_t *info, void *arg) {
struct bfs_bar *bar = arg;
bfs_bar_getsize(bar);
bfs_bar_resize(bar);
}
#endif
/** Reset the scrollable region and hide the bar. */
static int bfs_bar_reset(struct bfs_bar *bar) {
return bfs_bar_puts(bar,
"\0337" // DECSC: Save cursor
"\033[r" // DECSTBM: Reset scrollable region
"\0338" // DECRC: Restore cursor
"\033[J" // ED: Erase display from cursor to end
);
}
/** Signal handler for process-terminating signals. */
static void bfs_bar_sigexit(int sig, siginfo_t *info, void *arg) {
struct bfs_bar *bar = arg;
bfs_bar_reset(bar);
}
/** printf() to the status bar with a single write(). */
_printf(2, 3)
static int bfs_bar_printf(struct bfs_bar *bar, const char *format, ...) {
va_list args;
va_start(args, format);
dchar *str = dstrvprintf(format, args);
va_end(args);
if (!str) {
return -1;
}
int ret = bfs_bar_write(bar, str, dstrlen(str));
dstrfree(str);
return ret;
}
struct bfs_bar *bfs_bar_show(void) {
struct bfs_bar *bar = ALLOC(struct bfs_bar);
if (!bar) {
return NULL;
}
bar->fd = open_cterm(O_RDWR | O_CLOEXEC);
if (bar->fd < 0) {
goto fail;
}
if (bfs_bar_getsize(bar) != 0) {
goto fail_close;
}
bar->exit_hook = atsigexit(bfs_bar_sigexit, bar);
if (!bar->exit_hook) {
goto fail_close;
}
#ifdef SIGWINCH
bar->winch_hook = sighook(SIGWINCH, bfs_bar_sigwinch, bar, 0);
if (!bar->winch_hook) {
goto fail_hook;
}
#endif
bfs_bar_resize(bar);
return bar;
fail_hook:
sigunhook(bar->exit_hook);
fail_close:
close_quietly(bar->fd);
fail:
free(bar);
return NULL;
}
unsigned int bfs_bar_width(const struct bfs_bar *bar) {
return load(&bar->width, relaxed);
}
int bfs_bar_update(struct bfs_bar *bar, const char *str) {
unsigned int height = load(&bar->height, relaxed);
return bfs_bar_printf(bar,
"\0337" // DECSC: Save cursor
"\033[%u;0f" // HVP: Move cursor to row, column
"\033[K" // EL: Erase line
"\033[7m" // SGR reverse video
"%s"
"\033[27m" // SGR reverse video off
"\0338", // DECRC: Restore cursor
height,
str
);
}
void bfs_bar_hide(struct bfs_bar *bar) {
if (!bar) {
return;
}
sigunhook(bar->winch_hook);
sigunhook(bar->exit_hook);
bfs_bar_reset(bar);
xclose(bar->fd);
free(bar);
}
|
