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
|
/*
* fq [FILES...] - follow output of nq jobs, quitting when they are done
*
* To the extent possible under law,
* Christian Neukirchen <chneukirchen@gmail.com>
* has waived all copyright and related or neighboring rights to this work.
* http://creativecommons.org/publicdomain/zero/1.0/
*/
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define DELAY 250000
#ifdef __linux__
#define USE_INOTIFY
#endif
#ifdef USE_INOTIFY
#include <sys/inotify.h>
char ibuf[8192];
#endif
char buf[8192];
static int
islocked(int fd)
{
if (flock(fd, LOCK_EX|LOCK_NB) == -1) {
return (errno == EWOULDBLOCK);
} else {
flock(fd, LOCK_UN);
return 0;
}
}
static int
alphabetic(const void* a, const void* b)
{
return strcmp(*(char**)a, *(char **)b);
}
int
main(int argc, char *argv[])
{
int i, fd, dirfd;
off_t off, loff;
ssize_t rd;
int didsth = 0, seen_nl = 0;
int opt = 0, aflag = 0, qflag = 0;
char *path;
#ifdef USE_INOTIFY
int ifd, wd;
#endif
close(0);
while ((opt = getopt(argc, argv, "+aq")) != -1) {
switch (opt) {
case 'a':
aflag = 1;
break;
case 'q':
qflag = 1;
break;
default:
exit(1);
}
}
path = getenv("NQDIR");
if (!path)
path = ".";
dirfd = open(path, O_RDONLY);
if (dirfd < 0)
exit(111);
if (optind == argc) { /* behave as if $NQDIR/,* was passed. */
DIR *dir;
struct dirent *d;
int len = 0;
argc = 0;
argv = 0;
optind = 0;
dir = fdopendir(dirfd);
if (!dir)
exit(111);
while ((d = readdir(dir))) {
if (d->d_name[0] != ',')
continue;
if (argc >= len) {
len = 2*len + 1;
argv = realloc(argv, len * sizeof (char *));
if (!argv)
exit(222);
}
argv[argc] = strdup(d->d_name);
if (!argv[argc])
exit(222);
argc++;
}
qsort(argv, argc, sizeof (char *), alphabetic);
}
#ifdef USE_INOTIFY
ifd = inotify_init();
if (ifd < 0)
exit(111);
#endif
for (i = optind; i < argc; i++) {
loff = 0;
seen_nl = 0;
fd = openat(dirfd, argv[i], O_RDONLY);
if (fd < 0)
continue;
/* skip not running jobs, unless -a was passed, or we did not
* output anything yet and are at the last argument. */
if (!aflag && !islocked(fd) && (didsth || i != argc - 1))
continue;
write(1, "==> ", 4);
write(1, argv[i], strlen(argv[i]));
write(1, qflag ? " " : "\n", 1);
didsth = 1;
#ifdef USE_INOTIFY
wd = inotify_add_watch(ifd, argv[i], IN_MODIFY|IN_CLOSE_WRITE);
#endif
while (1) {
off = lseek(fd, 0, SEEK_END);
if (off < loff)
loff = off; /* file truncated */
if (off == loff) {
if (flock(fd, LOCK_EX|LOCK_NB) == -1 &&
errno == EWOULDBLOCK) {
#ifdef USE_INOTIFY
/* any inotify event is good */
read(ifd, ibuf, sizeof ibuf);
#else
/* poll for size change */
while (off == lseek(fd, 0, SEEK_END))
usleep(DELAY);
#endif
continue;
} else {
flock(fd, LOCK_UN);
break;
}
}
if (off - loff > sizeof buf)
off = loff + sizeof buf;
rd = pread(fd, &buf, off - loff, loff);
if (qflag) {
if (!seen_nl) {
char *s;
if ((s = memchr(buf, '\n', rd))) {
write(1, buf, s+1-buf);
seen_nl = 1;
} else {
write(1, buf, rd);
}
}
} else {
write(1, buf, rd);
}
loff += rd;
}
#ifdef USE_INOTIFY
inotify_rm_watch(ifd, wd);
#endif
close(fd);
}
#ifdef USE_INOTIFY
close(ifd);
#endif
return 0;
}
|
