xref: /openbsd/usr.bin/tmux/procname.c (revision 8932bfb7)
1 /* $OpenBSD: procname.c,v 1.7 2011/04/10 03:20:59 guenther Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/param.h>
20 #include <sys/sysctl.h>
21 #include <sys/stat.h>
22 
23 #include <errno.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #ifndef nitems
29 #define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
30 #endif
31 
32 #define is_runnable(p) \
33 	((p)->p_stat == SRUN || (p)->p_stat == SIDL || (p)->p_stat == SONPROC)
34 #define is_stopped(p) \
35 	((p)->p_stat == SSTOP || (p)->p_stat == SZOMB || (p)->p_stat == SDEAD)
36 
37 struct kinfo_proc	*cmp_procs(struct kinfo_proc *, struct kinfo_proc *);
38 char		*get_proc_name(int, char *);
39 
40 struct kinfo_proc *
41 cmp_procs(struct kinfo_proc *p1, struct kinfo_proc *p2)
42 {
43 	if (is_runnable(p1) && !is_runnable(p2))
44 		return (p1);
45 	if (!is_runnable(p1) && is_runnable(p2))
46 		return (p2);
47 
48 	if (is_stopped(p1) && !is_stopped(p2))
49 		return (p1);
50 	if (!is_stopped(p1) && is_stopped(p2))
51 		return (p2);
52 
53 	if (p1->p_estcpu > p2->p_estcpu)
54 		return (p1);
55 	if (p1->p_estcpu < p2->p_estcpu)
56 		return (p2);
57 
58 	if (p1->p_slptime < p2->p_slptime)
59 		return (p1);
60 	if (p1->p_slptime > p2->p_slptime)
61 		return (p2);
62 
63 	if ((p1->p_flag & P_SINTR) && !(p2->p_flag & P_SINTR))
64 		return (p1);
65 	if (!(p1->p_flag & P_SINTR) && (p2->p_flag & P_SINTR))
66 		return (p2);
67 
68 	if (strcmp(p1->p_comm, p2->p_comm) < 0)
69 		return (p1);
70 	if (strcmp(p1->p_comm, p2->p_comm) > 0)
71 		return (p2);
72 
73 	if (p1->p_pid > p2->p_pid)
74 		return (p1);
75 	return (p2);
76 }
77 
78 char *
79 get_proc_name(int fd, char *tty)
80 {
81 	int		 mib[6] = { CTL_KERN, KERN_PROC, KERN_PROC_PGRP, 0,
82 				    sizeof(struct kinfo_proc), 0 };
83 	struct stat	 sb;
84 	size_t		 len;
85 	struct kinfo_proc *buf, *newbuf, *bestp;
86 	u_int		 i;
87 	char		*name;
88 
89 	buf = NULL;
90 
91 	if (stat(tty, &sb) == -1)
92 		return (NULL);
93 	if ((mib[3] = tcgetpgrp(fd)) == -1)
94 		return (NULL);
95 
96 retry:
97 	if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) == -1)
98 		return (NULL);
99 	len = (len * 5) / 4;
100 
101 	if ((newbuf = realloc(buf, len)) == NULL)
102 		goto error;
103 	buf = newbuf;
104 
105 	mib[5] = (int)(len / sizeof(struct kinfo_proc));
106 	if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) == -1) {
107 		if (errno == ENOMEM)
108 			goto retry;
109 		goto error;
110 	}
111 
112 	bestp = NULL;
113 	for (i = 0; i < len / sizeof (struct kinfo_proc); i++) {
114 		if ((dev_t)buf[i].p_tdev != sb.st_rdev)
115 			continue;
116 		if (bestp == NULL)
117 			bestp = &buf[i];
118 		else
119 			bestp = cmp_procs(&buf[i], bestp);
120 	}
121 
122 	name = NULL;
123 	if (bestp != NULL)
124 		name = strdup(bestp->p_comm);
125 
126 	free(buf);
127 	return (name);
128 
129 error:
130 	free(buf);
131 	return (NULL);
132 }
133