1 /*
2 * mem_gnu.c - module to get memory/swap usages, for GNU/Hurd
3 *
4 * Copyright(C) 2014 Svante Signell <svante.signell@gmail.com>
5 * Copyright(C) 2001,2002 Seiichi SATO <ssato@sh.rim.or.jp>
6 * Copyright(C) 2001 John McCutchan <ttb@tentacle.dhs.org>
7 *
8 * licensed under the GPL
9 */
10
11 #ifdef HAVE_CONFIG_H
12 #include "config.h"
13 #endif
14
15 #include <stdio.h>
16 #include <unistd.h>
17 #include <stdlib.h>
18
19 #if defined(HAVE_STRING_H)
20 #include <string.h>
21 #elif defined(HAVE_STRINGS_H)
22 #include <strings.h>
23 #endif
24
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <fcntl.h>
28 #include <ctype.h>
29 #include <sys/utsname.h>
30 #include "mem.h"
31
32 #ifdef DEBUG
33 # define INLINE_STATIC static
34 #else
35 # define INLINE_STATIC static inline
36 #endif
37
38 /* initialize function */
mem_init(void)39 void mem_init(void)
40 {
41 struct utsname un;
42 int version, patchlevel;
43
44 /* get kernel version */
45 if (uname(&un) == -1)
46 perror("uname()");
47 sscanf(un.release, "%d.%d", &version, &patchlevel);
48 }
49
50
skip_line(const char * p)51 INLINE_STATIC char *skip_line(const char *p)
52 {
53 while (*p != '\n')
54 p++;
55 return (char *) ++p;
56 }
57
skip_token(const char * p)58 INLINE_STATIC char *skip_token(const char *p)
59 {
60 while (isspace(*p))
61 p++;
62 while (*p && !isspace(*p))
63 p++;
64 return (char *)p;
65 }
66
skip_multiple_token(const char * p,int count)67 INLINE_STATIC char *skip_multiple_token(const char *p, int count)
68 {
69 int i;
70 for (i = 0; i < count; i++)
71 p = skip_token(p);
72 return (char *)p;
73 }
74
75 /* return mem/swap usage in percent 0 to 100 */
mem_getusage(int * per_mem,int * per_swap,const struct mem_options * opts)76 void mem_getusage(int *per_mem, int *per_swap, const struct mem_options *opts)
77 {
78 char buffer[BUFSIZ], *p;
79 int fd, len, i;
80 u_int64_t mtotal, mused, mfree, mbuffer, mcached;
81 u_int64_t stotal, sused, sfree, scached = 0;
82
83 /* read /proc/meminfo */
84 fd = open("/proc/meminfo", O_RDONLY);
85 if (fd < 0) {
86 perror("can't open /proc/meminfo");
87 exit(1);
88 }
89 len = read(fd, buffer, BUFSIZ - 1);
90 if (len < 0) {
91 perror("can't read /proc/meminfo");
92 exit(1);
93 }
94 close(fd);
95
96 buffer[len] = '\0';
97 p = buffer;
98
99 p = skip_token(p);
100 /* examine each line of file */
101 mtotal = strtoul(p, &p, 0); p = skip_multiple_token(p, 2);
102 mfree = strtoul(p, &p, 0); p = skip_multiple_token(p, 2);
103 mbuffer = strtoul(p, &p, 0); p = skip_multiple_token(p, 2);
104 mcached = strtoul(p, &p, 0); p = skip_multiple_token(p, 2);
105 scached = strtoul(p, &p, 0);
106
107 /* skip N lines and examine info about swap */
108 while (isprint(p[0])) {
109 p = skip_line(p);
110 if (strncmp(p, "SwapTotal", 9) == 0)
111 break;
112 }
113
114 p = skip_token(p);
115 stotal = strtoul(p, &p, 0); p = skip_multiple_token(p, 2);
116 sfree = strtoul(p, &p, 0);
117
118 /* calculate memory usage in percent */
119 mused = mtotal - mfree;
120 if (opts->ignore_buffers)
121 mused -= mbuffer;
122 if (opts->ignore_cached)
123 mused -= mcached;
124 *per_mem = 100 * (double) mused / (double) mtotal;
125
126 /* calculate swap usage in percent */
127 sused = stotal - sfree;
128 if (opts->ignore_cached)
129 sused -= scached;
130 if (!stotal)
131 *per_swap = 0;
132 else
133 *per_swap = 100 * (double) sused / (double) stotal;
134
135 #if DEBUG
136 printf("-----------------------\n");
137 printf("MemTotal: %12ld\n", (unsigned long)mtotal);
138 printf("MemFree: %12ld\n", (unsigned long)mfree);
139 printf("Buffers: %12ld\n", (unsigned long)mbuffer);
140 printf("Cached: %12ld\n", (unsigned long)mcached);
141 printf("SwapTotal: %12ld\n", (unsigned long)stotal);
142 printf("SwapFree: %12ld\n", (unsigned long)sfree);
143 printf("SwapCached:%12ld\n", (unsigned long)scached);
144 printf("-----------------------\n\n");
145 #endif
146
147 }
148