wmmemload/src/mem_gnu.c

   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 */
  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
  51 INLINE_STATIC char *skip_line(const char *p)
  52 {
  53         while (*p != '\n')
  54                 p++;
  55         return (char *) ++p;
  56 }
  57
  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
  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 */
  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 }