Implement support for memory-usage on Linux

i3status.c

@@ -421,6 +421,22 @@ int main(int argc, char *argv[]) {
         CFG_CUSTOM_SEP_BLOCK_WIDTH_OPT,
         CFG_END()};
 
+    cfg_opt_t memory_opts[] = {
+        CFG_STR("format", "%used %free %available", CFGF_NONE),
+        CFG_STR("degraded_format_below_threshold", NULL, CFGF_NONE),
+        CFG_STR("degraded_threshold_type", "percentage_avail", CFGF_NONE),
+        CFG_FLOAT("degraded_low_threshold", 0, CFGF_NONE),
+        CFG_STR("critical_format_below_threshold", NULL, CFGF_NONE),
+        CFG_STR("critical_threshold_type", "percentage_avail", CFGF_NONE),
+        CFG_FLOAT("critical_low_threshold", 0, CFGF_NONE),
+        CFG_BOOL("use_available_memory", true, CFGF_NONE),
+        CFG_CUSTOM_ALIGN_OPT,
+        CFG_CUSTOM_COLOR_OPTS,
+        CFG_CUSTOM_MIN_WIDTH_OPT,
+        CFG_CUSTOM_SEPARATOR_OPT,
+        CFG_CUSTOM_SEP_BLOCK_WIDTH_OPT,
+        CFG_END()};
+
     cfg_opt_t usage_opts[] = {
         CFG_STR("format", "%usage", CFGF_NONE),
         CFG_STR("format_above_threshold", NULL, CFGF_NONE),
@@ -490,6 +506,7 @@ int main(int argc, char *argv[]) {
         CFG_SEC("tztime", tztime_opts, CFGF_TITLE | CFGF_MULTI),
         CFG_SEC("ddate", ddate_opts, CFGF_NONE),
         CFG_SEC("load", load_opts, CFGF_NONE),
+        CFG_SEC("memory", memory_opts, CFGF_NONE),
         CFG_SEC("cpu_usage", usage_opts, CFGF_NONE),
         CFG_END()};
 
@@ -724,6 +741,12 @@ int main(int argc, char *argv[]) {
                 SEC_CLOSE_MAP;
             }
 
+            CASE_SEC("memory") {
+                SEC_OPEN_MAP("memory");
+                print_memory(json_gen, buffer, cfg_getstr(sec, "format"), cfg_getstr(sec, "degraded_format_below_threshold"), cfg_getstr(sec, "degraded_threshold_type"), cfg_getfloat(sec, "degraded_low_threshold"), cfg_getstr(sec, "critical_format_below_threshold"), cfg_getstr(sec, "critical_threshold_type"), cfg_getfloat(sec, "critical_low_threshold"), cfg_getbool(sec, "use_available_memory"));
+                SEC_CLOSE_MAP;
+            }
+
             CASE_SEC("time") {
                 SEC_OPEN_MAP("time");
                 print_time(json_gen, buffer, NULL, cfg_getstr(sec, "format"), NULL, NULL, NULL, tv.tv_sec);

include/i3status.h

@@ -223,6 +223,7 @@ void print_cpu_temperature_info(yajl_gen json_gen, char *buffer, int zone, const
 void print_cpu_usage(yajl_gen json_gen, char *buffer, const char *format, const char *format_above_threshold, const char *format_above_degraded_threshold, const char *path, const float max_threshold, const float degraded_threshold);
 void print_eth_info(yajl_gen json_gen, char *buffer, const char *interface, const char *format_up, const char *format_down);
 void print_load(yajl_gen json_gen, char *buffer, const char *format, const char *format_above_threshold, const float max_threshold);
+void print_memory(yajl_gen json_gen, char *buffer, const char *format, const char *degraded_format_below_threshold, const char *degraded_threshold_type, const float degraded_low_threshold, const char *critical_format_below_threshold, const char *critical_threshold_type, const float critical_low_threshold, const bool use_available_memory);
 void print_volume(yajl_gen json_gen, char *buffer, const char *fmt, const char *fmt_muted, const char *device, const char *mixer, int mixer_idx);
 bool process_runs(const char *path);
 int volume_pulseaudio(uint32_t sink_idx, const char *sink_name);

man/i3status.man

@@ -55,6 +55,7 @@ order += "wireless wlan0"
 order += "ethernet eth0"
 order += "battery 0"
 order += "cpu_temperature 0"
+order += "memory"
 order += "load"
 order += "tztime local"
 order += "tztime berlin"
@@ -113,6 +114,10 @@ cpu_temperature 0 {
 	path = "/sys/devices/platform/coretemp.0/temp1_input"
 }
 
+memory {
+        format = "%used"
+}
+
 disk "/" {
 	format = "%free"
 }
@@ -424,6 +429,49 @@ starting from %cpu0. This feature is currently not supported in FreeBSD.
 
 *Example format_above_degraded_threshold*: +Warning above degraded threshold: %usage+
 
+=== Memory
+
+Gets the memory usage from system.
+On Linux, the information is taken from +/proc/meminfo+.
+
+These values can also be expressed in percentages with the +percentage_used+,
++percentage_free+ and +percentage_shared+ formats.
+
+If a +critical_low_threshold+ is defined, the output will be colored using
++color_bad+. The unit of this threshold is defined by the unit given in
++critical_threshold_type+, which can be one of "bytes_free", "bytes_avail",
+"percentage_free" and "percentage_avail". Additionally, the former two can be
+prefixed with one of "k", "m", "g" or "t" to change the exact unit.
+For example, setting critical_low_threshold to 2 and threshold_type to "gbytes_avail"
+causes available memory below 2 GiB to be colored with +color_bad+. The
+defaults are "percentage_avail" with a threshold of 0.
+Furthermore, the format used when the threshold is reached can be customized
+using the option +critical_format_below_threshold+.
+Same applies to +degraded_low_threshold+, +degraded_threshold_type+ and
++degraded_format_below_threshold+ using +color_degraded+.
+
+The most common one is:
+"used memory" = "total memory" - "free memory" - "buffers" - "cache"
+This is the default in i3status. Some other programs use
+"used memory" = "total memory" - "available memory"
+You can disable this behavior using +use_available_memory+.
+
+*Example order*: +memory+
+
+*Example format*: +%free %available (%used)/ %total+
+
+*Example format*: +used %percentage_used , free %percentage_free, shared %percentage_shared+
+
+*Example degraded_low_threshold*: +10+
+
+*Example degraded_threshold_type*: +percentage_free+
+
+*Example critical_low_threshold*: +5+
+
+*Example critical_format_below_threshold*: +Warning: %percentage_free+
+
+*Example use_available_memory: +false+
+
 === Load
 
 Gets the system load (number of processes waiting for CPU time in the last

src/print_mem.c

@@ -0,0 +1,208 @@
+// vim:ts=4:sw=4:expandtab
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <yajl/yajl_gen.h>
+#include <yajl/yajl_version.h>
+#include "i3status.h"
+
+#define BINARY_BASE UINT64_C(1024)
+
+#define MAX_EXPONENT 4
+static const char *const iec_symbols[MAX_EXPONENT + 1] = {"", "Ki", "Mi", "Gi", "Ti"};
+
+static const char filename[] = "/proc/meminfo";
+
+/*
+ * Prints the given amount of bytes in a human readable manner.
+ *
+ */
+static int print_bytes_human(char *outwalk, uint64_t bytes) {
+    double size = bytes;
+    int exponent = 0;
+    int bin_base = BINARY_BASE;
+    while (size >= bin_base && exponent < MAX_EXPONENT) {
+        size /= bin_base;
+        exponent += 1;
+    }
+    return sprintf(outwalk, "%.1f %sB", size, iec_symbols[exponent]);
+}
+
+/*
+ * Determines whether remaining bytes are below given threshold.
+ *
+ */
+static bool below_threshold(const long totalRam, const long usedRam, const char *threshold_type, const long low_threshold) {
+    // empty is available or free, based on "use_available_memory"
+    long empty = totalRam - usedRam;
+    if (BEGINS_WITH(threshold_type, "percentage_")) {
+        return 100.0 * empty / totalRam < low_threshold;
+    } else if (strcasecmp(threshold_type, "bytes_free") == 0) {
+        return empty < low_threshold;
+    } else if (threshold_type[0] != '\0' && strncasecmp(threshold_type + 1, "bytes_", strlen("bytes_")) == 0) {
+        uint64_t base = BINARY_BASE;
+        long factor = 1;
+
+        switch (threshold_type[0]) {
+            case 'T':
+            case 't':
+                factor *= base;
+            case 'G':
+            case 'g':
+                factor *= base;
+            case 'M':
+            case 'm':
+                factor *= base;
+            case 'K':
+            case 'k':
+                factor *= base;
+                break;
+            default:
+                return false;
+        }
+        return empty < low_threshold * factor;
+    }
+    return false;
+}
+
+void print_memory(yajl_gen json_gen, char *buffer, const char *format, const char *degraded_format_below_threshold, const char *degraded_threshold_type, const float degraded_low_threshold, const char *critical_format_below_threshold, const char *critical_threshold_type, const float critical_low_threshold, const bool use_available_memory) {
+    char *outwalk = buffer;
+
+#if defined(linux)
+    const char *selected_format = format;
+    const char *walk;
+    bool colorful_output = false;
+
+    long totalRam = -1;
+    long freeRam = -1;
+    long availableRam = -1;
+    long usedRam = -1;
+    long sharedRam = -1;
+    long cached = -1;
+    long buffers = -1;
+
+    FILE *file = fopen(filename, "r");
+    if (!file) {
+        goto error;
+    }
+    char line[128];
+    while (fgets(line, sizeof line, file)) {
+        if (BEGINS_WITH(line, "MemTotal:")) {
+            totalRam = strtol(line + strlen("MemTotal:"), NULL, 10);
+        }
+        if (BEGINS_WITH(line, "MemFree:")) {
+            freeRam = strtol(line + strlen("MemFree:"), NULL, 10);
+        }
+        if (BEGINS_WITH(line, "MemAvailable:")) {
+            availableRam = strtol(line + strlen("MemAvailable:"), NULL, 10);
+        }
+        if (BEGINS_WITH(line, "Buffers:")) {
+            buffers = strtol(line + strlen("Buffers:"), NULL, 10);
+        }
+        if (BEGINS_WITH(line, "Cached:")) {
+            cached = strtol(line + strlen("Cached:"), NULL, 10);
+        }
+        if (BEGINS_WITH(line, "Shmem:")) {
+            sharedRam = strtol(line + strlen("Shmem:"), NULL, 10);
+        }
+        if (totalRam != -1 && freeRam != -1 && availableRam != -1 && buffers != -1 && cached != -1 && sharedRam != -1) {
+            break;
+        }
+    }
+    fclose(file);
+
+    if (totalRam == -1 || freeRam == -1 || availableRam == -1 || buffers == -1 || cached == -1 || sharedRam == -1) {
+        goto error;
+    }
+
+    totalRam = totalRam * BINARY_BASE;
+    freeRam = freeRam * BINARY_BASE;
+    availableRam = availableRam * BINARY_BASE;
+    buffers = buffers * BINARY_BASE;
+    cached = cached * BINARY_BASE;
+    sharedRam = sharedRam * BINARY_BASE;
+    if (use_available_memory) {
+        usedRam = totalRam - availableRam;
+    } else {
+        usedRam = totalRam - freeRam - buffers - cached;
+    }
+
+    if (degraded_low_threshold > 0 && below_threshold(totalRam, usedRam, degraded_threshold_type, degraded_low_threshold)) {
+        if (critical_low_threshold > 0 && below_threshold(totalRam, usedRam, critical_threshold_type, critical_low_threshold)) {
+            START_COLOR("color_bad");
+            colorful_output = true;
+            if (critical_format_below_threshold != NULL)
+                selected_format = critical_format_below_threshold;
+        } else {
+            START_COLOR("color_degraded");
+            colorful_output = true;
+            if (degraded_format_below_threshold != NULL)
+                selected_format = degraded_format_below_threshold;
+        }
+    }
+
+    for (walk = selected_format; *walk != '\0'; walk++) {
+        if (*walk != '%') {
+            *(outwalk++) = *walk;
+            continue;
+        }
+        if (BEGINS_WITH(walk + 1, "total")) {
+            outwalk += print_bytes_human(outwalk, totalRam);
+            walk += strlen("total");
+        }
+
+        if (BEGINS_WITH(walk + 1, "used")) {
+            outwalk += print_bytes_human(outwalk, usedRam);
+            walk += strlen("used");
+        }
+
+        if (BEGINS_WITH(walk + 1, "free")) {
+            outwalk += print_bytes_human(outwalk, freeRam);
+            walk += strlen("free");
+        }
+
+        if (BEGINS_WITH(walk + 1, "available")) {
+            outwalk += print_bytes_human(outwalk, availableRam);
+            walk += strlen("available");
+        }
+
+        if (BEGINS_WITH(walk + 1, "shared")) {
+            outwalk += print_bytes_human(outwalk, sharedRam);
+            walk += strlen("shared");
+        }
+
+        if (BEGINS_WITH(walk + 1, "percentage_free")) {
+            outwalk += sprintf(outwalk, "%.01f%s", 100.0 * freeRam / totalRam, pct_mark);
+            walk += strlen("percentage_free");
+        }
+
+        if (BEGINS_WITH(walk + 1, "percentage_available")) {
+            outwalk += sprintf(outwalk, "%.01f%s", 100.0 * availableRam / totalRam, pct_mark);
+            walk += strlen("percentage_available");
+        }
+
+        if (BEGINS_WITH(walk + 1, "percentage_used")) {
+            outwalk += sprintf(outwalk, "%.01f%s", 100.0 * usedRam / totalRam, pct_mark);
+            walk += strlen("percentage_used");
+        }
+
+        if (BEGINS_WITH(walk + 1, "percentage_shared")) {
+            outwalk += sprintf(outwalk, "%.01f%s", 100.0 * sharedRam / totalRam, pct_mark);
+            walk += strlen("percentage_shared");
+        }
+    }
+
+    if (colorful_output)
+        END_COLOR;
+
+    *outwalk = '\0';
+    OUTPUT_FULL_TEXT(buffer);
+
+    return;
+error:
+    OUTPUT_FULL_TEXT("can't read memory");
+    fputs("i3status: Cannot read system memory using /proc/meminfo\n", stderr);
+#else
+    fputs("i3status: Memory status information is not supported on this system\n", stderr);
+#endif
+}