1 files changed, 88 insertions, 0 deletions
diff --git a/src/modules/cpu.c b/src/modules/cpu.c
new file mode 100644
index 0000000..cf70524
--- /dev/null
+++ b/src/modules/cpu.c
@@ -0,0 +1,88 @@
+#include "cpu.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <tgmath.h>
+
+#define VALUE_SIZE 32
+
+#define FILE_STAT_PATH "/proc/stat"
+
+struct cpu_stat {
+    unsigned long usage;
+    unsigned long total;
+};
+
+struct cpu {
+    char value[VALUE_SIZE];
+
+    struct cpu_stat last;
+    FILE * statfd;
+};
+
+static void
+parse_cpu_stat(struct cpu * c, struct cpu_stat * stat)
+{
+    char line[1024];
+    char * tok = line + 5;
+
+    stat->usage = 0;
+    stat->total = 0;
+
+    rewind(c->statfd);
+    fflush(c->statfd);
+    fgets(line, 1024, c->statfd);
+
+    stat->usage += strtoul(tok, &tok, 10);
+    stat->usage += strtoul(tok, &tok, 10);
+    stat->usage += strtoul(tok, &tok, 10);
+    stat->total += stat->usage + strtoul(tok, &tok, 10);
+}
+
+struct cpu *
+cpu_new()
+{
+    struct cpu * c = malloc(sizeof(struct cpu));
+    memset(c->value, '\0', VALUE_SIZE);
+    c->statfd = fopen(FILE_STAT_PATH, "r");
+
+    parse_cpu_stat(c, &c->last);
+
+    return c;
+}
+
+void
+cpu_free(struct cpu * c)
+{
+    fclose(c->statfd);
+    free(c);
+}
+
+void
+cpu_update(struct cpu * c)
+{
+    struct cpu_stat stat;
+    unsigned long usage_diff, total_diff;
+
+    unsigned short percent;
+
+    parse_cpu_stat(c, &stat);
+
+    usage_diff = stat.usage - c->last.usage;
+    total_diff = stat.total - c->last.total;
+
+    c->last = stat;
+
+    percent = round((100.0f / total_diff) * usage_diff);
+
+    snprintf(c->value, VALUE_SIZE, "\uf2db% 4d%%", percent);
+}
+
+const char *
+cpu_get_val(struct cpu * c)
+{
+    return c->value;
+}