added to git

readUtil.c

@@ -0,0 +1,75 @@
+#include "readUtil.h"
+#include "myMonitoringTool.h"
+#include <assert.h>
+
+// Rip an integer out of a string.
+int extract_int(char *str) {
+  ///_|> descry: takes an integer out of a string
+  ///_|> str: string to search
+  ///_|> returning: void
+  char num[LINE_BUF];
+  int num_idx = 0;
+
+  int str_idx = 0;
+  while (str[str_idx] != '\0') {
+    if (isdigit(str[str_idx])) {
+      num[num_idx] = str[str_idx];
+      num_idx++;
+    }
+    str_idx++;
+  }
+  num[num_idx] = '\0';
+
+  return atoi(num);
+}
+
+int get_file_line_value(char *filename, int linenum) {
+  ///_|> descry: Get the integer at a specific line in a value. First line in
+  /// file is line num
+  ///_|> filename: file to search
+  ///_|> linenum: line to read
+  ///_|> returning: integer thats found
+  FILE *file = fopen(filename, "r");
+  if (file == NULL) {
+    printf("could not open %s", filename);
+    exit(1);
+  }
+  char line[LINE_BUF];
+  for (int i = 0; i <= linenum; i++) {
+    fgets(line, LINE_BUF, file);
+  }
+  fclose(file);
+  char label[LINE_BUF];
+  char sep[LINE_BUF];
+  int value;
+  char tail[LINE_BUF];
+  sscanf(line, "%s %s %d %s", label, sep, &value, tail);
+  return extract_int(line);
+}
+
+long read_cpu_util() {
+  ///_|> decry: Read total cpu time usage from /proc/stat
+  ///_|> returning: cpu usage since boot
+  char dummy[LINE_BUF];
+  long user;
+  long nice;
+  long system;
+  long idle; // not counted
+  long io;
+  long intr;
+  long sintr;
+  long steal;
+  long guest;
+  long guest_nice;
+  FILE *file = fopen("/proc/stat", "r");
+  if (file == NULL) {
+    printf("could not open /proc/stat");
+    exit(1);
+  }
+  fscanf(file, "%s %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld", dummy, &user,
+         &nice, &system, &idle, &io, &intr, &sintr, &steal, &guest,
+         &guest_nice);
+  fclose(file);
+  // return value is in 1/100 s
+  return user + nice + system + io + intr + sintr;
+}