ex25

lcthw-remnants-2/ex25.c

@@ -0,0 +1,134 @@
+/** WARNING: This code is fresh and potentially isn't correct yet. */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include "dbg.h"
+
+#define MAX_DATA 100
+
+int read_string(char **out_string, int max_buffer)
+{
+  *out_string = calloc(1, max_buffer + 1);
+  check_mem(*out_string);
+
+  char *result = fgets(*out_string, max_buffer, stdin);
+  check(result != NULL, "Input error.");
+
+  return 0;
+
+error:
+  if(*out_string) free(*out_string);
+  *out_string = NULL;
+  return -1;
+}
+
+int read_int(int *out_int)
+{
+  char *input = NULL;
+  int rc = read_string(&input, MAX_DATA);
+  check(rc == 0, "Failed to read number.");
+
+  *out_int = atoi(input);
+
+  free(input);
+  return 0;
+
+error:
+  if(input) free(input);
+  return -1;
+}
+
+int read_scan(const char *fmt, ...)
+{
+  int i = 0;
+  int rc = 0;
+  int *out_int = NULL;
+  char *out_char = NULL;
+  char **out_string = NULL;
+  int max_buffer = 0;
+
+  va_list argp;
+  va_start(argp, fmt);
+
+  for(i = 0; fmt[i] != '\0'; i++) {
+    if(fmt[i] == '%') {
+      i++;
+      switch(fmt[i]) {
+        case '\0':
+          sentinel("Invalid format, you ended with %%.");
+          break;
+
+        case 'd':
+          out_int = va_arg(argp, int *);
+          rc = read_int(out_int);
+          check(rc == 0, "Failed to read int.");
+          break;
+
+        case 'c':
+          out_char = va_arg(argp, char *);
+          *out_char = fgetc(stdin);
+          break;
+
+        case 's':
+          max_buffer = va_arg(argp, int);
+          out_string = va_arg(argp, char **);
+          rc = read_string(out_string, max_buffer);
+          check(rc == 0, "Failed to read string.");
+          break;
+
+        default:
+          sentinel("Invalid format.");
+
+      }
+    } else {
+      fgetc(stdin);
+    }
+
+    check(!feof(stdin) && !ferror(stdin), "Input error.");
+  }
+
+  va_end(argp);
+  return 0;
+
+error:
+  va_end(argp);
+  return -1;
+}
+
+
+
+int main(int argc, char *argv[])
+{
+  char *first_name = NULL;
+  char initial = ' ';
+  char *last_name = NULL;
+  int age = 0;
+
+  printf("What's your first name? ");
+  int rc = read_scan("%s", MAX_DATA, &first_name);
+  check(rc == 0, "Failed first name.");
+
+  printf("What's your initial? ");
+  rc = read_scan("%c\n", &initial);
+  check(rc == 0, "Failed initial.");
+
+  printf("What's your last name? ");
+  rc = read_scan("%s", MAX_DATA, &last_name);
+  check(rc == 0, "Failed last name.");
+
+  printf("How old are you? ");
+  rc = read_scan("%d", &age);
+
+  printf("---- RESULTS ----\n");
+  printf("First Name: %s", first_name);
+  printf("Initial: '%c'\n", initial);
+  printf("Last Name: %s", last_name);
+  printf("Age: %d\n", age);
+
+  free(first_name);
+  free(last_name);
+  return 0;
+error:
+  return -1;
+}