src/variables.c


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/*
 * src/variables.c
 *
 * Local variable storage and access
 * CISC 301 -- Operating Systems, Project 2
 *
 * Copyright (C) 2025  Douglas B. Rumbaugh <dbrumbaugh@harrisburgu.edu>
 *
 * Distributed under the Modified BSD License
 *
 */
#include "variables.h"
#include "strmap.h"

static strmap *map;

bool init_variable_store(void) {
  map = strmap_create(hash_key);
  return map;
}

bool add_variable(const char *key, const char *val) {
  if (strmap_put(map, key, val) != STRMAP_OK) {
    return false;
  }

  return true;
}

const char *get_variable(const char *key) {
  key += (key[0] == '$');
  const char *val;
  strmap_status stat = strmap_get(map, key, &val);
  switch (stat) {
    case STRMAP_OK:
      break;
    case STRMAP_NOTFOUND:
      val = getenv(key);
      break;
    default:
      val = NULL;
      break;
  }

  return (val) ? val : "";
}

bool promote_variable_to_env(const char *key) {
  const char *val = get_variable(key);
  if (!val) {
    val = "";
  }

  return !setenv(key, val, 1);
}

void destroy_variable_store() {
  strmap_destroy(map);
}