/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-â
âvi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :viâ
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â Copyright 2020 Justine Alexandra Roberts Tunney                              â
â                                                                              â
â Permission to use, copy, modify, and/or distribute this software for         â
â any purpose with or without fee is hereby granted, provided that the         â
â above copyright notice and this permission notice appear in all copies.      â
â                                                                              â
â THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                â
â WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                â
â WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             â
â AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         â
â DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        â
â PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               â
â TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             â
â PERFORMANCE OF THIS SOFTWARE.                                                â
ââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââ*/
#include "libc/intrin/kmalloc.h"
#include "libc/intrin/strace.internal.h"
#include "libc/mem/internal.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"

/**
 * Copies variable to environment.
 *
 * @return 0 on success, or -1 w/ errno and environment is unchanged
 * @raise EINVAL if `name` is empty or contains `'='`
 * @raise ENOMEM if we require more vespene gas
 * @see putenv(), getenv()
 */
int setenv(const char *name, const char *value, int overwrite) {
  int rc;
  char *s;
  size_t n, m;
  const char *t;
  if (!name || !*name || !value) return einval();
  for (t = name; *t; ++t) {
    if (*t == '=') return einval();
  }
  n = strlen(name);
  m = strlen(value);
  if (!(s = kmalloc(n + 1 + m + 1))) return -1;
  memcpy(mempcpy(mempcpy(s, name, n), "=", 1), value, m + 1);
  rc = PutEnvImpl(s, overwrite);
  STRACE("setenv(%#s, %#s, %d) â %d% m", name, value, overwrite, rc);
  return rc;
}
