45 lines
1.3 KiB
C++
45 lines
1.3 KiB
C++
//===-- Implementation of getenv ------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "src/stdlib/getenv.h"
|
|
#include "config/linux/app.h"
|
|
#include "src/__support/CPP/string_view.h"
|
|
#include "src/__support/common.h"
|
|
|
|
#include <stddef.h> // For size_t.
|
|
|
|
namespace LIBC_NAMESPACE {
|
|
|
|
LLVM_LIBC_FUNCTION(char *, getenv, (const char *name)) {
|
|
char **env_ptr = reinterpret_cast<char **>(LIBC_NAMESPACE::app.env_ptr);
|
|
|
|
if (name == nullptr || env_ptr == nullptr)
|
|
return nullptr;
|
|
|
|
LIBC_NAMESPACE::cpp::string_view env_var_name(name);
|
|
if (env_var_name.size() == 0)
|
|
return nullptr;
|
|
for (char **env = env_ptr; *env != nullptr; env++) {
|
|
LIBC_NAMESPACE::cpp::string_view cur(*env);
|
|
if (!cur.starts_with(env_var_name))
|
|
continue;
|
|
|
|
if (cur[env_var_name.size()] != '=')
|
|
continue;
|
|
|
|
// Remove the name and the equals sign.
|
|
cur.remove_prefix(env_var_name.size() + 1);
|
|
// We know that data is null terminated, so this is safe.
|
|
return const_cast<char *>(cur.data());
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
} // namespace LIBC_NAMESPACE
|