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//===-- 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 "src/__support/macros/config.h"
#include <stddef.h> // For size_t.
namespace LIBC_NAMESPACE_DECL {
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_DECL
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