libcamera/jmondi/libcamera.git - Jacopo Mondi's clone of libcamera

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * utils.cpp - Miscellaneous utility functions
 */

#include <libcamera/base/utils.h>

#include <iomanip>
#include <locale.h>
#include <sstream>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/**
 * \file base/utils.h
 * \brief Miscellaneous utility functions
 */

namespace libcamera {

namespace utils {

/**
 * \brief Strip the directory prefix from the path
 * \param[in] path The path to process
 *
 * basename is implemented differently across different C libraries. This
 * implementation matches the one provided by the GNU libc, and does not
 * modify its input parameter.
 *
 * \return A pointer within the given path without any leading directory
 * components.
 */
const char *basename(const char *path)
{
	const char *base = strrchr(path, '/');
	return base ? base + 1 : path;
}

/**
 * \brief Get an environment variable
 * \param[in] name The name of the variable to return
 *
 * The environment list is searched to find the variable 'name', and the
 * corresponding string is returned.
 *
 * If 'secure execution' is required then this function always returns NULL to
 * avoid vulnerabilities that could occur if set-user-ID or set-group-ID
 * programs accidentally trust the environment.
 *
 * \note Not all platforms may support the features required to implement the
 * secure execution check, in which case this function behaves as getenv(). A
 * notable example of this is Android.
 *
 * \return A pointer to the value in the environment or NULL if the requested
 * environment variable doesn't exist or if secure execution is required.
 */
char *secure_getenv(const char *name)
{
#if HAVE_SECURE_GETENV
	return ::secure_getenv(name);
#else
#if HAVE_ISSETUGID
	if (issetugid())
		return NULL;
#endif
	return getenv(name);
#endif
}

/**
 * \brief Identify the dirname portion of a path
 * \param[in] path The full path to parse
 *
 * This function conforms with the behaviour of the %dirname() function as
 * defined by POSIX.
 *
 * \return A string of the directory component of the path
 */
std::string dirname(const std::string &path)
{
	if (path.empty())
		return ".";

	/*
	 * Skip all trailing slashes. If the path is only made of slashes,
	 * return "/".
	 */
	size_t pos = path.size() - 1;
	while (path[pos] == '/') {
		if (!pos)
			return "/";
		pos--;
	}

	/*
	 * Find the previous slash. If the path contains no non-trailing slash,
	 * return ".".
	 */
	while (path[pos] != '/') {
		if (!pos)
			return ".";
		pos--;
	}

	/*
	 * Return the directory name up to (but not including) any trailing
	 * slash. If this would result in an empty string, return "/".
	 */
	while (path[pos] == '/') {
		if (!pos)
Mode	Name	Size
-rw-r--r--	.clang-format	5235	log plain
-rw-r--r--	.clang-tidy	60	log plain
-rw-r--r--	.gitignore	82	log plain
d---------	.reuse	32	log plain
-rw-r--r--	COPYING.rst	3798	log plain
d---------	Documentation	588	log plain
d---------	LICENSES	518	log plain
-rw-r--r--	README.rst	5834	log plain
d---------	include	141	log plain
-rw-r--r--	meson.build	6242	log plain
-rw-r--r--	meson_options.txt	1708	log plain
d---------	package / gentoo / media-libs / libcamera	33	log plain
d---------	src	307	log plain
d---------	subprojects	115	log plain
d---------	test	1740	log plain
d---------	utils	676	log plain