lib/fstree/canonicalize_name.c


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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
 * canonicalize_name.c
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#include "config.h"

#include "fstree.h"

static void normalize_slashes(char *filename)
{
	char *dst = filename, *src = filename;

	while (*src == '/' || *src == '\\')
		++src;

	while (*src != '\0') {
		if (*src == '/' || *src == '\\') {
			while (*src == '/' || *src == '\\')
				++src;
			if (*src == '\0')
				break;
			*(dst++) = '/';
		} else {
			*(dst++) = *(src++);
		}
	}

	*dst = '\0';
}

int canonicalize_name(char *filename)
{
	char *dst = filename, *src = filename;

	normalize_slashes(filename);

	while (*src != '\0') {
		if (src[0] == '.') {
			if (src[1] == '\0')
				break;
			if (src[1] == '/') {
				src += 2;
				continue;
			}
			if (src[1] == '.' && (src[2] == '/' || src[2] == '\0'))
				return -1;
		}

		while (*src != '\0' && *src != '/')
			*(dst++) = *(src++);

		if (*src == '/')
			*(dst++) = *(src++);
	}

	*dst = '\0';
	normalize_slashes(filename);
	return 0;
}