about summary refs log tree commit diff
path: root/xdg.c
blob: 00cd021334a75ea2f981fab3807d9e1e3a3daaa7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/* Copyright (C) 2019, 2020  C. McEnroe <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * Additional permission under GNU GPL version 3 section 7:
 *
 * If you modify this Program, or any covered work, by linking or
 * combining it with OpenSSL (or a modified version of that library),
 * containing parts covered by the terms of the OpenSSL License and the
 * original SSLeay license, the licensors of this Program grant you
 * additional permission to convey the resulting work. Corresponding
 * Source for a non-source form of such a combination shall include the
 * source code for the parts of OpenSSL used as well as that of the
 * covered work.
 */

#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

#include "database.h"

#define SUBDIR "litterbox"

struct Base {
	const char *envHome;
	const char *envDirs;
	const char *defHome;
	const char *defDirs;
};

static const struct Base Config = {
	.envHome = "XDG_CONFIG_HOME",
	.envDirs = "XDG_CONFIG_DIRS",
	.defHome = ".config",
	.defDirs = "/etc/xdg",
};

static const struct Base Data = {
	.envHome = "XDG_DATA_HOME",
	.envDirs = "XDG_DATA_DIRS",
	.defHome = ".local/share",
	.defDirs = "/usr/local/share:/usr/share",
};

static const char *
basePath(struct Base base, const char **dirs, const char *path) {
	static char buf[PATH_MAX];

	if (*dirs) {
		if (!**dirs) return NULL;
		size_t len = strcspn(*dirs, ":");
		snprintf(buf, sizeof(buf), "%.*s/" SUBDIR "/%s", (int)len, *dirs, path);
		*dirs += len;
		if (**dirs) *dirs += 1;
		return buf;
	}

	if (path[0] == '/' || path[0] == '.') {
		*dirs = "";
		return path;
	}

	*dirs = getenv(base.envDirs);
	if (!*dirs) *dirs = base.defDirs;

	const char *home = getenv("HOME");
	const char *baseHome = getenv(base.envHome);
	if (baseHome) {
		snprintf(buf, sizeof(buf), "%s/" SUBDIR "/%s", baseHome, path);
	} else if (home) {
		snprintf(
			buf, sizeof(buf), "%s/%s/" SUBDIR "/%s",
			home, base.defHome, path
		);
	} else {
		return NULL;
	}
	return buf;
}

const char *configPath(const char **dirs, const char *path) {
	return basePath(Config, dirs, path);
}

const char *
dataPath(const char **dirs, const char *path) {
	return basePath(Data, dirs, path);
}

FILE *configOpen(const char *path, const char *mode) {
	const char *dirs = NULL;
	for (const char *abs; NULL != (abs = configPath(&dirs, path));) {
		FILE *file = fopen(abs, mode);
		if (file) return file;
		if (errno != ENOENT) warn("%s", abs);
	}
	FILE *file = fopen(path, mode);
	if (!file) warn("%s", path);
	return file;
}

void dataMkdir(const char *path) {
	const char *dirs = NULL;
	const char *abs = dataPath(&dirs, path);
	if (!abs) return;
	int error = mkdir(abs, S_IRWXU);
	if (error && errno != EEXIST) warn("%s", abs);
}

FILE *dataOpen(const char *path, const char *mode) {
	const char *dirs = NULL;
	for (const char *abs; NULL != (abs = dataPath(&dirs, path));) {
		FILE *file = fopen(abs, mode);
		if (file) return file;
		if (errno != ENOENT) warn("%s", abs);
	}

	if (mode[0] != 'r') {
		dataMkdir("");
		dirs = NULL;
		path = dataPath(&dirs, path);
		if (!path) {
			warn("HOME unset");
			return NULL;
		}
		FILE *file = fopen(path, mode);
		if (!file) warn("%s", path);
		return file;
	}

	FILE *file = fopen(path, mode);
	if (!file) warn("%s", path);
	return file;
}