summary refs log tree commit diff
path: root/config.c
blob: b3e42f9a1847e89fe5a75d3523efafe55867b5bd (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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/* Copyright (C) 2019  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/>.
 */

#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "chat.h"

#define CONFIG_DIR "catgirl"

FILE *configOpen(const char *path, const char *mode) {
	if (path[0] == '/' || path[0] == '.') goto local;

	const char *home = getenv("HOME");
	const char *configHome = getenv("XDG_CONFIG_HOME");
	const char *configDirs = getenv("XDG_CONFIG_DIRS");

	char buf[PATH_MAX];
	if (configHome) {
		snprintf(buf, sizeof(buf), "%s/" CONFIG_DIR "/%s", configHome, path);
	} else {
		if (!home) goto local;
		snprintf(buf, sizeof(buf), "%s/.config/" CONFIG_DIR "/%s", home, path);
	}
	FILE *file = fopen(buf, mode);
	if (file) return file;
	if (errno != ENOENT) return NULL;

	if (!configDirs) configDirs = "/etc/xdg";
	while (*configDirs) {
		size_t len = strcspn(configDirs, ":");
		snprintf(
			buf, sizeof(buf), "%.*s/" CONFIG_DIR "/%s",
			(int)len, configDirs, path
		);
		file = fopen(buf, mode);
		if (file) return file;
		if (errno != ENOENT) return NULL;
		configDirs += len;
		if (*configDirs) configDirs++;
	}

local:
	return fopen(path, mode);
}

#define WS "\t "

static const char *path;
static FILE *file;
static size_t num;
static char *line;
static size_t cap;

static int clean(int opt) {
	if (file) fclose(file);
	free(line);
	line = NULL;
	cap = 0;
	return opt;
}

int getopt_config(
	int argc, char *const *argv,
	const char *optstring, const struct option *longopts, int *longindex
) {
	static int opt;
	if (opt >= 0) {
		opt = getopt_long(argc, argv, optstring, longopts, longindex);
	}
	if (opt >= 0) return opt;

	for (;;) {
		if (!file) {
			if (optind < argc) {
				num = 0;
				path = argv[optind++];
				file = configOpen(path, "r");
				if (!file) {
					warn("%s", path);
					return clean('?');
				}
			} else {
				return clean(-1);
			}
		}

		for (;;) {
			ssize_t llen = getline(&line, &cap, file);
			if (ferror(file)) {
				warn("%s", path);
				return clean('?');
			}
			if (llen <= 0) break;
			if (line[llen - 1] == '\n') line[llen - 1] = '\0';
			num++;

			char *name = line + strspn(line, WS);
			size_t len = strcspn(name, WS "=");
			if (!name[0] || name[0] == '#') continue;

			const struct option *option;
			for (option = longopts; option->name; ++option) {
				if (strlen(option->name) != len) continue;
				if (!strncmp(option->name, name, len)) break;
			}
			if (!option->name) {
				warnx(
					"%s:%zu: unrecognized option `%.*s'",
					path, num, (int)len, name
				);
				return clean('?');
			}

			char *equal = &name[len] + strspn(&name[len], WS);
			if (*equal && *equal != '=') {
				warnx(
					"%s:%zu: option `%s' missing equals sign",
					path, num, option->name
				);
				return clean('?');
			}
			if (option->has_arg == no_argument && *equal) {
				warnx(
					"%s:%zu: option `%s' doesn't allow an argument",
					path, num, option->name
				);
				return clean('?');
			}
			if (option->has_arg == required_argument && !*equal) {
				warnx(
					"%s:%zu: option `%s' requires an argument",
					path, num, option->name
				);
				return clean(':');
			}

			optarg = NULL;
			if (*equal) {
				char *arg = &equal[1] + strspn(&equal[1], WS);
				optarg = strdup(arg);
				if (!optarg) {
					warn("getopt_config");
					return clean('?');
				}
			}

			if (longindex) *longindex = option - longopts;
			if (option->flag) {
				*option->flag = option->val;
				return 0;
			} else {
				return option->val;
			}
		}

		fclose(file);
		file = NULL;
	}
}