config.c


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


#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"

char *read_file(const char *filename, long *size) {
	/* Open the file. */
	FILE *fp = fopen(filename, "r");
	/* Size of the file, in bytes. */
	long filesize = 0;
	/* Buffer of the file contents. */
	char *buf;

	/* Return NULL, if we couldn't open the file. */
	if (fp == NULL) {
		fclose(fp);
		return NULL;
	}

	/* Return NULL, if we couldn't seek to the end of the file. */
	if (fseek(fp, 0L, SEEK_END)) {
		fclose(fp);
		return NULL;
	}

	/* Get the size of the file, in bytes. */
	filesize = ftell(fp);

	/* Return NULL, if the returned size is negative. */
	if (filesize < 0) {
		fclose(fp);
		return NULL;
	}

	/* Allocate enough space for the entire file, plus one. */
	buf = malloc(filesize+1);

	/* Return NULL, if the buffer wasn't allocated. */
	if (buf == NULL) {
		fclose(fp);
		free(cfg);
		return NULL;
	}

	/* Zero out the buffer. */
	memset(buf, 0, filesize+1);

	/* Seek back to the start of the file. */
	rewind(fp);
	/* Read the entire file contents into the buffer. */
	fread(buf, sizeof(char), filesize, fp);
	/* Close the file. */
	fclose(fp);

	/* Return the filesize, in bytes. */
	*size = filesize;
	/* Return the buffer. */
	return buf;
}

char *get_line(char **str) {
	char *s;
	size_t i;

	for (i = 0; *str[i] != '\n' && *str[i] != '\0'; i++);

	s = malloc(i+1);
	memset(s, 0, i+1);
	memcpy(s, *str, i);

	str += i;
	return s;
}

config_val parse_option_value(const config_opt *opt, char *value) {
	config_val val = {0};

	switch (opt->type) {
		case TYPE_INT	: (long)val.i = strtol(value, NULL, 0); break;
		case TYPE_STRING: val.str = value; break;
		case TYPE_FLOAT	: val.f = strtof(value, NULL); break;
		case TYPE_BOOL	: (long)val.b = strtol(value, NULL, 0); break;
		default		: break;
	}

	return val;
}

config *parse_config(const char *filename) {
	/* Size of the file, in bytes. */
	long filesize = 0;
	/* Config settings. */
	config *cfg;
	/* Buffer of the file contents. */
	char *buf = read_file(filename, &filesize);

	/* Return NULL, if the buffer wasn't allocated */
	if (buf == NULL) {
		return NULL;
	}

	cfg = malloc(sizeof(config));

	/* Return NULL, if cfg wasn't allocated. */
	if (cfg == NULL) {
		free(buf);
		return NULL;
	}

	while (*buf != '\0') {
		char *line = get_line(&buf);
		char *value;
		char *name = strtok_r(line, "=", &value);
		const config_opt *opt;

		/* Check to see if the config option name we got is valid. */
		for (opt = config_opts; opt->name != NULL && strcmp(name, opt->name); opt++);

		/* Is the config option valid? */
		if (opt->name != NULL) {
			config_val val = parse_option_value(opt, value);
		}
	}
}