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comparison config.c @ 430:7f84090ab1cd

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Add config file parser and default config file
author Mike Pavone <pavone@retrodev.com>
date Wed, 10 Jul 2013 09:38:05 -0700
parents
children 440efd7d27a9
comparison
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429:f6fdde540791 430:7f84090ab1cd
1 #include "tern.h"
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <stdarg.h>
6 #include <ctype.h>
7
8 #include <sys/types.h>
9 #include <sys/stat.h>
10 #include <unistd.h>
11
12 char * alloc_concat(char * first, char * second)
13 {
14 int flen = strlen(first);
15 int slen = strlen(second);
16 char * ret = malloc(flen + slen + 1);
17 memcpy(ret, first, flen);
18 memcpy(ret+flen, second, slen+1);
19 return ret;
20 }
21
22 char * alloc_concat_m(int num_parts, char ** parts)
23 {
24 int total = 0;
25 for (int i = 0; i < num_parts; i++) {
26 total += strlen(parts[i]);
27 }
28 char * ret = malloc(total + 1);
29 *ret = 0;
30 for (int i = 0; i < num_parts; i++) {
31 strcat(ret, parts[i]);
32 }
33 return ret;
34 }
35
36 long file_size(FILE * f)
37 {
38 fseek(f, 0, SEEK_END);
39 long fsize = ftell(f);
40 fseek(f, 0, SEEK_SET);
41 return fsize;
42 }
43
44 char * strip_ws(char * text)
45 {
46 while (*text && (!isprint(*text) || isblank(*text)))
47 {
48 text++;
49 }
50 char * ret = text;
51 text = ret + strlen(ret) - 1;
52 while (text > ret && (!isprint(*text) || isblank(*text)))
53 {
54 *text = 0;
55 text--;
56 }
57 return ret;
58 }
59
60 char * split_keyval(char * text)
61 {
62 while (*text && !isblank(*text))
63 {
64 text++;
65 }
66 if (!*text) {
67 return text;
68 }
69 *text = 0;
70 return text+1;
71 }
72
73 #define MAX_NEST 30 //way more than I'll ever need
74
75 tern_node * parse_config(char * config_data)
76 {
77 char *state, *curline;
78 char *prefix = NULL;
79 int nest_level = 0;
80 char * prefix_parts[MAX_NEST];
81 int line = 1;
82 tern_node * head = NULL;
83 while ((curline = strtok_r(config_data, "\n", &state)))
84 {
85 config_data = NULL;
86 curline = strip_ws(curline);
87 int len = strlen(curline);
88 if (!len) {
89 continue;
90 }
91 if (curline[0] == '#') {
92 continue;
93 }
94 if (curline[0] == '}') {
95 if (!nest_level) {
96 fprintf(stderr, "unexpected } on line %d\n", line);
97 exit(1);
98 }
99 if (prefix) {
100 free(prefix);
101 prefix = NULL;
102 }
103 nest_level--;
104 curline = strip_ws(curline+1);
105 }
106 char * end = curline + len - 1;
107 if (*end == '{') {
108 *end = 0;
109 curline = strip_ws(curline);
110 prefix_parts[nest_level++] = curline;
111 if (prefix) {
112 free(prefix);
113 prefix = NULL;
114 }
115 } else {
116 if (nest_level && !prefix) {
117 prefix = alloc_concat_m(nest_level, prefix_parts);
118 }
119 char * val = strip_ws(split_keyval(curline));
120 char * key = curline;
121 if (*key) {
122 if (prefix) {
123 key = alloc_concat(prefix, key);
124 }
125 head = tern_insert_ptr(head, key, val);
126 if (prefix) {
127 free(key);
128 }
129 }
130 }
131 }
132 if (prefix) {
133 free(prefix);
134 }
135 return head;
136 }
137
138 tern_node * parse_config_file(char * config_path)
139 {
140 tern_node * ret = NULL;
141 FILE * config_file = fopen(config_path, "r");
142 if (!config_file) {
143 goto open_fail;
144 }
145 long config_size = file_size(config_file);
146 if (!config_size) {
147 goto config_empty;
148 }
149 char * config_data = malloc(config_size);
150 if (fread(config_data, 1, config_size, config_file) != config_size) {
151 goto config_read_fail;
152 }
153 ret = parse_config(config_data);
154 config_read_fail:
155 free(config_data);
156 config_empty:
157 fclose(config_file);
158 open_fail:
159 return ret;
160 }
161
162 char * readlink_alloc(char * path)
163 {
164 char * linktext = NULL;
165 ssize_t linksize = 512;
166 ssize_t cursize = 0;
167 do {
168 if (linksize > cursize) {
169 cursize = linksize;
170 if (linktext) {
171 free(linktext);
172 }
173 }
174 linktext = malloc(cursize);
175 linksize = readlink(path, linktext, cursize-1);
176 if (linksize == -1) {
177 perror("readlink");
178 free(linktext);
179 linktext = NULL;
180 }
181 } while (linksize > cursize);
182 return linktext;
183 }
184
185 tern_node * load_config(char * expath)
186 {
187 char * linktext;
188 char * home = getenv("HOME");
189 if (!home) {
190 goto load_in_app_dir;
191 }
192 char * path = alloc_concat(home, "/.config/blastem/blastem.cfg");
193 tern_node * ret = parse_config_file(path);
194 if (ret) {
195 goto success;
196 }
197 free(path);
198 load_in_app_dir:
199
200 linktext = readlink_alloc("/proc/self/exe");
201 if (!linktext) {
202 goto link_prob;
203 }
204 char * cur;
205 int linksize = strlen(linktext);
206 for(cur = linktext + linksize - 1; cur != linktext; cur--)
207 {
208 if (*cur == '/') {
209 *cur = 0;
210 break;
211 }
212 }
213 if (cur == linktext) {
214 goto link_prob;
215 }
216 path = alloc_concat(linktext, "/default.cfg");
217 ret = parse_config_file(path);
218 success:
219 return ret;
220 link_prob:
221 if (linktext) {
222 free(linktext);
223 }
224 no_proc:
225 //TODO: Fall back to using expath if /proc is not available
226 fputs("Failed to find a config file in ~/.config/blastem/blastem.cfg or in the blastem executable directory\n", stderr);
227 exit(1);
228 }
229