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
179
180
181
182
183
184
185
186
|
#include <assert.h>
#include <ncurses.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "lua.h"
#include "lauxlib.h"
/* If you encounter assertion failures in this file and _didn't_ manually edit
* it, lease report the .tlv file that caused them: http://akkartik.name/contact.
*
* Manually edited files can have cryptic errors. Teliva's first priority is
* to be secure, so it requires a fairly rigid file format and errors out if
* things are even slightly amiss. */
/* This code is surprisingly hairy. Estimate of buffer overflows: 2. */
static void teliva_load_multiline_string(lua_State* L, FILE* in, char* line, int capacity) {
luaL_Buffer b;
luaL_buffinit(L, &b);
int expected_indent = -1;
while (1) {
if (feof(in)) break;
char c = fgetc(in);
ungetc(c, in);
if (c != ' ') {
/* new definition; signal end to caller without reading a new line */
strcpy(line, "-\n");
break;
}
memset(line, '\0', capacity);
if (fgets(line, capacity, in) == NULL) break; /* eof */
int max = strlen(line);
assert(line[max-1] == '\n');
int indent = 0;
while (indent < max-1 && line[indent] == ' ')
++indent;
if (line[indent] != '>') break; /* new key/value pair in definition */
if (expected_indent == -1)
expected_indent = indent;
else
assert(expected_indent == indent);
int start = indent+1; /* skip '>' */
luaL_addstring(&b, &line[start]); /* guaranteed to at least be null */
}
luaL_pushresult(&b);
/* final state of line goes out into the world */
}
/* leave a single table on stack containing the next top-level definition from the file */
static void teliva_load_definition(lua_State* L, FILE* in) {
lua_newtable(L);
int def_idx = lua_gettop(L);
char line[1024] = {'\0'};
do {
if (feof(in) || fgets(line, 1024, in) == NULL) {
lua_pushnil(L);
return;
}
} while (line[0] == '#'); /* comment at start of file */
assert(line[strlen(line)-1] == '\n');
do {
assert(line[0] == '-' || line[0] == ' ');
assert(line[1] == ' ');
/* key/value pair always indented at 0, never empty, unambiguously not a multiline string */
char key[512] = {'\0'};
char value[1024] = {'\0'};
assert(line[2] != ' ');
assert(line[2] != '>');
assert(line[2] != '\n');
assert(line[2] != '\0');
memset(key, 0, 512);
memset(value, 0, 1024);
sscanf(line+2, "%s%s", key, value);
assert(key[strlen(key)-1] == ':');
key[strlen(key)-1] = '\0';
lua_pushstring(L, key);
if (value[0] != '\0') {
lua_pushstring(L, value); /* value string on same line */
char c = fgetc(in);
ungetc(c, in);
if (c == '-') {
strcpy(line, "-\n");
}
else {
memset(line, '\0', 1024);
fgets(line, 1024, in);
}
}
else {
teliva_load_multiline_string(L, in, line, 1024); /* load from later lines */
}
lua_settable(L, def_idx);
} while (line[0] == ' ');
}
void load_tlv(lua_State* L, char* filename) {
lua_newtable(L);
int history_array = lua_gettop(L);
FILE* in = fopen(filename, "r");
if (in == NULL) {
endwin();
fprintf(stderr, "no such file\n");
exit(1);
}
for (int i = 1; !feof(in); ++i) {
teliva_load_definition(L, in);
if (lua_isnil(L, -1)) break;
lua_rawseti(L, history_array, i);
}
fclose(in);
lua_setglobal(L, "teliva_program");
}
static void emit_multiline_string(FILE* out, const char* value) {
fprintf(out, " >");
for (const char* curr = value; *curr != '\0'; ++curr) {
if (*curr == '\n' && *(curr+1) != '\0')
fprintf(out, "\n >");
else
fprintf(out, "%c", *curr);
}
}
extern int mkstemp(char *template);
extern FILE *fdopen(int fd, const char *mode);
void save_tlv(lua_State* L, char* filename) {
lua_getglobal(L, "teliva_program");
int history_array = lua_gettop(L);
int history_array_size = luaL_getn(L, history_array);
char outfilename[] = "teliva_out_XXXXXX";
int outfd = mkstemp(outfilename);
if (outfd == -1) {
endwin();
perror("save_tlv: error in creating temporary file");
abort();
}
FILE *out = fdopen(outfd, "w");
fprintf(out, "# .tlv file generated by https://github.com/akkartik/teliva\n");
fprintf(out, "# You may edit it if you are careful; however, you may see cryptic errors if you\n");
fprintf(out, "# violate Teliva's assumptions.\n");
fprintf(out, "#\n");
fprintf(out, "# .tlv files are representations of Teliva programs. Teliva programs consist of\n");
fprintf(out, "# sequences of definitions. Each definition is a table of key/value pairs. Keys\n");
fprintf(out, "# and values are both strings.\n");
fprintf(out, "#\n");
fprintf(out, "# Lines in .tlv files always follow exactly one of the following forms:\n");
fprintf(out, "# - comment lines at the top of the file starting with '#' at column 0\n");
fprintf(out, "# - beginnings of definitions starting with '- ' at column 0, followed by a\n");
fprintf(out, "# key/value pair\n");
fprintf(out, "# - key/value pairs consisting of ' ' at column 0, containing either a\n");
fprintf(out, "# spaceless value on the same line, or a multi-line value\n");
fprintf(out, "# - multiline values indented by more than 2 spaces, starting with a '>'\n");
fprintf(out, "#\n");
fprintf(out, "# If these constraints are violated, Teliva may unceremoniously crash. Please\n");
fprintf(out, "# report bugs at http://akkartik.name/contact\n");
for (int i = 1; i <= history_array_size; ++i) {
lua_rawgeti(L, history_array, i);
int table = lua_gettop(L);
int first = 1;
for (lua_pushnil(L); lua_next(L, table) != 0; lua_pop(L, 1)) {
if (first) fprintf(out, "- ");
else fprintf(out, " ");
first = 0;
const char* key = lua_tostring(L, -2);
if (strcmp(key, "__teliva_undo") == 0) {
fprintf(out, "%s: %ld\n", key, lua_tointeger(L, -1));
continue;
}
const char* value = lua_tostring(L, -1);
if (strchr(value, ' ') || strchr(value, '\n')) {
fprintf(out, "%s:\n", key);
emit_multiline_string(out, value);
}
else {
fprintf(out, "%s: %s\n", key, value);
}
}
lua_pop(L, 1);
}
fclose(out);
rename(outfilename, filename);
lua_pop(L, 1);
}
|