Repository navigation
Expand file tree
/
Copy pathex17.c
More file actions
248 lines (198 loc) · 4.65 KB
/
Copy pathex17.c
File metadata and controls
248 lines (198 loc) · 4.65 KB
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
<
10BC8
div data-line-number="46" class="react-line-number react-code-text" style="padding-right:16px">4647
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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_DATA 512
#define MAX_ROWS 100
struct Address {
int id;
int set;
char name[MAX_DATA];
char email[MAX_DATA];
};
struct Database {
struct Address rows[MAX_ROWS];
};
struct Connection {
FILE *file;
struct Database *db;
};
void Database_close(struct Connection *conn);
void die(struct Connection *conn, const char *message) {
if (errno) {
perror(message);
} else {
printf("ERROR: %s\n", message);
}
Database_close(conn);
exit(1);
}
void Address_print(struct Address *addr) {
printf("Address: %d %s %s\n", addr->id, addr->name, addr->email);
}
void Database_load(struct Connection *conn) {
int rc = fread(conn->db, sizeof(struct Database), 1, conn->file);
if (rc != 1) {
die(conn, "Failed to load database");
}
}
struct Connection *Database_open(const char *filename, char mode) {
struct Connection *conn = malloc(sizeof(struct Connection));
if (!conn) {
die(conn, "memory error");
}
conn->db = malloc(sizeof(struct Database));
if (!conn->db) {
die(conn, "memory error");
}
if (mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if (conn->file) {
Database_load(conn);
}
}
if (!conn->file) {
die(conn, "Failed to open the file");
}
return conn;
}
void Database_close(struct Connection *conn) {
if (conn) {
if (conn->file) {
fclose(conn->file);
}
if (conn->db) {
free(conn->db);
}
free(conn);
}
}
void Database_write(struct Connection *conn) {
rewind(conn->file);
int rc = fwrite(conn->db, sizeof(struct Database), 1, conn->file);
if (rc != 1) {
die(conn, "Failed to write database");
}
rc = fflush(conn->file);
if (rc == -1) {
die(conn, "Cannot flush db");
}
}
void Database_create(struct Connection *conn) {
int i = 0;
for (i = 0; i < MAX_ROWS; i++) {
// make a prototype to initialize it
struct Address addr = {.id = i, .set = 0};
// then just assign it
conn->db->rows[i] = addr;
}
}
void Database_set(struct Connection *conn, int id, const char *name,
const char *email) {
struct Address *addr = &conn->db->rows[id];
if (addr->set) {
die(conn, "Already set, delete it first");
}
addr->set = 1;
char *res = strncpy(addr->name, name, MAX_DATA);
if (!res) {
die(conn, "Name copy failed");
}
res[MAX_DATA - 1] = '\0';
res = strncpy(addr->email, email, MAX_DATA);
if (!res) {
die(conn, "Email copy failed");
}
res[MAX_DATA - 1] = '\0';
}
void Database_get(struct Connection *conn, int id) {
struct Address *addr = &conn->db->rows[id];
if (addr->set) {
Address_print(addr);
} else {
die(conn, "ID is not set");
}
}
void Database_delete(struct Connection *conn, int id) {
struct Address addr = {.id = id, .set = 0};
conn->db->rows[id] = addr;
}
void Database_list(struct Connection *conn) {
int i = 0;
struct Database *db = conn->db;
for (i = 0; i < MAX_ROWS; i++) {
struct Address *addr = &db->rows[i];
if (addr->set) {
Address_print(addr);
}
}
}
void Database_find(struct Connection *conn, char *term) {
int i = 0;
struct Database *db = conn->db;
for (i = 0; i < MAX_ROWS; i++) {
struct Address *addr = &db->rows[i];
if (addr->set) {
if (strstr(addr->name, term) != NULL || strstr(addr->email, term)) {
Address_print(addr);
}
}
}
}
int main(int argc, char *argv[]) {
if (argc < 3) {
die(NULL, "USAGE: ./ex17 <dbfile> <action> [action params]");
}
char *filename = argv[1];
char action = argv[2][0];
struct Connection *conn = Database_open(filename, action);
int id = 0;
if (argc > 3) {
id = atoi(argv[3]);
}
if (id >= MAX_ROWS) {
die(conn, "There's not that many records");
}
switch (action) {
case 'c':
Database_create(conn);
Database_write(conn);
break;
case 'g':
if (argc != 4) {
die(conn, "Need an id to get");
}
Database_get(conn, id);
break;
case 's':
if (argc != 6) {
die(conn, "Need an id, name, email to set");
}
Database_set(conn, id, argv[4], argv[5]);
Database_write(conn);
break;
case 'd':
if (argc != 4) {
die(conn, "Need id to delete");
}
Database_delete(conn, id);
Database_write(conn);
break;
case 'l':
Database_list(conn);
break;
case 'f':
if (argc < 4) {
die(conn, "Need a string to search for");
}
Database_find(conn, argv[3]);
break;
default:
die(conn,
"Invalid action: options are c=create, g=get, s=set, d=del, l=list");
}
Database_close(conn);
return 0;
}