1: /*
2: * MDBEDIT.C
3: *
4: * Program: Mini-Database
5: * Written by: Leor Zolman
6: * Module: Edit the Current Database
7: */
8:
9: #include <stdio.h>
10: #include <stdlib.h>
11: #include <string.h>
12: #include <ctype.h>
13:
14: #include "mdb.h"
15:
16: static void fix_db(void);
17:
18: #define LIST_RECS 1 /* Edit menu action codes */
19: #define NEXT 2
20: #define PREVIOUS 3
21: #define MODIFY 4
22: #define NEW 5
23: #define DELETE 6
24: #define UNDELETE 7
25: #define QUIT 8
26: #define SELECT 9
27: #define FIX 10
28:
29: static struct menu_item edit_menu[] =
30: {
31: {LIST_RECS, "List Records"},
32: {NEXT, "Go to Next Record"},
33: {PREVIOUS, "Go to Previous Record"},
34: {MODIFY, "Modify Current Record"},
35: {NEW, "Add New Record"},
36: {DELETE, "Delete Current Record"},
37: {UNDELETE, "Un-Delete Current Record"},
38: {SELECT, "Select Record (by Record Number)"},
39: {FIX, "Fix Up Database"},
40: {QUIT, "Return to main Menu"},
41: {NULL}
42: };
43:
44: /*
45: * Function: edit_db
46: * Purpose: Perform operations on current Database
47: * Parameter: Database Name
48: * Return Value: None
49: */
50:
51: void edit_db(char *db_name)
52: {
53: int cur_rec = 0; /* current record number */
54: struct record *rp; /* ptr to current record */
55: char buf[150];
56: int i;
57:
58: while (1)
59: {
60: rp = RECS[cur_rec];
61: printf("\nDatabase: %s\n", db_name);
62: if (n_recs)
63: {
64: printf("Current Record is #%d", cur_rec);
65: if (!rp->active)
66: printf(" (Deleted)");
67: printf(":\n");
68:
69: printf("Name: %s %s\n", rp->first, rp->last);
70: printf("ID#: %ld\n", rp->id);
71: printf("Age: %d\n", rp->age);
72: printf("Gender: %c\n", rp->gender);
73: printf("Salary: $%.2f\n", rp->salary);
74: }
75:
76: switch(do_menu(edit_menu, "Edit Menu"))
77: {
78: case LIST_RECS:
79: for (i = 0; i < n_recs; i++)
80: printf("%4d: %s%s\n", i, RECS[i]->last,
81: RECS[i]->active ? "" : " (Deleted)");
82: printf("Press RETURN to continue:");
83: gets(buf);
84: break;
85:
86: case NEXT: /* find next active record: */
87: for (i = cur_rec + 1; i < n_recs; i++)
88: if (RECS[i]->active) /* skip inactives */
89: break;
90: if (i == n_recs) /* over the top? */
91: {
92: printf("\aAt end of file.\n");
93: break;
94: }
95: cur_rec = i;
96: break;
97:
98: case PREVIOUS: /* find previous active record: */
99: for (i = cur_rec - 1; i >= 0; i--)
100: if (RECS[i]->active) /* skip inactives */
101: break;
102: if (i < 0) /* "under the bottom"? */
103: {
104: printf("\aAt beginning of file.\n");
105: break;
106: }
107: cur_rec = i;
108: break;
109:
110: case NEW:
111: if (n_recs+1 > max_recs)
112: {
113: printf("Maximum # of records ");
114: printf("(%d) reached.\n", max_recs);
115: break;
116: }
117:
118: if ((rp = alloc_rec()) == NULL)
119: {
120: printf("Out of memory. Try Fixing ");
121: printf("Database first...\n");
122: break;
123: }
124: /* make new record current: */
125: cur_rec = n_recs++;
126: RECS[cur_rec] = rp;
127: rp->active = TRUE;
128:
129: strcpy(rp->last,""); /* initialize the record */
130: strcpy(rp->first,"");
131: rp->id = 0;
132: rp->age = 0;
133: rp->gender = ' ';
134: rp->salary = 0.; /* fall through to MODIFY */
135:
136: case MODIFY:
137: printf("Last Name [%s]: ", rp->last);
138: if (strlen(gets(buf)) > 0)
139: strcpy(rp->last, buf);
140:
141: printf("First Name [%s]: ", rp->first);
142: if (strlen(gets(buf)) > 0)
143: strcpy(rp->first, buf);
144:
145: printf("ID# [%ld]: ", rp->id);
146: if (strlen(gets(buf)) > 0)
147: rp->id = atol(buf);
148:
149: printf("Age [%d] ", rp->age);
150: if (strlen(gets(buf)) > 0)
151: rp->age = atoi(buf);
152:
153: printf("Gender [%c]: ", rp->gender);
154: if (strlen(gets(buf)) > 0)
155: rp->gender = toupper(*buf);
156:
157: printf("Salary [%.2f]: ", rp->salary);
158: if (strlen(gets(buf)) > 0)
159: rp->salary = (float) atof(buf);
160: break;
161:
162: case DELETE:
163: if (!rp->active)
164: {
165: printf("Record is already deleted.\n");
166: break;
167: }
168: printf("Press 'y' to delete record,\n");
169: printf("anything else to abort: ");
170: gets(buf);
171: if (tolower(*buf) == 'y')
172: rp->active = FALSE;
173: break;
174:
175: case UNDELETE:
176: if (rp->active)
177: {
178: printf("Record is not deleted.\n");
179: break;
180: }
181: rp->active = TRUE;
182: printf("Record restored.\n");
183: break;
184:
185: case SELECT:
186: printf("Enter new record number: ");
187: i = atoi(gets(buf));
188: if (i < 0 || i > n_recs)
189: {
190: printf("Record # out of range.\n");
191: break;
192: }
193: cur_rec = i;
194: break;
195:
196: case FIX:
197: fix_db(); /* clean up database */
198: break;
199:
200: case QUIT:
201: return;
202: }
203: }
204: }
205:
206: /*
207: * Function: fix_db
208: * Purpose: Purge deleted records, sort Database
209: * Parameters: None
210: * Return Value: None
211: */
212:
213: static int compar( struct record **p1,
214: struct record **p2);
215:
216: static void fix_db() /* File Fix module */
217: {
218: int i, new_n_recs;
219:
220: for (i = 0, new_n_recs = 0; i < n_recs; i++)
221: {
222: RECS[new_n_recs] = RECS[i];
223: if (RECS[i]->active)
224: new_n_recs++;
225: else
226: free(RECS[i]);
227: }
228:
229: n_recs = new_n_recs;
230: qsort(RECS, new_n_recs,
231: sizeof(struct record *), compar);
232: }
233:
234: /*
235: * Function: compar
236: * Purpose: Comparison function for qsort(),
237: * sorting simply on last name
238: * Parameters: Two pointers to record pointers
239: * Return Value: As per strcmp()
240: */
241:
242: static int compar(struct record **p1,
243: struct record **p2)
244: {
245: return strcmp((*p1)->last, (*p2)->last);
246: }