/* Print out a summary giving the number of catalog entries
* and total number of tracks across all of them */
static void count_all_entries(void) {
int cd_entries_found = 0;
int track_entries_found = 0;
cdc_entry cdc_found; cdt_entry cdt_found;
int track_no = 1;
int first_time = 1;
char *search_string = "";
// loop over all cdc entries. The `first_time` is a flag which should
// be 1 ("first time = true") on the initial call; it gets set to 0 (note
// it's passed via ptr), and internally the database code tracks the
// progress of the search from that point forward
do {
cdc_found = search_cdc_entry(search_string, &first_time);
if (cdc_found.catalog[0]) {
cd_entries_found++;
track_no = 1;
do {
cdt_found = get_cdt_entry(cdc_found.catalog, track_no);
if (cdt_found.catalog[0]) {
track_entries_found++;
track_no++;
}
} while (cdt_found.catalog[0]);
}
} while (cdc_found.catalog[0]);
printf("Found %d CDs, with a total of %d tracks\n",
cd_entries_found, track_entries_found);
get_confirm("Press Enter");
}
static void count_all_entries(void)
{
int cd_entries_found = 0;
int track_entries_found = 0;
cdc_entry cdc_found;
cdt_entry cdt_found;
int track_no = 1;
int first_time = 1;
char *search_string = "";
do {
cdc_found = search_cdc_entry(search_string, &first_time);
if (cdc_found.catalog[0]) {
cd_entries_found++;
track_no = 1;
do {
cdt_found = get_cdt_entry(cdc_found.catalog, track_no);
if (cdt_found.catalog[0]) {
track_entries_found++;
track_no++;
}
} while (cdt_found.catalog[0]);
}
} while (cdc_found.catalog[0]);
printf("Found %d CDs, with a total of %d tracks\n", cd_entries_found,
track_entries_found);
(void)get_confirm("Press return");
}
static void enter_new_track_entries(const cdc_entry *entry_to_add_to)
{
cdt_entry new_track, existing_track;
char tmp_str[TMP_STRING_LEN + 1];
int track_no = 1;
if (entry_to_add_to->catalog[0] == '\0') {
return;
}
printf("\nUpdating tracks for %s\n", entry_to_add_to->catalog);
printf("Press return to leave existing description unchanged,\n");
printf(" a single d to delete this and remaining tracks,\n");
printf(" or new track description\n");
while (1) {
memset(&new_track, '\0', sizeof(new_track));
existing_track = get_cdt_entry(entry_to_add_to->catalog, track_no);
if (existing_track.catalog[0]) {
printf("\tTrack %d: %s\n", track_no,
existing_track.track_txt);
printf("\tNew text: ");
} else {
printf("\tTrack %d description: ", track_no);
}
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
if (strlen(tmp_str) == 0) {
if (existing_track.catalog[0] == '\0') {
/* no existing entry, so finish adding */
break;
} else {
/* leave existing entry, jump to next track */
track_no++;
continue;
}
}
if ((strlen(tmp_str) == 1) && tmp_str[0] == 'd') {
/* delete this and ramaining tracks */
while (del_cdt_entry(entry_to_add_to->catalog, track_no)) {
track_no++;
}
break;
}
strncpy(new_track.track_txt, tmp_str, TRACK_TTEXT_LEN - 1);
strcpy(new_track.catalog, entry_to_add_to->catalog);
new_track.track_no = track_no;
if (!add_cdt_entry(new_track)) {
fprintf(stderr, "Failed to add new track\n");
break;
}
track_no++;
} /* while */
}
/* prints out all tracks for a given catalog entry */
static void list_tracks(const cdc_entry *entry_to_use)
{
int track_no = 1;
cdt_entry entry_found;
display_cdc(entry_to_use);
printf("\nTracks\n");
do {
entry_found = get_cdt_entry(entry_to_use->catalog, track_no);
if (entry_found.catalog[0]) {
display_cdt(&entry_found);
track_no++;
}
} while(entry_found.catalog[0]);
get_confirm("Press return");
} /* list tracks */
/* list tracks for the active catalog */
static void list_tracks(const cdc_entry *entry_to_use) {
int track_no = 1;
cdt_entry entry_found;
// first display the current catalog
display_cdc(entry_to_use);
// loop over entries and display them
printf("\nTracks\n");
do {
entry_found = get_cdt_entry(entry_to_use->catalog, track_no);
if (entry_found.catalog[0]) {
display_cdt(&entry_found);
track_no++;
}
} while (entry_found.catalog[0]);
// let the user look before returning to menu
get_confirm("Press return");
}
/* Mildly misnamed function... it loops through existing track entries if
* there are any and the user can either edit description or delete this and
* all later entries. When it finishes looping over existing entries, the user
* can also add new ones. */
static void enter_new_track_entries(const cdc_entry *entry_to_add_to) {
cdt_entry new_track, existing_track;
char tmp_str[TMP_STRING_LEN + 1];
int track_no = 1;
// if there's no current catalog, do nothing
if (entry_to_add_to->catalog[0] == '\0') return;
// print out instructions
printf("Updating tracks for %s\n", entry_to_add_to->catalog);
printf("Press return to leave existing description unchanged,\n");
printf(" a single d to delete this and remaining tracks,\n");
printf(" or new track description\n");
// loop over tracks, let the user choose what to do with each one.
// note that dbm is helping a lot here - in our flat file curses impl
// from ch6, the only easy things to do were to keep all tracks or
// redo everything. Dbm makes single-track changes much easier.
// We are still somewhat limited because the track ids have to be in
// increaseing order. So you can edit descriptions atomically, but if
// you delete one you have to delete everything later. We could get
// around this, but it would be too much work for a demo program.
while (1) {
memset(&new_track, '\0', sizeof(new_track));
existing_track = get_cdt_entry(entry_to_add_to->catalog,
track_no);
// existing track.caltalog[0] is set to 0 by get_cdt_entry if there
// is no track with track number `track_no`. Hence..
if(existing_track.catalog[0]) {
// if we are here, there's a track description already
printf("\tTrack %d: %s\n", track_no, existing_track.track_txt);
printf("\tNew text: ");
} else {
// if we are here, there is not
printf("\tTrack %d description: ", track_no);
}
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
// If tmp_str has length 0, the user didn't want to do anything for
// this track.
if (strlen(tmp_str) == 0) {
if (existing_track.catalog[0] == '\0') {
// if this is true, then we had already seen all existing
// tracks, so we are done.
break;
} else {
// if we get here, it means the user didn't want to edit this
// track, so we go on to the next one.
track_no++;
continue;
}
}
// Entering a single 'd' is a special case for delete this track and
// all later tracks, as mentioned in the instructions printed above.
// So, loop through all remaining tracks, delete, then break.
if ((strlen(tmp_str) == 1) && tmp_str[0] == 'd') {
// del_cdt_entry will return 0 when we try to delete a nonexistant
// track_no, so we use that as our terminate condition.
while (del_cdt_entry(entry_to_add_to->catalog, track_no)) {
track_no++;
}
break;
}
// if we get here, it means the user made a new description, so we
// edit the existing track or add a new one (the api is the same, so
// we don't care at this point whether the track exists)
strncpy(new_track.track_txt, tmp_str, TTEXT_LEN - 1);
strcpy(new_track.catalog, entry_to_add_to->catalog);
new_track.track_no = track_no;
if (!add_cdt_entry(new_track)) {
fprintf(stderr, "Failed to add new track\n");
break;
}
track_no++;
} // end of the big while loop over track_no's
}
static void enter_new_track_entries(const cdc_entry *entry_to_add_to)
{
cdt_entry new_track, existing_track;
char tmp_str[TMP_STRING_LEN + 1];
int track_no = 1;
if (entry_to_add_to->catalog[0] == '\0') return;
printf("\nUpdating tracks for %s\n", entry_to_add_to->catalog);
printf("Press return to leave existing description unchanged,\n");
printf(" a single d to delete this and remaining tracks,\n");
printf(" or new track description\n");
while(1) {
/* First, we must check whether a track already exists with the current track number.
Depending on what we find, we change the prompt. */
memset(&new_track, '\0', sizeof(new_track));
existing_track = get_cdt_entry(entry_to_add_to->catalog,
track_no);
if (existing_track.catalog[0]) {
printf("\tTrack %d: %s\n", track_no,
existing_track.track_txt);
printf("\tNew text: ");
}
else {
printf("\tTrack %d description: ", track_no);
}
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
/* If there was no existing entry for this track and the user hasn't added one, we assume
that there are no more tracks to be added. */
if (strlen(tmp_str) == 0) {
if (existing_track.catalog[0] == '\0') {
/* no existing entry, so finished adding */
break;
}
else {
/* leave existing entry, jump to next track */
track_no++;
continue;
}
}
/* If the user enters a single d character, this deletes the current and any higher
numbered tracks.
The del_cdt_entry function will return false if it couldn't find a track to delete. */
if ((strlen(tmp_str) == 1) && tmp_str[0] == 'd') {
/* delete this and remaining tracks */
while (del_cdt_entry(entry_to_add_to->catalog, track_no)) {
track_no++;
}
break;
}
/* Here we get to the code for adding a new track, or updating an existing one.
We construct the cdt_entry structure new_track, then call the database function
add_cdt_entry to add it to the database. */
strncpy(new_track.track_txt, tmp_str, TRACK_TTEXT_LEN - 1);
strcpy(new_track.catalog, entry_to_add_to->catalog);
new_track.track_no = track_no;
if (!add_cdt_entry(new_track)) {
fprintf(stderr, "Failed to add new track\n");
break;
}
track_no++;
} /* while */
}
/* Enter new track entries for a cdc entry.
*
* You have the option of looping through some exiting tracks and leaving
* them unchanged, but if you do change anything, it and everything after it
* will get deleted. Then you can add lots of tracks if you want.
*
* You enter a blank line to indicate you are finished.
*/
static void enter_new_track_entries(const cdc_entry *entry_to_add_to) {
cdt_entry new_track, existing_track;
char tmp_str[TMP_STRING_LEN + 1];
int track_no = 1;
if (entry_to_add_to->catalog[0] == '\0') return;
printf("\nUpdating tracks for %s\n", entry_to_add_to->catalog);
printf("Press return to leave existing description unchanged,\n");
printf(" a single d to delete this and remaining tracks,\n");
printf(" or new track description\n");
while(1) {
// set up a prompt. Either the track exists and we give the user
// an option of changing the text, or if the track doesn't exist then
// we ask for a description.
memset(&new_track, '\0', sizeof(new_track));
existing_track = get_cdt_entry(entry_to_add_to->catalog,
track_no);
if (existing_track.catalog[0]) {
printf("\tTrack %d: %s\n", track_no,
existing_track.track_txt);
printf("\tNew text: ");
}
else {
printf("\tTrack %d description: ", track_no);
}
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
// if they entered a blank line *and* we already went through existing
// tracks, then we are done.
// If we aren't finished with existing tracks and they entered a blank
// line, just go on to the next one.
if (strlen(tmp_str) == 0) {
if (existing_track.catalog[0] == '\0') {
/* no existing entry, so finished adding */
break;
}
else {
/* leave existing entry, jump to next track */
track_no++;
continue;
}
}
// if they entered a d, delete this track and loop through all higher-
// numbered tracks and delete them, then exit.
if ((strlen(tmp_str) == 1) && tmp_str[0] == 'd') {
while (del_cdt_entry(entry_to_add_to->catalog, track_no)) {
track_no++;
}
break;
}
// otherwise, they entered new track data. Whether or not the track
// previously existed, we copy that data into a ctd entry and add it
// to the db on the current track_no
strncpy(new_track.track_txt, tmp_str, TRACK_TTEXT_LEN - 1);
strcpy(new_track.catalog, entry_to_add_to->catalog);
new_track.track_no = track_no;
if (!add_cdt_entry(new_track)) {
fprintf(stderr, "Failed to add new track\n");
break;
}
track_no++;
}
}