static int enter_new_cat_entry(cdc_entry *entry_to_update)
{
cdc_entry new_entry;
char tmp_str[TMP_STRING_LEN + 1];
memset(&new_entry, '\0', sizeof(new_entry));
printf("Enter catalog entry: ");
(void)fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.catalog, tmp_str, CAT_CAT_LEN - 1);
printf("Enter title: ");
(void)fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.title, tmp_str, CAT_TITLE_LEN - 1);
printf("Enter type: ");
(void)fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.type, tmp_str, CAT_TYPE_LEN - 1);
printf("Enter artist: ");
(void)fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.artist, tmp_str, CAT_ARTIST_LEN - 1);
printf("\nNew catalog entry entry is :-\n");
display_cdc(&new_entry);
if (get_confirm("Add this entry ?")) {
memcpy(entry_to_update, &new_entry, sizeof(new_entry));
return(1);
}
return(0);
}
obj eval_function(ref lt, rel rt) {//lt ÇÉXÉ^ÉbÉNêœÇ›Ç…
if(type(lt)== tInternalFn) goto ci;
if(type(lt)!=tClosure) {print((obj)lt); assert(0);}
{
list ll = seek_lamb(ul(lt), rt);
if(ll && type(first(ll))==tInternalFn) {
lt = first(ll);
goto ci;
}
if(! ll) error("no appropriate function.");
push(env);
obj vars = Assoc();
env = op(vars, retain(third(ll)));
bind_vars(&vars, first(ll), rt);
release(rt);
obj rr = exec(second(ll));
release(env);
env = pop(&is);
return strip_return(rr);
}
ci: try {
obj rr=(ufn(lt))(rt);
release(rt);
return rr;
} catch(eval_error){
error("not defined for that value.");
return nil;
}
}
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 */
}
obj eval_curry(obj exp, obj vars) { // envÇÕǢNjé¿çsíÜÇÃ
/* push(env);
env = op(vars, nil);
obj rr = exec(em1(exp));
pop(&env);
env = pop(&is);
return strip_return(rr);
/*/ env = op(vars, env);
obj rr = exec(em1(exp));
pop(&env);
return strip_return(rr);
/**/}
/* Gets a new cdc_entry from the user. If all goes well, saves the
* data to the location pointed to by `entry_to_update`
* returns 1 if update occurs, 0 if the user aborts */
static int enter_new_cat_entry(cdc_entry *entry_to_update) {
cdc_entry new_entry;
char tmp_str[TMP_STRING_LEN + 1];
memset(&new_entry, '\0', sizeof(new_entry)); // remember to do this!
// the code that follows is kind of copy-pastey, probably should be
// factored out.
printf("Enter catalog entry: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.catalog, tmp_str, CAT_LEN - 1);
printf("Enter title: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.title, tmp_str, TITLE_LEN - 1);
printf("Enter type: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.type, tmp_str, TYPE_LEN - 1);
printf("Enter artist: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.artist, tmp_str, ARTIST_LEN - 1);
printf("\nNew catalog entry entry is :-\n");
// get a user confirmation before continuint
display_cdc(&new_entry);
if (get_confirm("Add this entry ?")) {
memcpy(entry_to_update, &new_entry, sizeof(new_entry));
return(1);
}
return(0);
}
/* Get information for a new cdc entry.
* (just the metadata, not track information)
* We use strip_return to get rid of the '\n' that fgets returns.
* We avoid using gets, because it is unsafe (no buffer overflow size checks!)
* Return 1 on success, 0 if user doesn't confirm.
*/
static int enter_new_cat_entry(cdc_entry *entry_to_update)
{
// impl notes: we copy all the data into a new entry first so that we
// can display it and ask for confirmation. Only then do we copy into
// `entry_to_update`.
cdc_entry new_entry;
char tmp_str[TMP_STRING_LEN + 1];
memset(&new_entry, '\0', sizeof(new_entry));
printf("Enter catalog entry: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.catalog, tmp_str, CAT_CAT_LEN - 1);
printf("Enter title: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.title, tmp_str, CAT_TITLE_LEN - 1);
printf("Enter type: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.type, tmp_str, CAT_TYPE_LEN - 1);
printf("Enter artist: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
strncpy(new_entry.artist, tmp_str, CAT_ARTIST_LEN - 1);
printf("\nNew catalog entry entry is :-\n");
display_cdc(&new_entry);
if (get_confirm("Add this entry ?")) {
memcpy(entry_to_update, &new_entry, sizeof(new_entry));
return(1);
}
return(0);
}
/* Finds a catalog entry. It handles multiple matches by letting the user pick
* one of them. If there are no matches, search_cdc_entry will set item_found
* to be all 0 bytes and we will wind up with no active catalog entry. */
static cdc_entry find_cat(void) {
cdc_entry item_found;
char tmp_str[TMP_STRING_LEN + 1];
int first_call = 1;
int any_entry_found = 0;
int string_ok;
int entry_selected = 0;
// get a search string, checking that the string isn't too long
do {
string_ok = 1;
printf("Enter string to search for in catalog entry: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
if (strlen(tmp_str) > CAT_LEN) {
fprintf(stderr, "Sorry, string too long, maximum %d characters",
CAT_LEN);
string_ok = 0;
}
} while (!string_ok);
// 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
while (!entry_selected) {
item_found = search_cdc_entry(tmp_str, &first_call);
if (item_found.catalog[0] != '\0') {
any_entry_found = 1;
printf("\n");
display_cdc(&item_found);
if (get_confirm("This entry? ")) {
entry_selected = 1;
}
} else {
// we can get here either because the user didn't select any
// of the matches, or because there weren't any.
if (any_entry_found) {
printf("Sorry, no more matches found\n");
} else {
printf("Sorry, no matches found\n");
}
break;
}
}
return item_found;
}
obj udef_op0(obj ope, obj v){
assert(type(ope)==tSymbol);
obj lamb = find_var(ope);
if(!lamb) return nil;
assert(type(lamb)==tClosure);
list ll = seek_lamb(ul(lamb), v);
if(! ll) {
return nil;
}
if(type(first(ll))==tInternalFn) error("user-defined operator not defined for the type.");
obj vars = Assoc();
bind_vars(&vars, first(ll), v);
push(env);
env = op(vars, retain(third(ll)));
release(lamb); //execÇÃǻǩÇ≈lambÇ™çÌèúÇ≥ÇÍÇÈâ¬î\ê´Ç†ÇË
obj rr = exec(second(ll));
release(env);
env = pop(&is);
return strip_return(rr);
}
/* A simple catalog search facility. We allow the user to
* enter a string, then check for catalog entries that contain the string.
* Since there could be multiple entries that match, we simply offer the user
* each match in turn. */
static cdc_entry find_cat(void)
{
cdc_entry item_found;
char tmp_str[TMP_STRING_LEN + 1];
int first_call = 1;
int any_entry_found = 0;
int string_ok;
int entry_selected = 0;
do {
string_ok = 1;
printf("Enter string to search for in catalog entry: ");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
if (strlen(tmp_str) > CAT_CAT_LEN) {
fprintf(stderr, "Sorry, string too long, maximum %d \
characters\n", CAT_CAT_LEN);
string_ok = 0;
}
} while (!string_ok);
while (!entry_selected) {
// the first_call flag starts as 1, and is set to 0 inside of the
// search_cdc_entry function, which uses module-level variables to
// handle the "curser" over results.
item_found = search_cdc_entry(tmp_str, &first_call);
if (item_found.catalog[0] != '\0') {
any_entry_found = 1;
printf("\n");
display_cdc(&item_found);
if (get_confirm("This entry? ")) {
entry_selected = 1;
}
} else {
if (any_entry_found) printf("Sorry, no more matches found\n");
else printf("Sorry, nothing found\n");
break;
}
}
return(item_found);
}
static cdc_entry find_cat(void) {
cdc_entry item_found;
char tmp_str[TMP_STRING_LEN + 1];
int first_call = 1;
int any_entry_found = 0;
int string_ok;
int entry_selected = 0;
do {
string_ok = 1;
printf("Enter string to search for in catalog entry: \n");
fgets(tmp_str, TMP_STRING_LEN, stdin);
strip_return(tmp_str);
if (strlen(tmp_str) > CAT_CAT_LEN) {
fprintf(stderr, "Sorry, string too long, maxmium %d \
characters\n", CAT_CAT_LEN);
string_ok = 0;
}
} while (!string_ok);
while (!entry_selected) {
item_found = search_cdc_entry(tmp_str, &first_call);
if (item_found.catalog[0] != '\0') {
any_entry_found = 1;
printf("\n");
display_cdc(&item_found);
if (get_confirm("This entry? ")) {
entry_selected = 1;
}
} else {
if (any_entry_found)
printf("Sorry, no more matches found\n");
else
printf("Sorry, nothing found\n");
break;
}
}
return item_found;
}
char *url_decode(char *str)
{
int cpt[2];
char nb[5];
memset(nb, 0, 5);
for (cpt[0] = cpt[1] = 0; str[cpt[0]]; cpt[0]++, cpt[1]++)
if (str[cpt[0]] == '%' && str[cpt[0] + 1] &&
((str[cpt[0] + 1] >= '0' && str[cpt[0] + 1] <= '9') ||
(str[cpt[0] + 1] >= 'A' && str[cpt[0] + 1] <= 'F') ||
(str[cpt[0] + 1] >= 'a' && str[cpt[0] + 1] <= 'f')))
{
sprintf(nb, "0x%.2s", str + cpt[0] + 1);
str[cpt[1]] = strtol(nb, 0, 16);
cpt[0] += 2;
}
else
str[cpt[1]] = str[cpt[0]];
str[cpt[1]] = 0;
str = strip_return(str);
return (str);
}
/* 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++;
}
}
