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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sqlite3.h>
#define TRUE 1
#define FALSE 0
char* escape(const char *message) {
int i, count = 0, length_orig = strlen(message);
for (i = 0; i < length_orig; i++) {
if (strchr("\"\\", message[i])) {
count++;
}
}
char *copy = malloc(length_orig + count + 1);
char *p = copy;
while (*message) {
if (strchr("\"\\", *message)) {
*p = '\\';
p++;
}
*p = *message;
message++;
p++;
}
*p = '\0';
return copy;
}
void send_error(int code, const char *message) {
char *escaped = escape(message);
printf("error %d \"%s\"\n", code, escaped);
free(escaped);
}
typedef struct {
char *buffer;
size_t size;
} buffer;
buffer* buffer_create() {
buffer *buffer = malloc(sizeof(buffer));
buffer->size = 4096;
buffer->buffer = malloc(buffer->size * sizeof(char));
return buffer;
}
int buffer_grow(buffer *buffer) {
unsigned factor = 2;
char *newbuffer = realloc(buffer->buffer, buffer->size * factor);
if (newbuffer == NULL) {
return FALSE;
}
buffer->buffer = newbuffer;
buffer->size *= factor;
return TRUE;
}
int buffer_read(buffer *buffer, size_t count) {
while (buffer->size < count + 1) {
if (buffer_grow(buffer) == FALSE) {
return FALSE;
}
}
size_t in = fread((void *) buffer->buffer, 1, count, stdin);
buffer->buffer[count] = '\0';
return in == count;
}
void buffer_free(buffer *buffer) {
free(buffer->buffer);
free(buffer);
}
int main(int argc, char **argv) {
char *file = NULL;
if (argc != 2) {
fprintf(stderr,
"error: require exactly one argument, the DB filename\n");
exit(EXIT_FAILURE);
} else {
file = argv[1];
}
/* On Windows stderr is not always unbuffered. */
#if defined(_WIN32) || defined(WIN32) || defined(__MINGW32__)
setvbuf(stderr, NULL, _IONBF, 0);
#endif
sqlite3* db = NULL;
if (sqlite3_initialize() != SQLITE_OK) {
fprintf(stderr, "error: failed to initialize sqlite\n");
exit(EXIT_FAILURE);
}
int flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
if (sqlite3_open_v2(file, &db, flags, NULL) != SQLITE_OK) {
fprintf(stderr, "error: failed to open %s\n", file);
exit(EXIT_FAILURE);
}
buffer *input = buffer_create();
while (TRUE) {
printf("#\n");
fflush(stdout);
/* Gather input from Emacs. */
unsigned length;
int result = scanf("%u ", &length);
if (result == EOF) {
break;
} else if (result != 1) {
send_error(SQLITE_ERROR, "middleware parsing error");
break; /* stream out of sync: quit program */
}
if (!buffer_read(input, length)) {
send_error(SQLITE_NOMEM, "middleware out of memory");
continue;
}
/* Parse SQL statement. */
sqlite3_stmt *stmt = NULL;
result = sqlite3_prepare_v2(db, input->buffer, length, &stmt, NULL);
if (result != SQLITE_OK) {
send_error(sqlite3_errcode(db), sqlite3_errmsg(db));
continue;
}
/* Print out rows. */
int first = TRUE, ncolumns = sqlite3_column_count(stmt);
printf("(");
while (sqlite3_step(stmt) == SQLITE_ROW) {
if (first) {
printf("(");
first = FALSE;
} else {
printf("\n (");
}
int i;
for (i = 0; i < ncolumns; i++) {
if (i > 0) {
printf(" ");
}
int type = sqlite3_column_type(stmt, i);
switch (type) {
case SQLITE_INTEGER:
printf("%lld", sqlite3_column_int64(stmt, i));
break;
case SQLITE_FLOAT:
printf("%f", sqlite3_column_double(stmt, i));
break;
case SQLITE_NULL:
printf("nil");
break;
case SQLITE_TEXT:
fwrite(sqlite3_column_text(stmt, i), 1,
sqlite3_column_bytes(stmt, i), stdout);
break;
case SQLITE_BLOB:
printf("nil");
break;
}
}
printf(")");
}
printf(")\n");
if (sqlite3_finalize(stmt) != SQLITE_OK) {
/* Despite any error code, the statement is still freed.
* http://stackoverflow.com/a/8391872
*/
send_error(sqlite3_errcode(db), sqlite3_errmsg(db));
} else {
printf("success\n");
}
}
buffer_free(input);
sqlite3_close(db);
sqlite3_shutdown();
return EXIT_SUCCESS;
}
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