modified to work with MacOS (High Sierra, at least)

.gitignore

@@ -0,0 +1,2 @@
+.idea/
+*.so

Makefile

@@ -8,10 +8,10 @@ prefix=/usr
 .PHONY : install dist clean
 
 pcre.so : pcre.c
- ${CC} -shared -o $@ ${CFLAGS} -W -Werror pcre.c ${LIBS} -Wl,-z,defs
+ ${CC} -shared -o $@ ${CFLAGS} -W -Werror pcre.c ${LIBS}
 
 install : pcre.so
- ${INSTALL} -pD -m755 pcre.so ${DESTDIR}${prefix}/lib/sqlite3/pcre.so
+ sudo ${INSTALL} -p pcre.so ${prefix}/lib/sqlite3/pcre.so
 
 dist : clean
  mkdir sqlite3-pcre-${VERSION}

README.md

@@ -0,0 +1,29 @@
+# Sqlite3-pcre: Regex Extension (MacOS Version)
+This is sqlite3-pcre, an extension for sqlite3 that uses libpcre to provide the REGEXP() function.
+
+The original source code was written by Alexey Tourbin and can be found at:
+
+[http:https://git.altlinux.org/people/at/packages/?p=sqlite3-pcre.git](http:https://git.altlinux.org/people/at/packages/?p=sqlite3-pcre.git) 
+
+## 2020 UPDATE:
+Updated to work with MacOS. Modified the Makefile to compile and install on MacOS, changed C source code to get rid of "no string" error. 
+
+## Usage
+```bash
+git clone https://github.com/MatthewWolff/sqlite3-pcre
+cd sqlite3-pcre
+make
+make install
+```
+
+You can then define a command line function to search whatever database you desire—I wanted to search all my iMessages. 
+```bash
+search_messages() {
+ regex="$@"
+ database="$HOME/library/messages/chat.db"
+ use_extension=".load /usr/lib/sqlite3/pcre.so"
+ query="SELECT text FROM message WHERE text REGEXP '$regex'"
+ sqlite3 "$database" -cmd "$use_extension" "$query"
+}
+```
+

pcre.c

@@ -11,6 +11,7 @@
 #include <string.h>
 #include <pcre.h>
 #include <sqlite3ext.h>
+
 SQLITE_EXTENSION_INIT1
 
 typedef struct {
@@ -24,8 +25,7 @@ typedef struct {
 #endif
 
 static
-void regexp(sqlite3_context *ctx, int argc, sqlite3_value **argv)
-{
+void regexp(sqlite3_context *ctx, int argc, sqlite3_value **argv) {
  const char *re, *str;
  pcre *p;
  pcre_extra *e;
@@ -34,86 +34,85 @@ void regexp(sqlite3_context *ctx, int argc, sqlite3_value **argv)
 
  re = (const char *) sqlite3_value_text(argv[0]);
  if (!re) {
- sqlite3_result_error(ctx, "no regexp", -1);
- return;
+ sqlite3_result_error(ctx, "no regexp", -1);
+ return;
  }
 
  str = (const char *) sqlite3_value_text(argv[1]);
  if (!str) {
- sqlite3_result_error(ctx, "no string", -1);
- return;
+// sqlite3_result_error(ctx, "no string", -1);
+ sqlite3_result_int(ctx, 0); // if no string, just say no match found
+ return;
  }
 
  /* simple LRU cache */
  {
- int i;
- int found = 0;
- cache_entry *cache = sqlite3_user_data(ctx);
+ int i;
+ int found = 0;
+ cache_entry *cache = sqlite3_user_data(ctx);
 
- assert(cache);
+ assert(cache);
 
- for (i = 0; i < CACHE_SIZE && cache[i].s; i++)
- if (strcmp(re, cache[i].s) == 0) {
- found = 1;
- break;
- }
- if (found) {
- if (i > 0) {
- cache_entry c = cache[i];
- memmove(cache + 1, cache, i * sizeof(cache_entry));
- cache[0] = c;
- }
- }
- else {
- cache_entry c;
- const char *err;
- int pos;
- c.p = pcre_compile(re, 0, &err, &pos, NULL);
- if (!c.p) {
- char *e2 = sqlite3_mprintf("%s: %s (offset %d)", re, err, pos);
- sqlite3_result_error(ctx, e2, -1);
- sqlite3_free(e2);
- return;
- }
- c.e = pcre_study(c.p, 0, &err);
- c.s = strdup(re);
- if (!c.s) {
- sqlite3_result_error(ctx, "strdup: ENOMEM", -1);
- pcre_free(c.p);
- pcre_free(c.e);
- return;
- }
- i = CACHE_SIZE - 1;
- if (cache[i].s) {
- free(cache[i].s);
- assert(cache[i].p);
- pcre_free(cache[i].p);
- pcre_free(cache[i].e);
- }
- memmove(cache + 1, cache, i * sizeof(cache_entry));
- cache[0] = c;
- }
- p = cache[0].p;
- e = cache[0].e;
+ for (i = 0; i < CACHE_SIZE && cache[i].s; i++)
+ if (strcmp(re, cache[i].s) == 0) {
+ found = 1;
+ break;
+ }
+ if (found) {
+ if (i > 0) {
+ cache_entry c = cache[i];
+ memmove(cache + 1, cache, i * sizeof(cache_entry));
+ cache[0] = c;
+ }
+ } else {
+ cache_entry c;
+ const char *err;
+ int pos;
+ c.p = pcre_compile(re, 0, &err, &pos, NULL);
+ if (!c.p) {
+ char *e2 = sqlite3_mprintf("%s: %s (offset %d)", re, err, pos);
+ sqlite3_result_error(ctx, e2, -1);
+ sqlite3_free(e2);
+ return;
+ }
+ c.e = pcre_study(c.p, 0, &err);
+ c.s = strdup(re);
+ if (!c.s) {
+ sqlite3_result_error(ctx, "strdup: ENOMEM", -1);
+ pcre_free(c.p);
+ pcre_free(c.e);
+ return;
+ }
+ i = CACHE_SIZE - 1;
+ if (cache[i].s) {
+ free(cache[i].s);
+ assert(cache[i].p);
+ pcre_free(cache[i].p);
+ pcre_free(cache[i].e);
+ }
+ memmove(cache + 1, cache, i * sizeof(cache_entry));
+ cache[0] = c;
+ }
+ p = cache[0].p;
+ e = cache[0].e;
  }
 
  {
- int rc;
- assert(p);
- rc = pcre_exec(p, e, str, strlen(str), 0, 0, NULL, 0);
- sqlite3_result_int(ctx, rc >= 0);
- return;
+ int rc;
+ assert(p);
+ rc = pcre_exec(p, e, str, strlen(str), 0, 0, NULL, 0);
+ sqlite3_result_int(ctx, rc >= 0);
+ return;
  }
 }
 
-int sqlite3_extension_init(sqlite3 *db, char **err, const sqlite3_api_routines *api)
-{
- SQLITE_EXTENSION_INIT2(api)
- cache_entry *cache = calloc(CACHE_SIZE, sizeof(cache_entry));
- if (!cache) {
- *err = "calloc: ENOMEM";
- return 1;
- }
- sqlite3_create_function(db, "REGEXP", 2, SQLITE_UTF8, cache, regexp, NULL, NULL);
- return 0;
+int sqlite3_extension_init(sqlite3 *db, char **err, const sqlite3_api_routines *api) {
+ SQLITE_EXTENSION_INIT2(api)
+ cache_entry *cache = calloc(CACHE_SIZE, sizeof(cache_entry));
+ if (!cache) {
+ *err = "calloc: ENOMEM";
+ return 1;
+ }
+ sqlite3_create_function(db, "REGEXP", 2, SQLITE_UTF8, cache, regexp, NULL, NULL);
+ return 0;
 }