]> git.sesse.net Git - plocate/blobdiff - plocate.cpp
Release plocate 1.1.22.
[plocate] / plocate.cpp
index 2f3129326662bd52512f9ed50ba011acf627627f..519024e07c5b31d04f96db1cc085e8313bb4c39b 100644 (file)
@@ -1,6 +1,9 @@
+#include "access_rx_cache.h"
+#include "complete_pread.h"
 #include "db.h"
 #include "dprintf.h"
 #include "io_uring_engine.h"
+#include "needle.h"
 #include "parse_trigrams.h"
 #include "serializer.h"
 #include "turbopfor.h"
 #include <condition_variable>
 #include <deque>
 #include <fcntl.h>
-#include <fnmatch.h>
 #include <functional>
 #include <getopt.h>
 #include <inttypes.h>
 #include <iterator>
 #include <limits>
 #include <locale.h>
-#include <map>
 #include <memory>
 #include <mutex>
 #include <regex.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdint.h>
 #include <string.h>
 #include <string>
 #include <string_view>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 #include <thread>
 #include <tuple>
 #include <unistd.h>
 using namespace std;
 using namespace std::chrono;
 
-#define DEFAULT_DBPATH "/var/lib/mlocate/plocate.db"
-
-const char *dbpath = DEFAULT_DBPATH;
 bool ignore_case = false;
 bool only_count = false;
 bool print_nul = false;
 bool use_debug = false;
+bool flush_cache = false;
 bool patterns_are_regex = false;
 bool use_extended_regex = false;
+bool match_basename = false;
+bool check_existence = false;
+bool ignore_visibility = false;
 int64_t limit_matches = numeric_limits<int64_t>::max();
 int64_t limit_left = numeric_limits<int64_t>::max();
+bool stdout_is_tty = false;
+bool literal_printing = false;
+static bool in_forked_child = false;
 
 steady_clock::time_point start;
 ZSTD_DDict *ddict = nullptr;
 
-regex_t compile_regex(const string &needle);
-
-struct Needle {
-       enum { STRSTR,
-              REGEX,
-              GLOB } type;
-       string str;  // Filled in no matter what.
-       regex_t re;  // For REGEX.
-};
-
-bool matches(const Needle &needle, const char *haystack)
-{
-       if (needle.type == Needle::STRSTR) {
-               return strstr(haystack, needle.str.c_str()) != nullptr;
-       } else if (needle.type == Needle::GLOB) {
-               int flags = ignore_case ? FNM_CASEFOLD : 0;
-               return fnmatch(needle.str.c_str(), haystack, flags) == 0;
-       } else {
-               assert(needle.type == Needle::REGEX);
-               return regexec(&needle.re, haystack, /*nmatch=*/0, /*pmatch=*/nullptr, /*flags=*/0) == 0;
-       }
-}
-
-class AccessRXCache {
-public:
-       AccessRXCache(IOUringEngine *engine)
-               : engine(engine) {}
-       void check_access(const char *filename, bool allow_async, function<void(bool)> cb);
-
-private:
-       unordered_map<string, bool> cache;
-       struct PendingStat {
-               string filename;
-               function<void(bool)> cb;
-       };
-       map<string, vector<PendingStat>> pending_stats;
-       IOUringEngine *engine;
-       mutex mu;
-};
-
-void AccessRXCache::check_access(const char *filename, bool allow_async, function<void(bool)> cb)
-{
-       lock_guard<mutex> lock(mu);
-       if (engine == nullptr || !engine->get_supports_stat()) {
-               allow_async = false;
-       }
-
-       for (const char *end = strchr(filename + 1, '/'); end != nullptr; end = strchr(end + 1, '/')) {
-               string parent_path(filename, end - filename);  // string_view from C++20.
-               auto cache_it = cache.find(parent_path);
-               if (cache_it != cache.end()) {
-                       // Found in the cache.
-                       if (!cache_it->second) {
-                               cb(false);
-                               return;
-                       }
-                       continue;
-               }
-
-               if (!allow_async) {
-                       bool ok = access(parent_path.c_str(), R_OK | X_OK) == 0;
-                       cache.emplace(parent_path, ok);
-                       if (!ok) {
-                               cb(false);
-                               return;
-                       }
-                       continue;
-               }
-
-               // We want to call access(), but it could block on I/O. io_uring doesn't support
-               // access(), but we can do a dummy asynchonous statx() to populate the kernel's cache,
-               // which nearly always makes the next access() instantaneous.
-
-               // See if there's already a pending stat that matches this,
-               // or is a subdirectory.
-               auto it = pending_stats.lower_bound(parent_path);
-               if (it != pending_stats.end() && it->first.size() >= parent_path.size() &&
-                   it->first.compare(0, parent_path.size(), parent_path) == 0) {
-                       it->second.emplace_back(PendingStat{ filename, move(cb) });
-               } else {
-                       it = pending_stats.emplace(filename, vector<PendingStat>{}).first;
-                       engine->submit_stat(filename, [this, it, filename{ strdup(filename) }, cb{ move(cb) }] {
-                               // The stat returned, so now do the actual access() calls.
-                               // All of them should be in cache, so don't fire off new statx()
-                               // calls during that check.
-                               check_access(filename, /*allow_async=*/false, move(cb));
-                               free(filename);
-
-                               // Call all others that waited for the same stat() to finish.
-                               // They may fire off new stat() calls if needed.
-                               vector<PendingStat> pending = move(it->second);
-                               pending_stats.erase(it);
-                               for (PendingStat &ps : pending) {
-                                       check_access(ps.filename.c_str(), /*allow_async=*/true, move(ps.cb));
-                               }
-                       });
-               }
-               return;  // The rest will happen in async context.
-       }
-
-       // Passed all checks.
-       cb(true);
-}
-
 class Corpus {
 public:
-       Corpus(int fd, IOUringEngine *engine);
+       Corpus(int fd, const char *filename_for_errors, IOUringEngine *engine);
        ~Corpus();
        void find_trigram(uint32_t trgm, function<void(const Trigram *trgmptr, size_t len)> cb);
        void get_compressed_filename_block(uint32_t docid, function<void(string_view)> cb) const;
@@ -181,11 +85,10 @@ public:
        Header hdr;
 };
 
-Corpus::Corpus(int fd, IOUringEngine *engine)
+Corpus::Corpus(int fd, const char *filename_for_errors, IOUringEngine *engine)
        : fd(fd), engine(engine)
 {
-       // Enable to test cold-cache behavior (except for access()).
-       if (false) {
+       if (flush_cache) {
                off_t len = lseek(fd, 0, SEEK_END);
                if (len == -1) {
                        perror("lseek");
@@ -196,11 +99,11 @@ Corpus::Corpus(int fd, IOUringEngine *engine)
 
        complete_pread(fd, &hdr, sizeof(hdr), /*offset=*/0);
        if (memcmp(hdr.magic, "\0plocate", 8) != 0) {
-               fprintf(stderr, "plocate.db is corrupt or an old version; please rebuild it.\n");
+               fprintf(stderr, "%s: database is corrupt or not a plocate database; please rebuild it.\n", filename_for_errors);
                exit(1);
        }
        if (hdr.version != 0 && hdr.version != 1) {
-               fprintf(stderr, "plocate.db has version %u, expected 0 or 1; please rebuild it.\n", hdr.version);
+               fprintf(stderr, "%s: has version %u, expected 0 or 1; please rebuild it.\n", filename_for_errors, hdr.version);
                exit(1);
        }
        if (hdr.version == 0) {
@@ -208,6 +111,13 @@ Corpus::Corpus(int fd, IOUringEngine *engine)
                hdr.zstd_dictionary_offset_bytes = 0;
                hdr.zstd_dictionary_length_bytes = 0;
        }
+       if (hdr.max_version < 2) {
+               // This too. (We ignore the other max_version 2 fields.)
+               hdr.check_visibility = true;
+       }
+       if (ignore_visibility) {
+               hdr.check_visibility = false;
+       }
 }
 
 Corpus::~Corpus()
@@ -249,8 +159,24 @@ size_t Corpus::get_num_filename_blocks() const
        return hdr.num_docids;
 }
 
+template<class T>
+void stat_if_needed(const char *filename, bool access_ok, IOUringEngine *engine, T cb)
+{
+       if (!access_ok || !check_existence) {
+               // Doesn't have access or doesn't care about existence, so no need to stat.
+               cb(access_ok);
+       } else if (engine == nullptr || !engine->get_supports_stat()) {
+               // Do a synchronous stat.
+               struct stat buf;
+               bool ok = lstat(filename, &buf) == 0;
+               cb(ok);
+       } else {
+               engine->submit_stat(filename, cb);
+       }
+}
+
 void scan_file_block(const vector<Needle> &needles, string_view compressed,
-                     AccessRXCache *access_rx_cache, uint64_t seq, ResultReceiver *serializer,
+                     IOUringEngine *engine, AccessRXCache *access_rx_cache, uint64_t seq, ResultReceiver *serializer,
                      atomic<uint64_t> *matched)
 {
        unsigned long long uncompressed_len = ZSTD_getFrameContentSize(compressed.data(), compressed.size());
@@ -279,14 +205,16 @@ void scan_file_block(const vector<Needle> &needles, string_view compressed,
        block[block.size() - 1] = '\0';
 
        auto test_candidate = [&](const char *filename, uint64_t local_seq, uint64_t next_seq) {
-               access_rx_cache->check_access(filename, /*allow_async=*/true, [matched, serializer, local_seq, next_seq, filename{ strdup(filename) }](bool ok) {
-                       if (ok) {
-                               ++*matched;
-                               serializer->print(local_seq, next_seq - local_seq, filename);
-                       } else {
-                               serializer->print(local_seq, next_seq - local_seq, "");
-                       }
-                       free(filename);
+               access_rx_cache->check_access(filename, /*allow_async=*/true, [matched, engine, serializer, local_seq, next_seq, filename{ strdup(filename) }](bool ok) {
+                       stat_if_needed(filename, ok, engine, [matched, serializer, local_seq, next_seq, filename](bool ok) {
+                               if (ok) {
+                                       ++*matched;
+                                       serializer->print(local_seq, next_seq - local_seq, filename);
+                               } else {
+                                       serializer->print(local_seq, next_seq - local_seq, "");
+                               }
+                               free(filename);
+                       });
                });
        };
 
@@ -298,9 +226,19 @@ void scan_file_block(const vector<Needle> &needles, string_view compressed,
        for (const char *filename = block.data();
             filename != block.data() + block.size();
             filename += strlen(filename) + 1) {
+               const char *haystack = filename;
+               if (match_basename) {
+                       haystack = strrchr(filename, '/');
+                       if (haystack == nullptr) {
+                               haystack = filename;
+                       } else {
+                               ++haystack;
+                       }
+               }
+
                bool found = true;
                for (const Needle &needle : needles) {
-                       if (!matches(needle, filename)) {
+                       if (!matches(needle, haystack)) {
                                found = false;
                                break;
                        }
@@ -323,12 +261,12 @@ void scan_file_block(const vector<Needle> &needles, string_view compressed,
 size_t scan_docids(const vector<Needle> &needles, const vector<uint32_t> &docids, const Corpus &corpus, IOUringEngine *engine)
 {
        Serializer docids_in_order;
-       AccessRXCache access_rx_cache(engine);
+       AccessRXCache access_rx_cache(engine, corpus.get_hdr().check_visibility);
        atomic<uint64_t> matched{ 0 };
        for (size_t i = 0; i < docids.size(); ++i) {
                uint32_t docid = docids[i];
-               corpus.get_compressed_filename_block(docid, [i, &matched, &needles, &access_rx_cache, &docids_in_order](string_view compressed) {
-                       scan_file_block(needles, compressed, &access_rx_cache, i, &docids_in_order, &matched);
+               corpus.get_compressed_filename_block(docid, [i, &matched, &needles, &access_rx_cache, engine, &docids_in_order](string_view compressed) {
+                       scan_file_block(needles, compressed, engine, &access_rx_cache, i, &docids_in_order, &matched);
                });
        }
        engine->finish();
@@ -399,12 +337,12 @@ uint64_t scan_all_docids(const vector<Needle> &needles, int fd, const Corpus &co
                }
        }
 
-       AccessRXCache access_rx_cache(nullptr);
+       AccessRXCache access_rx_cache(nullptr, corpus.get_hdr().check_visibility);
        Serializer serializer;
        uint32_t num_blocks = corpus.get_num_filename_blocks();
        unique_ptr<uint64_t[]> offsets(new uint64_t[num_blocks + 1]);
        complete_pread(fd, offsets.get(), (num_blocks + 1) * sizeof(uint64_t), corpus.offset_for_block(0));
-       atomic<uint64_t> matched{0};
+       atomic<uint64_t> matched{ 0 };
 
        mutex mu;
        condition_variable queue_added, queue_removed;
@@ -433,7 +371,7 @@ uint64_t scan_all_docids(const vector<Needle> &needles, int fd, const Corpus &co
                                string compressed;
 
                                {
-                                       unique_lock<mutex> lock(mu);
+                                       unique_lock lock(mu);
                                        queue_added.wait(lock, [&work_queue, &done] { return !work_queue.empty() || done; });
                                        if (done && work_queue.empty()) {
                                                return;
@@ -446,7 +384,8 @@ uint64_t scan_all_docids(const vector<Needle> &needles, int fd, const Corpus &co
                                for (uint32_t docid = io_docid; docid < last_docid; ++docid) {
                                        size_t relative_offset = offsets[docid] - offsets[io_docid];
                                        size_t len = offsets[docid + 1] - offsets[docid];
-                                       scan_file_block(*use_needles, { &compressed[relative_offset], len }, &access_rx_cache, docid, &receiver, &matched);
+                                       // IOUringEngine isn't thread-safe, so we do any needed stat()s synchronously (nullptr engine).
+                                       scan_file_block(*use_needles, { &compressed[relative_offset], len }, /*engine=*/nullptr, &access_rx_cache, docid, &receiver, &matched);
                                }
                        }
                });
@@ -462,7 +401,7 @@ uint64_t scan_all_docids(const vector<Needle> &needles, int fd, const Corpus &co
                complete_pread(fd, &compressed[0], io_len, offsets[io_docid]);
 
                {
-                       unique_lock<mutex> lock(mu);
+                       unique_lock lock(mu);
                        queue_removed.wait(lock, [&work_queue] { return work_queue.size() < 256; });  // Allow ~2MB of data queued up.
                        work_queue.emplace_back(io_docid, last_docid, move(compressed));
                        queue_added.notify_one();  // Avoid the thundering herd.
@@ -533,11 +472,11 @@ bool new_posting_list_read(TrigramDisjunction *td, vector<uint32_t> decoded, vec
        return false;
 }
 
-void do_search_file(const vector<Needle> &needles, const char *filename)
+uint64_t do_search_file(const vector<Needle> &needles, const std::string &filename)
 {
-       int fd = open(filename, O_RDONLY);
+       int fd = open(filename.c_str(), O_RDONLY);
        if (fd == -1) {
-               perror(filename);
+               perror(filename.c_str());
                exit(1);
        }
 
@@ -550,11 +489,11 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
        start = steady_clock::now();
        if (access("/", R_OK | X_OK)) {
                // We can't find anything, no need to bother...
-               return;
+               return 0;
        }
 
        IOUringEngine engine(/*slop_bytes=*/16);  // 16 slop bytes as described in turbopfor.h.
-       Corpus corpus(fd, &engine);
+       Corpus corpus(fd, filename.c_str(), &engine);
        dprintf("Corpus init done after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
 
        vector<TrigramDisjunction> trigram_groups;
@@ -593,10 +532,9 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
                // the pattern and done a union of them, but that's a lot of
                // work for fairly unclear gain.)
                uint64_t matched = scan_all_docids(needles, fd, corpus);
-               if (only_count) {
-                       printf("%" PRId64 "\n", matched);
-               }
-               return;
+               dprintf("Done in %.1f ms, found %" PRId64 " matches.\n",
+                       1e3 * duration<float>(steady_clock::now() - start).count(), matched);
+               return matched;
        }
 
        // Sneak in fetching the dictionary, if present. It's not necessarily clear
@@ -615,18 +553,30 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
        }
 
        // Look them all up on disk.
+       bool should_early_exit = false;
        for (auto &[trgm, trigram_groups] : trigrams_to_lookup) {
-               corpus.find_trigram(trgm, [trgm{ trgm }, trigram_groups{ &trigram_groups }](const Trigram *trgmptr, size_t len) {
+               corpus.find_trigram(trgm, [trgm{ trgm }, trigram_groups{ &trigram_groups }, &should_early_exit](const Trigram *trgmptr, size_t len) {
                        if (trgmptr == nullptr) {
                                dprintf("trigram %s isn't found\n", print_trigram(trgm).c_str());
                                for (TrigramDisjunction *td : *trigram_groups) {
                                        --td->remaining_trigrams_to_read;
+
+                                       // If we now know this trigram group doesn't match anything at all,
+                                       // we can do early exit; however, if we're in a forked child,
+                                       // that would confuse the parent process (since we don't write
+                                       // our count to the pipe), so we wait until we're back in to the
+                                       // regular (non-async) context. This is a fairly rare case anyway,
+                                       // and the gains from dropping the remaining trigram reads are limited.
                                        if (td->remaining_trigrams_to_read == 0 && td->read_trigrams.empty()) {
-                                               dprintf("zero matches in %s, so we are done\n", print_td(*td).c_str());
-                                               if (only_count) {
-                                                       printf("0\n");
+                                               if (in_forked_child) {
+                                                       should_early_exit = true;
+                                               } else {
+                                                       dprintf("zero matches in %s, so we are done\n", print_td(*td).c_str());
+                                                       if (only_count) {
+                                                               printf("0\n");
+                                                       }
+                                                       exit(1);
                                                }
-                                               exit(0);
                                        }
                                }
                                return;
@@ -641,6 +591,10 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
        engine.finish();
        dprintf("Hashtable lookups done after %.1f ms.\n", 1e3 * duration<float>(steady_clock::now() - start).count());
 
+       if (should_early_exit) {
+               return 0;
+       }
+
        for (TrigramDisjunction &td : trigram_groups) {
                // Reset for reads.
                td.remaining_trigrams_to_read = td.read_trigrams.size();
@@ -692,7 +646,7 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
                                if (done)
                                        return;
 
-                               uint32_t trgm __attribute__((unused)) = trgmptr.trgm;
+                               uint32_t trgm = trgmptr.trgm;
                                const unsigned char *pldata = reinterpret_cast<const unsigned char *>(s.data());
                                size_t num = trgmptr.num_docids;
                                decoded.resize(num);
@@ -723,7 +677,7 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
        }
        engine.finish();
        if (done) {
-               return;
+               return 0;
        }
        dprintf("Intersection done after %.1f ms. Doing final verification and printing:\n",
                1e3 * duration<float>(steady_clock::now() - start).count());
@@ -731,45 +685,121 @@ void do_search_file(const vector<Needle> &needles, const char *filename)
        uint64_t matched = scan_docids(needles, cur_candidates, corpus, &engine);
        dprintf("Done in %.1f ms, found %" PRId64 " matches.\n",
                1e3 * duration<float>(steady_clock::now() - start).count(), matched);
-
-       if (only_count) {
-               printf("%" PRId64 "\n", matched);
-       }
+       return matched;
 }
 
-string unescape_glob_to_plain_string(const string &needle)
+// Run do_search_file() in a child process.
+//
+// The reason for this is that we're not robust against malicious input, so we need
+// to drop privileges after opening the file. (Otherwise, we could fall prey to an attack
+// where a user does locate -d badfile.db:/var/lib/plocate/plocate.db, badfile.db contains
+// a buffer overflow that takes over the process, and then uses the elevated privileges
+// to print out otherwise inaccessible paths.) We solve this by forking and treating the
+// child process as untrusted after it has dropped its privileges (which it does before
+// reading any data from the file); it returns a single 64-bit number over a pipe,
+// and that's it. The parent keeps its privileges, and can then fork out new children
+// without fear of being taken over. (The child keeps stdout for outputting results.)
+//
+// The count is returned over the pipe, because it's needed both for --limit and --count.
+uint64_t do_search_file_in_child(const vector<Needle> &needles, const std::string &filename)
 {
-       string unescaped;
-       for (size_t i = 0; i < needle.size(); i += read_unigram(needle, i).second) {
-               uint32_t ch = read_unigram(needle, i).first;
-               assert(ch != WILDCARD_UNIGRAM);
-               if (ch == PREMATURE_END_UNIGRAM) {
-                       fprintf(stderr, "Pattern '%s' ended prematurely\n", needle.c_str());
-                       exit(1);
+       int pipefd[2];
+       if (pipe(pipefd) == -1) {
+               perror("pipe");
+               exit(EXIT_FAILURE);
+       }
+
+       pid_t child_pid = fork();
+       switch (child_pid) {
+       case 0: {
+               // Child.
+               close(pipefd[0]);
+               in_forked_child = true;
+               uint64_t matched = do_search_file(needles, filename);
+               int ret;
+               do {
+                       ret = write(pipefd[1], &matched, sizeof(matched));
+               } while (ret == -1 && errno == EINTR);
+               if (ret != sizeof(matched)) {
+                       perror("write");
+                       _exit(EXIT_FAILURE);
+               }
+               fflush(stdout);
+               _exit(EXIT_SUCCESS);
+       }
+       case -1:
+               // Error.
+               perror("fork");
+               exit(EXIT_FAILURE);
+       default:
+               // Parent.
+               close(pipefd[1]);
+               break;
+       }
+
+       // Wait for the child to finish.
+       int wstatus;
+       pid_t err;
+       do {
+               err = waitpid(child_pid, &wstatus, 0);
+       } while (err == -1 && errno == EINTR);
+       if (err == -1) {
+               perror("waitpid");
+               exit(EXIT_FAILURE);
+       }
+       if (WIFEXITED(wstatus)) {
+               if (WEXITSTATUS(wstatus) != 0) {
+                       // The child has probably already printed out its error, so just propagate the exit status.
+                       exit(WEXITSTATUS(wstatus));
                }
-               unescaped.push_back(ch);
+               // Success!
+       } else if (!WIFEXITED(wstatus)) {
+               fprintf(stderr, "FATAL: Child died unexpectedly while processing %s\n", filename.c_str());
+               exit(1);
        }
-       return unescaped;
+
+       // Now get the number of matches from the child.
+       uint64_t matched;
+       int ret;
+       do {
+               ret = read(pipefd[0], &matched, sizeof(matched));
+       } while (ret == -1 && errno == EINTR);
+       if (ret == -1) {
+               perror("read");
+               exit(EXIT_FAILURE);
+       } else if (ret != sizeof(matched)) {
+               fprintf(stderr, "FATAL: Short read through pipe (got %d bytes)\n", ret);
+               exit(EXIT_FAILURE);
+       }
+       close(pipefd[0]);
+       return matched;
 }
 
-regex_t compile_regex(const string &needle)
+// Parses a colon-separated list of strings and appends them onto the given vector.
+// Backslash escapes whatever comes after it.
+void parse_dbpaths(const char *ptr, vector<string> *output)
 {
-       regex_t re;
-       int flags = REG_NOSUB;
-       if (ignore_case) {
-               flags |= REG_ICASE;
-       }
-       if (use_extended_regex) {
-               flags |= REG_EXTENDED;
-       }
-       int err = regcomp(&re, needle.c_str(), flags);
-       if (err != 0) {
-               char errbuf[256];
-               regerror(err, &re, errbuf, sizeof(errbuf));
-               fprintf(stderr, "Error when compiling regex '%s': %s\n", needle.c_str(), errbuf);
-               exit(1);
+       string str;
+       while (*ptr != '\0') {
+               if (*ptr == '\\') {
+                       if (ptr[1] == '\0') {
+                               fprintf(stderr, "ERROR: Escape character at the end of string\n");
+                               exit(EXIT_FAILURE);
+                       }
+                       // Escape.
+                       str.push_back(ptr[1]);
+                       ptr += 2;
+                       continue;
+               }
+               if (*ptr == ':') {
+                       // Separator.
+                       output->push_back(move(str));
+                       ++ptr;
+                       continue;
+               }
+               str.push_back(*ptr++);
        }
-       return re;
+       output->push_back(move(str));
 }
 
 void usage()
@@ -777,21 +807,24 @@ void usage()
        printf(
                "Usage: plocate [OPTION]... PATTERN...\n"
                "\n"
+               "  -b, --basename         search only the file name portion of path names\n"
                "  -c, --count            print number of matches instead of the matches\n"
                "  -d, --database DBPATH  search for files in DBPATH\n"
-               "                         (default is " DEFAULT_DBPATH ")\n"
+               "                         (default is " DBFILE ")\n"
                "  -i, --ignore-case      search case-insensitively\n"
                "  -l, --limit LIMIT      stop after LIMIT matches\n"
                "  -0, --null             delimit matches by NUL instead of newline\n"
+               "  -N, --literal          do not quote filenames, even if printing to a tty\n"
                "  -r, --regexp           interpret patterns as basic regexps (slow)\n"
                "      --regex            interpret patterns as extended regexps (slow)\n"
+               "  -w, --wholename        search the entire path name (default; see -b)\n"
                "      --help             print this help\n"
                "      --version          print version information\n");
 }
 
 void version()
 {
-       printf("plocate %s\n", PLOCATE_VERSION);
+       printf("%s %s\n", PACKAGE_NAME, PACKAGE_VERSION);
        printf("Copyright 2020 Steinar H. Gunderson\n");
        printf("License GPLv2+: GNU GPL version 2 or later <https://gnu.org/licenses/gpl.html>.\n");
        printf("This is free software: you are free to change and redistribute it.\n");
@@ -801,34 +834,57 @@ void version()
 
 int main(int argc, char **argv)
 {
+       vector<string> dbpaths;
+
        constexpr int EXTENDED_REGEX = 1000;
+       constexpr int FLUSH_CACHE = 1001;
+       constexpr int IGNORE_VISIBILITY = 1002;
        static const struct option long_options[] = {
                { "help", no_argument, 0, 'h' },
                { "count", no_argument, 0, 'c' },
+               { "all", no_argument, 0, 'A' },
+               { "basename", no_argument, 0, 'b' },
                { "database", required_argument, 0, 'd' },
+               { "existing", no_argument, 0, 'e' },
                { "ignore-case", no_argument, 0, 'i' },
                { "limit", required_argument, 0, 'l' },
+               { "literal", no_argument, 0, 'N' },
                { "null", no_argument, 0, '0' },
                { "version", no_argument, 0, 'V' },
                { "regexp", no_argument, 0, 'r' },
                { "regex", no_argument, 0, EXTENDED_REGEX },
+               { "wholename", no_argument, 0, 'w' },
                { "debug", no_argument, 0, 'D' },  // Not documented.
+               // Enable to test cold-cache behavior (except for access()). Not documented.
+               { "flush-cache", no_argument, 0, FLUSH_CACHE },
+               // Mostly useful to dump out the entire database, even if the given directories
+               // are gone. Disables sgid due to security. Not documented.
+               { "ignore-visibility", no_argument, 0, IGNORE_VISIBILITY },
                { 0, 0, 0, 0 }
        };
 
        setlocale(LC_ALL, "");
        for (;;) {
                int option_index = 0;
-               int c = getopt_long(argc, argv, "cd:hil:n:0VD", long_options, &option_index);
+               int c = getopt_long(argc, argv, "Abcd:ehil:n:N0rwVD", long_options, &option_index);
                if (c == -1) {
                        break;
                }
                switch (c) {
+               case 'A':
+                       // Ignored.
+                       break;
+               case 'b':
+                       match_basename = true;
+                       break;
                case 'c':
                        only_count = true;
                        break;
                case 'd':
-                       dbpath = strdup(optarg);
+                       parse_dbpaths(optarg, &dbpaths);
+                       break;
+               case 'e':
+                       check_existence = true;
                        break;
                case 'h':
                        usage();
@@ -844,6 +900,9 @@ int main(int argc, char **argv)
                                exit(1);
                        }
                        break;
+               case 'N':
+                       literal_printing = true;
+                       break;
                case '0':
                        print_nul = true;
                        break;
@@ -854,27 +913,44 @@ int main(int argc, char **argv)
                        patterns_are_regex = true;
                        use_extended_regex = true;
                        break;
+               case 'w':
+                       match_basename = false;  // No-op unless -b is given first.
+                       break;
                case 'D':
                        use_debug = true;
                        break;
+               case FLUSH_CACHE:
+                       flush_cache = true;
+                       break;
                case 'V':
                        version();
                        break;
+               case IGNORE_VISIBILITY:
+                       ignore_visibility = true;
+                       break;
                default:
                        exit(1);
                }
        }
 
-       if (use_debug) {
+       if (use_debug || flush_cache || ignore_visibility) {
                // Debug information would leak information about which files exist,
                // so drop setgid before we open the file; one would either need to run
-               // as root, or use a locally-built file.
+               // as root, or use a locally-built file. Doing the same thing for
+               // flush_cache is mostly paranoia, in an attempt to prevent random users
+               // from making plocate slow for everyone else.
+               // --ignore-visibility is obvious; if we allowed to keep sgid with
+               // that flag on, it would subvert the entire security model.
                if (setgid(getgid()) != 0) {
                        perror("setgid");
                        exit(EXIT_FAILURE);
                }
        }
 
+       if (!print_nul) {
+               stdout_is_tty = isatty(1);
+       }
+
        vector<Needle> needles;
        for (int i = optind; i < argc; ++i) {
                Needle needle;
@@ -909,7 +985,34 @@ int main(int argc, char **argv)
        }
        if (needles.empty()) {
                fprintf(stderr, "plocate: no pattern to search for specified\n");
-               exit(0);
+               exit(1);
+       }
+
+       if (dbpaths.empty()) {
+               // No -d given, so use our default. Note that this happens
+               // even if LOCATE_PATH exists, to match mlocate behavior.
+               dbpaths.push_back(DBFILE);
+       }
+
+       const char *locate_path = getenv("LOCATE_PATH");
+       if (locate_path != nullptr) {
+               parse_dbpaths(locate_path, &dbpaths);
+       }
+
+       uint64_t matched = 0;
+       for (size_t i = 0; i < dbpaths.size(); ++i) {
+               uint64_t this_matched;
+               if (i != dbpaths.size() - 1) {
+                       this_matched = do_search_file_in_child(needles, dbpaths[i]);
+               } else {
+                       this_matched = do_search_file(needles, dbpaths[i]);
+               }
+               matched += this_matched;
+               limit_left -= this_matched;
        }
-       do_search_file(needles, dbpath);
+       if (only_count) {
+               printf("%" PRId64 "\n", matched);
+       }
+
+       return matched == 0;
 }