Adopt use of nullptr

Modern C++ practice.

26 files changed, 169 insertions, 168 deletions

diff --git a/src/Command.cc b/src/Command.cc
index f031d8e..17ecb4d 100644
--- a/src/Command.cc
+++ b/src/Command.cc
@@ -37,35 +37,35 @@ enum {
 };
 
 const struct option Command::options[] = {
-  { "help", no_argument, 0, 'h' },
-  { "version", no_argument, 0, 'V' },
-  { "backup", no_argument, 0, 'b' },
-  { "html", required_argument, 0, 'H' },
-  { "text", required_argument, 0, 'T' },
-  { "email", required_argument, 0, 'e' },
-  { "prune", no_argument, 0, 'p' },
-  { "prune-incomplete", no_argument, 0, 'P' },
-  { "store", required_argument, 0, 's' },
-  { "retire-device", no_argument, 0, RETIRE_DEVICE },
-  { "retire", no_argument, 0, RETIRE },
-  { "config", required_argument, 0, 'c' },
-  { "wait", no_argument, 0, 'w' },
-  { "force", no_argument, 0, 'f' },
-  { "dry-run", no_argument, 0, 'n' },
-  { "verbose", no_argument, 0, 'v' },
-  { "warn-unknown", no_argument, 0, WARN_UNKNOWN },
-  { "warn-store", no_argument, 0, WARN_STORE },
-  { "warn-unreachable", no_argument, 0, WARN_UNREACHABLE },
-  { "warn-partial", no_argument, 0, WARN_PARTIAL },
-  { "no-warn-partial", no_argument, 0, NO_WARN_PARTIAL },
-  { "errors", no_argument, 0, REPEAT_ERRORS },
-  { "no-errors", no_argument, 0, NO_REPEAT_ERRORS },
-  { "warn-all", no_argument, 0, 'W' },
-  { "debug", no_argument, 0, 'd' },
-  { "logs", required_argument, 0, LOG_VERBOSITY },
-  { "dump-config", no_argument, 0, DUMP_CONFIG },
-  { "database", required_argument, 0, 'D' },
-  { 0, 0, 0, 0 }
+  { "help", no_argument, nullptr, 'h' },
+  { "version", no_argument, nullptr, 'V' },
+  { "backup", no_argument, nullptr, 'b' },
+  { "html", required_argument, nullptr, 'H' },
+  { "text", required_argument, nullptr, 'T' },
+  { "email", required_argument, nullptr, 'e' },
+  { "prune", no_argument, nullptr, 'p' },
+  { "prune-incomplete", no_argument, nullptr, 'P' },
+  { "store", required_argument, nullptr, 's' },
+  { "retire-device", no_argument, nullptr, RETIRE_DEVICE },
+  { "retire", no_argument, nullptr, RETIRE },
+  { "config", required_argument, nullptr, 'c' },
+  { "wait", no_argument, nullptr, 'w' },
+  { "force", no_argument, nullptr, 'f' },
+  { "dry-run", no_argument, nullptr, 'n' },
+  { "verbose", no_argument, nullptr, 'v' },
+  { "warn-unknown", no_argument, nullptr, WARN_UNKNOWN },
+  { "warn-store", no_argument, nullptr, WARN_STORE },
+  { "warn-unreachable", no_argument, nullptr, WARN_UNREACHABLE },
+  { "warn-partial", no_argument, nullptr, WARN_PARTIAL },
+  { "no-warn-partial", no_argument, nullptr, NO_WARN_PARTIAL },
+  { "errors", no_argument, nullptr, REPEAT_ERRORS },
+  { "no-errors", no_argument, nullptr, NO_REPEAT_ERRORS },
+  { "warn-all", no_argument, nullptr, 'W' },
+  { "debug", no_argument, nullptr, 'd' },
+  { "logs", required_argument, nullptr, LOG_VERBOSITY },
+  { "dump-config", no_argument, nullptr, DUMP_CONFIG },
+  { "database", required_argument, nullptr, 'D' },
+  { nullptr, 0, nullptr, 0 }
 };
 
 Command::Command(): backup(false),
@@ -74,9 +74,9 @@ Command::Command(): backup(false),
                     retire(false),
                     retireDevice(false),
                     dumpConfig(false),
-                    html(NULL),
-                    text(NULL),
-                    email(NULL),
+                    html(nullptr),
+                    text(nullptr),
+                    email(nullptr),
                     configPath(DEFAULT_CONFIG),
                     wait(false),
                     act(true),
@@ -156,7 +156,7 @@ void Command::parse(int argc, const char *const *argv) {
   // Parse options
   optind = 1;
   while((n = getopt_long(argc, (char *const *)argv,
-                         "+hVbH:T:e:pPs:c:wnfvdWD:", options, 0)) >= 0) {
+                         "+hVbH:T:e:pPs:c:wnfvdWD:", options, nullptr)) >= 0) {
     switch(n) {
     case 'h': help();
     case 'V': version();
diff --git a/src/Command.h b/src/Command.h
index 79da9f3..34f9c8e 100644
--- a/src/Command.h
+++ b/src/Command.h
@@ -91,13 +91,13 @@ public:
   /** @brief @c --dump-config action */
   bool dumpConfig;
 
-  /** @brief Output file for HTML report or @c NULL */
+  /** @brief Output file for HTML report or null pointer */
   std::string *html;
 
-  /** @brief Output file for text report or @c NULL */
+  /** @brief Output file for text report or null pointer */
   std::string *text;
 
-  /** @brief Address for email report or @c NULL */
+  /** @brief Address for email report or null pointer */
   std::string *email;
 
   /** @brief Explicitly specified stores */
diff --git a/src/Conf.cc b/src/Conf.cc
index 565ae76..dee69e6 100644
--- a/src/Conf.cc
+++ b/src/Conf.cc
@@ -37,7 +37,7 @@ struct ConfContext {
    * @param conf_ Root configuration node
    */
   ConfContext(Conf *conf_):
-    conf(conf_), context(conf_), host(NULL), volume(NULL) {}
+    conf(conf_), context(conf_), host(nullptr), volume(nullptr) {}
 
   /** @brief Root of configuration */
   Conf *conf;
@@ -124,7 +124,7 @@ struct HostOnlyDirective: public Directive {
   HostOnlyDirective(const char *name_, int min_=0, int max_=INT_MAX):
     Directive(name_, min_, max_) {}
   virtual void check(const ConfContext &cc) const {
-    if(cc.host == NULL)
+    if(cc.host == nullptr)
       throw SyntaxError("'" + name + "' command without 'host'");
     Directive::check(cc);
   }
@@ -141,7 +141,7 @@ struct VolumeOnlyDirective: public Directive {
   VolumeOnlyDirective(const char *name_, int min_=0, int max_=INT_MAX):
     Directive(name_, min_, max_) {}
   virtual void check(const ConfContext &cc) const {
-    if(cc.volume == NULL)
+    if(cc.volume == nullptr)
       throw SyntaxError("'" + name + "' command without 'volume'");
     Directive::check(cc);
   }
@@ -397,7 +397,7 @@ static const struct HostDirective: public Directive {
     if(cc.conf->hosts.find(cc.bits[1]) != cc.conf->hosts.end())
       throw SyntaxError("duplicate host");
     cc.context = cc.host = new Host(cc.conf, cc.bits[1]);
-    cc.volume = NULL;
+    cc.volume = nullptr;
     cc.host->hostname = cc.bits[1];
   }
 } host_directive;
@@ -641,20 +641,20 @@ void Conf::addHost(Host *h) {
 // Find a host by name
 Host *Conf::findHost(const std::string &hostName) const {
   auto it = hosts.find(hostName);
-  return it != hosts.end() ? it->second : NULL;
+  return it != hosts.end() ? it->second : nullptr;
 }
 
 // Find a volume by name
 Volume *Conf::findVolume(const std::string &hostName,
                          const std::string &volumeName) const {
   Host *host = findHost(hostName);
-  return host ? host->findVolume(volumeName) : NULL;
+  return host ? host->findVolume(volumeName) : nullptr;
 }
 
 // Find a device by name
 Device *Conf::findDevice(const std::string &deviceName) const {
   auto it = devices.find(deviceName);
-  return it != devices.end() ? it->second : NULL;
+  return it != devices.end() ? it->second : nullptr;
 }
 
 // Read in logfiles
@@ -714,7 +714,7 @@ void Conf::readState() {
     // Skip empty files
     if(contents.size() == 0) {
       if(progress)
-        progressBar(IO::err, NULL, 0, 0);
+        progressBar(IO::err, nullptr, 0, 0);
       warning("empty file: %s", files[n].c_str());
       continue;
     }
@@ -743,7 +743,7 @@ void Conf::readState() {
 
     if(command.act) {
       // addBackup might fail to set volume
-      if(backup.volume != NULL) {
+      if(backup.volume != nullptr) {
         if(upgraded.size() == 0)
           getdb()->begin();
         try {
@@ -755,7 +755,7 @@ void Conf::readState() {
         upgraded.push_back(files[n]);
       } else {
         if(progress)
-          progressBar(IO::err, NULL, 0, 0);
+          progressBar(IO::err, nullptr, 0, 0);
         warning("cannot upgrade %s", files[n].c_str());
       }
     }
@@ -775,7 +775,7 @@ void Conf::readState() {
       throw SystemError("could not remove old logfiles");
   }
   if(progress)
-    progressBar(IO::err, NULL, 0, 0);
+    progressBar(IO::err, nullptr, 0, 0);
 }
 
 void Conf::addBackup(Backup &backup,
@@ -792,7 +792,7 @@ void Conf::addBackup(Backup &backup,
     if(unknownDevices.find(backup.deviceName) == unknownDevices.end()) {
       if(command.warnUnknown || forceWarn) {
         if(progress)
-          progressBar(IO::err, NULL, 0, 0);
+          progressBar(IO::err, nullptr, 0, 0);
         warning("unknown device %s", backup.deviceName.c_str());
       }
       unknownDevices.insert(backup.deviceName);
@@ -807,7 +807,7 @@ void Conf::addBackup(Backup &backup,
     if(unknownHosts.find(hostName) == unknownHosts.end()) {
       if(command.warnUnknown || forceWarn) {
         if(progress)
-          progressBar(IO::err, NULL, 0, 0);
+          progressBar(IO::err, nullptr, 0, 0);
         warning("unknown host %s", hostName.c_str());
       }
       unknownHosts.insert(hostName);
@@ -820,7 +820,7 @@ void Conf::addBackup(Backup &backup,
     if(host->unknownVolumes.find(volumeName) == host->unknownVolumes.end()) {
       if(command.warnUnknown || forceWarn) {
         if(progress)
-          progressBar(IO::err, NULL, 0, 0);
+          progressBar(IO::err, nullptr, 0, 0);
         warning("unknown volume %s:%s",
                 hostName.c_str(), volumeName.c_str());
       }
@@ -910,7 +910,7 @@ void Conf::createTables() {
 }
 
 ConfBase *Conf::getParent() const {
-  return NULL;
+  return nullptr;
 }
 
 // Regexp for parsing log filenames
diff --git a/src/Conf.h b/src/Conf.h
index 0c86d23..002010c 100644
--- a/src/Conf.h
+++ b/src/Conf.h
@@ -109,7 +109,7 @@ public:
   virtual void write(std::ostream &os, int step = 0) const;
 
   /** @brief Return the parent of this configuration node
-   * @return Parent node or NULL
+   * @return Parent node or null pointer
    */
   virtual ConfBase *getParent() const = 0;
 
@@ -172,7 +172,7 @@ public:
           unknownObjects(0),
           logsRead(false),
           devicesIdentified(false),
-          db(NULL) { }
+          db(nullptr) { }
 
   /** @brief Map of host names to configuration */
   hosts_type hosts;
@@ -258,21 +258,21 @@ public:
 
   /** @brief Find a host by name
    * @param hostName Host to find
-   * @return Host, or NULL
+   * @return Host, or null pointer
    */
   Host *findHost(const std::string &hostName) const;
 
   /** @brief Find a volume by name
    * @param hostName Name of host containing volume
    * @param volumeName Name of volume to find
-   * @return Volume, or NULL
+   * @return Volume, or null pointer
    */
   Volume *findVolume(const std::string &hostName,
                      const std::string &volumeName) const;
 
   /** @brief Find a device by name
    * @param deviceName Name of device to find
-   * @return Device, or NULL
+   * @return Device, or null pointer
    */
   Device *findDevice(const std::string &deviceName) const;
 
@@ -401,12 +401,12 @@ public:
   /** @brief Constructor
    * @param name_ Name of device
    */
-  Device(const std::string &name_): name(name_), store(NULL) {}
+  Device(const std::string &name_): name(name_), store(nullptr) {}
 
   /** @brief Name of device */
   std::string name;
 
-  /** @brief Store for this device, or NULL
+  /** @brief Store for this device, or null pointer
    *
    * Set by Store::identify().
    */
@@ -485,7 +485,7 @@ public:
 
   /** @brief Find a volume by name
    * @param volumeName Name of volume to find
-   * @return Volume or NULL
+   * @return Volume or null pointer
    */
   Volume *findVolume(const std::string &volumeName) const;
 
@@ -511,7 +511,7 @@ public:
   static bool valid(const std::string &n);
 
   /** @brief Invoke a command on the host and return its exit status
-   * @param capture Where to put capture stdout, or NULL
+   * @param capture Where to put capture stdout, or null pointer
    * @param cmd Command to invoke
    * @param ... Arguments to command, terminatd by a null pointer
    * @return Exit status
@@ -603,7 +603,7 @@ public:
 
   /** @brief Return containing device
    *
-   * TODO could this be NULL if device has been retired?
+   * TODO could this be null pointer if device has been retired?
    */
   Device *getDevice() const;
 
@@ -625,7 +625,8 @@ public:
   void remove(Database *db) const;
 
   /** @brief Constructor */
-  inline Backup(): status(UNKNOWN), rc(0), time(0), pruned(0), volume(NULL) {}
+  inline Backup(): status(UNKNOWN), rc(0), time(0), pruned(0), volume(nullptr) {
+  }
 
   /** @brief Retrieve status of this backup */
   inline int getStatus() const {
@@ -755,16 +756,16 @@ public:
   bool removeBackup(const Backup *backup);
 
   /** @brief Find the most recent backup
-   * @param device If not NULL, only consider backups from this device
-   * @return Most recent backup or NULL
+   * @param device If not null pointer, only consider backups from this device
+   * @return Most recent backup or null pointer
    */
-  const Backup *mostRecentBackup(const Device *device = NULL) const;
+  const Backup *mostRecentBackup(const Device *device = nullptr) const;
 
   /** @brief Find the most recent failedbackup
-   * @param device If not NULL, only consider backups from this device
-   * @return Most recent failed backup or NULL
+   * @param device If not null pointer, only consider backups from this device
+   * @return Most recent failed backup or null pointer
    */
-  const Backup *mostRecentFailedBackup(const Device *device = NULL) const;
+  const Backup *mostRecentFailedBackup(const Device *device = nullptr) const;
 
   virtual ConfBase *getParent() const;
 
diff --git a/src/Database.cc b/src/Database.cc
index f0328f7..bf9d6f1 100644
--- a/src/Database.cc
+++ b/src/Database.cc
@@ -23,7 +23,7 @@ Database::Database(const std::string &path, bool rw) {
                            &db,
                            rw ? SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE
                               : SQLITE_OPEN_READONLY,
-                           NULL);
+                           nullptr);
   if(rc != SQLITE_OK)
     error("sqlite3_open_v2 " + path, rc);
 }
@@ -69,7 +69,7 @@ void Database::rollback() {
 Database::~Database() {
   // Really want sqlite3_close_v2 but not available in wheezy
   int rc = sqlite3_close(db);
-  db = NULL;
+  db = nullptr;
   if(rc != SQLITE_OK)
     error("sqlite3_close", rc);
 }
@@ -77,7 +77,7 @@ Database::~Database() {
 // Database::Statement --------------------------------------------------------
 
 Database::Statement::Statement(Database *d, const char *cmd, ...):
-  stmt(NULL), db(d->db), param(0) {
+  stmt(nullptr), db(d->db), param(0) {
   va_list ap;
   va_start(ap, cmd);
   try {
@@ -90,7 +90,7 @@ Database::Statement::Statement(Database *d, const char *cmd, ...):
 }
 
 Database::Statement::Statement(Database &d, const char *cmd, ...):
-  stmt(NULL), db(d.db), param(0) {
+  stmt(nullptr), db(d.db), param(0) {
   va_list ap;
   va_start(ap, cmd);
   try {
@@ -129,7 +129,7 @@ void Database::Statement::vprepare(const char *cmd, va_list ap) {
     vbind(ap);
   } catch(std::runtime_error &e) {
     sqlite3_finalize(stmt);
-    stmt = NULL;
+    stmt = nullptr;
     throw;
   }
 }
diff --git a/src/Database.h b/src/Database.h
index 073ef84..e0e2100 100644
--- a/src/Database.h
+++ b/src/Database.h
@@ -51,13 +51,13 @@ public:
      * @param d Database
      * @throw DatabaseError if an error occurs
      */
-    inline Statement(Database *d): stmt(NULL), db(d->db), param(0) {}
+    inline Statement(Database *d): stmt(nullptr), db(d->db), param(0) {}
 
     /** @brief Create a statement
      * @param d Database
      * @throw DatabaseError if an error occurs
      */
-    inline Statement(Database &d): stmt(NULL), db(d.db), param(0) {}
+    inline Statement(Database &d): stmt(nullptr), db(d.db), param(0) {}
 
     /** @brief Create a statement, prepare it with a command and bind data it
      * @param d Database
diff --git a/src/Date.cc b/src/Date.cc
index f482339..a3f53e3 100644
--- a/src/Date.cc
+++ b/src/Date.cc
@@ -130,7 +130,7 @@ time_t Date::now() {
   const char *override = getenv("RSBACKUP_TODAY");
   if(override)
     return Date(override).toTime();
-  return time(NULL);
+  return time(nullptr);
 }
 
 int Date::monthLength(int y, int m) {
diff --git a/src/Directory.cc b/src/Directory.cc
index e0df6a0..ce962cf 100644
--- a/src/Directory.cc
+++ b/src/Directory.cc
@@ -35,7 +35,7 @@ void Directory::close() {
   if(!dp)
     throw std::logic_error("Directory::close on closed directory");
   closedir(dp);
-  dp = NULL;
+  dp = nullptr;
   path.clear();
 }
 
diff --git a/src/Document.cc b/src/Document.cc
index a943625..c838d55 100644
--- a/src/Document.cc
+++ b/src/Document.cc
@@ -93,6 +93,6 @@ Document::Cell *Document::Table::occupied(int x, int y) const {
        && y >= cell->y && y < cell->y + cell->h)
       return cell;
   }
-  return NULL;
+  return nullptr;
 }
 
diff --git a/src/Document.h b/src/Document.h
index b2d6cf3..f278152 100644
--- a/src/Document.h
+++ b/src/Document.h
@@ -428,7 +428,7 @@ public:
     /** @brief Find the cell at a position
      * @param x X position
      * @param y Y position
-     * @return @p cell or NULL
+     * @return @p cell or null pointer
      */
     Cell *occupied(int x, int y) const;
 
diff --git a/src/EventLoop.cc b/src/EventLoop.cc
index c8c5607..f6e3a44 100644
--- a/src/EventLoop.cc
+++ b/src/EventLoop.cc
@@ -53,12 +53,12 @@ EventLoop::EventLoop() {
   sigset_t ss;
   sigemptyset(&ss);
   sigaddset(&ss, SIGCHLD);
-  if(sigprocmask(SIG_BLOCK, &ss, NULL) < 0)
+  if(sigprocmask(SIG_BLOCK, &ss, nullptr) < 0)
     throw SystemError("sigprocmask", errno);
   sa.sa_handler = EventLoop::signalled;
   sigfillset(&sa.sa_mask);
   sa.sa_flags = SA_RESTART;
-  if(sigaction(SIGCHLD, &sa, NULL) < 0)
+  if(sigaction(SIGCHLD, &sa, nullptr) < 0)
     throw SystemError("sigaction", errno);
   if(pipe(sigpipe) < 0)
     throw SystemError("pipe", errno);
@@ -72,7 +72,7 @@ EventLoop::~EventLoop() {
   signal(SIGCHLD, SIG_DFL);
   sigemptyset(&ss);
   sigaddset(&ss, SIGCHLD);
-  if(sigprocmask(SIG_UNBLOCK, &ss, NULL) < 0)
+  if(sigprocmask(SIG_UNBLOCK, &ss, nullptr) < 0)
     throw SystemError("sigprocmask", errno);
   close(sigpipe[0]);
   close(sigpipe[1]);
@@ -120,7 +120,7 @@ void EventLoop::whenWaited(pid_t pid, Reactor *r) {
 
 void EventLoop::wait() {
   sigset_t ss;
-  if(sigprocmask(SIG_SETMASK, NULL, &ss) < 0)
+  if(sigprocmask(SIG_SETMASK, nullptr, &ss) < 0)
     throw SystemError("sigprocmask", errno);
   sigdelset(&ss, SIGCHLD);
   while(readers.size() > 1 || writers.size() > 0 || waiters.size() > 0) {
@@ -142,7 +142,7 @@ void EventLoop::wait() {
         ts.tv_sec = 10;
       tsp = &ts;
     } else
-      tsp = NULL;
+      tsp = nullptr;
     FD_ZERO(&rfds);
     FD_ZERO(&wfds);
     for(auto it = readers.begin(); it != readers.end(); ++it) {
@@ -153,7 +153,7 @@ void EventLoop::wait() {
       FD_SET(it->first, &wfds);
       maxfd = std::max(maxfd, it->first);
     }
-    n = pselect(maxfd + 1, &rfds, &wfds, NULL, tsp, &ss);
+    n = pselect(maxfd + 1, &rfds, &wfds, nullptr, tsp, &ss);
     if(n < 0) {
       if(errno != EINTR)
         throw IOError("pselect", errno);
@@ -211,7 +211,7 @@ void EventLoop::getTimestamp(struct timespec &now) {
     throw IOError("clock_gettime", errno);
 #else
   struct timeval tv;
-  if(gettimeofday(&tv, NULL) < 0)
+  if(gettimeofday(&tv, nullptr) < 0)
     throw IOError("gettimeofday", errno);
   now.tv_sec = tv.tv_sec;
   now.tv_nsec = tv.tv_sec * 1000;
diff --git a/src/HTML.cc b/src/HTML.cc
index ac9161f..725747a 100644
--- a/src/HTML.cc
+++ b/src/HTML.cc
@@ -90,27 +90,27 @@ void Document::String::renderHtml(std::ostream &os) const {
 }
 
 void Document::LinearContainer::renderHtml(std::ostream &os) const {
-  renderHtmlOpenTag(os, "div", (char *)0);
+  renderHtmlOpenTag(os, "div", (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, "div");
 }
 
 void Document::Paragraph::renderHtml(std::ostream &os) const {
-  renderHtmlOpenTag(os, "p", (char *)0);
+  renderHtmlOpenTag(os, "p", (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, "p");
 }
 
 void Document::Verbatim::renderHtml(std::ostream &os) const {
-  renderHtmlOpenTag(os, "pre", (char *)0);
+  renderHtmlOpenTag(os, "pre", (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, "pre");
 }
 
 void Document::List::renderHtml(std::ostream &os) const {
   switch(type) {
-  case OrderedList: renderHtmlOpenTag(os, "ol", (char *)0); break;
-  case UnorderedList: renderHtmlOpenTag(os, "ul", (char *)0); break;
+  case OrderedList: renderHtmlOpenTag(os, "ol", (char *)nullptr); break;
+  case UnorderedList: renderHtmlOpenTag(os, "ul", (char *)nullptr); break;
   }
   renderHtmlContents(os);
   switch(type) {
@@ -120,7 +120,7 @@ void Document::List::renderHtml(std::ostream &os) const {
 }
 
 void Document::ListEntry::renderHtml(std::ostream &os) const {
-  renderHtmlOpenTag(os, "li", (char *)0);
+  renderHtmlOpenTag(os, "li", (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, "li");
 }
@@ -130,7 +130,7 @@ void Document::Heading::renderHtml(std::ostream &os) const {
     throw std::runtime_error("heading level too high");
   char tag[64];
   snprintf(tag, sizeof tag, "h%d", level);
-  renderHtmlOpenTag(os, tag, (char *)0);
+  renderHtmlOpenTag(os, tag, (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, tag);
 }
@@ -141,22 +141,22 @@ void Document::Cell::renderHtml(std::ostream &os) const {
   snprintf(ws, sizeof ws, "%d", w);
   snprintf(hs, sizeof hs, "%d", h);
   if(w > 1 && h > 1)
-    renderHtmlOpenTag(os, tag, "colspan", ws, "rowspan", hs, (char *)0);
+    renderHtmlOpenTag(os, tag, "colspan", ws, "rowspan", hs, (char *)nullptr);
   else if(w > 1)
-    renderHtmlOpenTag(os, tag, "colspan", ws, (char *)0);
+    renderHtmlOpenTag(os, tag, "colspan", ws, (char *)nullptr);
   else if(h > 1)
-    renderHtmlOpenTag(os, tag, "rowspan", hs, (char *)0);
+    renderHtmlOpenTag(os, tag, "rowspan", hs, (char *)nullptr);
   else
-    renderHtmlOpenTag(os, tag, (char *)0);
+    renderHtmlOpenTag(os, tag, (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, tag);
 }
 
 void Document::Table::renderHtml(std::ostream &os) const {
-  renderHtmlOpenTag(os, "table", (char *)0);
+  renderHtmlOpenTag(os, "table", (char *)nullptr);
   const int w = width(), h = height();
   for(int row = 0; row < h; ++row) {
-    renderHtmlOpenTag(os, "tr", (char *)0);
+    renderHtmlOpenTag(os, "tr", (char *)nullptr);
     for(int col = 0; col < w;) {
       int skip = 0;
       for(size_t n = 0; n < cells.size(); ++n) {
@@ -169,7 +169,7 @@ void Document::Table::renderHtml(std::ostream &os) const {
       }
       if(!skip) {
         if(!occupied(col, row)) {
-          renderHtmlOpenTag(os, "td", (char *)0);
+          renderHtmlOpenTag(os, "td", (char *)nullptr);
           renderHtmlCloseTag(os, "td");
         }
         skip = 1;
@@ -182,7 +182,7 @@ void Document::Table::renderHtml(std::ostream &os) const {
 }
 
 void Document::RootContainer::renderHtml(std::ostream &os) const {
-  renderHtmlOpenTag(os, "body", (char *)0);
+  renderHtmlOpenTag(os, "body", (char *)nullptr);
   renderHtmlContents(os);
   renderHtmlCloseTag(os, "body");
 }
diff --git a/src/Host.cc b/src/Host.cc
index 4017789..33e5128 100644
--- a/src/Host.cc
+++ b/src/Host.cc
@@ -47,7 +47,7 @@ void Host::addVolume(Volume *v) {
 
 Volume *Host::findVolume(const std::string &volumeName) const {
   auto it = volumes.find(volumeName);
-  return it != volumes.end() ? it->second : NULL;
+  return it != volumes.end() ? it->second : nullptr;
 }
 
 std::string Host::userAndHost() const {
@@ -65,7 +65,7 @@ bool Host::available() const {
   // localhost is always available
   if(hostname == "localhost")
     return true;
-  return invoke(NULL, "true", (const char *)NULL) == 0;
+  return invoke(nullptr, "true", (const char *)nullptr) == 0;
 }
 
 void Host::write(std::ostream &os, int step) const {
diff --git a/src/IO.cc b/src/IO.cc
index aba3686..634e8a9 100644
--- a/src/IO.cc
+++ b/src/IO.cc
@@ -67,7 +67,7 @@ void IO::popen(const std::vector<std::string> &command,
 
 int IO::close(bool checkStatus) {
   FILE *fpSave = fp;
-  fp = NULL;
+  fp = nullptr;
   if(fclose(fpSave) < 0) {
     if(abortOnError)
       abort();
diff --git a/src/IO.h b/src/IO.h
index b932136..800ce84 100644
--- a/src/IO.h
+++ b/src/IO.h
@@ -48,8 +48,8 @@ class Subprocess;
 class IO {
 public:
   /** @brief Constructor */
-  IO(): fp(NULL),
-        subprocess(NULL),
+  IO(): fp(nullptr),
+        subprocess(nullptr),
         closeFile(false),
         abortOnError(false) {}
 
@@ -60,7 +60,7 @@ public:
   IO(FILE *fp_,
      const std::string &path_): fp(fp_),
                                   path(path_),
-                                  subprocess(NULL),
+                                  subprocess(nullptr),
                                   closeFile(false),
                                   abortOnError(false) {}
 
@@ -159,7 +159,7 @@ private:
      const std::string &path_,
      bool abortOnError_): fp(fp_),
                           path(path_),
-                          subprocess(NULL),
+                          subprocess(nullptr),
                           closeFile(false),
                           abortOnError(abortOnError_) {}
 
@@ -169,7 +169,7 @@ private:
   /** @brief Path to open file */
   std::string path;
 
-  /** @brief Subprocess handler or @c NULL
+  /** @brief Subprocess handler or null pointer
    *
    * Used by @ref popen().
    */
@@ -195,7 +195,7 @@ private:
 class Directory {
 public:
   /** @brief Constructor */
-  Directory(): dp(NULL) {}
+  Directory(): dp(nullptr) {}
 
   /** @brief Destructor
    *
diff --git a/src/MakeBackup.cc b/src/MakeBackup.cc
index 5f1a57a..890c1f9 100644
--- a/src/MakeBackup.cc
+++ b/src/MakeBackup.cc
@@ -129,7 +129,7 @@ MakeBackup::MakeBackup(Volume *volume_, Device *device_):
   incompletePath(backupPath + ".incomplete"),
   sourcePath(volume->path),
   what("pending"),
-  outcome(NULL) {
+  outcome(nullptr) {
 }
 
 MakeBackup::~MakeBackup() {
@@ -156,7 +156,7 @@ const Backup *MakeBackup::getLastBackup() {
       return backup;
   }
   // Otherwise there is nothing to link to.
-  return NULL;
+  return nullptr;
 }
 
 void MakeBackup::hookEnvironment(Subprocess &sp) {
@@ -240,7 +240,7 @@ int MakeBackup::rsyncBackup() {
     for(size_t n = 0; n < volume->exclude.size(); ++n)
       cmd.push_back("--exclude=" + volume->exclude[n]);
     const Backup *lastBackup = getLastBackup();
-    if(lastBackup != NULL)
+    if(lastBackup != nullptr)
       cmd.push_back("--link-dest=" + lastBackup->backupPath());
     // Source
     cmd.push_back(host->sshPrefix() + sourcePath + "/.");
diff --git a/src/Report.cc b/src/Report.cc
index e5a44c0..aafbc7b 100644
--- a/src/Report.cc
+++ b/src/Report.cc
@@ -178,7 +178,7 @@ Document::Table *Report::reportSummary() {
         t->addCell(new Document::Cell(new Document::String(perDevice.count)))
           ->style = perDevice.count ? "good" : "bad";
         // Look for the most recent attempt at this device
-        const Backup *most_recent_backup = NULL;
+        const Backup *most_recent_backup = nullptr;
         for(backups_type::const_reverse_iterator bit = volume->backups.rbegin();
             bit != volume->backups.rend();
             ++bit) {
@@ -234,7 +234,7 @@ bool Report::suitableLog(const Volume *volume, const Backup *backup) {
 
 // Generate the report of backup logfiles for a volume
 void Report::reportLogs(const Volume *volume) {
-  Document::LinearContainer *lc = NULL;
+  Document::LinearContainer *lc = nullptr;
   Host *host = volume->parent;
   // Backups for a volume are ordered primarily by date and secondarily by
   // device.  The most recent backups are the most interesting so they are
diff --git a/src/RetireVolumes.cc b/src/RetireVolumes.cc
index 1f49921..22df63d 100644
--- a/src/RetireVolumes.cc
+++ b/src/RetireVolumes.cc
@@ -56,7 +56,7 @@ struct Retirable {
    * @param i Backup ID
    */
   inline Retirable(const std::string &h, const std::string &v, Device *d, std::string i):
-    hostName(h), volumeName(v), device(d), id(i), b(NULL) {
+    hostName(h), volumeName(v), device(d), id(i), b(nullptr) {
   }
 
   /** @brief Destructor */
diff --git a/src/Store.cc b/src/Store.cc
index b421a7b..b303b33 100644
--- a/src/Store.cc
+++ b/src/Store.cc
@@ -23,7 +23,7 @@
 
 // Identify the device on this store, if any
 void Store::identify() {
-  IO *f = NULL;
+  IO *f = nullptr;
   try {
     struct stat sb;
 
diff --git a/src/Store.h b/src/Store.h
index f14d53d..1c6ba3e 100644
--- a/src/Store.h
+++ b/src/Store.h
@@ -33,7 +33,7 @@ public:
    * @param path_ Location of store
    */
   Store(const std::string &path_): path(path_),
-                                   device(NULL),
+                                   device(nullptr),
                                    state(Enabled) {
   }
 
@@ -51,9 +51,9 @@ public:
 
   /** @param Device mounted at this store
    *
-   * Set to NULL before checking, or if no device is mounted here
+   * Set to null pointer before checking, or if no device is mounted here
    */
-  Device *device;                       // device for this, or NULL
+  Device *device;
 
   /** @brief State of this store */
   State state;
diff --git a/src/Subprocess.cc b/src/Subprocess.cc
index 3a2c22a..7c4125f 100644
--- a/src/Subprocess.cc
+++ b/src/Subprocess.cc
@@ -31,8 +31,8 @@
 Subprocess::Subprocess(): pid(-1),
                           timeout(0),
                           status(-1),
-                          actionlist(NULL),
-                          eventloop(NULL) {
+                          actionlist(nullptr),
+                          eventloop(nullptr) {
 }
 
 Subprocess::Subprocess(const std::vector<std::string> &cmd_):
@@ -40,8 +40,8 @@ Subprocess::Subprocess(const std::vector<std::string> &cmd_):
   cmd(cmd_),
   timeout(0),
   status(-1),
-  actionlist(NULL),
-  eventloop(NULL) {
+  actionlist(nullptr),
+  eventloop(nullptr) {
 }
 
 Subprocess::~Subprocess() {
@@ -91,7 +91,7 @@ pid_t Subprocess::launch(EventLoop *e) {
   std::vector<const char *> args;
   for(size_t n = 0; n < cmd.size(); ++n)
     args.push_back(cmd[n].c_str());
-  args.push_back(NULL);
+  args.push_back(nullptr);
   // Start the subprocess
   switch(pid = fork()) {
   case -1:
@@ -202,7 +202,7 @@ int Subprocess::wait(bool checkStatus) {
   setup(eventloop);
   eventloop->wait();
   delete eventloop;
-  eventloop = NULL;
+  eventloop = nullptr;
   pid = -1;
   if(checkStatus && status) {
     if(WIFSIGNALED(status) && WTERMSIG(status) == SIGPIPE)
@@ -240,7 +240,7 @@ void Subprocess::getTimestamp(struct timespec &now) {
     throw IOError("clock_gettime", errno);
 #else
   struct timeval tv;
-  if(gettimeofday(&tv, NULL) < 0)
+  if(gettimeofday(&tv, nullptr) < 0)
     throw IOError("gettimeofday", errno);
   now.tv_sec = tv.tv_sec;
   now.tv_nsec = tv.tv_sec * 1000;
diff --git a/src/Unicode.cc b/src/Unicode.cc
index 566c410..0d9a130 100644
--- a/src/Unicode.cc
+++ b/src/Unicode.cc
@@ -31,7 +31,7 @@
 void toUnicode(std::wstring &u, const std::string &mbs) {
   static iconv_t cd;
 
-  if(cd == 0) {
+  if(cd == nullptr) {
     char *mbsEncoding = nl_langinfo(CODESET);
     cd = iconv_open(ENCODING, mbsEncoding);
     if(!cd)
diff --git a/src/Volume.cc b/src/Volume.cc
index 12c5352..ae86f9c 100644
--- a/src/Volume.cc
+++ b/src/Volume.cc
@@ -83,7 +83,7 @@ bool Volume::removeBackup(const Backup *backup) {
 }
 
 const Backup *Volume::mostRecentBackup(const Device *device) const {
-  const Backup *result = NULL;
+  const Backup *result = nullptr;
   for(auto it = backups.begin(); it != backups.end(); ++it) {
     const Backup *b = *it;
     if(!device || b->getDevice() == device) {
@@ -95,7 +95,7 @@ const Backup *Volume::mostRecentBackup(const Device *device) const {
 }
 
 const Backup *Volume::mostRecentFailedBackup(const Device *device) const {
-  const Backup *result = NULL;
+  const Backup *result = nullptr;
   for(auto it = backups.begin(); it != backups.end(); ++it) {
     const Backup *b = *it;
     if(!device || b->getDevice() == device) {
@@ -114,7 +114,7 @@ bool Volume::available() const {
     const char *option;
     // Guess which version of stat to use based on uname.
     if(parent->invoke(&os,
-                      "uname", "-s", (const char *)NULL) != 0)
+                      "uname", "-s", (const char *)nullptr) != 0)
       return false;
     if(os == "Darwin"
        || (os.size() >= 3
@@ -129,7 +129,7 @@ bool Volume::available() const {
                       "stat", option, "%d",
                       path.c_str(),
                       parent_directory.c_str(),
-                      (const char *)NULL))
+                      (const char *)nullptr))
       return false;
     // Split output into lines
     std::vector<std::string> lines;
@@ -146,8 +146,8 @@ bool Volume::available() const {
     std::string file = (checkFile[0] == '/'
                         ? checkFile
                         : path + "/" + checkFile);
-    if(parent->invoke(NULL,
-                      "test", "-e", file.c_str(), (const char *)NULL) != 0)
+    if(parent->invoke(nullptr,
+                      "test", "-e", file.c_str(), (const char *)nullptr) != 0)
       return false;
   }
   return true;
diff --git a/src/rsbackup.cc b/src/rsbackup.cc
index 09dd1d1..8f6cf12 100644
--- a/src/rsbackup.cc
+++ b/src/rsbackup.cc
@@ -35,7 +35,7 @@
 
 int main(int argc, char **argv) {
   try {
-    if(setlocale(LC_CTYPE, "") == NULL)
+    if(setlocale(LC_CTYPE, "") == nullptr)
       throw std::runtime_error(std::string("setlocale: ") + strerror(errno));
 
     // Parse command line
diff --git a/src/test-check.cc b/src/test-check.cc
index f62d175..2e750b3 100644
--- a/src/test-check.cc
+++ b/src/test-check.cc
@@ -27,7 +27,7 @@ static bool result;
 
 static void *background(void *) {
   result = check("%s", "spong");
-  return NULL;
+  return nullptr;
 }
 
 /* We can't use stdio here because reading from an unbuffered file causes a
@@ -58,14 +58,14 @@ static char *fd_fgets(char buffer[], size_t bufsize, int fd) {
       break;
   }
   buffer[index] = 0;
-  return ch < 0 ? NULL : buffer;
+  return ch < 0 ? nullptr : buffer;
 }
 
 static void test(const char *typed, const char *typed2, bool expect) {
   pthread_t tid;
   char buffer[1024];
 
-  assert(pthread_create(&tid, NULL, background, NULL) == 0);
+  assert(pthread_create(&tid, nullptr, background, nullptr) == 0);
   assert(fd_fgets(buffer, sizeof buffer, output));
   assert(std::string(buffer) == "spong\n");
   assert(fd_getc(output) == 'y');
@@ -96,7 +96,7 @@ static void test(const char *typed, const char *typed2, bool expect) {
     assert(fflush(input) >= 0);
   }
 
-  assert(pthread_join(tid, NULL) == 0);
+  assert(pthread_join(tid, nullptr) == 0);
   assert(result == expect);
 }
 
@@ -104,8 +104,8 @@ static void test_force(void) {
   pthread_t tid;
 
   command.force = true;
-  assert(pthread_create(&tid, NULL, background, NULL) == 0);
-  assert(pthread_join(tid, NULL) == 0);
+  assert(pthread_create(&tid, nullptr, background, nullptr) == 0);
+  assert(pthread_join(tid, nullptr) == 0);
   assert(result == true);
   command.force = false;
 }
@@ -122,8 +122,8 @@ int main() {
   assert((input = fdopen(i[1], "w")));
   output = o[0];
 
-  test("yes", NULL, true);
-  test("no", NULL, false);
+  test("yes", nullptr, true);
+  test("no", nullptr, false);
   test("", "yes", true);
   test("whatever", "yes", true);
   test_force();
diff --git a/src/test-command.cc b/src/test-command.cc
index b97fdc4..760dca6 100644
--- a/src/test-command.cc
+++ b/src/test-command.cc
@@ -20,7 +20,7 @@
 #include <cassert>
 
 static void test_action_backup(void) {
-  static const char *argv[] = { "rsbackup", "--backup", NULL };
+  static const char *argv[] = { "rsbackup", "--backup", nullptr };
   Command c;
   assert(c.backup == false);
   c.parse(2, argv);
@@ -28,34 +28,34 @@ static void test_action_backup(void) {
 }
 
 static void test_action_html(void) {
-  static const char *argv[] = { "rsbackup", "--html", "PATH", NULL };
+  static const char *argv[] = { "rsbackup", "--html", "PATH", nullptr };
   Command c;
-  assert(c.html == NULL);
+  assert(c.html == nullptr);
   c.parse(3, argv);
-  assert(c.html != NULL);
+  assert(c.html != nullptr);
   assert(*c.html == "PATH");
 }
 
 static void test_action_text(void) {
-  static const char *argv[] = { "rsbackup", "--text", "PATH", NULL };
+  static const char *argv[] = { "rsbackup", "--text", "PATH", nullptr };
   Command c;
-  assert(c.text == NULL);
+  assert(c.text == nullptr);
   c.parse(3, argv);
-  assert(c.text != NULL);
+  assert(c.text != nullptr);
   assert(*c.text == "PATH");
 }
 
 static void test_action_email(void) {
-  static const char *argv[] = { "rsbackup", "--email", "user@domain", NULL };
+  static const char *argv[] = { "rsbackup", "--email", "user@domain", nullptr };
   Command c;
-  assert(c.email == NULL);
+  assert(c.email == nullptr);
   c.parse(3, argv);
-  assert(c.email != NULL);
+  assert(c.email != nullptr);
   assert(*c.email == "user@domain");
 }
 
 static void test_action_prune(void) {
-  static const char *argv[] = { "rsbackup", "--prune", NULL };
+  static const char *argv[] = { "rsbackup", "--prune", nullptr };
   Command c;
   assert(c.prune == false);
   c.parse(2, argv);
@@ -63,7 +63,7 @@ static void test_action_prune(void) {
 }
 
 static void test_action_prune_incomplete(void) {
-  static const char *argv[] = { "rsbackup", "--prune-incomplete", NULL };
+  static const char *argv[] = { "rsbackup", "--prune-incomplete", nullptr };
   Command c;
   assert(c.pruneIncomplete == false);
   c.parse(2, argv);
@@ -71,7 +71,7 @@ static void test_action_prune_incomplete(void) {
 }
 
 static void test_action_retire(void) {
-  static const char *argv[] = { "rsbackup", "--retire", "VOLUME", NULL };
+  static const char *argv[] = { "rsbackup", "--retire", "VOLUME", nullptr };
   Command c;
   assert(c.retire == false);
   c.parse(3, argv);
@@ -88,7 +88,7 @@ static void test_action_retire(void) {
 }
 
 static void test_action_retire_device(void) {
-  static const char *argv[] = { "rsbackup", "--retire-device", "DEVICE", NULL };
+  static const char *argv[] = { "rsbackup", "--retire-device", "DEVICE", nullptr };
   Command c;
   assert(c.retireDevice == false);
   c.parse(3, argv);
@@ -106,7 +106,7 @@ static void test_action_retire_device(void) {
 }
 
 static void test_action_dump_config(void) {
-  static const char *argv[] = { "rsbackup", "--dump-config", "JUNK", NULL };
+  static const char *argv[] = { "rsbackup", "--dump-config", "JUNK", nullptr };
   Command c;
   assert(c.dumpConfig == false);
   c.parse(2, argv);
@@ -122,7 +122,7 @@ static void test_action_dump_config(void) {
 }
 
 static void test_action_none(void) {
-  static const char *argv[] = { "rsbackup", NULL };
+  static const char *argv[] = { "rsbackup", nullptr };
   Command c;
   try {
     c.parse(1, argv);
@@ -133,7 +133,7 @@ static void test_action_none(void) {
 
 static void test_action_incompatible(void) {
   try {
-    static const char *argv[] = { "rsbackup", "--retire", "--retire-device", "XYZ", NULL };
+    static const char *argv[] = { "rsbackup", "--retire", "--retire-device", "XYZ", nullptr };
     Command c;
     c.parse(4, argv);
     assert(!"unexpectedly succeeded");
@@ -142,7 +142,7 @@ static void test_action_incompatible(void) {
            != std::string::npos);
   }
   try {
-    static const char *argv[] = { "rsbackup", "--retire", "--backup", "XYZ", NULL };
+    static const char *argv[] = { "rsbackup", "--retire", "--backup", "XYZ", nullptr };
     Command c;
     c.parse(4, argv);
     assert(!"unexpectedly succeeded");
@@ -151,7 +151,7 @@ static void test_action_incompatible(void) {
            != std::string::npos);
   }
   try {
-    static const char *argv[] = { "rsbackup", "--retire-device", "--backup", "XYZ", NULL };
+    static const char *argv[] = { "rsbackup", "--retire-device", "--backup", "XYZ", nullptr };
     Command c;
     c.parse(4, argv);
     assert(!"unexpectedly succeeded");
@@ -160,7 +160,7 @@ static void test_action_incompatible(void) {
            != std::string::npos);
   }
   try {
-    static const char *argv[] = { "rsbackup", "--dump-config", "--backup", "XYZ", NULL };
+    static const char *argv[] = { "rsbackup", "--dump-config", "--backup", "XYZ", nullptr };
     Command c;
     c.parse(4, argv);
     assert(!"unexpectedly succeeded");
@@ -174,7 +174,7 @@ static void test_action_incompatible(void) {
 static void test_selection(void) {
   {
     static const char *argv[] = { "rsbackup", "--backup", "A", "-A:B", "!C",
-                                  NULL };
+                                  nullptr };
     Command c;
     c.parse(5, argv);
     assert(c.backup == true);
@@ -192,7 +192,7 @@ static void test_selection(void) {
 
   try {
     static const char *argv[] = { "rsbackup", "--backup", "~A",
-                                  NULL };
+                                  nullptr };
     Command c;
     c.parse(3, argv);
     assert(!"unexpectedly succeeded");
@@ -201,7 +201,7 @@ static void test_selection(void) {
 
   try {
     static const char *argv[] = { "rsbackup", "--backup", "A:~",
-                                  NULL };
+                                  nullptr };
     Command c;
     c.parse(3, argv);
     assert(!"unexpectedly succeeded");
@@ -210,7 +210,7 @@ static void test_selection(void) {
 
   try {
     static const char *argv[] = { "rsbackup", "--backup", "A:B:C",
-                                  NULL };
+                                  nullptr };
     Command c;
     c.parse(3, argv);
     assert(!"unexpectedly succeeded");
@@ -219,7 +219,7 @@ static void test_selection(void) {
 
   try {
     static const char *argv[] = { "rsbackup", "--backup", "*:C",
-                                  NULL };
+                                  nullptr };
     Command c;
     c.parse(3, argv);
     assert(!"unexpectedly succeeded");