diff -Nru clamz-0.3/clamz.1 clamz-0.4/clamz.1
--- clamz-0.3/clamz.1	2010-04-01 03:59:38.000000000 +0100
+++ clamz-0.4/clamz.1	2010-05-01 03:37:41.000000000 +0100
@@ -1,4 +1,4 @@
-.TH clamz 1 "March 2010" "Clamz 0.3"
+.TH clamz 1 "April 2010" "Clamz 0.4"
 .SH NAME
 clamz \- download MP3 music files from Amazon.com
 .SH SYNOPSIS
@@ -90,8 +90,14 @@
 
 .SS FORMAT VARIABLES
 As part of a \fIname-format\fR or \fIdirectory-format\fR option, you
-may include references to environment variables (e.g., \fB$HOME\fR) as
-well as any of the following special variables:
+may include references to environment variables (e.g., \fB$HOME\fR) or
+to the `xdg-user-dirs' configuration variables (e.g.,
+\fB$XDG_MUSIC_DIR\fR or \fB$XDG_DESKTOP_DIR\fR.)
+
+In addition, the following special variables are defined for each
+track, based on the information provided in the AMZ file, and subject
+to the above configuration options (\fB--forbid-chars\fR,
+\fB--forbid-uppercase\fR, etc.)
 .TP
 \fB${title}\fR, \fB${creator}\fR, \fB${tracknum}\fR, \fB${discnum}\fR, \fB${genre}\fR, \fB${asin}\fR
 Title, creator, track number, disc number, genre, and ASIN (Amazon
@@ -109,6 +115,18 @@
 These variables formerly contained metadata for the AMZ file as a
 whole; current AMZ files do not contain this information.  Using these
 variables is not recommended.
+.PP
+Similar to shell variable expansion, you can also use the following
+conditional expressions:
+.TP
+\fB${\fIvar\fB:-\fIstring\fB}\fR
+Expands to the value of variable \fIvar\fR if it is defined and
+non-empty; otherwise, expands to \fIstring\fR (which may itself
+contain variable references.)
+.TP
+\fB${\fIvar\fB:+\fIstring\fB}\fR
+Expands to \fIstring\fR if the variable \fIvar\fR is defined and
+non-empty; otherwise, expands to an empty string.
 
 .SH FILES
 .TP
@@ -119,6 +137,9 @@
 .TP
 $HOME/.clamz/amzfiles/
 Directory containing backup copies of AMZ files.
+.TP
+$HOME/.clamz/logs/
+Directory containing log files.
 
 .SH ENVIRONMENT
 .TP
diff -Nru clamz-0.3/clamz.c clamz-0.4/clamz.c
--- clamz-0.3/clamz.c	2010-04-01 01:42:54.000000000 +0100
+++ clamz-0.4/clamz.c	2010-05-01 03:15:01.000000000 +0100
@@ -25,6 +25,7 @@
 #include <string.h>
 #include <stdarg.h>
 #include <unistd.h>
+#include <ctype.h>
 
 #include <locale.h>
 #include <langinfo.h>
@@ -96,16 +97,29 @@
   }
 }
 
+static const char *getbasename(const char *fname)
+{
+  const char *b;
+
+  while ((b = strchr(fname, '/')))
+    fname = b + 1;
+
+  return fname;
+}
+
 static int run_amz_file(clamz_downloader *dl,
 			const clamz_config *cfg,
 			FILE *amzfile,
 			const char *fname)
 {
   char *inbuf;
+  unsigned char *xml;
   size_t sz;
   clamz_playlist *pl;
   int i;
   int status, rv = 0;
+  char *logname;
+  FILE *logfile;
 
   sz = 0;
   inbuf = NULL;
@@ -122,8 +136,7 @@
     fclose(amzfile);
 
   if (cfg->printonly && cfg->printasxml) {
-    unsigned char *xml = decrypt_amz_file(inbuf, sz, fname);
-
+    xml = decrypt_amz_file(inbuf, sz, fname);
     if (!xml) {
       free(inbuf);
       return 2;
@@ -133,11 +146,10 @@
     free(xml);
     free(inbuf);
     return 0;
-
-  } else {
-
+  }
+  else {
     if (!cfg->printonly) {
-      if (write_backup_file(inbuf, sz, fname)) {
+      if (write_backup_file(inbuf, sz, getbasename(fname))) {
         free(inbuf);
         return 3;
       }
@@ -151,9 +163,30 @@
       return 2;
     }
 
+    if (!cfg->printonly) {
+      logname = get_config_file_name("logs", getbasename(fname), ".log");
+      if (!logname) {
+        free(inbuf);
+	return 1;
+      }
+
+      logfile = fopen(logname, "w");
+      if (!logfile) {
+	perror(logname);
+	free(logname);
+        free(inbuf);
+	return 3;
+      }
+
+      free(logname);
+      set_download_log_file(dl, logfile);
+    }
+    else {
+      logfile = NULL;
+    }
+
     if (cfg->printonly || cfg->verbose)
       print_pl_info(pl, fname);
-  
 
     for (i = 0; i < pl->num_tracks; i++) {
       if (cfg->printonly || cfg->verbose)
@@ -165,12 +198,105 @@
       fputc('\n', stderr);
     }
 
+    set_download_log_file(dl, NULL);
+
     free(inbuf);
     free_playlist(pl);
+    if (logfile)
+      fclose(logfile);
     return rv;
   }
 }
 
+/* Parse XDG user-dirs configuration file and set environment
+   variables (XDG_DESKTOP_DIR, XDG_MUSIC_DIR, etc.) */
+static void set_xdg_user_dirs()
+{
+  const char *p, *q, *home;
+  char *cfgfname;
+  FILE *cfgfile;
+  char buf[1024];
+  char *envstr;
+
+  home = getenv("HOME");
+  if (!home)
+    return;
+
+  if ((p = getenv("XDG_CONFIG_HOME"))) {
+    cfgfname = strdup(p);
+    if (!cfgfname)
+      return;
+  }
+  else {
+    cfgfname = strdup(home);
+    if (!cfgfname)
+      return;
+    if (concatenate(&cfgfname, "/.config", strlen("/.config"))) {
+      free(cfgfname);
+      return;
+    }
+  }
+
+  if (concatenate(&cfgfname, "/user-dirs.dirs", strlen("/user-dirs.dirs"))) {
+    free(cfgfname);
+    return;
+  }
+
+  cfgfile = fopen(cfgfname, "r");
+  free(cfgfname);
+  if (!cfgfile)
+    return;
+
+  while (fgets(buf, sizeof(buf), cfgfile)) {
+    p = buf;
+    while (*p == ' ' || *p == '\t')
+      p++;
+    if (strncmp(p, "XDG_", 4))
+      continue;
+
+    q = p;
+    while (isalnum((int) (unsigned char) *q) || *q == '_')
+      q++;
+    if (q == p || q[0] != '=' || q[1] != '"')
+      continue;
+
+    q++;
+    envstr = NULL;
+    if (concatenate(&envstr, p, q - p)) {
+      free(envstr);
+      fclose(cfgfile);
+      return;
+    }
+
+    q++;
+    if (!strncmp(q, "$HOME", 5)) {
+      if (concatenate(&envstr, home, strlen(home))) {
+	free(envstr);
+	fclose(cfgfile);
+	return;
+      }
+      q += 5;
+    }
+
+    while (*q && *q != '"') {
+      if (q[0] == '\\' && q[1])
+	q++;
+      if (concatenate(&envstr, q, 1)) {
+	free(envstr);
+	fclose(cfgfile);
+	return;
+      }
+      q++;
+    }
+
+    putenv(envstr);
+  }
+
+  fclose(cfgfile);
+}
+
+static int utf8locale;
+
 int main(int argc, char **argv)
 {
   clamz_config cfg;
@@ -193,9 +319,11 @@
   setlocale(LC_ALL, "");
   str = nl_langinfo(CODESET);
   if (!strcasecmp(str, "UTF-8") || !strcasecmp(str, "UTF8"))
-    cfg.utf8locale = 1;
+    utf8locale = cfg.utf8locale = 1;
   else
-    cfg.utf8locale = 0;
+    utf8locale = cfg.utf8locale = 0;
+
+  set_xdg_user_dirs();
 
   if (parse_args(&argc, argv, &cfg)) {
     if (cfg.output_dir) free(cfg.output_dir);
@@ -298,7 +426,7 @@
 void print_progress(const clamz_track *tr, const char *filename,
 		    int progress)
 {
-  int i;
+  int i, j;
   const char *name;
 
   fputc('\r', stderr);
@@ -308,8 +436,23 @@
   else
     name = filename;
 
-  for (i = 0; i < 32 && name[i]; i++)
-    fputc(name[i], stderr);
+  for (i = j = 0; i < 32 && name[j]; i++) {
+    if ((unsigned char) name[j] & 0x80) {
+      if (!utf8locale)
+	fputc('?', stderr);
+
+      do {
+	if (utf8locale)
+	  fputc(name[j], stderr);
+	j++;
+      } while (((unsigned char) name[j] & 0xc0) == 0x80);
+    }
+    else {
+      fputc(name[j], stderr);
+      j++;
+    }
+  }
+
   for (; i < 32; i++)
     fputc(' ', stderr);
 
diff -Nru clamz-0.3/clamz.desktop clamz-0.4/clamz.desktop
--- clamz-0.3/clamz.desktop	2010-04-01 04:18:04.000000000 +0100
+++ clamz-0.4/clamz.desktop	2010-04-30 03:52:29.000000000 +0100
@@ -2,7 +2,7 @@
 Encoding=UTF-8
 Name=Clamz MP3 Downloader (command-line)
 Comment=Download MP3 files from AmazonMP3.com
-Exec=clamz "--default-output-dir=\\$HOME/Music/\\${album_artist}/\\${album}"
+Exec=clamz "--default-output-dir=\\${XDG_MUSIC_DIR:-\\$HOME/Music}/\\${album_artist}/\\${album}"
 Terminal=true
 Type=Application
 Categories=Network;
diff -Nru clamz-0.3/clamz.h clamz-0.4/clamz.h
--- clamz-0.3/clamz.h	2010-03-31 10:48:44.000000000 +0100
+++ clamz-0.4/clamz.h	2010-04-22 18:14:37.000000000 +0100
@@ -100,12 +100,18 @@
 		      const char *fname);
 
 /* options.c */
-char *get_config_file_name(const char *name);
+char *get_config_file_name(const char *subdir, const char *name,
+			   const char *suffix);
 int parse_args(int *argc, char **argv, clamz_config *cfg);
 
+/* vars.c */
+int expand_file_name(const clamz_config *cfg, const clamz_track *tr,
+		     char **filename, const char *format);
+
 /* download.c */
 clamz_downloader *new_downloader(const clamz_config *cfg);
 void free_downloader(clamz_downloader *dl);
+void set_download_log_file(clamz_downloader *dl, FILE *log);
 int download_track(clamz_downloader *dl, clamz_track *tr);
 
 /* clamz.c */
diff -Nru clamz-0.3/configure clamz-0.4/configure
--- clamz-0.3/configure	2010-04-01 02:17:45.000000000 +0100
+++ clamz-0.4/configure	2010-04-29 04:57:49.000000000 +0100
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.65 for Clamz 0.3.
+# Generated by GNU Autoconf 2.65 for Clamz 0.4.
 #
 # Report bugs to <floppusmaximus@users.sf.net>.
 #
@@ -552,8 +552,8 @@
 # Identity of this package.
 PACKAGE_NAME='Clamz'
 PACKAGE_TARNAME='clamz'
-PACKAGE_VERSION='0.3'
-PACKAGE_STRING='Clamz 0.3'
+PACKAGE_VERSION='0.4'
+PACKAGE_STRING='Clamz 0.4'
 PACKAGE_BUGREPORT='floppusmaximus@users.sf.net'
 PACKAGE_URL=''
 
@@ -1218,7 +1218,7 @@
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures Clamz 0.3 to adapt to many kinds of systems.
+\`configure' configures Clamz 0.4 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1279,7 +1279,7 @@
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of Clamz 0.3:";;
+     short | recursive ) echo "Configuration of Clamz 0.4:";;
    esac
   cat <<\_ACEOF
 
@@ -1384,7 +1384,7 @@
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-Clamz configure 0.3
+Clamz configure 0.4
 generated by GNU Autoconf 2.65
 
 Copyright (C) 2009 Free Software Foundation, Inc.
@@ -1649,7 +1649,7 @@
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by Clamz $as_me 0.3, which was
+It was created by Clamz $as_me 0.4, which was
 generated by GNU Autoconf 2.65.  Invocation command line was
 
   $ $0 $@
@@ -4515,7 +4515,7 @@
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by Clamz $as_me 0.3, which was
+This file was extended by Clamz $as_me 0.4, which was
 generated by GNU Autoconf 2.65.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -4577,7 +4577,7 @@
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-Clamz config.status 0.3
+Clamz config.status 0.4
 configured by $0, generated by GNU Autoconf 2.65,
   with options \\"\$ac_cs_config\\"
 
diff -Nru clamz-0.3/configure.ac clamz-0.4/configure.ac
--- clamz-0.3/configure.ac	2009-07-18 02:58:59.000000000 +0100
+++ clamz-0.4/configure.ac	2010-04-29 04:57:42.000000000 +0100
@@ -1,5 +1,5 @@
 AC_PREREQ(2.61)
-AC_INIT([Clamz], [0.3], [floppusmaximus@users.sf.net])
+AC_INIT([Clamz], [0.4], [floppusmaximus@users.sf.net])
 AC_CONFIG_SRCDIR([clamz.h])
 AC_CONFIG_HEADER([config.h])
 
diff -Nru clamz-0.3/debian/changelog clamz-0.4/debian/changelog
--- clamz-0.3/debian/changelog	2010-04-11 09:49:22.000000000 +0100
+++ clamz-0.4/debian/changelog	2010-05-23 18:44:12.000000000 +0100
@@ -1,3 +1,10 @@
+clamz (0.4-1) lucid; urgency=low
+
+  * New upstream release
+  * added libgcrypt11, libcurl3, libexpat1 as dependencies
+
+ -- Dabang <dabang@funzt.info>  Sat, 23 May 2010 19:32:00 +0200
+
 clamz (0.3-2) lucid; urgency=low
 
   * Added patch to remove update-mime-database and update-desktop-
diff -Nru clamz-0.3/debian/control clamz-0.4/debian/control
--- clamz-0.3/debian/control	2010-04-11 09:25:30.000000000 +0100
+++ clamz-0.4/debian/control	2010-05-23 18:44:12.000000000 +0100
@@ -8,6 +8,6 @@
 
 Package: clamz
 Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}, shared-mime-info, desktop-file-utils
+Depends: ${shlibs:Depends}, ${misc:Depends}, shared-mime-info, desktop-file-utils, libgcrypt11, libcurl3, libexpat1
 Description: Clamz is a little command-line program to download MP3 files from Amazon.com's music store
  Clamz is a little command-line program to download MP3 files from Amazon.com's music store. It is intended to serve as a substitute for Amazon's official MP3 Downloader, which is not free software (and therefore is only available in binary form for a limited set of platforms.) Clamz can be used to download either individual songs or complete albums that you have purchased from Amazon.
diff -Nru clamz-0.3/debian/patches/01_Makefile.dpatch clamz-0.4/debian/patches/01_Makefile.dpatch
--- clamz-0.3/debian/patches/01_Makefile.dpatch	2010-04-10 19:04:20.000000000 +0100
+++ clamz-0.4/debian/patches/01_Makefile.dpatch	2010-05-23 18:52:49.000000000 +0100
@@ -1,14 +1,14 @@
 #! /bin/sh /usr/share/dpatch/dpatch-run
-## 01_Makefile.dpatch by Dabang <dabang@funzt.info>
+## 01_Makefile.dpatch by  <dabang@funzt.info>
 ##
 ## All lines beginning with `## DP:' are a description of the patch.
-## DP: removing 'update-mime database' from makefile
+## DP: removing update-mime-database and update-desktop-database from makefile.
 
 @DPATCH@
-diff -urNad clamz-0.3~/Makefile.in clamz-0.3/Makefile.in
---- clamz-0.3~/Makefile.in	2010-04-01 03:30:17.000000000 +0200
-+++ clamz-0.3/Makefile.in	2010-04-10 20:01:56.067907980 +0200
-@@ -67,12 +67,12 @@
+diff -urNad clamz-0.4~/Makefile.in clamz-0.4/Makefile.in
+--- clamz-0.4~/Makefile.in	2010-04-29 05:49:49.000000000 +0200
++++ clamz-0.4/Makefile.in	2010-05-23 19:49:59.459750780 +0200
+@@ -70,12 +70,12 @@
  install-desktop:
  	$(INSTALL) -d -m 755 $(DESTDIR)$(applications_dir)
  	$(INSTALL) -m 644 $(srcdir)/clamz.desktop $(DESTDIR)$(applications_dir)
@@ -23,7 +23,7 @@
  
  ## Uninstallation ##
  
-@@ -84,11 +84,11 @@
+@@ -87,11 +87,11 @@
  
  uninstall-desktop:
  	rm -f $(DESTDIR)$(applications_dir)/clamz.desktop
diff -Nru clamz-0.3/debian/tmp/DEBIAN/control clamz-0.4/debian/tmp/DEBIAN/control
--- clamz-0.3/debian/tmp/DEBIAN/control	2010-04-11 09:51:32.000000000 +0100
+++ clamz-0.4/debian/tmp/DEBIAN/control	2010-05-23 18:53:43.000000000 +0100
@@ -1,8 +1,8 @@
 Package: clamz
-Version: 0.3-2
-Architecture: i386
+Version: 0.4-1
+Architecture: amd64
 Maintainer: Dabang <dabang@funzt.info>
-Installed-Size: 116
+Installed-Size: 120
 Depends: libc6 (>= 2.4), libcurl3 (>= 7.16.2-1), libexpat1 (>= 1.95.8), libgcrypt11 (>= 1.4.2), shared-mime-info, desktop-file-utils
 Section: misc
 Priority: extra
diff -Nru clamz-0.3/debian/tmp/DEBIAN/md5sums clamz-0.4/debian/tmp/DEBIAN/md5sums
--- clamz-0.3/debian/tmp/DEBIAN/md5sums	2010-04-11 09:51:32.000000000 +0100
+++ clamz-0.4/debian/tmp/DEBIAN/md5sums	2010-05-23 18:53:43.000000000 +0100
@@ -1,8 +1,8 @@
-9602a26c2524016e375556bd3bc246fa  usr/share/doc/clamz/changelog.Debian.gz
+84e367a34879f441b4847b6259fd3eea  usr/share/man/man1/clamz.1.gz
+746c37fcf17db3cf16686655f88bd1c5  usr/share/mime/packages/clamz.xml
+17a83548e3c79234e91b4a85a55b903a  usr/share/applications/clamz.desktop
 8d2de7badae35d3c7140c82fa5d25649  usr/share/doc/clamz/COPYING.gz
-6bd13e7e01f7ec54b449b972133ddddb  usr/share/doc/clamz/README.gz
+4c2d1507b4cbbb3aa8c2ad4a64377c8e  usr/share/doc/clamz/README.gz
 5ebb5e6ed7d1f1eeed39875a50479925  usr/share/doc/clamz/copyright
-746c37fcf17db3cf16686655f88bd1c5  usr/share/mime/packages/clamz.xml
-62393c284b30d2bbecd23a606baf5eae  usr/share/man/man1/clamz.1.gz
-309b539a5df27c985c9b28d952f1202b  usr/share/applications/clamz.desktop
-e0e22ccd20f3d78ad2d790d841ff8473  usr/bin/clamz
+467e74ed6fac873ea5362ba680eeb22d  usr/share/doc/clamz/changelog.Debian.gz
+443a5f6281dc0836dba58ede377a481b  usr/bin/clamz
Binary files /tmp/P7EYdUAptB/clamz-0.3/debian/tmp/usr/bin/clamz and /tmp/12YaUe11qM/clamz-0.4/debian/tmp/usr/bin/clamz differ
diff -Nru clamz-0.3/debian/tmp/usr/share/applications/clamz.desktop clamz-0.4/debian/tmp/usr/share/applications/clamz.desktop
--- clamz-0.3/debian/tmp/usr/share/applications/clamz.desktop	2010-04-11 09:51:22.000000000 +0100
+++ clamz-0.4/debian/tmp/usr/share/applications/clamz.desktop	2010-05-23 18:53:39.000000000 +0100
@@ -2,7 +2,7 @@
 Encoding=UTF-8
 Name=Clamz MP3 Downloader (command-line)
 Comment=Download MP3 files from AmazonMP3.com
-Exec=clamz "--default-output-dir=\\$HOME/Music/\\${album_artist}/\\${album}"
+Exec=clamz "--default-output-dir=\\${XDG_MUSIC_DIR:-\\$HOME/Music}/\\${album_artist}/\\${album}"
 Terminal=true
 Type=Application
 Categories=Network;
Binary files /tmp/P7EYdUAptB/clamz-0.3/debian/tmp/usr/share/doc/clamz/changelog.Debian.gz and /tmp/12YaUe11qM/clamz-0.4/debian/tmp/usr/share/doc/clamz/changelog.Debian.gz differ
Binary files /tmp/P7EYdUAptB/clamz-0.3/debian/tmp/usr/share/doc/clamz/README.gz and /tmp/12YaUe11qM/clamz-0.4/debian/tmp/usr/share/doc/clamz/README.gz differ
Binary files /tmp/P7EYdUAptB/clamz-0.3/debian/tmp/usr/share/man/man1/clamz.1.gz and /tmp/12YaUe11qM/clamz-0.4/debian/tmp/usr/share/man/man1/clamz.1.gz differ
diff -Nru clamz-0.3/download.c clamz-0.4/download.c
--- clamz-0.3/download.c	2010-04-01 04:40:37.000000000 +0100
+++ clamz-0.4/download.c	2010-04-22 18:20:40.000000000 +0100
@@ -27,7 +27,6 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/stat.h>
-#include <ctype.h>
 
 #include <curl/curl.h>
 
@@ -40,6 +39,9 @@
   int outfd;
   clamz_track *track;
   int last_progress;
+  curl_off_t startpos;
+  char error_buf[CURL_ERROR_SIZE];
+  FILE *log_file;
 };
 
 /* Initialize downloader state */
@@ -47,6 +49,7 @@
 {
   clamz_downloader *dl = malloc(sizeof(clamz_downloader));
   char *cookiejar;
+  char useragent[100];
 
   if (!dl) {
     print_error("Out of memory");
@@ -62,13 +65,16 @@
       return NULL;
     }
 
+    curl_easy_setopt(dl->curl, CURLOPT_ERRORBUFFER, dl->error_buf);
     curl_easy_setopt(dl->curl, CURLOPT_NOPROGRESS, 0L);
     curl_easy_setopt(dl->curl, CURLOPT_FAILONERROR, 1L);
     curl_easy_setopt(dl->curl, CURLOPT_FOLLOWLOCATION, 1L);
     curl_easy_setopt(dl->curl, CURLOPT_COOKIEFILE, "");
-    curl_easy_setopt(dl->curl, CURLOPT_USERAGENT, PACKAGE_STRING);
 
-    cookiejar = get_config_file_name("cookies");
+    sprintf(useragent, "Amazon MP3 Downloader (%s)", PACKAGE_STRING);
+    curl_easy_setopt(dl->curl, CURLOPT_USERAGENT, useragent);
+
+    cookiejar = get_config_file_name(NULL, "cookies", NULL);
     if (cookiejar) {
       curl_easy_setopt(dl->curl, CURLOPT_COOKIEJAR, cookiejar);
       free(cookiejar);
@@ -96,176 +102,59 @@
   free(dl);
 }
 
-/* Convert a string according to user's preferences */
-static char *convert_string(const clamz_config *cfg, const char *s)
+/* Callback for debug info logging */
+static int write_debug_info(CURL *curl UNUSED, curl_infotype type, char *text,
+			    size_t length, void *data)
 {
-  const unsigned char *us = (const unsigned char*) s;
-  char *converted;
-  int len;
-  int i, j;
+  clamz_downloader *dl = data;
 
-  len = strlen(s) + 1;
-  converted = malloc(len * sizeof(char));
+  if (dl->log_file) {
+    switch (type) {
+    case CURLINFO_TEXT:
+      fprintf(dl->log_file, "* ");
+      fwrite(text, 1, length, dl->log_file);
+      fflush(dl->log_file);
+      break;
 
-  if (!converted) {
-    print_error("Out of memory");
-    return NULL;
-  }
+    case CURLINFO_HEADER_IN:
+      fprintf(dl->log_file, "< ");
+      fwrite(text, 1, length, dl->log_file);
+      fflush(dl->log_file);
+      break;
 
-  i = j = 0;
-  while (s[i]) {
-    if (j >= len - 1) {
-      len *= 2;
-      converted = realloc(converted, len * sizeof(char));
-
-      if (!converted) {
-	print_error("Out of memory");
-	return NULL;
-      }
-    }
+    case CURLINFO_HEADER_OUT:
+      fprintf(dl->log_file, "> ");
+      fwrite(text, 1, length, dl->log_file);
+      fflush(dl->log_file);
+      break;
 
-    if (us[i] & 0x80) {
-      if (cfg->allowutf8) {
-	converted[j++] = s[i++];
-      }
-      else {
-	converted[j++] = '_';
-	do
-	  i++;
-	while (((unsigned char) s[i] & 0xc0) == 0x80);
-      }
-    }
-    else if (s[i] == '/' || iscntrl(us[i])) {
-      converted[j++] = '_';
-      i++;
-    }
-    else if (isupper(us[i]) && !cfg->allowupper) {
-      converted[j++] = tolower(s[i++]);
-    }
-    else if (cfg->forbid_chars && strchr(cfg->forbid_chars, s[i])) {
-      converted[j++] = '_';
-      i++;
-    }
-    else {
-      converted[j++] = s[i++];
+    default:
+      /* ignore other types of log message */
+      break;
     }
   }
 
-  converted[j] = 0;
-
-  return converted;
+  return 0;
 }
 
-static int append_subst_str(char **filename, const char *format,
-			    clamz_downloader *dl)
+/* Write curl log to given file */
+void set_download_log_file(clamz_downloader *dl, FILE *log)
 {
-  const char *p, *q;
-  const char *f = format;
-  const char *value;
-  char *var, *converted;
-  int subst_raw;
-
-  while (*f) {
-    if ((p = strchr(f, '$'))) {
-      if (p != f
-	  && concatenate(filename, f, p - f))
-	return 1;
-
-      p++;
-      if (*p == '{') {
-	p++;
-	q = strchr(p, '}');
-	if (!q) {
-	  print_error("Invalid variable reference in '%s'", format);
-	  return 1;
-	}
-	f = q + 1;
-      }
-      else {
-	q = p;
-	while (isalnum((int) (unsigned char) *q) || *q == '_')
-	  q++;
-	f = q;
-      }
+  dl->log_file = log;
 
-      subst_raw = 0;
-
-      if (p == q)
-	value = "$";
-      else {
-	var = NULL;
-	if (concatenate(&var, p, q - p))
-	  return 1;
-
-	if (!strcasecmp(var, "title"))
-	  value = dl->track->title;
-	else if (!strcasecmp(var, "creator"))
-	  value = dl->track->creator;
-	else if (!strcasecmp(var, "album"))
-	  value = dl->track->album;
-	else if (!strcasecmp(var, "tracknum")) {
-	  value = dl->track->trackNum;
-	  if (value[0] && !value[1]) {
-	    if (concatenate(filename, "0", 1))
-	      return 1;
-	  }
-	}
-	else if (!strcasecmp(var, "album_artist"))
-	  value = find_meta(dl->track->meta, TMETA_ALBUM_ARTIST);
-	else if (!strcasecmp(var, "genre"))
-	  value = find_meta(dl->track->meta, TMETA_GENRE);
-	else if (!strcasecmp(var, "discnum"))
-	  value = find_meta(dl->track->meta, TMETA_DISC_NUM);
-	else if (!strcasecmp(var, "suffix")) {
-	  value = find_meta(dl->track->meta, TMETA_TRACK_TYPE);
-	  if (!value)
-	    value = "mp3";
-	}
-	else if (!strcasecmp(var, "asin"))
-	  value = find_meta(dl->track->meta, TMETA_ASIN);
-	else if (!strcasecmp(var, "album_asin"))
-	  value = find_meta(dl->track->meta, TMETA_ALBUM_ASIN);
-	else if (!strcasecmp(var, "amz_title"))
-	  value = dl->track->playlist->title;
-	else if (!strcasecmp(var, "amz_creator"))
-	  value = dl->track->playlist->creator;
-	else if (!strcasecmp(var, "amz_asin"))
-	  value = find_meta(dl->track->playlist->meta, PMETA_ASIN);
-	else if (!strcasecmp(var, "amz_genre"))
-	  value = find_meta(dl->track->playlist->meta, PMETA_GENRE);
-	else {
-	  value = getenv(var);
-	  subst_raw = 1;
-	}
-
-	free(var);
-      }
-
-      if (value) {
-	if (subst_raw) {
-	  if (concatenate(filename, value, strlen(value)))
-	    return 1;
-	}
-	else {
-	  converted = convert_string(dl->cfg, value);
-	  if (!converted)
-	    return 1;
-	  if (concatenate(filename, converted, strlen(converted))) {
-	    free(converted);
-	    return 1;
-	  }
-	  free(converted);
-	}
-      }
+  if (dl->curl) {
+    if (log) {
+      curl_easy_setopt(dl->curl, CURLOPT_VERBOSE, 1);
+      curl_easy_setopt(dl->curl, CURLOPT_DEBUGFUNCTION, write_debug_info);
+      curl_easy_setopt(dl->curl, CURLOPT_DEBUGDATA, dl);
     }
     else {
-      return concatenate(filename, f, strlen(f));
+      curl_easy_setopt(dl->curl, CURLOPT_VERBOSE, 0);
     }
   }
-
-  return 0;
 }
 
+/* Create parent directories if they do not already exist */
 static int create_parents(char *filename)
 {
   char *p;
@@ -289,7 +178,7 @@
   return 0;
 }
 
-
+/* Callback for writing downloaded data to the output file */
 static size_t write_output(void *ptr, size_t size, size_t n, void *data)
 {
   clamz_downloader *dl = data;
@@ -304,7 +193,7 @@
     return r;
 }
 
-
+/* Callback for displaying progress of transfer */
 static int show_progress(void *data, double dltotal, double dlnow,
 			 double ultotal UNUSED, double ulnow UNUSED)
 {
@@ -314,10 +203,14 @@
   if (dl->cfg->quiet)
     return 0;
 
-  if (dltotal > 0)
+  if (dltotal > 0) {
+    dlnow += dl->startpos;
+    dltotal += dl->startpos;
     progress = (int) (100 * dlnow / dltotal);
-  else
+  }
+  else {
     progress = -1;
+  }
 
   if (progress != dl->last_progress) {
     dl->last_progress = progress;
@@ -332,7 +225,6 @@
   int i;
   char *s;
   CURLcode err;
-  off_t startpos;
 
   if (!tr->location) {
     print_error("No URL provided for this track");
@@ -348,17 +240,18 @@
   /* ignore output_dir if name_format is an absolute path */
   if (dl->cfg->output_dir
       && (!dl->cfg->name_format || dl->cfg->name_format[0] != '/')) {
-    if (append_subst_str(&dl->filename, dl->cfg->output_dir, dl))
+    if (expand_file_name(dl->cfg, tr, &dl->filename, dl->cfg->output_dir))
       return 1;
-    if (append_subst_str(&dl->filename, "/", dl))
+    if (expand_file_name(dl->cfg, tr, &dl->filename, "/"))
       return 1;
   }
 
   if (dl->cfg->name_format) {
-    if (append_subst_str(&dl->filename, dl->cfg->name_format, dl))
+    if (expand_file_name(dl->cfg, tr, &dl->filename, dl->cfg->name_format))
       return 1;
   }
-  else {
+
+  if (!dl->filename || !dl->filename[0]) {
     print_error("No output filename specified");
     return 1;
   }
@@ -428,9 +321,8 @@
 
     curl_easy_setopt(dl->curl, CURLOPT_URL, tr->location);
 
-    startpos = lseek(dl->outfd, (off_t) 0, SEEK_END);
-    curl_easy_setopt(dl->curl, CURLOPT_RESUME_FROM_LARGE,
-		     (curl_off_t) startpos);
+    dl->startpos = lseek(dl->outfd, (off_t) 0, SEEK_END);
+    curl_easy_setopt(dl->curl, CURLOPT_RESUME_FROM_LARGE, dl->startpos);
 
     err = curl_easy_perform(dl->curl);
 
@@ -439,7 +331,7 @@
       break;
     }
 
-    if (startpos != 0 && err == CURLE_HTTP_RANGE_ERROR) {
+    if (dl->startpos != 0 && err == CURLE_HTTP_RANGE_ERROR) {
       /* assume that this means we've already downloaded the whole
 	 thing... I guess */
       print_progress(tr, dl->filename, 100);
@@ -447,7 +339,7 @@
       break;
     }
 
-    print_error("Error downloading file: %s", curl_easy_strerror(err));
+    print_error("Error downloading file: %s", dl->error_buf);
     if (i < dl->cfg->maxattempts)
       sleep(2);
 
diff -Nru clamz-0.3/Makefile.in clamz-0.4/Makefile.in
--- clamz-0.3/Makefile.in	2010-04-11 10:02:54.000000000 +0100
+++ clamz-0.4/Makefile.in	2010-05-23 19:04:16.000000000 +0100
@@ -30,7 +30,7 @@
 VPATH = @srcdir@
 
 distname = @PACKAGE_TARNAME@-@PACKAGE_VERSION@
-distfiles = clamz.c playlist.c options.c download.c clamz.h \
+distfiles = clamz.c playlist.c options.c download.c vars.c clamz.h \
 	README COPYING clamz.1 configure install-sh \
 	configure.ac Makefile.in config.h.in \
 	clamz.desktop clamz.xml
@@ -39,8 +39,8 @@
 
 ## Building clamz ##
 
-clamz@EXEEXT@: clamz.@OBJEXT@ options.@OBJEXT@ playlist.@OBJEXT@ download.@OBJEXT@
-	$(link) -o clamz@EXEEXT@ clamz.@OBJEXT@ options.@OBJEXT@ playlist.@OBJEXT@ download.@OBJEXT@ $(LIBGCRYPT_LIBS) $(LIBCURL_LIBS) $(LIBS)
+clamz@EXEEXT@: clamz.@OBJEXT@ options.@OBJEXT@ playlist.@OBJEXT@ download.@OBJEXT@ vars.@OBJEXT@
+	$(link) -o clamz@EXEEXT@ clamz.@OBJEXT@ options.@OBJEXT@ playlist.@OBJEXT@ download.@OBJEXT@ vars.@OBJEXT@ $(LIBGCRYPT_LIBS) $(LIBCURL_LIBS) $(LIBS)
 
 clamz.@OBJEXT@: clamz.c clamz.h config.h
 	$(compile) -c $(srcdir)/clamz.c
@@ -54,6 +54,9 @@
 download.@OBJEXT@: download.c clamz.h config.h
 	$(compile) -c $(srcdir)/download.c
 
+vars.@OBJEXT@: vars.c clamz.h config.h
+	$(compile) -c $(srcdir)/vars.c
+
 ## Installation ##
 
 install: install-clamz install-desktop install-mime
@@ -105,7 +108,7 @@
 
 clean:
 	rm -f clamz@EXEEXT@
-	rm -f clamz.@OBJEXT@ options.@OBJEXT@ playlist.@OBJEXT@ download.@OBJEXT@
+	rm -f clamz.@OBJEXT@ options.@OBJEXT@ playlist.@OBJEXT@ download.@OBJEXT@ vars.@OBJEXT@
 
 distclean: clean
 	rm -rf $(distname)
diff -Nru clamz-0.3/options.c clamz-0.4/options.c
--- clamz-0.3/options.c	2010-04-01 04:38:27.000000000 +0100
+++ clamz-0.4/options.c	2010-04-19 00:28:51.000000000 +0100
@@ -28,15 +28,25 @@
 
 #include "clamz.h"
 
-char *get_config_file_name(const char *name)
+char *get_config_file_name(const char *subdir, const char *base,
+			   const char *suffix)
 {
   char *home = getenv("HOME");
   char *s;
+  int n;
 
-  if (!home)
+  if (!home) {
+    print_error("$HOME not defined");
     return NULL;
+  }
+
+  n = strlen(home) + strlen("/.clamz/") + strlen(base) + 1;
+  if (subdir)
+    n += strlen(subdir) + 1;
+  if (suffix)
+    n += strlen(suffix);
 
-  s = malloc((strlen(home) + strlen(name) + 9) * sizeof(char));
+  s = malloc(n * sizeof(char));
   if (!s) {
     print_error("Out of memory");
     return NULL;
@@ -46,8 +56,17 @@
   strcat(s, "/.clamz");
   mkdir(s, 0775);
 
+  if (subdir) {
+    strcat(s, "/");
+    strcat(s, subdir);
+    mkdir(s, 0775);
+  }
+
   strcat(s, "/");
-  strcat(s, name);
+  strcat(s, base);
+  if (suffix)
+    strcat(s, suffix);
+
   return s;
 }
 
@@ -192,7 +211,7 @@
   int linenum = 0;
   char *p;
 
-  cfgname = get_config_file_name("config");
+  cfgname = get_config_file_name(NULL, "config", NULL);
   if (!cfgname)
     return 1;
 
diff -Nru clamz-0.3/playlist.c clamz-0.4/playlist.c
--- clamz-0.3/playlist.c	2010-04-01 01:42:05.000000000 +0100
+++ clamz-0.4/playlist.c	2010-04-20 00:01:59.000000000 +0100
@@ -550,44 +550,24 @@
 int write_backup_file(const char* b64data, unsigned long b64len,
 		      const char* fname)
 {
-  char *p = get_config_file_name("amzfiles");
-  char *q;
-  const char *b;
-  int n;
+  char *name;
   FILE *f;
 
-  while ((b = strchr(fname, '/')))
-    fname = b + 1;
+  name = get_config_file_name("amzfiles", fname, NULL);
 
-  if (!p) {
+  if (!name) {
     print_error("Unable to open configuration directory");
     return 1;
   }
 
-  mkdir(p, 0775);
-
-  n = strlen(p);
-  q = malloc((n + strlen(fname) + 2) * sizeof(char));
-  if (!q) {
-    print_error("Out of memory");
-    free(p);
-    return 1;
-  }
-
-  strcpy(q, p);
-  strcat(q, "/");
-  strcat(q, fname);
-
-  f = fopen(q, "wb");
+  f = fopen(name, "wb");
   if (!f) {
-    perror(q);
-    free(p);
-    free(q);
+    perror(name);
+    free(name);
     return 1;
   }
 
-  free(p);
-  free(q);
+  free(name);
 
   if (fwrite(b64data, 1, b64len, f) < b64len) {
     print_error("Unable to write backup file");
diff -Nru clamz-0.3/README clamz-0.4/README
--- clamz-0.3/README	2010-04-01 04:39:31.000000000 +0100
+++ clamz-0.4/README	2010-05-01 03:42:33.000000000 +0100
@@ -1,4 +1,4 @@
-Clamz 0.3
+Clamz 0.4
 ---------
 
  Clamz is a little command-line program to download MP3 files from
@@ -77,11 +77,16 @@
  Let's hope there aren't any.  If you do encounter a problem, here's
  what to do:
 
-  - KEEP A SECOND COPY OF THE AMZ FILE.  Watch out -- if you try to
-    use Amazon's official MP3 Downloader to open the AMZ file, you'll
-    find it automatically deletes the file after reading it!  Make
-    sure to keep an extra copy around -- it will be useful in figuring
-    out what went wrong.
+  - Keep a second copy of the AMZ file.  Clamz will automatically save
+    a copy in the ~/.clamz/amzfiles/ directory.  Be aware, however,
+    that if you try to use Amazon's official MP3 Downloader to open
+    the AMZ file, it will automatically delete the file after reading
+    it!  Make sure to keep an extra copy around -- it will be useful
+    in figuring out what went wrong.
+
+  - Clamz keeps detailed logs of its interactions with the Amazon web
+    servers; these are stored in the ~/.clamz/logs/ directory.  These
+    log files may also be useful in figuring out what went wrong.
 
   - Use clamz -i to print out the details of the AMZ file, if
     possible.  There are basically two ways Amazon might try to break
@@ -91,13 +96,43 @@
     able to download the files by other means, such as through a web
     browser.
 
-  - Please report any problems you encounter to me at
-    floppusmaximus@users.sf.net.
+  - Please report any problems you encounter.  You can use the Clamz
+    bug tracker (http://code.google.com/p/clamz/issues/list), or
+    contact me directly at floppusmaximus@users.sf.net.
 
 
 History
 -------
 
+Version 0.4 -- 2010-04-30
+
+ * Changed the User-Agent string, to accomodate Amazon's UK servers.
+   Clamz should work fine with the Amazon UK store, but as I
+   personally have no way of testing it, your bug reports are always
+   appreciated!
+
+ * Interactions with the server are recorded to a log file, stored in
+   the ~/.clamz/logs/ directory.
+
+ * When clamz is launched directly from a web browser, files are
+   stored in the desktop "music" directory by default.  (This is
+   normally defined in the file ~/.config/user-dirs.dirs if you are
+   running a desktop environment such as GNOME or KDE.  If not,
+   $HOME/Music is used instead.)
+
+ * File names may include the user-dirs variables ($XDG_DESKTOP_DIR,
+   $XDG_MUSIC_DIR, etc.), and may include conditional variable
+   expressions (${foo:-bar} and ${foo:+bar}), similar to shell
+   variable expansion.
+
+ * Improved curl error reporting.
+
+ * When resuming a partial download, the progress display takes the
+   existing portion of the file into account.
+
+ * Non-ASCII characters are handled better in the progress display.
+
+
 Version 0.3 -- 2010-03-31
 
  * Added MIME info and desktop files for GNOME/KDE/etc.  Your web
diff -Nru clamz-0.3/vars.c clamz-0.4/vars.c
--- clamz-0.3/vars.c	1970-01-01 01:00:00.000000000 +0100
+++ clamz-0.4/vars.c	2010-04-22 18:23:31.000000000 +0100
@@ -0,0 +1,303 @@
+/*
+ * clamz - Command-line downloader for the Amazon.com MP3 store
+ * Copyright (c) 2008-2010 Benjamin Moody
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "clamz.h"
+
+/* Convert a string according to user's preferences */
+static char *convert_string(const clamz_config *cfg, const char *s)
+{
+  const unsigned char *us = (const unsigned char*) s;
+  char *converted;
+  int len;
+  int i, j;
+
+  len = strlen(s) + 1;
+  converted = malloc(len * sizeof(char));
+
+  if (!converted) {
+    print_error("Out of memory");
+    return NULL;
+  }
+
+  i = j = 0;
+  while (s[i]) {
+    if (j >= len - 1) {
+      len *= 2;
+      converted = realloc(converted, len * sizeof(char));
+
+      if (!converted) {
+	print_error("Out of memory");
+	return NULL;
+      }
+    }
+
+    if (us[i] & 0x80) {
+      if (cfg->allowutf8) {
+	converted[j++] = s[i++];
+      }
+      else {
+	converted[j++] = '_';
+	do
+	  i++;
+	while (((unsigned char) s[i] & 0xc0) == 0x80);
+      }
+    }
+    else if (s[i] == '/' || iscntrl(us[i])) {
+      converted[j++] = '_';
+      i++;
+    }
+    else if (isupper(us[i]) && !cfg->allowupper) {
+      converted[j++] = tolower(s[i++]);
+    }
+    else if (cfg->forbid_chars && strchr(cfg->forbid_chars, s[i])) {
+      converted[j++] = '_';
+      i++;
+    }
+    else {
+      converted[j++] = s[i++];
+    }
+  }
+
+  converted[j] = 0;
+
+  return converted;
+}
+
+/* Get value of an environment variable or special format variable. */
+static char *get_file_var(const clamz_config *cfg, const clamz_track *tr,
+			  const char *var, int use_fallback)
+{
+  const char *s;
+  const char *fallback = "Unknown";
+  char nbuf[3];
+  char *value;
+  int subst_raw = 0;
+
+  if (!strcasecmp(var, "title"))
+    s = tr->title;
+  else if (!strcasecmp(var, "creator"))
+    s = tr->creator;
+  else if (!strcasecmp(var, "album"))
+    s = tr->album;
+  else if (!strcasecmp(var, "tracknum")) {
+    s = tr->trackNum;
+    if (s && s[0] && !s[1]) {
+      nbuf[0] = '0';
+      nbuf[1] = s[0];
+      nbuf[2] = 0;
+      s = nbuf;
+    }
+    fallback = "00";
+  }
+  else if (!strcasecmp(var, "album_artist"))
+    s = find_meta(tr->meta, TMETA_ALBUM_ARTIST);
+  else if (!strcasecmp(var, "genre"))
+    s = find_meta(tr->meta, TMETA_GENRE);
+  else if (!strcasecmp(var, "discnum")) {
+    s = find_meta(tr->meta, TMETA_DISC_NUM);
+    fallback = "1";
+  }
+  else if (!strcasecmp(var, "suffix")) {
+    s = find_meta(tr->meta, TMETA_TRACK_TYPE);
+    fallback = "mp3";
+  }
+  else if (!strcasecmp(var, "asin"))
+    s = find_meta(tr->meta, TMETA_ASIN);
+  else if (!strcasecmp(var, "album_asin"))
+    s = find_meta(tr->meta, TMETA_ALBUM_ASIN);
+  else if (!strcasecmp(var, "amz_title"))
+    s = tr->playlist->title;
+  else if (!strcasecmp(var, "amz_creator"))
+    s = tr->playlist->creator;
+  else if (!strcasecmp(var, "amz_asin"))
+    s = find_meta(tr->playlist->meta, PMETA_ASIN);
+  else if (!strcasecmp(var, "amz_genre"))
+    s = find_meta(tr->playlist->meta, PMETA_GENRE);
+  else {
+    s = getenv(var);
+    fallback = "";
+    subst_raw = 1;
+  }
+
+  if (!s || !s[0]) {
+    if (use_fallback)
+      s = fallback;
+    else
+      s = "";
+  }
+
+  if (subst_raw) {
+    value = strdup(s);
+    if (!value)
+      print_error("Out of memory");
+    return value;
+  }
+  else {
+    return convert_string(cfg, s);
+  }
+}
+
+/* Concatenate value of a variable onto a filename.  Add an extra '_'
+   if necessary to avoid starting a file/directory name with a dot. */
+static int concatenate_var(char **filename, const char *s)
+{
+  if (s[0] == '.'
+      && (!*filename || !(*filename)[0]
+	  || (*filename)[strlen(*filename) - 1] == '/')) {
+    if (concatenate(filename, "_", 1))
+      return 1;
+  }
+
+  return concatenate(filename, s, strlen(s));
+}
+
+/* Expand a variable reference and append to filename. */
+static int expand_file_var(const clamz_config *cfg, const clamz_track *tr,
+			   char **filename, char *var, const char *format)
+{
+  char *p, *value;
+
+  if ((p = strchr(var, ':'))) {
+    if (p[1] == '-') {
+      /* ${VAR:-ALT} -- substitute VAR if defined, otherwise ALT */
+      *p = 0;
+      if (!(value = get_file_var(cfg, tr, var, 0)))
+	return 1;
+
+      if (value[0]) {
+	if (concatenate_var(filename, value)) {
+	  free(value);
+	  return 1;
+	}
+
+	free(value);
+	return 0;
+      }
+      else {
+	free(value);
+	return expand_file_name(cfg, tr, filename, p + 2);
+      }
+    }
+    else if (p[1] == '+') {
+      /* ${VAR:+ALT} -- substitute ALT if VAR is defined */
+      *p = 0;
+      if (!(value = get_file_var(cfg, tr, var, 0)))
+	return 1;
+
+      if (value[0]) {
+	if (expand_file_name(cfg, tr, filename, p + 2)) {
+	  free(value);
+	  return 1;
+	}
+      }
+
+      free(value);
+      return 0;
+    }
+    else {
+      print_error("Invalid expression '${%s}' in '%s'", var, format);
+      return 1;
+    }
+  }
+  else {
+    if (!(value = get_file_var(cfg, tr, var, 1)))
+      return 1;
+
+    if (concatenate_var(filename, value)) {
+      free(value);
+      return 1;
+    }
+
+    free(value);
+    return 0;
+  }
+}
+
+/* Expand variable references in a filename format string, and append
+   result to filename. */
+int expand_file_name(const clamz_config *cfg, const clamz_track *tr,
+		     char **filename, const char *format)
+{
+  const char *p, *q;
+  const char *f = format;
+  char *var;
+  int n;
+
+  while (*f) {
+    if ((p = strchr(f, '$'))) {
+      if (p != f
+	  && concatenate(filename, f, p - f))
+	return 1;
+
+      p++;
+      if (*p == '{') {
+	p++;
+	q = p;
+	n = 1;
+	while (*q && n) {
+	  if (*q == '{')
+	    n++;
+	  else if (*q == '}')
+	    n--;
+	  q++;
+	}
+	if (n) {
+	  print_error("Missing '}' in '%s'", format);
+	  return 1;
+	}
+	q--;
+	f = q + 1;
+      }
+      else {
+	q = p;
+	while (isalnum((int) (unsigned char) *q) || *q == '_')
+	  q++;
+	f = q;
+      }
+
+      if (p == q) {
+	if (concatenate(filename, "$", 1))
+	  return 1;
+      }
+      else {
+	var = NULL;
+	if (concatenate(&var, p, q - p))
+	  return 1;
+	if (expand_file_var(cfg, tr, filename, var, format)) {
+	  free(var);
+	  return 1;
+	}
+	free(var);
+      }
+    }
+    else {
+      return concatenate(filename, f, strlen(f));
+    }
+  }
+
+  return 0;
+}