Add --cached option to speed up matching against files previously sca…

…nned.

Makefile.am

@@ -47,7 +47,19 @@ fdupes_SOURCES += filegroup.h\
  positive_wcwidth.c\
  positive_wcwidth.h
 dist_man7_MANS = fdupes-help.7
+endif
 
+if WITH_SQLITE
+fdupes_SOURCES += getrealpath.c\
+ getrealpath.h\
+ sdirname.c\
+ sdirname.h\
+ sbasename.c\
+ sbasename.h\
+ xdgbase.c\
+ xdgbase.h\
+ hashdb.c\
+ hashdb.h
 endif
 
 EXTRA_DIST = testdir CHANGES CONTRIBUTORS

configure.ac

@@ -22,6 +22,9 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 	[AC_DEFINE([_XOPEN_SOURCE], [700], [enable certain X/Open and POSIX features])]
 )
 
+#
+# NCURSES library
+#
 AC_ARG_WITH([ncurses], AS_HELP_STRING([--without-ncurses], [Do not use ncurses interface]))
 
 AC_CHECK_HEADERS([getopt.h ncursesw/curses.h])
@@ -42,6 +45,19 @@ AS_IF([test x"$with_ncurses" != x"no"],
 
 AM_CONDITIONAL([WITH_NCURSES], [test x"$with_ncurses" != x"no"])
 
+#
+# SQLITE library
+#
+AC_ARG_WITH([sqlite], AS_HELP_STRING([--without-sqlite], [Do not use sqlite database]))
+
+AS_IF([test x"$with_sqlite" != x"no"],
+	[AC_SEARCH_LIBS([sqlite3_prepare_v2], [sqlite3], [], [AC_ERROR([sqlite3 library not found])])],
+
+	[AC_DEFINE([NO_SQLITE], [], [Do not compile against sqlite])]
+	)
+
+AM_CONDITIONAL([WITH_SQLITE], [test x"$with_sqlite" != x"no"])
+
 unescaped_program_transform_name=`echo "${program_transform_name}"|sed -e "s&\\\\$\\\\$&\\\\$&g"`
 transformed_program_name=`echo "${PACKAGE_NAME}"|sed -e "${unescaped_program_transform_name}"|sed -e "s&\\\\\\\\&\\\\\\\\\\\\\\\\&g"`
 transformed_manpage_name=`echo "${PACKAGE_NAME}-help"|sed -e "${unescaped_program_transform_name}"`
@@ -54,6 +70,10 @@ AC_DEFINE([CHUNK_SIZE], [8192], [number of bytes to read per read call])
 AC_DEFINE([PARTIAL_MD5_SIZE], [4096], [maximum number of bytes to use when calculating partial hashes])
 AC_DEFINE([INPUT_SIZE], [256], [size of command buffer (plain interactive mode only)])
 
+AC_DEFINE([FDUPES_CACHE_DIRECTORY], ["fdupes"], [default subdirectory for fdupes config files])
+AC_DEFINE([FDUPES_CACHE_DIRECTORY_PERMISSIONS], [0700], [directory permissions for fdupes config directory])
+AC_DEFINE([FDUPES_HASH_DATABASE_NAME], ["hash.db"], [filename for fdupes hash database])
+
 AC_CONFIG_FILES([Makefile])
 AC_PROG_CC
 AC_OUTPUT

confirmmatch.c

@@ -20,7 +20,9 @@
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
 
 #include "config.h"
+#include "sigint.h"
 #include "confirmmatch.h"
+#include <stdlib.h>
 #include <memory.h>
 
 /* Do a bit-for-bit comparison in case two different files produce the
@@ -37,6 +39,12 @@ int confirmmatch(FILE *file1, FILE *file2)
   fseek(file2, 0, SEEK_SET);
 
   do {
+    if (got_sigint) {
+      fclose(file1);
+      fclose(file2);
+      exit(0);
+    }
+
     r1 = fread(c1, sizeof(unsigned char), sizeof(c1), file1);
     r2 = fread(c2, sizeof(unsigned char), sizeof(c2), file2);
 

fdupes.1

@@ -39,6 +39,33 @@ Consider only files greater than or equal to SIZE in bytes.
 .B -L --maxsize\fR=\fISIZE\fR
 Consider only files less than or equal to SIZE in bytes.
 .TP
+.B -c --cache
+Speed up file comparisons by keeping track of their signatures in a
+database; additional parameters may be provided using one or more
+cache parameters (as indicated below). Please note that this option
+may not be available on some systems.
+.TP
+.B -x cache.\fIOPTION\fR
+Supply an optional cache parameter, where OPTION is one of the keywords
+below and multiple options may be supplied via successive -x arguments:
+
+  \fIreadonly\fR
+    read but do not update file signatures
+
+  \fIprune\fR
+    look through entire cache and delete orphaned entries
+
+  \fIclear\fR
+    clear all entries from cache
+
+  \fIvacuum\fR
+    reduce size of DB file, if possible
+
+The options prune, clear, and vacuum may be employed without
+supplying a DIRECTORY argument, and will take effect even if readonly
+is also specified. The order of operations is always clear, prune,
+update signatures (unless readonly), and vacuum.
+.TP
 .B -n --noempty
 Exclude zero-length files from consideration.
 .TP
@@ -73,8 +100,10 @@ In interactive mode, defer byte-for-byte confirmation of
 duplicates until just before file deletion.
 .TP
 .B -P --plain
-With --delete, use line-based prompt (as with older versions of
-fdupes) instead of screen-mode interface.
+With --delete, use a line-based prompt (as with older versions of
+fdupes) instead of the new screen-mode interface. On installations
+where the screen-mode interface is not supported, fdupes will
+default to a line-based prompt.
 .TP
 .B -N --noprompt
 When used together with \-\-delete, preserve the first file in each