initial oshash commit

.bzrignore

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+oshash

Makefile

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+PROG =  oshash
+SRC  =	src/oshash.c
+
+PREFIX	?=	/usr/local
+BINDIR	?=	${DESTDIR}${PREFIX}/bin
+MAN1DIR ?=	${DESTDIR}${PREFIX}/man/man1
+
+CC 	   ?=	gcc
+CFLAGS +=	-Wall -ffast-math -fsigned-char
+CFLAGS +=	-I. -Isrc
+
+INSTALL =	install
+
+all: ${PROG}
+
+
+${PROG}: ${SRC}
+	${CC} ${CFLAGS} -o ${PROG} $< ${LDFLAGS}
+
+clean:
+	-@rm -f ${PROG} *~ core *.core src/*.o
+
+install: ${PROG}
+	${INSTALL} -c -m 555 -o root -g bin ${PROG} ${BINDIR}
+
+uninstall:
+	@rm -f ${BINDIR}/${PROG}
+
+.PHONY: all install uninstall

README

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+oshash - Print oshash for files.
+
+Hash code is based on  Media Player Classic.
+In natural language it calculates:
+ size + 64bit chksum of the first and last 64k
+ (even if they overlap because the file is smaller than 128k).
+
+This hash can be used to check for subtitles on opensubtitles.org
+ http://trac.opensubtitles.org/projects/opensubtitles/wiki/MovieIdentification
+

src/oshash.c

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+/* -*- tab-width:4;c-file-style:"cc-mode"; -*- */
+/*
+ * oshash.c -- generate oshash for provided files 
+ * Copyright (C) 2011-2011 <j@v2v.cc>
+ *
+ * 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 2 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/>.
+ */
+
+#if !defined(_GNU_SOURCE)
+#define _GNU_SOURCE
+#endif
+#if !defined(_LARGEFILE_SOURCE)
+#define _LARGEFILE_SOURCE
+#endif
+#if !defined(_LARGEFILE64_SOURCE)
+#define _LARGEFILE64_SOURCE
+#endif
+#if !defined(_FILE_OFFSET_BITS)
+#define _FILE_OFFSET_BITS 64
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <getopt.h>
+#include <math.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+#ifndef WIN32
+#if !defined(off64_t)
+#define off64_t off_t
+#endif
+#endif
+
+#ifdef WIN32
+#define fseeko fseeko64
+#define ftello ftello64
+#endif
+
+#ifdef _BIG_ENDIAN
+#define htonll(x) \
+((((x) & 0xff00000000000000LL) >> 56) | \
+(((x) & 0x00ff000000000000LL) >> 40) | \
+(((x) & 0x0000ff0000000000LL) >> 24) | \
+(((x) & 0x000000ff00000000LL) >> 8) | \
+(((x) & 0x00000000ff000000LL) << 8) | \
+(((x) & 0x0000000000ff0000LL) << 24) | \
+(((x) & 0x000000000000ff00LL) << 40) | \
+(((x) & 0x00000000000000ffLL) << 56))
+#else
+#define htonll(x) x
+#endif
+
+/* 
+ * os hash
+ * based on public domain example from
+ * http://trac.opensubtitles.org/projects/opensubtitles/wiki/HashSourceCodes   
+ * 
+ * plus modification for files < 64k, buffer is filled with file data and padded with 0
+ */
+
+unsigned long long gen_oshash(char const *filename) {
+    FILE *file;
+    int i;
+    unsigned long long t1=0;
+    unsigned long long buffer1[8192*2];
+    int used = 8192*2;
+    file = fopen(filename, "rb");
+    if (file) {
+        //add filesize
+        fseeko(file, 0, SEEK_END);
+        t1 = ftello(file);
+        fseeko(file, 0, SEEK_SET);
+
+        if(t1 < 65536) {
+            used = t1/8;
+            fread(buffer1, used, 8, file);
+        } else {
+            fread(buffer1, 8192, 8, file);
+            fseeko(file, -65536, SEEK_END);
+            fread(&buffer1[8192], 8192, 8, file); 
+        }
+        for (i=0; i < used; i++)
+            t1+=htonll(buffer1[i]);
+        fclose(file);
+    }
+    return t1;
+}
+
+void print_oshash(FILE *output, char const *filename) {
+    char hash[32];
+#ifdef WIN32
+    sprintf(hash, "%016I64x", gen_oshash(filename));
+#else
+    sprintf(hash, "%016qx", gen_oshash(filename));
+#endif
+    if (strcmp(hash,"0000000000000000") > 0)
+        fprintf(output, "%s  %s\n", hash, filename);
+}
+
+int main(int argc, char **argv) {
+    int i;
+    FILE* output = stdout;
+    
+    if(argc == 1) {
+        fprintf(stderr, "usage: %s [filename]\n", argv[0]);
+        exit(1);
+    }
+    for(i=1;i<argc;i++)
+        print_oshash(output, argv[i]);
+    return 0;
+}