diff --git a/lib/dictBuilder.c b/lib/dictBuilder.c
index fe40bea464906bdfa9711fb7bc8cdeefe86f55f3..50b67d58d78c65750cb50e31a2951662ba82ad16 100644
--- a/lib/dictBuilder.c
+++ b/lib/dictBuilder.c
@@ -28,7 +28,7 @@
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
-       - Zstd source repository : https://www.zstd.net
+    - Zstd homepage : https://www.zstd.net
 */
 
 /*-**************************************
@@ -124,23 +124,6 @@ void ZDICT_printHex(U32 dlevel, const void* ptr, size_t length)
 }
 
 
-/*-*************************************
-*  Exceptions
-***************************************/
-#ifndef DEBUG
-#  define DEBUG 0
-#endif
-#define DEBUGOUTPUT(...) if (DEBUG) DISPLAY(__VA_ARGS__);
-#define EXM_THROW(error, ...)                                             \
-{                                                                         \
-    DEBUGOUTPUT("Error defined at %s, line %i : \n", __FILE__, __LINE__); \
-    DISPLAYLEVEL(1, "Error %i : ", error);                                \
-    DISPLAYLEVEL(1, __VA_ARGS__);                                         \
-    DISPLAYLEVEL(1, "\n");                                                \
-    exit(error);                                                          \
-}
-
-
 /*-********************************************************
 *  Helper functions
 **********************************************************/
@@ -516,7 +499,7 @@ static U32 ZDICT_dictSize(const dictItem* dictList)
 }
 
 
-static void ZDICT_trainBuffer(dictItem* dictList, U32 dictListSize,
+static size_t ZDICT_trainBuffer(dictItem* dictList, U32 dictListSize,
                             const void* const buffer, const size_t bufferSize,   /* buffer must end with noisy guard band */
                             const size_t* fileSizes, unsigned nbFiles,
                             U32 shiftRatio, unsigned maxDictSize)
@@ -528,18 +511,21 @@ static void ZDICT_trainBuffer(dictItem* dictList, U32 dictListSize,
     U32* filePos = (U32*)malloc(nbFiles * sizeof(*filePos));
     U32 minRatio = nbFiles >> shiftRatio;
     int divSuftSortResult;
+    size_t result = 0;
 
     /* init */
     DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
-    if (!suffix0 || !reverseSuffix || !doneMarks || !filePos)
-        EXM_THROW(1, "not enough memory for ZDICT_trainBuffer");
+    if (!suffix0 || !reverseSuffix || !doneMarks || !filePos) {
+        result = ERROR(memory_allocation);
+        goto _cleanup;
+    }
     if (minRatio < MINRATIO) minRatio = MINRATIO;
     memset(doneMarks, 0, bufferSize+16);
 
     /* sort */
     DISPLAYLEVEL(2, "sorting %u files of total size %u MB ...\n", nbFiles, (U32)(bufferSize>>20));
     divSuftSortResult = divsufsort((const unsigned char*)buffer, suffix, (int)bufferSize, 0);
-    if (divSuftSortResult != 0) EXM_THROW(2, "sort failed");
+    if (divSuftSortResult != 0) { result = ERROR(GENERIC); goto _cleanup; }
     suffix[bufferSize] = (int)bufferSize;   /* leads into noise */
     suffix0[0] = (int)bufferSize;           /* leads into noise */
     {
@@ -578,10 +564,12 @@ static void ZDICT_trainBuffer(dictItem* dictList, U32 dictListSize,
         dictList->pos = n;
     }
 
+_cleanup:
     free(suffix0);
     free(reverseSuffix);
     free(doneMarks);
     free(filePos);
+    return result;
 }
 
 
@@ -661,7 +649,11 @@ static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
     esr.ref = ZSTD_createCCtx();
     esr.zc = ZSTD_createCCtx();
     esr.workPlace = malloc(BLOCKSIZE);
-    if (!esr.ref || !esr.zc || !esr.workPlace) EXM_THROW(30, "Not enough memory");
+    if (!esr.ref || !esr.zc || !esr.workPlace) {
+            eSize = ERROR(memory_allocation);
+            DISPLAYLEVEL(1, "Not enough memory");
+            goto _cleanup;
+    }
     if (compressionLevel==0) compressionLevel=g_compressionLevel_default;
     params = ZSTD_getParams(compressionLevel, dictBufferSize + 15 KB);
     params.strategy = ZSTD_greedy;
@@ -677,50 +669,82 @@ static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
 
     /* analyze */
     errorCode = HUF_buildCTable (hufTable, countLit, 255, huffLog);
-    if (HUF_isError(errorCode)) EXM_THROW(31, "HUF_buildCTable error");
+    if (HUF_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "HUF_buildCTable error");
+        goto _cleanup;
+    }
     huffLog = (U32)errorCode;
 
     total=0; for (u=0; u<=OFFCODE_MAX; u++) total+=offcodeCount[u];
     errorCode = FSE_normalizeCount(offcodeNCount, Offlog, offcodeCount, total, OFFCODE_MAX);
-    if (FSE_isError(errorCode)) EXM_THROW(32, "FSE_normalizeCount error with offcodeCount");
+    if (FSE_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "FSE_normalizeCount error with offcodeCount");
+        goto _cleanup;
+    }
     Offlog = (U32)errorCode;
 
     total=0; for (u=0; u<=MaxML; u++) total+=matchLengthCount[u];
     errorCode = FSE_normalizeCount(matchLengthNCount, mlLog, matchLengthCount, total, MaxML);
-    if (FSE_isError(errorCode)) EXM_THROW(33, "FSE_normalizeCount error with matchLengthCount");
+    if (FSE_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "FSE_normalizeCount error with matchLengthCount");
+        goto _cleanup;
+    }
     mlLog = (U32)errorCode;
 
     total=0; for (u=0; u<=MaxLL; u++) total+=litlengthCount[u];
     errorCode = FSE_normalizeCount(litlengthNCount, llLog, litlengthCount, total, MaxLL);
-    if (FSE_isError(errorCode)) EXM_THROW(34, "FSE_normalizeCount error with litlengthCount");
+    if (FSE_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "FSE_normalizeCount error with litlengthCount");
+        goto _cleanup;
+    }
     llLog = (U32)errorCode;
 
     /* write result to buffer */
     errorCode = HUF_writeCTable(dstBuffer, maxDstSize, hufTable, 255, huffLog);
-    if (HUF_isError(errorCode)) EXM_THROW(41, "HUF_writeCTable error");
+    if (HUF_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "HUF_writeCTable error");
+        goto _cleanup;
+    }
     dstBuffer = (char*)dstBuffer + errorCode;
     maxDstSize -= errorCode;
     eSize += errorCode;
 
     errorCode = FSE_writeNCount(dstBuffer, maxDstSize, offcodeNCount, OFFCODE_MAX, Offlog);
-    if (FSE_isError(errorCode)) EXM_THROW(42, "FSE_writeNCount error with offcodeNCount");
+    if (FSE_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "FSE_writeNCount error with offcodeNCount");
+        goto _cleanup;
+    }
     dstBuffer = (char*)dstBuffer + errorCode;
     maxDstSize -= errorCode;
     eSize += errorCode;
 
     errorCode = FSE_writeNCount(dstBuffer, maxDstSize, matchLengthNCount, MaxML, mlLog);
-    if (FSE_isError(errorCode)) EXM_THROW(43, "FSE_writeNCount error with matchLengthNCount");
+    if (FSE_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "FSE_writeNCount error with matchLengthNCount");
+        goto _cleanup;
+    }
     dstBuffer = (char*)dstBuffer + errorCode;
     maxDstSize -= errorCode;
     eSize += errorCode;
 
     errorCode = FSE_writeNCount(dstBuffer, maxDstSize, litlengthNCount, MaxLL, llLog);
-    if (FSE_isError(errorCode)) EXM_THROW(43, "FSE_writeNCount error with litlengthNCount");
+    if (FSE_isError(errorCode)) {
+        eSize = ERROR(GENERIC);
+        DISPLAYLEVEL(1, "FSE_writeNCount error with litlengthNCount");
+        goto _cleanup;
+    }
     dstBuffer = (char*)dstBuffer + errorCode;
     maxDstSize -= errorCode;
     eSize += errorCode;
 
-    /* clean */
+_cleanup:
     ZSTD_freeCCtx(esr.ref);
     ZSTD_freeCCtx(esr.zc);
     free(esr.workPlace);
@@ -730,12 +754,12 @@ static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
 
 
 #define DIB_FASTSEGMENTSIZE 64
-/*! ZDICT_fastSampling (based on an idea by Giuseppe Ottaviano)
-    Fill `dictBuffer` with stripes of size DIB_FASTSEGMENTSIZE from `samplesBuffer`
+/*! ZDICT_fastSampling()  (based on an idea proposed by Giuseppe Ottaviano) :
+    Fill `dictBuffer` with stripes of size DIB_FASTSEGMENTSIZE from `samplesBuffer`,
     up to `dictSize`.
     Filling starts from the end of `dictBuffer`, down to maximum possible.
     if `dictSize` is not a multiply of DIB_FASTSEGMENTSIZE, some bytes at beginning of `dictBuffer` won't be used.
-    @return : amount of data written into `dictBuffer`
+    @return : amount of data written into `dictBuffer`,
               or an error code
 */
 static size_t ZDICT_fastSampling(void* dictBuffer, size_t dictSize,
diff --git a/programs/Makefile b/programs/Makefile
index a23b2f7f1e88689402f720b60e1e86532a20c677..97da43997759dd61ee8c7911f42d597639a422f6 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -53,7 +53,7 @@ BINDIR  = $(PREFIX)/bin
 MANDIR  = $(PREFIX)/share/man/man1
 ZSTDDIR = ../lib
 
-ZSTD_FILES := $(ZSTDDIR)/zstd_compress.c $(ZSTDDIR)/zstd_decompress.c $(ZSTDDIR)/fse.c $(ZSTDDIR)/huff0.c
+ZSTD_FILES := $(ZSTDDIR)/zstd_compress.c $(ZSTDDIR)/zstd_decompress.c $(ZSTDDIR)/fse.c $(ZSTDDIR)/huff0.c 
 ZSTD_LEGACY:= $(ZSTDDIR)/legacy/zstd_v01.c $(ZSTDDIR)/legacy/zstd_v02.c $(ZSTDDIR)/legacy/zstd_v03.c $(ZSTDDIR)/legacy/zstd_v04.c
 
 ifeq ($(ZSTD_LEGACY_SUPPORT), 0)
@@ -84,12 +84,12 @@ default: zstd
 
 all: zstd zstd32 fullbench fullbench32 fuzzer fuzzer32 zbufftest zbufftest32 paramgrill datagen
 
-zstd  : $(ZSTD_FILES) $(ZSTDDIR)/zstd_buffered.c \
-        zstdcli.c fileio.c $(ZSTD_FILEIO_LEGACY) bench.c xxhash.c datagen.c 
+zstd  : $(ZSTD_FILES) $(ZSTDDIR)/zstd_buffered.c $(ZSTDDIR)/dictBuilder.c $(ZSTDDIR)/divsufsort.c \
+        zstdcli.c fileio.c $(ZSTD_FILEIO_LEGACY) bench.c xxhash.c datagen.c dibio.c
 	$(CC)      $(FLAGS) $^ -o $@$(EXT)
 
-zstd32: $(ZSTD_FILES) $(ZSTDDIR)/zstd_buffered.c \
-        zstdcli.c fileio.c $(ZSTD_FILEIO_LEGACY) bench.c xxhash.c datagen.c 
+zstd32: $(ZSTD_FILES) $(ZSTDDIR)/zstd_buffered.c $(ZSTDDIR)/dictBuilder.c $(ZSTDDIR)/divsufsort.c \
+        zstdcli.c fileio.c $(ZSTD_FILEIO_LEGACY) bench.c xxhash.c datagen.c dibio.c 
 	$(CC) -m32 $(FLAGS) $^ -o $@$(EXT)
 
 zstd_nolegacy :
@@ -101,12 +101,12 @@ zstd-pgo : clean zstd
 	rm zstd
 	$(MAKE) zstd MOREFLAGS=-fprofile-use
 
-zstd-noBench: $(ZSTD_FILES) $(ZSTDDIR)/zstd_buffered.c \
+zstd-frugal: $(ZSTD_FILES) $(ZSTDDIR)/zstd_buffered.c \
         zstdcli.c fileio.c $(ZSTD_FILEIO_LEGACY)
-	$(CC)      $(FLAGS) -DZSTD_NOBENCH $^ -o zstd$(EXT)
+	$(CC)      $(FLAGS) -DZSTD_NOBENCH -DZSTD_NODICT $^ -o zstd$(EXT)
 
-zstd-frugal: clean 
-	$(MAKE) zstd-noBench ZSTD_LEGACY_SUPPORT=0 
+zstd-small: clean 
+	CFLAGS=-Os $(MAKE) zstd-frugal ZSTD_LEGACY_SUPPORT=0 
 
 fullbench  : $(ZSTD_FILES) \
         datagen.c fullbench.c
@@ -140,7 +140,7 @@ datagen : datagen.c datagencli.c
 	$(CC)      $(FLAGS) $^ -o $@$(EXT)
 
 clean:
-	@rm -f core *.o tmp* result* *.gcda \
+	@rm -f core *.o tmp* result* *.gcda dictionary *.zst \
         zstd$(EXT) zstd32$(EXT) \
         fullbench$(EXT) fullbench32$(EXT) \
         fuzzer$(EXT) fuzzer32$(EXT) zbufftest$(EXT) zbufftest32$(EXT) \
diff --git a/programs/dibio.c b/programs/dibio.c
new file mode 100644
index 0000000000000000000000000000000000000000..a471d5450af6cf3662d621bd3c1b85657dc438f3
--- /dev/null
+++ b/programs/dibio.c
@@ -0,0 +1,275 @@
+/*
+    dibio - I/O API for dictionary builder
+    Copyright (C) Yann Collet 2016
+
+    GPL v2 License
+
+    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, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+    You can contact the author at :
+    - zstd homepage : http://www.zstd.net/
+*/
+
+/*-**************************************
+*  Compiler Options
+****************************************/
+/* Disable some Visual warning messages */
+#ifdef _MSC_VER
+#  define _CRT_SECURE_NO_WARNINGS                /* fopen */
+#  pragma warning(disable : 4127)                /* disable: C4127: conditional expression is constant */
+#endif
+
+/* Unix Large Files support (>4GB) */
+#define _FILE_OFFSET_BITS 64
+#if (defined(__sun__) && (!defined(__LP64__)))   /* Sun Solaris 32-bits requires specific definitions */
+#  define _LARGEFILE_SOURCE
+#elif ! defined(__LP64__)                        /* No point defining Large file for 64 bit */
+#  define _LARGEFILE64_SOURCE
+#endif
+
+
+/*-*************************************
+*  Includes
+***************************************/
+#include <stdlib.h>         /* malloc, free */
+#include <string.h>         /* memset */
+#include <stdio.h>          /* fprintf, fopen, ftello64 */
+#include <sys/types.h>      /* stat64 */
+#include <sys/stat.h>       /* stat64 */
+#include <time.h>           /* clock */
+
+#include "mem.h"            /* read */
+#include "error_private.h"
+#include "dictBuilder_static.h"
+
+/*-*************************************
+*  Compiler specifics
+***************************************/
+#if !defined(S_ISREG)
+#  define S_ISREG(x) (((x) & S_IFMT) == S_IFREG)
+#endif
+
+
+/*-*************************************
+*  Constants
+***************************************/
+#define KB *(1 <<10)
+#define MB *(1 <<20)
+#define GB *(1U<<30)
+
+#define DICTLISTSIZE 10000
+#define MEMMULT 11
+static const size_t maxMemory = (sizeof(size_t) == 4) ? (2 GB - 64 MB) : ((size_t)(512 MB) << sizeof(size_t));
+
+#define NOISELENGTH 32
+#define PRIME1   2654435761U
+#define PRIME2   2246822519U
+
+
+/*-*************************************
+*  Console display
+***************************************/
+#define DISPLAY(...)         fprintf(stderr, __VA_ARGS__)
+#define DISPLAYLEVEL(l, ...) if (g_displayLevel>=l) { DISPLAY(__VA_ARGS__); }
+static unsigned g_displayLevel = 0;   /* 0 : no display;   1: errors;   2: default;  4: full information */
+void DiB_setNotificationLevel(unsigned l) { g_displayLevel=l; ZDICT_setNotificationLevel(l); }
+
+void DiB_printHex(U32 dlevel, const void* ptr, size_t length)
+{
+    const BYTE* const b = (const BYTE*)ptr;
+    size_t u;
+    for (u=0; u<length; u++) {
+        BYTE c = b[u];
+        if (c<32 || c>126) c = '.';   /* non-printable char */
+        DISPLAYLEVEL(dlevel, "%c", c);
+    }
+}
+
+
+/*-*************************************
+*  Exceptions
+***************************************/
+#ifndef DEBUG
+#  define DEBUG 0
+#endif
+#define DEBUGOUTPUT(...) if (DEBUG) DISPLAY(__VA_ARGS__);
+#define EXM_THROW(error, ...)                                             \
+{                                                                         \
+    DEBUGOUTPUT("Error defined at %s, line %i : \n", __FILE__, __LINE__); \
+    DISPLAYLEVEL(1, "Error %i : ", error);                                \
+    DISPLAYLEVEL(1, __VA_ARGS__);                                         \
+    DISPLAYLEVEL(1, "\n");                                                \
+    exit(error);                                                          \
+}
+
+
+/* ********************************************************
+*  Helper functions
+**********************************************************/
+unsigned DiB_isError(size_t errorCode) { return ERR_isError(errorCode); }
+
+const char* DiB_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
+
+
+/* ********************************************************
+*  File related operations
+**********************************************************/
+static unsigned long long DiB_getFileSize(const char* infilename)
+{
+    int r;
+#if defined(_MSC_VER)
+    struct _stat64 statbuf;
+    r = _stat64(infilename, &statbuf);
+#else
+    struct stat statbuf;
+    r = stat(infilename, &statbuf);
+#endif
+    if (r || !S_ISREG(statbuf.st_mode)) return 0;   /* No good... */
+    return (unsigned long long)statbuf.st_size;
+}
+
+
+static unsigned long long DiB_getTotalFileSize(const char** fileNamesTable, unsigned nbFiles)
+{
+    unsigned long long total = 0;
+    unsigned n;
+    for (n=0; n<nbFiles; n++)
+        total += DiB_getFileSize(fileNamesTable[n]);
+    return total;
+}
+
+
+static void DiB_loadFiles(void* buffer, size_t bufferSize,
+                          size_t* fileSizes,
+                          const char** fileNamesTable, unsigned nbFiles)
+{
+    char* buff = (char*)buffer;
+    size_t pos = 0;
+    unsigned n;
+
+    for (n=0; n<nbFiles; n++) {
+        size_t readSize;
+        unsigned long long fileSize = DiB_getFileSize(fileNamesTable[n]);
+        FILE* f = fopen(fileNamesTable[n], "rb");
+        if (f==NULL) EXM_THROW(10, "impossible to open file %s", fileNamesTable[n]);
+        DISPLAYLEVEL(2, "Loading %s...       \r", fileNamesTable[n]);
+        if (fileSize > bufferSize-pos) fileSize = 0;  /* stop there, not enough memory to load all files */
+        readSize = fread(buff+pos, 1, (size_t)fileSize, f);
+        if (readSize != (size_t)fileSize) EXM_THROW(11, "could not read %s", fileNamesTable[n]);
+        pos += readSize;
+        fileSizes[n] = (size_t)fileSize;
+        fclose(f);
+    }
+}
+
+
+/*-********************************************************
+*  Dictionary training functions
+**********************************************************/
+static size_t DiB_findMaxMem(unsigned long long requiredMem)
+{
+    size_t step = 8 MB;
+    void* testmem = NULL;
+
+    requiredMem = (((requiredMem >> 23) + 1) << 23);
+    requiredMem += 2 * step;
+    if (requiredMem > maxMemory) requiredMem = maxMemory;
+
+    while (!testmem) {
+        requiredMem -= step;
+        testmem = malloc((size_t)requiredMem);
+    }
+
+    free(testmem);
+    return (size_t)(requiredMem - step);
+}
+
+
+static void DiB_fillNoise(void* buffer, size_t length)
+{
+    unsigned acc = PRIME1;
+    size_t p=0;;
+
+    for (p=0; p<length; p++) {
+        acc *= PRIME2;
+        ((unsigned char*)buffer)[p] = (unsigned char)(acc >> 21);
+    }
+}
+
+
+static void DiB_saveDict(const char* dictFileName,
+                         const void* buff, size_t buffSize)
+{
+    FILE* f;
+    size_t n;
+
+    f = fopen(dictFileName, "wb");
+    if (f==NULL) EXM_THROW(3, "cannot open %s ", dictFileName);
+
+    n = fwrite(buff, 1, buffSize, f);
+    if (n!=buffSize) EXM_THROW(4, "%s : write error", dictFileName)
+
+    n = (size_t)fclose(f);
+    if (n!=0) EXM_THROW(5, "%s : flush error", dictFileName)
+}
+
+
+int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
+                       const char** fileNamesTable, unsigned nbFiles,
+                       ZDICT_params_t params)
+{
+    void* srcBuffer;
+    size_t benchedSize;
+    size_t* fileSizes = (size_t*)malloc(nbFiles * sizeof(size_t));
+    unsigned long long totalSizeToLoad = DiB_getTotalFileSize(fileNamesTable, nbFiles);
+    void* dictBuffer = malloc(maxDictSize);
+    size_t dictSize;
+    int result = 0;
+
+    /* init */
+    benchedSize = DiB_findMaxMem(totalSizeToLoad * MEMMULT) / MEMMULT;
+    if ((unsigned long long)benchedSize > totalSizeToLoad) benchedSize = (size_t)totalSizeToLoad;
+    if (benchedSize < totalSizeToLoad)
+        DISPLAYLEVEL(1, "Not enough memory; training on %u MB only...\n", (unsigned)(benchedSize >> 20));
+
+    /* Memory allocation & restrictions */
+    srcBuffer = malloc(benchedSize+NOISELENGTH);     /* + noise */
+    if ((!fileSizes) || (!srcBuffer) || (!dictBuffer)) EXM_THROW(12, "not enough memory for DiB_trainFiles");  /* should not happen */
+
+    /* Load input buffer */
+    DiB_loadFiles(srcBuffer, benchedSize, fileSizes, fileNamesTable, nbFiles);
+    DiB_fillNoise((char*)srcBuffer + benchedSize, NOISELENGTH);   /* guard band, for end of buffer condition */
+
+    /* call buffer version */
+    dictSize = ZDICT_trainFromBuffer_unsafe(dictBuffer, maxDictSize,
+                        srcBuffer, fileSizes, nbFiles,
+                        params);
+    if (ZDICT_isError(dictSize)) {
+        DISPLAYLEVEL(1, "dictionary training failed : %s", ZDICT_getErrorName(dictSize));   /* should not happen */
+        result = 1;
+        goto _cleanup;
+    }
+
+    /* save dict */
+    DISPLAYLEVEL(2, "Save dictionary of size %u into file %s \n", (U32)dictSize, dictFileName);
+    DiB_saveDict(dictFileName, dictBuffer, dictSize);
+
+    /* clean up */
+_cleanup:
+    free(srcBuffer);
+    free(dictBuffer);
+    free(fileSizes);
+    return result;
+}
diff --git a/programs/dibio.h b/programs/dibio.h
new file mode 100644
index 0000000000000000000000000000000000000000..9b8deb54b1ac4111288d5ef5aad9254a281edefb
--- /dev/null
+++ b/programs/dibio.h
@@ -0,0 +1,63 @@
+/*
+    dibio.h - I/O API for dictionary builder
+    Copyright (C) Yann Collet 2016
+
+    GPL v2 License
+
+    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, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+    You can contact the author at :
+    - zstd homepage : http://www.zstd.net/
+*/
+
+/* This library is designed for a single-threaded console application.
+*  It exit() and printf() into stderr when it encounters an error condition. */
+
+#ifndef DIBIO_H_003
+#define DIBIO_H_003
+
+
+/*-*************************************
+*  Dependencies
+***************************************/
+#include "dictBuilder_static.h"   /* ZDICT_params_t */
+
+
+/*-*************************************
+*  Public functions
+***************************************/
+/*! DiB_trainFromFiles() :
+    Train a dictionary from a set of files provided by `fileNamesTable`.
+    Resulting dictionary is written into file `dictFileName`.
+    `parameters` is optional and can be provided with values set to 0, meaning "default".
+    @return : 0 == ok. Any other : error.
+*/
+int DiB_trainFromFiles(const char* dictFileName, unsigned maxDictSize,
+                       const char** fileNamesTable, unsigned nbFiles,
+                       ZDICT_params_t parameters);
+
+
+/*-*************************************
+*  Helper functions
+***************************************/
+/*! DiB_setNotificationLevel
+    Set amount of notification to be displayed on the console.
+    default initial value : 0 = no console notification.
+    Note : not thread-safe (use a global constant)
+*/
+void DiB_setNotificationLevel(unsigned l);
+
+
+#endif
diff --git a/programs/zstdcli.c b/programs/zstdcli.c
index 3f3c5cd51e33393787bfbac092eef629698f69d1..21ec9ecd9bf359134898a23679e8fa1ea86a7ad8 100644
--- a/programs/zstdcli.c
+++ b/programs/zstdcli.c
@@ -22,10 +22,9 @@
   - zstd homepage : http://www.zstd.net/
 */
 /*
-  Note : this is user program.
-  It is not part of zstd compression library.
-  The license of this compression CLI program is GPLv2.
-  The license of zstd library is BSD.
+  Note : this is user program, not part of libzstd.
+  The license of this command line program is GPLv2.
+  The license of libzstd is BSD.
 */
 
 
@@ -46,7 +45,10 @@
 #ifndef ZSTD_NOBENCH
 #  include "bench.h"  /* BMK_benchFiles, BMK_SetNbIterations */
 #endif
-#include "zstd.h"     /* ZSTD version numbers */
+#include "zstd_static.h" /* ZSTD_maxCLevel, ZSTD version numbers  */
+#ifndef ZSTD_NODICT
+#  include "dibio.h"  /* BMK_benchFiles, BMK_SetNbIterations */
+#endif
 
 
 /*-************************************
@@ -55,9 +57,6 @@
 #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__)
 #  include <fcntl.h>    /* _O_BINARY */
 #  include <io.h>       /* _setmode, _isatty */
-#  ifdef __MINGW32__
-   /* int _fileno(FILE *stream);   // seems no longer useful // MINGW somehow forgets to include this windows declaration into <stdio.h> */
-#  endif
 #  define SET_BINARY_MODE(file) _setmode(_fileno(file), _O_BINARY)
 #  define IS_CONSOLE(stdStream) _isatty(_fileno(stdStream))
 #else
@@ -78,6 +77,7 @@
 #endif
 #define AUTHOR "Yann Collet"
 #define WELCOME_MESSAGE "*** %s %i-bits %s, by %s ***\n", COMPRESSOR_NAME, (int)(sizeof(void*)*8), ZSTD_VERSION, AUTHOR
+
 #define ZSTD_EXTENSION ".zst"
 #define ZSTD_CAT "zstdcat"
 #define ZSTD_UNZSTD "unzstd"
@@ -86,6 +86,11 @@
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
+static const char* g_defaultDictName = "dictionary";
+static const unsigned g_defaultMaxDictSize = 110 KB;
+static const unsigned g_defaultDictCLevel = 5;
+static const unsigned g_defaultSelectivityLevel = 9;
+
 
 /*-************************************
 *  Display Macros
@@ -96,35 +101,21 @@ static FILE* displayOut;
 static unsigned displayLevel = 2;   /* 0 : no display,  1: errors,  2 : + result + interaction + warnings,  3 : + progression,  4 : + information */
 
 
-/*-************************************
-*  Exceptions
-**************************************/
-#define DEBUG 0
-#define DEBUGOUTPUT(...) if (DEBUG) DISPLAY(__VA_ARGS__);
-#define EXM_THROW(error, ...)                                             \
-{                                                                         \
-    DEBUGOUTPUT("Error defined at %s, line %i : \n", __FILE__, __LINE__); \
-    DISPLAYLEVEL(1, "Error %i : ", error);                                \
-    DISPLAYLEVEL(1, __VA_ARGS__);                                         \
-    DISPLAYLEVEL(1, "\n");                                                \
-    exit(error);                                                          \
-}
-
-
 /*-************************************
 *  Command Line
 **************************************/
 static int usage(const char* programName)
 {
     DISPLAY( "Usage :\n");
-    DISPLAY( "      %s [arg] [input] [output]\n", programName);
+    DISPLAY( "      %s [args] [FILE(s)] [-o file]\n", programName);
     DISPLAY( "\n");
-    DISPLAY( "input   : a filename\n");
+    DISPLAY( "FILE    : a filename\n");
     DISPLAY( "          with no FILE, or when FILE is - , read standard input\n");
     DISPLAY( "Arguments :\n");
-    DISPLAY( " -#     : # compression level (1-19, default:1) \n");
+    DISPLAY( " -#     : # compression level (1-%u, default:1) \n", ZSTD_maxCLevel());
     DISPLAY( " -d     : decompression \n");
     DISPLAY( " -D file: use `file` as Dictionary \n");
+    DISPLAY( " -o file: result stored into `file` (only possible if 1 input file) \n");
     DISPLAY( " -f     : overwrite output without prompting \n");
     DISPLAY( " -h/-H  : display help/long help and exit\n");
     return 0;
@@ -139,14 +130,20 @@ static int usage_advanced(const char* programName)
     DISPLAY( " -V     : display Version number and exit\n");
     DISPLAY( " -v     : verbose mode\n");
     DISPLAY( " -q     : suppress warnings; specify twice to suppress errors too\n");
-    DISPLAY( " -m     : multiple input filenames mode \n");
     DISPLAY( " -c     : force write to standard output, even if it is the console\n");
+#ifndef ZSTD_NODICT
+    DISPLAY( "Dictionary builder :\n");
+    DISPLAY( "--train : Create a dictionary from a set of files \n");
+    DISPLAY( " -o file: `file` is dictionary name (default: %s) \n", g_defaultDictName);
+    DISPLAY( "--maxdict:limit dictionary to specified size (default : %u) \n", g_defaultMaxDictSize);
+    DISPLAY( " -s#    : dictionary selectivity level (default: %u)\n", g_defaultSelectivityLevel);
+#endif
 #ifndef ZSTD_NOBENCH
     DISPLAY( "Benchmark arguments :\n");
     DISPLAY( " -b#    : benchmark file(s), using # compression level (default : 1) \n");
-    DISPLAY( " -B#    : cut file into independent blocks of size # (default : no block)\n");
+    DISPLAY( " -B#    : cut file into independent blocks of size # (default: no block)\n");
     DISPLAY( " -i#    : iteration loops [1-9](default : 3)\n");
-    DISPLAY( " -r#    : test all compression levels from 1 to # (default : disabled)\n");
+    DISPLAY( " -r#    : test all compression levels from 1 to # (default: disabled)\n");
 #endif
     return 0;
 }
@@ -176,8 +173,10 @@ int main(int argCount, const char** argv)
         forceStdout=0,
         main_pause=0,
         nextEntryIsDictionary=0,
-        multiple=0,
-        operationResult=0;
+        operationResult=0,
+        dictBuild=0,
+        nextArgumentIsOutFileName=0,
+        nextArgumentIsMaxDict=0;
     unsigned cLevel = 1;
     const char** filenameTable = (const char**)malloc(argCount * sizeof(const char*));   /* argCount >= 1 */
     unsigned filenameIdx = 0;
@@ -185,11 +184,13 @@ int main(int argCount, const char** argv)
     const char* outFileName = NULL;
     const char* dictFileName = NULL;
     char* dynNameSpace = NULL;
-    const char extension[] = ZSTD_EXTENSION;
     int rangeBench = 1;
+    unsigned maxDictSize = g_defaultMaxDictSize;
+    unsigned dictCLevel = g_defaultDictCLevel;
+    unsigned dictSelect = g_defaultSelectivityLevel;
 
     /* init */
-    (void)rangeBench;   /* not used when ZSTD_NOBENCH set */
+    (void)rangeBench; (void)dictCLevel;   /* not used when ZSTD_NOBENCH / ZSTD_NODICT set */
     if (filenameTable==NULL) { DISPLAY("not enough memory\n"); exit(1); }
     displayOut = stderr;
     /* Pick out program name from path. Don't rely on stdlib because of conflicting behavior */
@@ -208,32 +209,32 @@ int main(int argCount, const char** argv)
         /* long commands (--long-word) */
         if (!strcmp(argument, "--version")) { displayOut=stdout; DISPLAY(WELCOME_MESSAGE); return 0; }
         if (!strcmp(argument, "--help")) { displayOut=stdout; return usage_advanced(programName); }
-        if (!strcmp(argument, "--multiple")) { multiple=1; continue; }
         if (!strcmp(argument, "--verbose")) { displayLevel=4; continue; }
         if (!strcmp(argument, "--quiet")) { displayLevel--; continue; }
+        if (!strcmp(argument, "--train")) { dictBuild=1; outFileName=g_defaultDictName; continue; }
+        if (!strcmp(argument, "--maxdict")) { nextArgumentIsMaxDict=1; continue; }
+
+        /* '-' means stdin/stdout */
+        if (!strcmp(argument, "-")){
+            if (!filenameIdx) { filenameIdx=1, filenameTable[0]=stdinmark; continue; }
+            outFileName=stdoutmark; continue;
+        }
 
         /* Decode commands (note : aggregated commands are allowed) */
         if (argument[0]=='-') {
-            /* '-' means stdin/stdout */
-            if (argument[1]==0) {
-                if (!filenameIdx) { filenameIdx=1, filenameTable[0]=stdinmark; continue; }
-                outFileName=stdoutmark; continue;
-            }
-
             argument++;
 
-            while (argument[0]!=0)
-            {
+            while (argument[0]!=0) {
+
                 /* compression Level */
-                if ((*argument>='0') && (*argument<='9'))
-                {
+                if ((*argument>='0') && (*argument<='9')) {
                     cLevel = 0;
-                    while ((*argument >= '0') && (*argument <= '9'))
-                    {
+                    while ((*argument >= '0') && (*argument <= '9')) {
                         cLevel *= 10;
                         cLevel += *argument - '0';
                         argument++;
                     }
+                    dictCLevel = cLevel;
                     continue;
                 }
 
@@ -247,9 +248,6 @@ int main(int argCount, const char** argv)
                      /* Decoding */
                 case 'd': decode=1; argument++; break;
 
-                    /* Multiple input files */
-                case 'm': multiple=1; argument++; break;
-
                     /* Force stdout, even if stdout==console */
                 case 'c': forceStdout=1; outFileName=stdoutmark; displayLevel=1; argument++; break;
 
@@ -268,6 +266,9 @@ int main(int argCount, const char** argv)
                     /* keep source file (default anyway, so useless; for gzip/xz compatibility) */
                 case 'k': argument++; break;
 
+                    /* dictionary name */
+                case 'o': nextArgumentIsOutFileName=1; argument++; break;
+
 #ifndef ZSTD_NOBENCH
                     /* Benchmark */
                 case 'b': bench=1; argument++; break;
@@ -304,6 +305,13 @@ int main(int argCount, const char** argv)
                         break;
 #endif   /* ZSTD_NOBENCH */
 
+                    /* Selection level */
+                case 's': argument++;
+                    dictSelect = 0;
+                    while ((*argument >= '0') && (*argument <= '9'))
+                        dictSelect *= 10, dictSelect += *argument++ - '0';
+                    break;
+
                     /* Pause at the end (hidden option) */
                 case 'p': main_pause=1; argument++; break;
 
@@ -314,13 +322,29 @@ int main(int argCount, const char** argv)
             continue;
         }
 
-        /* dictionary */
         if (nextEntryIsDictionary) {
             nextEntryIsDictionary = 0;
             dictFileName = argument;
             continue;
         }
 
+        if (nextArgumentIsOutFileName) {
+            nextArgumentIsOutFileName = 0;
+            outFileName = argument;
+            if (!strcmp(outFileName, "-")) outFileName = stdoutmark;
+            continue;
+        }
+
+        if (nextArgumentIsMaxDict) {
+            nextArgumentIsMaxDict = 0;
+            maxDictSize = 0;
+            while ((*argument>='0') && (*argument<='9'))
+                maxDictSize = maxDictSize * 10 + (*argument - '0'), argument++;
+            if (*argument=='k' || *argument=='K')
+                maxDictSize <<= 10;
+            continue;
+        }
+
         /* add filename to list */
         filenameTable[filenameIdx++] = argument;
     }
@@ -336,65 +360,47 @@ int main(int argCount, const char** argv)
         goto _end;
     }
 
+    /* Check if dictionary builder is selected */
+    if (dictBuild) {
+#ifndef ZSTD_NODICT
+        ZDICT_params_t dictParams;
+        dictParams.compressionLevel = dictCLevel;
+        dictParams.selectivityLevel = dictSelect;
+        DiB_setNotificationLevel(displayLevel);
+        DiB_trainFromFiles(outFileName, maxDictSize, filenameTable, filenameIdx, dictParams);
+#endif
+        goto _end;
+    }
+
     /* No input filename ==> use stdin */
     if(!filenameIdx) filenameIdx=1, filenameTable[0]=stdinmark;
 
-    /* Check if input defined as console; trigger an error in this case */
+    /* Check if input/output defined as console; trigger an error in this case */
     if (!strcmp(filenameTable[0], stdinmark) && IS_CONSOLE(stdin) ) return badusage(programName);
+    if (outFileName && !strcmp(outFileName, stdoutmark) && IS_CONSOLE(stdout) && !forceStdout) return badusage(programName);
 
-    /* No output filename ==> try to select one automatically (when possible) */
-    if (filenameIdx>=2) outFileName = filenameTable[1];
-    while (!outFileName) {   /* while : just to allow break statement */
-        if (!IS_CONSOLE(stdout)) { outFileName=stdoutmark; break; }   /* Default to stdout whenever possible (i.e. not a console) */
-        if (!decode) {  /* compression to file */
-            size_t l = strlen(filenameTable[0]);
-            dynNameSpace = (char*)calloc(1,l+5);
-            if (dynNameSpace==NULL) { DISPLAY("not enough memory\n"); exit(1); }
-            strcpy(dynNameSpace, filenameTable[0]);
-            strcpy(dynNameSpace+l, ZSTD_EXTENSION);
-            outFileName = dynNameSpace;
-            DISPLAYLEVEL(2, "Compressed filename will be : %s \n", outFileName);
-            break;
-        }
-        /* decompression to file (automatic name will work only if input filename has correct format extension) */
-        {
-            size_t filenameSize = strlen(filenameTable[0]);
-            if (strcmp(filenameTable[0] + (filenameSize-4), extension)) {
-                 DISPLAYLEVEL(1, "unknown suffix - cannot determine destination filename\n");
-                 return badusage(programName);
-            }
-            dynNameSpace = (char*)calloc(1,filenameSize+1);
-            if (dynNameSpace==NULL) { DISPLAY("not enough memory\n"); exit(1); }
-            outFileName = dynNameSpace;
-            strcpy(dynNameSpace, filenameTable[0]);
-            dynNameSpace[filenameSize-4]=0;
-            DISPLAYLEVEL(2, "Decoding file %s \n", outFileName);
-    }   }
-
-    /* Check if output is defined as console; trigger an error in this case */
-    if (!strcmp(outFileName,stdoutmark) && IS_CONSOLE(stdout) && !forceStdout) return badusage(programName);
-
-    /* No warning message in pure pipe mode (stdin + stdout) or multiple mode */
+    /* No warning message in pipe mode (stdin + stdout) or multiple mode */
     if (!strcmp(filenameTable[0], stdinmark) && !strcmp(outFileName,stdoutmark) && (displayLevel==2)) displayLevel=1;
-    if (multiple && (displayLevel==2)) displayLevel=1;
+    if ((filenameIdx>1) && (displayLevel==2)) displayLevel=1;
 
-    if ((!multiple) && (filenameIdx>2)) {
-        DISPLAY("Too many files on the command line (%u > 2). Do you mean -m ? \n", filenameIdx);
+    /* user-selected output filename only possible with a single file */
+    if ((outFileName) && (filenameIdx>1)) {
+        DISPLAY("Too many files (%u) on the command line. \n", filenameIdx);
         return filenameIdx;
     }
 
     /* IO Stream/File */
     FIO_setNotificationLevel(displayLevel);
     if (decode) {
-      if (multiple)
-        operationResult = FIO_decompressMultipleFilenames(filenameTable, filenameIdx, ZSTD_EXTENSION, dictFileName);
-      else
+      if (outFileName)
         operationResult = FIO_decompressFilename(outFileName, filenameTable[0], dictFileName);
+      else
+        operationResult = FIO_decompressMultipleFilenames(filenameTable, filenameIdx, ZSTD_EXTENSION, dictFileName);
     } else {  /* compression */
-        if (multiple)
-          operationResult = FIO_compressMultipleFilenames(filenameTable, filenameIdx, ZSTD_EXTENSION, dictFileName, cLevel);
-        else
+        if (outFileName)
           operationResult = FIO_compressFilename(outFileName, filenameTable[0], dictFileName, cLevel);
+        else
+          operationResult = FIO_compressMultipleFilenames(filenameTable, filenameIdx, ZSTD_EXTENSION, dictFileName, cLevel);
     }
 
 _end: