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diff --git a/src/zstd/examples/common.h b/src/zstd/examples/common.h
new file mode 100644
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+/*
+ * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+/*
+ * This header file has common utility functions used in examples.
+ */
+#ifndef COMMON_H
+#define COMMON_H
+
+#include <stdlib.h>    // malloc, free, exit
+#include <stdio.h>     // fprintf, perror, fopen, etc.
+#include <string.h>    // strerror
+#include <errno.h>     // errno
+#include <sys/stat.h>  // stat
+#include <zstd.h>
+
+/*
+ * Define the returned error code from utility functions.
+ */
+typedef enum {
+    ERROR_fsize = 1,
+    ERROR_fopen = 2,
+    ERROR_fclose = 3,
+    ERROR_fread = 4,
+    ERROR_fwrite = 5,
+    ERROR_loadFile = 6,
+    ERROR_saveFile = 7,
+    ERROR_malloc = 8,
+    ERROR_largeFile = 9,
+} COMMON_ErrorCode;
+
+/*! CHECK
+ * Check that the condition holds. If it doesn't print a message and die.
+ */
+#define CHECK(cond, ...)                        \
+    do {                                        \
+        if (!(cond)) {                          \
+            fprintf(stderr,                     \
+                    "%s:%d CHECK(%s) failed: ", \
+                    __FILE__,                   \
+                    __LINE__,                   \
+                    #cond);                     \
+            fprintf(stderr, "" __VA_ARGS__);    \
+            fprintf(stderr, "\n");              \
+            exit(1);                            \
+        }                                       \
+    } while (0)
+
+/*! CHECK_ZSTD
+ * Check the zstd error code and die if an error occurred after printing a
+ * message.
+ */
+#define CHECK_ZSTD(fn, ...)                                      \
+    do {                                                         \
+        size_t const err = (fn);                                 \
+        CHECK(!ZSTD_isError(err), "%s", ZSTD_getErrorName(err)); \
+    } while (0)
+
+/*! fsize_orDie() :
+ * Get the size of a given file path.
+ *
+ * @return The size of a given file path.
+ */
+static size_t fsize_orDie(const char *filename)
+{
+    struct stat st;
+    if (stat(filename, &st) != 0) {
+        /* error */
+        perror(filename);
+        exit(ERROR_fsize);
+    }
+
+    off_t const fileSize = st.st_size;
+    size_t const size = (size_t)fileSize;
+    /* 1. fileSize should be non-negative,
+     * 2. if off_t -> size_t type conversion results in discrepancy,
+     *    the file size is too large for type size_t.
+     */
+    if ((fileSize < 0) || (fileSize != (off_t)size)) {
+        fprintf(stderr, "%s : filesize too large \n", filename);
+        exit(ERROR_largeFile);
+    }
+    return size;
+}
+
+/*! fopen_orDie() :
+ * Open a file using given file path and open option.
+ *
+ * @return If successful this function will return a FILE pointer to an
+ * opened file otherwise it sends an error to stderr and exits.
+ */
+static FILE* fopen_orDie(const char *filename, const char *instruction)
+{
+    FILE* const inFile = fopen(filename, instruction);
+    if (inFile) return inFile;
+    /* error */
+    perror(filename);
+    exit(ERROR_fopen);
+}
+
+/*! fclose_orDie() :
+ * Close an opened file using given FILE pointer.
+ */
+static void fclose_orDie(FILE* file)
+{
+    if (!fclose(file)) { return; };
+    /* error */
+    perror("fclose");
+    exit(ERROR_fclose);
+}
+
+/*! fread_orDie() :
+ *
+ * Read sizeToRead bytes from a given file, storing them at the
+ * location given by buffer.
+ *
+ * @return The number of bytes read.
+ */
+static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file)
+{
+    size_t const readSize = fread(buffer, 1, sizeToRead, file);
+    if (readSize == sizeToRead) return readSize;   /* good */
+    if (feof(file)) return readSize;   /* good, reached end of file */
+    /* error */
+    perror("fread");
+    exit(ERROR_fread);
+}
+
+/*! fwrite_orDie() :
+ *
+ * Write sizeToWrite bytes to a file pointed to by file, obtaining
+ * them from a location given by buffer.
+ *
+ * Note: This function will send an error to stderr and exit if it
+ * cannot write data to the given file pointer.
+ *
+ * @return The number of bytes written.
+ */
+static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file)
+{
+    size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file);
+    if (writtenSize == sizeToWrite) return sizeToWrite;   /* good */
+    /* error */
+    perror("fwrite");
+    exit(ERROR_fwrite);
+}
+
+/*! malloc_orDie() :
+ * Allocate memory.
+ *
+ * @return If successful this function returns a pointer to allo-
+ * cated memory.  If there is an error, this function will send that
+ * error to stderr and exit.
+ */
+static void* malloc_orDie(size_t size)
+{
+    void* const buff = malloc(size);
+    if (buff) return buff;
+    /* error */
+    perror("malloc");
+    exit(ERROR_malloc);
+}
+
+/*! loadFile_orDie() :
+ * load file into buffer (memory).
+ *
+ * Note: This function will send an error to stderr and exit if it
+ * cannot read data from the given file path.
+ *
+ * @return If successful this function will load file into buffer and
+ * return file size, otherwise it will printout an error to stderr and exit.
+ */
+static size_t loadFile_orDie(const char* fileName, void* buffer, size_t bufferSize)
+{
+    size_t const fileSize = fsize_orDie(fileName);
+    CHECK(fileSize <= bufferSize, "File too large!");
+
+    FILE* const inFile = fopen_orDie(fileName, "rb");
+    size_t const readSize = fread(buffer, 1, fileSize, inFile);
+    if (readSize != (size_t)fileSize) {
+        fprintf(stderr, "fread: %s : %s \n", fileName, strerror(errno));
+        exit(ERROR_fread);
+    }
+    fclose(inFile);  /* can't fail, read only */
+    return fileSize;
+}
+
+/*! mallocAndLoadFile_orDie() :
+ * allocate memory buffer and then load file into it.
+ *
+ * Note: This function will send an error to stderr and exit if memory allocation
+ * fails or it cannot read data from the given file path.
+ *
+ * @return If successful this function will return buffer and bufferSize(=fileSize),
+ * otherwise it will printout an error to stderr and exit.
+ */
+static void* mallocAndLoadFile_orDie(const char* fileName, size_t* bufferSize) {
+    size_t const fileSize = fsize_orDie(fileName);
+    *bufferSize = fileSize;
+    void* const buffer = malloc_orDie(*bufferSize);
+    loadFile_orDie(fileName, buffer, *bufferSize);
+    return buffer;
+}
+
+/*! saveFile_orDie() :
+ *
+ * Save buffSize bytes to a given file path, obtaining them from a location pointed
+ * to by buff.
+ *
+ * Note: This function will send an error to stderr and exit if it
+ * cannot write to a given file.
+ */
+static void saveFile_orDie(const char* fileName, const void* buff, size_t buffSize)
+{
+    FILE* const oFile = fopen_orDie(fileName, "wb");
+    size_t const wSize = fwrite(buff, 1, buffSize, oFile);
+    if (wSize != (size_t)buffSize) {
+        fprintf(stderr, "fwrite: %s : %s \n", fileName, strerror(errno));
+        exit(ERROR_fwrite);
+    }
+    if (fclose(oFile)) {
+        perror(fileName);
+        exit(ERROR_fclose);
+    }
+}
+
+#endif