Try to use fcntl to create sparse files in Darwin.

setter/src/darwin/CMakeLists.txt

@@ -32,11 +32,11 @@ project(fssetter-darwin
 
 find_library(CARBON_LIBRARY NAMES Carbon)
 
-set(PLATFORM_SOURCES os.c darwin.h volume.c volume.h attr.c attr.h rsrcfork.c rsrcfork.h)
+set(PLATFORM_SOURCES os.c darwin.h volume.c volume.h attr.c attr.h rsrcfork.c rsrcfork.h sparse.c xattr.c xattr.h)
 
 if(CARBON_LIBRARY)
     add_definitions("-DHAVE_CARBON")
-    set(PLATFORM_SOURCES ${PLATFORM_SOURCES} carbon.c carbon.h xattr.c xattr.h)
+    set(PLATFORM_SOURCES ${PLATFORM_SOURCES} carbon.c carbon.h)
 endif()
 
 set(EXECUTABLE_NAME "fssetter-${CMAKE_SYSTEM_NAME}-${CMAKE_SYSTEM_PROCESSOR}")

setter/src/darwin/darwin.h

@@ -13,5 +13,6 @@ void DarwinResourceFork(const char* path);
 void DarwinFileAttributes(const char* path);
 void DarwinExtendedAttributes(const char* path);
 void DarwinVolumeAttributes(const char* path);
+int  DarwinSparse(const char* path);
 
 #endif // SETTER_SRC_DARWIN_DARWIN_H_

setter/src/darwin/sparse.c

@@ -0,0 +1,151 @@
+/****************************************************************************
+Aaru Data Preservation Suite
+-----------------------------------------------------------------------------
+
+    Author(s)      : Natalia Portillo
+
+--[ 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 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/>.
+
+-----------------------------------------------------------------------------
+Copyright (C) 2011-2021 Natalia Portillo
+*****************************************************************************/
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "../include/consts.h"
+#include "../log.h"
+
+int DarwinSparse(const char* path)
+{
+    int          ret;
+    int          rc, wRc, cRc, sRc;
+    FILE*        h;
+    int          i;
+    int          fd;
+    int          done = -1;
+    fpunchhole_t fphole;
+    memset(&fphole, 0, sizeof(fpunchhole_t));
+
+    ret = chdir(path);
+
+    if(ret)
+    {
+        log_write("Error %d changing to specified path.\n", errno);
+        return done;
+    }
+
+    ret = mkdir("SPARSE", 0755);
+
+    if(ret)
+    {
+        log_write("Error %d creating working directory.\n", errno);
+        return done;
+    }
+
+    ret = chdir("SPARSE");
+
+    if(ret)
+    {
+        log_write("Error %d changing to working directory.\n", errno);
+        return done;
+    }
+
+    done = 0;
+
+    log_write("Creating sparse files.\n");
+
+    h   = fopen("SMALL", "w+");
+    rc  = 0;
+    wRc = 0;
+    cRc = 0;
+    sRc = 0;
+    if(h == NULL) { rc = errno; }
+    else
+    {
+        for(i = 0; i < 4096 * 3; i += CLAUNIA_SIZE)
+        {
+            ret = fwrite(clauniaBytes, CLAUNIA_SIZE, 1, h);
+            if(ret < 0)
+            {
+                wRc = errno;
+                break;
+            }
+        }
+
+        fd               = fileno(h);
+        fphole.fp_offset = 4096;
+        fphole.fp_length = 8192;
+        ret              = fcntl(fd, F_PUNCHHOLE, &fphole);
+        if(ret) sRc = errno;
+        else
+            done++;
+
+        ret = fclose(h);
+        if(ret) cRc = errno;
+    }
+
+    log_write("\tFile name = \"%s\", size = %d, rc = %d, wRc = %d, cRc = %d, sRc = %d\n",
+              "SMALL",
+              4096 * 4,
+              rc,
+              wRc,
+              cRc,
+              sRc);
+
+    h   = fopen("BIG", "w+");
+    rc  = 0;
+    wRc = 0;
+    cRc = 0;
+    sRc = 0;
+    if(h == NULL) { rc = errno; }
+    else
+    {
+        for(i = 0; i < 4096 * 30; i += CLAUNIA_SIZE)
+        {
+            ret = fwrite(clauniaBytes, CLAUNIA_SIZE, 1, h);
+            if(ret < 0)
+            {
+                wRc = errno;
+                break;
+            }
+        }
+
+        fd               = fileno(h);
+        fphole.fp_offset = 32768;
+        fphole.fp_length = 81920;
+        ret              = fcntl(fd, F_PUNCHHOLE, &fphole);
+        if(ret) sRc = errno;
+        else
+            done++;
+
+        ret = fclose(h);
+        if(ret) cRc = errno;
+    }
+
+    log_write("\tFile name = \"%s\", size = %d, rc = %d, wRc = %d, cRc = %d, sRc = %d\n",
+              "BIG",
+              4096 * 30,
+              rc,
+              wRc,
+              cRc,
+              sRc);
+
+    return done;
+}

setter/src/unix/sparse.c

@@ -23,11 +23,11 @@ Copyright (C) 2011-2021 Natalia Portillo
 *****************************************************************************/
 
 #if defined(__linux__) || defined(__LINUX__) || defined(__gnu_linux)
-#define _GNU_SOURCE
-
 #include <dlfcn.h>
 
 #include "../linux/linux.h"
+#elif defined(__APPLE__) && defined(__MACH__)
+#include "../darwin/darwin.h"
 #endif
 
 #include <errno.h>
@@ -57,6 +57,13 @@ void Sparse(const char* path)
 
         return;
     }
+#elif defined(__APPLE__) && defined(__MACH__)
+    ret = DarwinSparse(path);
+
+    if(ret > 0) return;
+
+    ret = chdir(path);
+    rmdir("SPARSE");
 #endif
 
     ret = chdir(path);