diff --git a/include/messageFormat.h b/include/messageFormat.h
index 637fabf1d..3c1fe4d09 100644
--- a/include/messageFormat.h
+++ b/include/messageFormat.h
@@ -7,30 +7,48 @@
 #ifndef MESSAGEFORMAT_H_
 #define MESSAGEFORMAT_H_
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdint.h>
+
+
 namespace storagemanager
 {
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-variable"
 
+#pragma pack(push, 1)
+struct sm_msg_header {
+    uint32_t type;   // SM_MSG_{START,CONT,END}
+    uint32_t payloadLen;
+    uint8_t payload[];
+};
+
+struct sm_msg_resp {
+    uint32_t type;
+    uint32_t payloadLen;
+    int32_t returnCode;   // if < 0 it indicates an error, and payload contains a 4-byte errno value
+    uint8_t payload[];
+};
+
 // all msgs to and from StorageManager begin with this magic and a payload length
-static const uint SM_MSG_START=0xbf65a7e1;
+static const uint32_t SM_MSG_START=0xbf65a7e1;
 
 // for read/write/append, which may break a message into chunks, messages not the 
 // beginning or end of the larger message will preface a chunk with this magic 
-static const uint SM_MSG_CONT=0xfa371bd2;
+static const uint32_t SM_MSG_CONT=0xfa371bd2;
 
 // for read/write/append, the last chunk of a message should begin with this magic
-static const uint SM_MSG_END=0x9d5bc31b;
+static const uint32_t SM_MSG_END=0x9d5bc31b;
 
-static const uint SM_HEADER_LEN = 8;
+static const uint32_t SM_HEADER_LEN = sizeof(sm_msg_header);
 
 // the unix socket StorageManager is listening on
 static const char *socket_name = "\0storagemanager";
 
 #pragma GCC diagnostic pop
 
-
 // opcodes understood by StorageManager.  Cast these to
 // a uint8_t to use them.
 enum Opcodes {
@@ -57,7 +75,9 @@ enum Opcodes {
     On success, what follows is any output parameters from the call.
     
     TBD: Require filenames to be NULL-terminated.  Currently they are not.
+*/
 
+/*
     OPEN
     ----
     command format:
@@ -65,7 +85,19 @@ enum Opcodes {
 
     response format:
     struct stat
+*/
+struct open_cmd {
+    uint8_t opcode;   // == OPEN 
+    int32_t openmode;
+    uint32_t flen;
+    char filename[];
+};
 
+struct open_resp {
+    struct stat statbuf;
+};
+
+/*
     READ
     ----
     command format:
@@ -73,28 +105,66 @@ enum Opcodes {
 
     response format:
     data (size is stored in the return code)
+*/
+struct read_cmd {
+    uint8_t opcode;   // == READ
+    size_t count;
+    off_t offset;
+    uint32_t flen;
+    char filename[];
+};
 
+typedef uint8_t read_resp;
+        
+/*
     WRITE
     -----
     command format:
     1-byte opcode|size_t count|off_t offset|4-byte filename length|filename|data
 
     response format:
+*/
+struct write_cmd {
+    uint8_t opcode;   // == WRITE
+    size_t count;
+    off_t offset;
+    uint32_t flen;
+    char filename[];
+    // after this is the data to be written, ie at &filename[flen]
+};    
 
+/*
     APPEND
     ------
     command format:
-    1-byte opcode|4-byte filename length|filename|size_t count|data
+    1-byte opcode|size_t count|4-byte filename length|filename|data
 
     response format:
+*/
+struct append_cmd {
+    uint8_t opcode;    // == APPEND
+    size_t count;
+    uint32_t flen;
+    char filename[];
+    // after this is the data to be written, ie at &filename[flen]
+};
 
+/*
     UNLINK
     ------
     command format:
     1-byte opcode|4-byte filename length|filename
 
     response format:
-    
+*/
+struct unlink_cmd {
+    uint8_t opcode; // == UNLINK
+    uint32_t flen;
+    char filename[];
+};
+
+/*
+
     STAT
     ----
     command format:
@@ -102,7 +172,19 @@ enum Opcodes {
 
     response format:
     struct stat
+*/
+struct stat_cmd {
+    uint8_t opcode;   // == STAT
+    uint32_t flen;
+    char filename[];
+};
 
+struct stat_resp {
+    struct stat statbuf;
+}
+
+/*
+    
     TRUNCATE
     --------
     command format:
@@ -128,6 +210,8 @@ enum Opcodes {
 
 */
 
+#pragma pack(pop)
+
 }
 
 #endif
diff --git a/src/AppendTask.cpp b/src/AppendTask.cpp
index 8561bb384..947c70524 100644
--- a/src/AppendTask.cpp
+++ b/src/AppendTask.cpp
@@ -34,16 +34,21 @@ void AppendTask::run()
     uint8_t cmdbuf[1024] = {0};
     int err;
     
-    success = read(cmdbuf, sizeof(struct cmd_overlay));
+    success = read(cmdbuf, sizeof(append_cmd));
     check_error("AppendTask read");
-    cmd_overlay *cmd = (cmd_overlay *) cmdbuf;
+    append_cmd *cmd = (append_cmd *) cmdbuf;
     
-    success = read(&cmdbuf[sizeof(*cmd)], min(cmd->filename_len, 1024 - sizeof(*cmd) - 1));
+    if (cmd->flen > 1023 - sizeof(*cmd))
+    {
+        handleError("AppendTask", ENAMETOOLONG);
+        return;
+    }
+    success = read(&cmdbuf[sizeof(*cmd)], cmd->flen);
     check_error("AppendTask read");
     
     size_t readCount = 0, writeCount = 0;
     vector<uint8_t> databuf;
-    uint bufsize = 1 << 20;   // 1 MB
+    uint bufsize = min(1 << 20, cmd->count);   // 1 MB
     databuf.resize(bufsize);
     
     while (readCount < cmd->count)
@@ -52,31 +57,34 @@ void AppendTask::run()
         success = read(&databuf[0], toRead);
         check_error("AppendTask read data");
         readCount += toRead;
+        uint writePos = 0;
         while (writeCount < readCount)
         {
-            int err = ioc->append(cmd->filename, &databuf[writeCount], readCount - writeCount);
+            int err = ioc->append(cmd->filename, &databuf[writePos], toRead - writePos);
             if (err <= 0)
                 break;
             writeCount += err;
+            writePos += err;
         }
         if (readCount != writeCount)
             break;
     }
     
-    uint32_t response[4];
-    response[0] = SM_MSG_START;
+    uint8_t respbuf[sizeof(sm_msg_resp) + 4];
+    sm_msg_resp *resp = (sm_msg_resp *) respbuf;
+    resp->type = SM_MSG_START;
     if (cmd->count != 0 && writeCount == 0)
     {
-        response[1] = 8;
-        response[2] = -1;
-        response[3] = errno;
-        write((uint8_t *) response, 16);
+        resp->payloadLen = 8;
+        resp->returnCode = -1;
+        *((int *) &resp[1]) = errno;
+        write((uint8_t *) respbuf, sizeof(sm_msg_resp) + 4);
     }
     else
     {
-        response[1] = 4;
-        response[2] = writeCount;
-        write((uint8_t *) response, 12);
+        resp->payloadLen = 4;
+        resp->returnCode = writeCount;
+        write((uint8_t *) respbuf, sizeof(sm_msg_resp));
     }
 }
 
diff --git a/src/AppendTask.h b/src/AppendTask.h
index cfcdae25f..6183801b0 100644
--- a/src/AppendTask.h
+++ b/src/AppendTask.h
@@ -18,12 +18,6 @@ class AppendTask : public PosixTask
     
     private:
         AppendTask();
-        
-        struct cmd_overlay {
-            size_t count;
-            uint filename_len;
-            char filename[];
-        };
 };
 
 }
diff --git a/src/IOCoordinator.cpp b/src/IOCoordinator.cpp
index 95eead2f0..5982010e7 100644
--- a/src/IOCoordinator.cpp
+++ b/src/IOCoordinator.cpp
@@ -37,7 +37,7 @@ struct scoped_closer {
 };
 
 #define OPEN(name, mode) \
-    fd = ::open(filename, mode); \
+    fd = ::open(filename, mode, 0666); \
     if (fd < 0) \
         return fd; \
     scoped_closer sc(fd);
diff --git a/src/OpenTask.cpp b/src/OpenTask.cpp
index 1aef69573..cf2f9e773 100644
--- a/src/OpenTask.cpp
+++ b/src/OpenTask.cpp
@@ -45,19 +45,20 @@ void OpenTask::run()
         return;
     }
     
-    cmd_overlay *cmd = (cmd_overlay *) buf;
-    
-    int err = ioc->open(cmd->filename, cmd->openmode, (struct stat *) &buf[SM_HEADER_LEN]);
+    open_cmd *cmd = (open_cmd *) buf;
+
+    int err = ioc->open(cmd->filename, cmd->openmode, (struct stat *) &buf[sizeof(sm_msg_resp)]);
     if (err)
     {
         handleError("OpenTask open", errno);
         return;
     }
     
-    uint32_t *buf32 = (uint32_t *) buf;
-    buf32[0] = SM_MSG_START;
-    buf32[1] = sizeof(struct stat);
-    success = write(buf, sizeof(struct stat) + SM_HEADER_LEN);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    resp->type = SM_MSG_START;
+    resp->payloadLen = sizeof(struct stat) + 4;
+    resp->returnCode = 0;
+    success = write(buf, sizeof(struct stat) + sizeof(sm_msg_resp));
     if (!success)
         handleError("OpenTask write", errno);
 }
diff --git a/src/OpenTask.h b/src/OpenTask.h
index f29b84052..0bba356a6 100644
--- a/src/OpenTask.h
+++ b/src/OpenTask.h
@@ -17,12 +17,6 @@ class OpenTask : public PosixTask
     
     private:
         OpenTask();
-        
-        struct cmd_overlay {
-            int openmode;
-            uint flen;
-            char filename[];
-        };
 };
 
 
diff --git a/src/PosixTask.cpp b/src/PosixTask.cpp
index 813acb289..6a95d6000 100644
--- a/src/PosixTask.cpp
+++ b/src/PosixTask.cpp
@@ -36,15 +36,15 @@ void PosixTask::handleError(const char *name, int errCode)
     char buf[80];
     
     // send an error response if possible
-    int32_t *buf32 = (int32_t *) buf;
-    buf32[0] = SM_MSG_START;
-    buf32[1] = 8;
-    buf32[2] = -1;
-    buf32[3] = errCode;
-    write((uint8_t *) buf, 16);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    resp->type = SM_MSG_START;
+    resp->payloadLen = 8;
+    resp->returnCode = -1;
+    *((int *) resp->payload) = errCode;
+    write((uint8_t *) buf, sizeof(*resp) + 4);
     
     // TODO: construct and log a message
-    cout << name << " caught an error reading from a socket: " << strerror_r(errCode, buf, 80) << endl;
+    cout << name << " caught an error: " << strerror_r(errCode, buf, 80) << endl;
     socketError();
 }
 
diff --git a/src/ProcessTask.cpp b/src/ProcessTask.cpp
index 94239e373..bf47e2576 100644
--- a/src/ProcessTask.cpp
+++ b/src/ProcessTask.cpp
@@ -14,6 +14,8 @@
 #include "UnlinkTask.h"
 #include "WriteTask.h"
 
+#include <sys/socket.h>
+
 using namespace std;
 
 namespace storagemanager
@@ -50,8 +52,7 @@ void ProcessTask::operator()()
     int err;
     uint8_t opcode;
     
-    /* D'oh, a 1-byte read....   TODO! */
-    err = ::read(sock, &opcode, 1);
+    err = ::recv(sock, &opcode, 1, MSG_PEEK);
     if (err <= 0)
     {
         handleError(errno);
diff --git a/src/ReadTask.cpp b/src/ReadTask.cpp
index 7d9fe044c..cb364ccd7 100644
--- a/src/ReadTask.cpp
+++ b/src/ReadTask.cpp
@@ -49,6 +49,7 @@ void ReadTask::run()
     outbuf32[1] = cmd->count;
     
     // todo: do the reading and writing in chunks
+    // todo: need to make this use O_DIRECT
     ioc->willRead(cmd->filename, cmd->offset, cmd->count);
     int count = 0, err;
     while (count < cmd->count)
diff --git a/src/UnlinkTask.cpp b/src/UnlinkTask.cpp
index aa28dccd1..b21712bff 100644
--- a/src/UnlinkTask.cpp
+++ b/src/UnlinkTask.cpp
@@ -39,7 +39,7 @@ void UnlinkTask::run()
     
     success = read(buf, getLength());
     check_error("UnlinkTask read");
-    cmd_overlay *cmd = (cmd_overlay *) buf;
+    unlink_cmd *cmd = (unlink_cmd *) buf;
     
     int err = ioc->unlink(cmd->filename);
     if (err)
@@ -48,11 +48,11 @@ void UnlinkTask::run()
         return;
     }
     
-    uint32_t *buf32 = (uint32_t *) buf;
-    buf32[0] = SM_MSG_START;
-    buf32[1] = 4;
-    buf32[2] = 0;
-    write(buf, 12);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    resp->type = SM_MSG_START;
+    resp->payloadLen = 4;
+    resp->returnCode = 0;
+    write(buf, sizeof(*resp));
 }
 
 }
diff --git a/src/UnlinkTask.h b/src/UnlinkTask.h
index 61e515a9a..a92521763 100644
--- a/src/UnlinkTask.h
+++ b/src/UnlinkTask.h
@@ -17,11 +17,6 @@ class UnlinkTask : public PosixTask
     
     private:
         UnlinkTask();
-        
-        struct cmd_overlay {
-            uint flen;
-            char filename[];
-        };
 };
 
 
diff --git a/src/WriteTask.cpp b/src/WriteTask.cpp
index f850582f2..d0ba240a3 100644
--- a/src/WriteTask.cpp
+++ b/src/WriteTask.cpp
@@ -32,17 +32,22 @@ void WriteTask::run()
 {
     bool success;
     uint8_t cmdbuf[1024] = {0};
-
-    success = read(cmdbuf, sizeof(struct cmd_overlay));
-    check_error("WriteTask read");
-    cmd_overlay *cmd = (cmd_overlay *) cmdbuf;
     
-    success = read(&cmdbuf[sizeof(*cmd)], min(cmd->filename_len, 1024 - sizeof(*cmd) - 1));
+    success = read(cmdbuf, sizeof(write_cmd));
+    check_error("WriteTask read");
+    write_cmd *cmd = (write_cmd *) cmdbuf;
+    
+    if (cmd->flen > 1023 - sizeof(*cmd))
+    {
+        handleError("WriteTask", ENAMETOOLONG);
+        return;
+    }
+    success = read(&cmdbuf[sizeof(*cmd)], cmd->flen);
     check_error("WriteTask read");
             
     size_t readCount = 0, writeCount = 0;
     vector<uint8_t> databuf;
-    uint bufsize = 1 << 20;   // 1 MB
+    uint bufsize = min(1 << 20, cmd->count);   // 1 MB
     databuf.resize(bufsize);
 
     while (readCount < cmd->count)
@@ -51,31 +56,34 @@ void WriteTask::run()
         success = read(&databuf[0], toRead);
         check_error("WriteTask read data");
         readCount += toRead;
+        uint writePos = 0;
         while (writeCount < readCount)
         {
-            int err = ioc->write(cmd->filename, &databuf[writeCount], cmd->offset + writeCount, readCount - writeCount);
+            int err = ioc->append(cmd->filename, &databuf[writePos], toRead - writePos);
             if (err <= 0)
                 break;
             writeCount += err;
+            writePos += err;
         }
         if (writeCount != readCount)
             break;
     }
     
-    uint32_t response[4];
-    response[0] = SM_MSG_START;
+    uint8_t respbuf[sizeof(sm_msg_resp) + 4];
+    sm_msg_resp *resp = (sm_msg_resp *) respbuf;
+    resp->type = SM_MSG_START;
     if (cmd->count != 0 && writeCount == 0)
     {
-        response[1] = 8;
-        response[2] = -1;
-        response[3] = errno;
-        write((uint8_t *) response, 16);
+        resp->payloadLen = 8;
+        resp->returnCode = -1;
+        *((int *) &resp[1]) = errno;
+        write((uint8_t *) respbuf, sizeof(sm_msg_resp) + 4);
     }
     else
     {
-        response[1] = 4;
-        response[2] = writeCount;
-        write((uint8_t *) response, 12);
+        resp->payloadLen = 4;
+        resp->returnCode = writeCount;
+        write((uint8_t *) respbuf, sizeof(sm_msg_resp));
     }
 }
 
diff --git a/src/WriteTask.h b/src/WriteTask.h
index e00243b5b..a0194f451 100644
--- a/src/WriteTask.h
+++ b/src/WriteTask.h
@@ -18,13 +18,6 @@ class WriteTask : public PosixTask
     
     private:
         WriteTask();
-        
-        struct cmd_overlay {
-            size_t count;
-            off_t offset;
-            uint filename_len;
-            char filename[];
-        };
 };
 
 }
diff --git a/src/unit_tests.cpp b/src/unit_tests.cpp
index a9a4a7519..737dfe5b3 100644
--- a/src/unit_tests.cpp
+++ b/src/unit_tests.cpp
@@ -1,5 +1,9 @@
 #include "OpenTask.h"
+#include "WriteTask.h"
+#include "AppendTask.h"
+#include "UnlinkTask.h"
 #include "IOCoordinator.h"
+#include "messageFormat.h"
 #include <iostream>
 #include <stdlib.h>
 #include <unistd.h>
@@ -24,7 +28,6 @@ struct scoped_closer {
     scoped_closer(int f) : fd(f) { }
     ~scoped_closer() { 
         int s_errno = errno;
-        cout << "closing " << fd << endl;
         ::close(fd);
         errno = s_errno; 
     }
@@ -38,8 +41,9 @@ int getSocket()
     return sock;
 }
 
-int sessionSock = -1;
-int serverSock = -1;
+int sessionSock = -1;  // tester uses this end of the connection
+int serverSock = -1;   
+int clientSock = -1;   // have the Tasks use this end of the connection
 
 void acceptConnection()
 {
@@ -61,8 +65,9 @@ void acceptConnection()
     sessionSock = ::accept(serverSock, NULL, NULL);
     assert(sessionSock > 0);
 }
-    
-bool opentask()
+
+// connects sessionSock to clientSock
+void makeConnection()
 {
     boost::thread t(acceptConnection);
     struct sockaddr_un sa;
@@ -70,43 +75,195 @@ bool opentask()
     sa.sun_family = AF_UNIX;
     memcpy(&sa.sun_path[1], "testing", 7);
     
-    int clientSock = ::socket(AF_UNIX, SOCK_STREAM, 0);
+    clientSock = ::socket(AF_UNIX, SOCK_STREAM, 0);
     assert(clientSock > 0);
-    scoped_closer s2(clientSock);
     sleep(1);   // let server thread get to accept()
     int err = ::connect(clientSock, (struct sockaddr *) &sa, sizeof(sa));
     assert(err == 0);
     t.join();
-    scoped_closer s3(sessionSock);
+}
+
     
+bool opentask()
+{
     // going to rely on msgs being smaller than the buffer here
     uint8_t buf[1024];
-    uint32_t *buf32 = (uint32_t *) buf;
+    sm_msg_header *hdr = (sm_msg_header *) buf;
+    open_cmd *cmd = (open_cmd *) &hdr[1];
     
     // open/create a file named 'opentest1'
     const char *filename = "opentest1";
-    buf32[0] = O_WRONLY | O_CREAT;
-    buf32[1] = 9;
-    strcpy((char *) &buf32[2], "opentest1");
-    uint msg_len = 17;
+    hdr->type = SM_MSG_START;
+    hdr->payloadLen = sizeof(*cmd) + 9;
+    cmd->opcode = OPEN;
+    cmd->openmode = O_WRONLY | O_CREAT;
+    cmd->flen = 9;
+    strcpy((char *) cmd->filename, filename);
     
     ::unlink(filename);
-    ::write(sessionSock, buf, msg_len);
-    OpenTask o(clientSock, msg_len);
+    ::write(sessionSock, cmd, hdr->payloadLen);
+    OpenTask o(clientSock, hdr->payloadLen);
     o.run();
     
     // read the response
+    int err = ::recv(sessionSock, buf, 1024, MSG_DONTWAIT);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    assert(err == sizeof(struct stat) + sizeof(sm_msg_resp));
+    assert(resp->type == SM_MSG_START);
+    assert(resp->payloadLen == sizeof(struct stat) + 4);
+    assert(resp->returnCode == 0);
+    struct stat *_stat = (struct stat *) resp->payload;
     
+    // what can we verify about the stat...
+    assert(_stat->st_uid == getuid());
+    assert(_stat->st_gid == getgid());
+    assert(_stat->st_size == 0);
     
     /* verify the file is there */
     assert(boost::filesystem::exists(filename));
     ::unlink(filename);
+    cout << "opentask OK" << endl;
+    return true;
 }
 
+bool writetask()
+{
+    // make an empty file to write to
+    const char *filename = "writetest1";
+    ::unlink(filename);
+    int fd = ::open(filename, O_CREAT | O_RDWR, 0666);
+    assert(fd > 0);
+    scoped_closer f(fd);
+ 
+    uint8_t buf[1024];
+    sm_msg_header *hdr = (sm_msg_header *) buf;
+    write_cmd *cmd = (write_cmd *) &hdr[1];
+    uint8_t *data;
+    
+    cmd->opcode = WRITE;
+    cmd->offset = 0;
+    cmd->count = 9;
+    cmd->flen = 10;
+    memcpy(&cmd->filename, filename, cmd->flen);
+    data = (uint8_t *) &cmd->filename[cmd->flen];
+    memcpy(data, "123456789", cmd->count);
+    
+    hdr->type = SM_MSG_START;
+    hdr->payloadLen = sizeof(*cmd) + cmd->flen + cmd->count;
+    
+    WriteTask w(clientSock, hdr->payloadLen);
+    ::write(sessionSock, cmd, hdr->payloadLen);
+    w.run();
+    
+    // verify response
+    int err = ::recv(sessionSock, buf, 1024, MSG_DONTWAIT);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    assert(err == sizeof(*resp));
+    assert(resp->type == SM_MSG_START);
+    assert(resp->payloadLen == 4);
+    assert(resp->returnCode == 9);
+    
+    //check file contents
+    err = ::read(fd, buf, 1024);
+    assert(err == 9);
+    buf[9] = 0;
+    assert(!strcmp("123456789", (const char *) buf));
+    ::unlink(filename);
+    cout << "write task OK" << endl;
+    return true;
+}
+
+bool appendtask()
+{
+    // make a file and put some stuff in it
+    const char *filename = "appendtest1";
+    ::unlink(filename);
+    int fd = ::open(filename, O_CREAT | O_RDWR, 0666);
+    assert(fd > 0);
+    scoped_closer f(fd);
+    int err = ::write(fd, "testjunk", 8);
+    assert(err == 8);
+ 
+    uint8_t buf[1024];
+    append_cmd *cmd = (append_cmd *) buf;
+    uint8_t *data;
+    
+    cmd->opcode = APPEND;
+    cmd->count = 9;
+    cmd->flen = 11;
+    memcpy(&cmd->filename, filename, cmd->flen);
+    data = (uint8_t *) &cmd->filename[cmd->flen];
+    memcpy(data, "123456789", cmd->count);
+    
+    int payloadLen = sizeof(*cmd) + cmd->flen + cmd->count;
+    
+    AppendTask a(clientSock, payloadLen);
+    ::write(sessionSock, cmd, payloadLen);
+    a.run();
+    
+    // verify response
+    err = ::recv(sessionSock, buf, 1024, MSG_DONTWAIT);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    assert(err == sizeof(*resp));
+    assert(resp->type == SM_MSG_START);
+    assert(resp->payloadLen == 4);
+    assert(resp->returnCode == 9);
+    
+    //check file contents
+    ::lseek(fd, 0, SEEK_SET);
+    err = ::read(fd, buf, 1024);
+    assert(err == 17);
+    buf[17] = 0;
+    assert(!strcmp("testjunk123456789", (const char *) buf));
+    ::unlink(filename);
+    cout << "append task OK" << endl;
+    return true;
+}
+
+bool unlinktask()
+{
+    // make a file and delete it
+    const char *filename = "unlinktest1";
+    ::unlink(filename);
+    int fd = ::open(filename, O_CREAT | O_RDWR, 0666);
+    assert(fd > 0);
+    scoped_closer f(fd);
+    
+    uint8_t buf[1024];
+    unlink_cmd *cmd = (unlink_cmd *) buf;
+    uint8_t *data;
+    
+    cmd->opcode = UNLINK;
+    cmd->flen = strlen(filename);
+    memcpy(&cmd->filename, filename, cmd->flen);
+    
+    UnlinkTask u(clientSock, sizeof(unlink_cmd) + cmd->flen);
+    ::write(sessionSock, cmd, sizeof(unlink_cmd) + cmd->flen);
+    u.run();
+    
+    // verify response
+    int err = ::recv(sessionSock, buf, 1024, MSG_DONTWAIT);
+    sm_msg_resp *resp = (sm_msg_resp *) buf;
+    assert(err == sizeof(*resp));
+    assert(resp->type == SM_MSG_START);
+    assert(resp->payloadLen == 4);
+    assert(resp->returnCode == 0);
+    
+    // confirm it no longer exists
+    assert(!boost::filesystem::exists(filename));
+    cout << "unlink task OK" << endl;
+}
 
 int main()
 {
     ioc = new IOCoordinator();
+    cout << "connecting" << endl;
+    makeConnection();
+    cout << "connected" << endl;
+    scoped_closer sc1(serverSock), sc2(sessionSock), sc3(clientSock);
     opentask();
+    writetask();
+    appendtask();
+    unlinktask();
     return 0;
 }