A bottom-up look or Ubuntu Server for an electronics developer. Part 2

CC=g++
UNAME := $(shell uname)
ifeq ($(UNAME), Darwin)
	DEPENDENCIES := -lpthread -ldl -lobjc -framework IOKit -framework CoreFoundation
else
	DEPENDENCIES := -lpthread -ldl -lrt
endif
CFLAGS=$(DEPENDENCIES) -Wall -Wextra -std=c++11
STATLIB=libftd3xx.a
APP = prgr
all: $(APP)
$(APP): main.o 
	$(CC) -o $(APP) main.o $(STATLIB) $(CFLAGS)
main.o: main.cpp
	$(CC) -c -o main.o main.cpp $(CFLAGS)
clean:
	rm -f *.o ; rm $(APP)

void SetPidFile(char* Filename)
{
    FILE* f;
    f = fopen(Filename, "w+");
    if (f)
    {
        fprintf(f, "%u", getpid());
        fclose(f);
    }
}
int main( int argc, char** argv )
{
    char toolfile[32];
    char folder[32];
    intptr_t ret;
    FILE* logfile;
    if( argc!=3 )
    {
        printf( "Write address of the program and name: /home/ubuntu/tool/ tool\n");
        return -1;
    }
    pid_t pid, sid;
    pid = fork();
    if (pid < 0)
    {
        sleep(1);
        return -1;
    }
    //We got a good pid, Close the Parent Process
    if (pid > 0) {
        return 0;
    }
    //Create a new Signature Id for our child
    sid = setsid();
    if (sid < 0)
    {
        return -1;
    }
    //Change File Mask
    umask(0);
    //Save PID
    memcpy( toolfile, argv[0], strlen(argv[0]) );
    memcpy( toolfile + strlen(argv[0]), ".log", 4 );
    memset( toolfile + strlen(argv[0]) + 4, 0, 1 );
    printf( "Daemon:: log to:%s\n", toolfile );
    logfile = fopen( toolfile, "w" );
    fprintf( logfile, "Daemon:: started with 0=%s 1=%s 2=%s\n", argv[0], argv[1], argv[2] );
    memset( toolfile, 0, 32 );
    memcpy( toolfile, argv[0], strlen(argv[0]) );
    memcpy( toolfile + strlen(argv[0]), ".pid", 4 );
    memset( toolfile + strlen(argv[0]) + 4, 0, 1 );
    SetPidFile( toolfile );
    fprintf( logfile, "Daemon:: PID=%u saved in the %s\n", getpid(), toolfile );
    memset( folder, 0, 32 );
    memcpy( folder, argv[1], strlen(argv[1]) );
    fflush ( logfile );
    memset( toolfile, 0, 32 );
    memcpy( toolfile, folder, strlen(argv[1]) );
    memset( toolfile + strlen(argv[1]), '/', 1 );
    memcpy( toolfile + strlen(argv[1]) + 1, argv[2], strlen(argv[2]) );
    //Change Directory
    //If we cant find the directory we exit with failure.
    if ((chdir(folder)) < 0)
    {
        fprintf( logfile, "Daemon:: Program folder was not found:%s\n", folder );
        fclose( logfile );
        return -1;
    }
    //Close Standard File Descriptors
    close(STDIN_FILENO);
    close(STDOUT_FILENO);
    close(STDERR_FILENO);
    fprintf( logfile, "Daemon:: Program started\n" );
    fflush ( logfile );
    ret = execl( toolfile, folder, NULL );
    if( ret==-1 )
    {
        fprintf( logfile, "Daemon:: execl error: %s. File=%s Folder=%s\n", strerror(errno), toolfile, folder );
        fclose( logfile );
        return -1;
    }
    fprintf( logfile, "Daemon:: closed\n" );
    fclose( logfile );
    return 0;
}

[Unit]
Description=my service
After=network.target
After=isc-dhcp-server.service
[Service]
Type=forking
PIDFile=/home/ubuntu/daemon/daemon.pid
ExecStartPre=/bin/sh /home/ubuntu/daemon/prgr.strt
ExecStart=/home/ubuntu/daemon/daemon /home/ubuntu/daemon/prgr prgr
ExecStop=/bin/sh /home/ubuntu/daemon/prgr.stop
Restart=always
TimeoutSec=5
[Install]
WantedBy=multi-user.target