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Old 03-09-2009, 10:06 AM   #1
pstevens57
LQ Newbie
 
Registered: Mar 2009
Posts: 2

Rep: Reputation: 0
error: invalid conversion from `void*' to `char*'


New to C/C++ programming. I am compiling courier-0.61.1 on Solaris 9 x86 box using g++. Since there is no setenv for Solaris I found code to
use mysetenv and putenv as an alternative. My problem is when I run make I get the above error message. The file where I inserted the code is webmlmdcmlm.C. See attached.


/*
** $Id: webmlmdcmlm.C,v 1.5 2008/05/18 00:20:00 mrsam Exp $
**
** Copyright 2007 Double Precision, Inc.
** See COPYING for distribution information.
*/
#include "config.h"
#include "webmlmd.H"
#include "webmlmdcmlm.H"
#include <sstream>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <signal.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include "bindir.h"
#include "rfc822/rfc822.h"

#if HAVE_SETENV
#else
static void mysetenv (const char *name, const char *value, int overwrite)
{
int length = strlen(name) + strlen(value) + 2;
char *buffer = malloc(length);
if (buffer == 0)
{
perror("malloc");
exit(1);
}
if (!overwrite && getenv(name)) return;
snprintf (buffer, length, "%s=%s", name, value);
putenv(buffer);
free(buffer);
}
#endif

using namespace webmlmd;

cmlm::filep::filep() : fp(NULL)
{
}

cmlm::filep::~filep()
{
close();
}

void cmlm::filep::close()
{
if (fp)
fclose(fp);
fp=NULL;
}

cmlm::cmlm() : pid(-1)
{
}

cmlm::~cmlm()
{
}

bool cmlm::start(std::string extension,
std::string sender,
std::string command,
const std::vector<std::string> &args)

{
int pipefd[2];

stdout_filep.close();
if ((stdout_filep.fp=tmpfile()) == NULL)
return false;

if (pipe(pipefd) < 0)
{
return false;
}

pid=fork();

if (pid < 0)
{
close(pipefd[0]);
close(pipefd[1]);
return false;
}

if (pid == 0)
{
if (dup2(pipefd[0], 0) < 0)
{
exit(1);
}

if (dup2(fileno(stdout_filep.fp), 1) < 0 || dup2(1, 2) < 0)
{
exit(1);
}
stdout_filep.close();
fcntl(1, F_SETFD, 0);

close(pipefd[0]);
close(pipefd[1]);


#if HAVE_SETENV
setenv("DEFAULT", extension.c_str(), 1);
setenv("SENDER", sender.c_str(), 1);
#else
mysetenv("DEFAULT", extension.c_str(), 1);
mysetenv("SENDER", sender.c_str(), 1);
#endif

std::vector< std::vector<char> > argv_buf;

{
std::vector<char> v;

v.insert(v.end(), command.begin(), command.end() );
v.push_back(0);

argv_buf.push_back(v);
}

// Second arg to couriermlm is list directory, always "."

{
std::vector<char> v;

v.push_back('.');
v.push_back(0);

argv_buf.push_back(v);
}

std::vector<std::string>::const_iterator ab=args.begin(),
ae=args.end();

while (ab != ae)
{
std::vector<char> v;

v.insert(v.end(), ab->begin(), ab->end());
v.push_back(0);

argv_buf.push_back(v);
++ab;
}

std::vector<const char *> argv;

argv.push_back(BINDIR "/couriermlm");

std::vector< std::vector<char> >::iterator vb=argv_buf.begin(),
ve=argv_buf.end();

while (vb != ve)
{
argv.push_back( & (*vb)[0] );
++vb;
}

argv.push_back(NULL);

execv(argv[0], (char **)&argv[0]);
perror(argv[0]);
exit(1);
}

close(pipefd[0]);

signal(SIGPIPE, SIG_IGN);
stdin_filep.close();
stdin_filep.fp=fdopen(pipefd[1], "w");
return true;
}

bool cmlm::wait()
{
int waitstat;
pid_t p;

stdin_filep.close();

while ((p= ::wait(&waitstat)) != pid)
{
if (p == -1)
{
if (errno == EINTR)
continue;
fseek(stdout_filep.fp, 0L, SEEK_END);
fseek(stdout_filep.fp, 0L, SEEK_SET);
return false;
}
}

fseek(stdout_filep.fp, 0L, SEEK_END);
fseek(stdout_filep.fp, 0L, SEEK_SET);

return waitstat == 0;
}

void cmlm::mk_received_header()
{
char buf[100];
const char *ip=getenv("REMOTE_ADDR");

rfc822_mkdate_buf(time(NULL), buf);

fprintf(stdin_filep.fp, "Received: from ([%s]) via http; %s\n",
ip ? ip:"(unknown)", buf);
}

std::string cmlm::format_error_message()
{
std::string errmsg;

if (!stdout_filep.fp)
errmsg=strerror(errno);
else
{
char buf[BUFSIZ];

std:stringstream o;

while (fgets(buf, sizeof(buf), stdout_filep.fp) != NULL)
o << webmlmd::html_escape(std::string(buf));
errmsg=o.str();
}

if (errmsg == "")
{
errmsg="An error has occured while processing this command\n"
"No further information is available\n";
}

return "<blockquote class='error'><pre>" + errmsg + "</pre></blockquote>";
}
 
Old 03-09-2009, 10:29 AM   #2
johnsfine
LQ Guru
 
Registered: Dec 2007
Distribution: Centos
Posts: 5,286

Rep: Reputation: 1197Reputation: 1197Reputation: 1197Reputation: 1197Reputation: 1197Reputation: 1197Reputation: 1197Reputation: 1197Reputation: 1197
Try changing
Code:
char *buffer = malloc(length);
to
Code:
char *buffer = (char*)malloc(length);
Next time you ask for help (or this time if the above suggestion doesn't fix it) try to post an easier to read question.

1) Use code tags around the code to make it more readable.

2) Do something to identify the line for which you got the error message. The compiler gave you a line number. You should take the time to find that line in a text editor so you can tell us in a meaningful way which line it is in the code you quote.

3) Try to quote less code for a simple error like this. That's always a tricky judgment call. People often quote too little code. But in this case, the function containing the error should have been enough.
 
Old 03-10-2009, 01:57 PM   #3
pstevens57
LQ Newbie
 
Registered: Mar 2009
Posts: 2

Original Poster
Rep: Reputation: 0
Thanks so much for you help. Sorry for not pointing out file error and line code.
 
  


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