lyx_mirror/src/support/environment.cpp
Richard Heck fdbe775b9f This is the result of an audit of all static variables, looking
for possible thread conflicts, of the sort Georg resolved at
6a30211f. I have made static variables const where possible,
and marked cases that looked potentially problematic with the
comment:
	// FIXME THREAD
Many of these definitely are vulnerable to concurrent access, such
as the static variables declared at the start of output_latex.cpp.
Suppose, e.g., we were outputting latex and also displaying the
source of a different document.

I'd appreciate it if others could grep for "FIXME THREAD" and see
if some of these are harmless, or what.
2014-04-21 11:51:57 -04:00

151 lines
3.9 KiB
C++

/**
* \file environment.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Angus Leeming
* \author João Luis M. Assirati
* \author Lars Gullik Bjønnes
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "support/environment.h"
#include "support/docstring.h"
#include "support/os.h"
#include <boost/tokenizer.hpp>
#include <cstdlib>
#include <map>
#include <sstream>
using namespace std;
namespace lyx {
namespace support {
bool hasEnv(string const & name)
{
return getenv(name.c_str());
}
string const getEnv(string const & name)
{
// f.ex. what about error checking?
char const * const ch = getenv(name.c_str());
return ch ? to_utf8(from_local8bit(ch)) : string();
}
vector<string> const getEnvPath(string const & name)
{
typedef boost::char_separator<char> Separator;
typedef boost::tokenizer<Separator> Tokenizer;
string const env_var = getEnv(name);
Separator const separator(string(1, os::path_separator()).c_str());
Tokenizer const tokens(env_var, separator);
Tokenizer::const_iterator it = tokens.begin();
Tokenizer::const_iterator const end = tokens.end();
vector<string> vars;
for (; it != end; ++it)
vars.push_back(os::internal_path(*it));
return vars;
}
bool setEnv(string const & name, string const & value)
{
// CHECK Look at and fix this.
// f.ex. what about error checking?
string const encoded = to_local8bit(from_utf8(value));
#if defined (HAVE_SETENV)
return ::setenv(name.c_str(), encoded.c_str(), 1) == 0;
#elif defined (HAVE_PUTENV)
// According to http://pubs.opengroup.org/onlinepubs/9699919799/functions/putenv.html
// the argument of putenv() needs to be static, because changing its
// value will change the environment. Therefore we need a different static
// storage for each variable.
// FIXME THREAD
static map<string, string> varmap;
varmap[name] = name + '=' + encoded;
return ::putenv(const_cast<char*>(varmap[name].c_str())) == 0;
#else
#error No environment-setting function has been defined.
#endif
return false;
}
void setEnvPath(string const & name, vector<string> const & env)
{
char const separator(os::path_separator());
ostringstream ss;
vector<string>::const_iterator const begin = env.begin();
vector<string>::const_iterator const end = env.end();
vector<string>::const_iterator it = begin;
for (; it != end; ++it) {
if (it != begin)
ss << separator;
ss << os::external_path(*it);
}
setEnv(name, ss.str());
}
void prependEnvPath(string const & name, string const & prefix)
{
vector<string> env_var = getEnvPath(name);
typedef boost::char_separator<char> Separator;
typedef boost::tokenizer<Separator> Tokenizer;
Separator const separator(string(1, os::path_separator()).c_str());
// Prepend each new element to the list, removing identical elements
// that occur later in the list.
Tokenizer const tokens(prefix, separator);
vector<string> reversed_tokens(tokens.begin(), tokens.end());
typedef vector<string>::const_reverse_iterator token_iterator;
token_iterator it = reversed_tokens.rbegin();
token_iterator const end = reversed_tokens.rend();
for (; it != end; ++it) {
vector<string>::iterator remove_it =
remove(env_var.begin(), env_var.end(), *it);
env_var.erase(remove_it, env_var.end());
env_var.insert(env_var.begin(), *it);
}
setEnvPath(name, env_var);
}
bool unsetEnv(string const & name)
{
#if defined(HAVE_UNSETENV)
// FIXME: does it leak?
return ::unsetenv(name.c_str()) == 0;
#elif defined(HAVE_PUTENV)
// This is OK with MSVC and MinGW at least.
// The argument of putenv() does not need to be a static variable in this
// case, since the variable is removed from the environment.
return ::putenv(const_cast<char*>((name + "=").c_str())) == 0;
#else
#error No environment-unsetting function has been defined.
#endif
}
} // namespace support
} // namespace lyx