A Simple Win32 Command-Line Parser

Environment: VC6, WIN 9x

A Simple Win32 Command-Line Parser

I was disapointed when I first discovered that (non-console)
Win32 apps did not have argc and argv. This class is my solution.
CmdLineArgs is a subclass of STL vector. After instantiation, it
contains the command line args for your app.

argc – size()
argv – operator[]

Here’s an example of it’s use…


int main ()
{
CmdLineArgs args;

for (int i = 0; i < args.size(); i++) puts (args[i]); return 0; }

Here’s a test run of the example code above…


C:>test.exe This “is” a “”test”” “of the parsing” alg”o”rithm.
C:Test.exe
This
is
a
“test”
of the parsing
alg”o”rithm.

The class…


class CmdLineArgs : public std::vector
{
public:
CmdLineArgs ()
{
// Save local copy of the command line string, because
// ParseCmdLine() modifies this string while parsing it.
PSZ cmdline = GetCommandLine();
m_cmdline = new char [strlen (cmdline) + 1];
if (m_cmdline)
{
strcpy (m_cmdline, cmdline);
ParseCmdLine();
}
}
~CmdLineArgs()
{
delete m_cmdline;
}

private:
PSZ m_cmdline; // the command line string

////////////////////////////////////////////////////////////////////////////////
// Parse m_cmdline into individual tokens, which are delimited by spaces. If a
// token begins with a quote, then that token is terminated by the next quote
// followed immediately by a space or terminator. This allows tokens to contain
// spaces.
// This input string: This “is” a “”test”” “of the parsing” alg”o”rithm.
// Produces these tokens: This, is, a, “test”, of the parsing, alg”o”rithm
////////////////////////////////////////////////////////////////////////////////
void ParseCmdLine ()
{
enum { TERM = ‘’,
QUOTE = ‘”‘ };

bool bInQuotes = false;
PSZ pargs = m_cmdline;

while (*pargs)
{
while (isspace (*pargs)) // skip leading whitespace
pargs++;

bInQuotes = (*pargs == QUOTE); // see if this token is quoted

if (bInQuotes) // skip leading quote
pargs++;

push_back (pargs); // store position of current token

// Find next token.
// NOTE: Args are normally terminated by whitespace, unless the
// arg is quoted. That’s why we handle the two cases separately,
// even though they are very similar.
if (bInQuotes)
{
// find next quote followed by a space or terminator
while (*pargs &&
!(*pargs == QUOTE && (isspace (pargs[1]) || pargs[1] == TERM)))
pargs++;
if (*pargs)
{
*pargs = TERM; // terminate token
if (pargs[1]) // if quoted token not followed by a terminator
pargs += 2; // advance to next token
}
}
else
{
// skip to next non-whitespace character
while (*pargs && !isspace (*pargs))
pargs++;
if (*pargs && isspace (*pargs)) // end of token
{
*pargs = TERM; // terminate token
pargs++; // advance to next token or terminator
}
}
} // while (*pargs)
} // ParseCmdLine()
}; // class CmdLineArgs

Download demo project – 5 Kb

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