I am looking for a command line parser for Qt4.
I did a small google search, and found this: http://www.froglogic.com/pg?id=PublicationsFreeware&category=getopt however it lacks support for "--enable-foo" and "--disable-foo" switches. Besides that, it looks like a real winner.
EDIT:
It seems Frologic removed this. So the best options I see are using Boost (which is not API nor ABI stable) or forking the support for kdelibs. Yay...
Does it have to be Qt4 specific? If not, GNU Getopt is really nice, although licensing may be a problem if you are not doing open source software.
That package does support --disable-foo and --enable-foo via opts.addSwitch("disable-foo", &foo_disabled); and opts.addSwitch("enable-foo", &foo_enabled);. You need handle checking both, and dealing with someone specifying both (oops).
What I don't understand is how this has anything to do with QT4...
QCoreApplication's constructors require (int &argc, char **argv) (and QApplication inherits from QCoreApplication). As the documentation states, it is highly recommended that
Since QApplication also deals with common command line arguments, it is usually a good idea to create it before any interpretation or modification of
argvis done in the application itself.
And if you're letting Qt get the first pass at handling arguments anyways, it would also be a good idea to use QStringList QCoreApplication::arguments() instead of walking through argv; QApplication may remove some of the arguments that it has taken for its own use.
This doesn't lend itself to being very compatible with other argument-parsing libraries...
However, kdelibs does come with a nice argument parser, KCmdLineArgs. It is LGPL and can be used without KApplication if you really want (call KCmdLineArgs::init).
KCmdLineOptions options;
options.add("enable-foo", ki18n("enables foo"));
options.add("nodisable-foo", ki18n("disables foo"));
// double negatives are confusing, but this makes disable-foo enabled by default
KCmdLineArgs::addCmdLineOptions(options);
KApplication app;
KCmdLineArgs *args = KCmdLineArgs::parsedArgs();
if (args->isSet("enable-foo") && !args->isSet("disable-foo"))
cout << "foo enabled" << endl;
else
cout << "foo disabled" << endl;
Untested (who ever tests what they post on S.O.?).
A really simple method is to scan "key=value" args,
put them in a table say zz.map: QString -> QVariant,
and get their values with zz.map.value( key, default ).
An example:
#include "ztest.h"
Ztest zz;
int main( int argc, char* argv[] )
{
zz.eqargs( ++ argv ); // scan test=2 x=str ... to zz.map
QString xx = zz.map.value( "xx", "" );
if( Zint( Size, 10 )) // a #def -> zz.map.value( "Size", 10 )
...
ztest.h is < 1 page, below; same for Python ~ 10 lines.
(Everybody has his/her favorite options parser;
this one's about the simplest.
Worth repeating: however you specify options, echo them to output files --
"every scientist I know has trouble keeping track
of what parameters they used last time they ran a script".)
To make QPoints etc work one of course needs a QString -> QPoint parser. Anyone know offhand why this doesn't work (in Qt 4.4.3) ?
QPoint pt(0,0);
QDataStream s( "QPoint(1,2)" );
s >> pt;
qDebug() << "pt:" << pt; // QPoint(1364225897,1853106225) ??
Added 25nov --
// ztest.h: scan args x=2 s=str ... to a key -> string table
// usage:
// Ztest ztest;
// int main( int argc, char* argv[] )
// {
// QApplication app( argc, argv );
// ztest.eqargs( ++ argv ); // scan leading args name=value ...
// int x = Zint( x, 10 ); // arg x= or default 10
// qreal ff = Zreal( ff, 3.14 );
// QString s = Zstr( s, "default" );
// care: int misspelled = Zint( misspellled ) -- you lose
//version: 2009-06-09 jun denis
#ifndef ztest_h
#define ztest_h
#include <QHash>
#include <QString>
#include <QVariant>
#include <QRegExp>
//------------------------------------------------------------------------------
class Ztest {
public:
QHash< QString, QVariant > map;
int test; // arg test=num, if( ztest.test )
Ztest() : test( 0 ) {}
QVariant val( const QString& key, const QVariant& default_ = 0 )
{
return map.value( key, default_ );
}
void setval( const QString& key, const QVariant& val )
{
map[key] = val;
if( key == "test" || key == "Test" )
test = val.toInt();
}
//------------------------------------------------------------------------------
// ztest.eqargs( ++ argv ) scans test=2 x=3 ... -> ztest table
void eqargs( char** argv )
{
char** argv0 = argv;
char *arg;
QRegExp re( "(\\w+)=(.*)" ); // name= anything, but not ./file=name
for( ; (arg = *argv) && re.exactMatch( arg ); argv ++ ){
setval( re.cap(1), re.cap(2) );
}
// change argv[0..] -> args after all name=values
while(( *argv0++ = *argv++) != 0 ) {}
}
};
extern Ztest ztest;
// macros: int x = Zint( x, 10 ): x= arg or default 10
#define Zstr( key, default ) ztest.val( #key, default ).toString()
#define Zint( key, default ) ztest.val( #key, default ).toInt()
#define Zreal( key, default ) ztest.val( #key, default ).toDouble()
#endif
Another option I ran across while looking to do this, too:
http://code.google.com/p/qgetopts/
I haven't used it though.
This is more or less the same answer as ephemient, but with a simple regexp to help parse the args. (This way could be useful if you only need a handful of args)
Run with this:
./QArgTest --pid=45
And the code:
int main(int argc, char *argv[])
{
QApplication app(argc, argv, false);
qDebug() << "QApp arg test app";
QStringList args = app.arguments();
int index;
int pid;
QRegExp rxArgPid("--pid=([0-9]{1,})");
for (int i = 1; i < args.size(); ++i)
{
index = rxArgPid.indexIn(args.at(i));
if (index != -1 ) {
pid = rxArgPid.cap(1).toInt();
qDebug() << i << ":" << args.at(i) << rxArgPid.cap(1) << pid;
} else {
qDebug() << "Uknown arg:" << args.at(i);
}
}
}