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/*
This file is part of the KDE libraries
Copyright (c) 2002-2003 Oswald Buddenhagen <ossi@kde.org>
Copyright (c) 2003 Waldo Bastian <bastian@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef KMACROEXPANDER_H
#define KMACROEXPANDER_H
#include <kdecore_export.h>
#include <QtCore/QChar>
class QString;
class QStringList;
template <typename KT, typename VT> class QHash;
class KMacroExpanderBasePrivate;
/**
* \class KMacroExpanderBase kmacroexpander.h <KMacroExpanderBase>
*
* Abstract base class for the worker classes behind the KMacroExpander namespace
* and the KCharMacroExpander and KWordMacroExpander classes.
*
* @author Oswald Buddenhagen <ossi@kde.org>
*/
class KDECORE_EXPORT KMacroExpanderBase {
public:
/**
* Constructor.
* @param c escape char indicating start of macros, or QChar::null for none
*/
explicit KMacroExpanderBase( QChar c = QLatin1Char('%') );
/**
* Destructor.
*/
virtual ~KMacroExpanderBase();
/**
* Perform safe macro expansion (substitution) on a string.
*
* @param str the string in which macros are expanded in-place
*/
void expandMacros( QString &str );
// TODO: This documentation is relevant for end-users. Where to put it?
/**
* Perform safe macro expansion (substitution) on a string for use
* in shell commands.
*
* <h3>*NIX notes</h3>
*
* Explicitly supported shell constructs:
* \ '' "" $'' $"" {} () $(()) ${} $() ``
*
* Implicitly supported shell constructs:
* (())
*
* Unsupported shell constructs that will cause problems:
* Shortened "<tt>case $v in pat)</tt>" syntax. Use
* "<tt>case $v in (pat)</tt>" instead.
*
* The rest of the shell (incl. bash) syntax is simply ignored,
* as it is not expected to cause problems.
*
* Note that bash contains a bug which makes macro expansion within
* double quoted substitutions (<tt>"${VAR:-%macro}"</tt>) inherently
* insecure.
*
* For security reasons, @em never put expandos in command line arguments
* that are shell commands by themselves -
* "<tt>sh -c 'foo \%f'</tt>" is taboo.
* "<tt>file=\%f sh -c 'foo "$file"'</tt>" is OK.
*
* <h3>Windows notes</h3>
*
* All quoting syntax supported by KShell is supported here as well.
* Additionally, command grouping via parentheses is recognized - note
* however, that the parser is much stricter about unquoted parentheses
* than cmd itself.
* The rest of the cmd syntax is simply ignored, as it is not expected
* to cause problems - do not use commands that embed other commands,
* though - "<tt>for /f ...</tt>" is taboo.
*
* @param str the string in which macros are expanded in-place
* @param pos the position inside the string at which parsing/substitution
* should start, and upon exit where processing stopped
* @return false if the string could not be parsed and therefore no safe
* substitution was possible. Note that macros will have been processed
* up to the point where the error occurred. An unmatched closing paren
* or brace outside any shell construct is @em not an error (unlike in
* the function below), but still prematurely terminates processing.
*/
bool expandMacrosShellQuote( QString &str, int &pos );
/**
* Same as above, but always starts at position 0, and unmatched closing
* parens and braces are treated as errors.
*/
bool expandMacrosShellQuote( QString &str );
/**
* Set the macro escape character.
* @param c escape char indicating start of macros, or QChar::null if none
*/
void setEscapeChar( QChar c );
/**
* Obtain the macro escape character.
* @return escape char indicating start of macros, or QChar::null if none
*/
QChar escapeChar() const;
protected:
/**
* This function is called for every single char within the string if
* the escape char is QChar::null. It should determine whether the
* string starting at @p pos within @p str is a valid macro and return
* the substitution value for it if so.
* @param str the input string
* @param pos the offset within @p str
* @param ret return value: the string to substitute for the macro
* @return If greater than zero, the number of chars at @p pos in @p str
* to substitute with @p ret (i.e., a valid macro was found). If less
* than zero, subtract this value from @p pos (to skip a macro, i.e.,
* substitute it with itself). If zero, no macro starts at @p pos.
*/
virtual int expandPlainMacro( const QString &str, int pos, QStringList &ret );
/**
* This function is called every time the escape char is found if it is
* not QChar::null. It should determine whether the
* string starting at @p pos witin @p str is a valid macro and return
* the substitution value for it if so.
* @param str the input string
* @param pos the offset within @p str. Note that this is the position of
* the occurrence of the escape char
* @param ret return value: the string to substitute for the macro
* @return If greater than zero, the number of chars at @p pos in @p str
* to substitute with @p ret (i.e., a valid macro was found). If less
* than zero, subtract this value from @p pos (to skip a macro, i.e.,
* substitute it with itself). If zero, scanning continues as if no
* escape char was encountered at all.
*/
virtual int expandEscapedMacro( const QString &str, int pos, QStringList &ret );
private:
KMacroExpanderBasePrivate * const d;
};
/**
* \class KWordMacroExpander kmacroexpander.h <KMacroExpanderBase>
*
* Abstract base class for simple word macro substitutors. Use this instead of
* the functions in the KMacroExpander namespace if speculatively pre-filling
* the substitution map would be too expensive.
*
* A typical application:
*
* \code
* class MyClass {
* ...
* private:
* QString m_str;
* ...
* friend class MyExpander;
* };
*
* class MyExpander : public KWordMacroExpander {
* public:
* MyExpander( MyClass *_that ) : KWordMacroExpander(), that( _that ) {}
* protected:
* virtual bool expandMacro( const QString &str, QStringList &ret );
* private:
* MyClass *that;
* };
*
* bool MyExpander::expandMacro( const QString &str, QStringList &ret )
* {
* if (str == "macro") {
* ret += complexOperation( that->m_str );
* return true;
* }
* return false;
* }
*
* ... MyClass::...(...)
* {
* QString str;
* ...
* MyExpander mx( this );
* mx.expandMacrosShellQuote( str );
* ...
* }
* \endcode
*
* Alternatively MyClass could inherit from KWordMacroExpander directly.
*
* @author Oswald Buddenhagen <ossi@kde.org>
*/
class KDECORE_EXPORT KWordMacroExpander : public KMacroExpanderBase {
public:
/**
* Constructor.
* @param c escape char indicating start of macros, or QChar::null for none
*/
explicit KWordMacroExpander( QChar c = QLatin1Char('%') ) : KMacroExpanderBase( c ) {}
protected:
/** \internal Not to be called or reimplemented. */
virtual int expandPlainMacro( const QString &str, int pos, QStringList &ret );
/** \internal Not to be called or reimplemented. */
virtual int expandEscapedMacro( const QString &str, int pos, QStringList &ret );
/**
* Return substitution list @p ret for string macro @p str.
* @param str the macro to expand
* @param ret return variable reference. It is guaranteed to be empty
* when expandMacro is entered.
* @return @c true iff @p chr was a recognized macro name
*/
virtual bool expandMacro( const QString &str, QStringList &ret ) = 0;
};
/**
* \class KCharMacroExpander kmacroexpander.h <KMacroExpanderBase>
*
* Abstract base class for single char macro substitutors. Use this instead of
* the functions in the KMacroExpander namespace if speculatively pre-filling
* the substitution map would be too expensive.
*
* See KWordMacroExpander for a sample application.
*
* @author Oswald Buddenhagen <ossi@kde.org>
*/
class KDECORE_EXPORT KCharMacroExpander : public KMacroExpanderBase {
public:
/**
* Constructor.
* @param c escape char indicating start of macros, or QChar::null for none
*/
explicit KCharMacroExpander( QChar c = QLatin1Char('%') ) : KMacroExpanderBase( c ) {}
protected:
/** \internal Not to be called or reimplemented. */
virtual int expandPlainMacro( const QString &str, int pos, QStringList &ret );
/** \internal Not to be called or reimplemented. */
virtual int expandEscapedMacro( const QString &str, int pos, QStringList &ret );
/**
* Return substitution list @p ret for single-character macro @p chr.
* @param chr the macro to expand
* @param ret return variable reference. It is guaranteed to be empty
* when expandMacro is entered.
* @return @c true iff @p chr was a recognized macro name
*/
virtual bool expandMacro( QChar chr, QStringList &ret ) = 0;
};
/**
* A group of functions providing macro expansion (substitution) in strings,
* optionally with quoting appropriate for shell execution.
*/
namespace KMacroExpander {
/**
* Perform safe macro expansion (substitution) on a string.
* The escape char must be quoted with itself to obtain its literal
* representation in the resulting string.
*
* @param str The string to expand
* @param map map with substitutions
* @param c escape char indicating start of macro, or QChar::null if none
* @return the string with all valid macros expanded
*
* \code
* // Code example
* QHash<QChar,QString> map;
* map.insert('u', "/tmp/myfile.txt");
* map.insert('n', "My File");
* QString s = "%% Title: %u:%n";
* s = KMacroExpander::expandMacros(s, map);
* // s is now "% Title: /tmp/myfile.txt:My File";
* \endcode
*/
KDECORE_EXPORT QString expandMacros( const QString &str, const QHash<QChar,QString> &map, QChar c = QLatin1Char('%') );
/**
* Perform safe macro expansion (substitution) on a string for use
* in shell commands.
* The escape char must be quoted with itself to obtain its literal
* representation in the resulting string.
*
* @param str The string to expand
* @param map map with substitutions
* @param c escape char indicating start of macro, or QChar::null if none
* @return the string with all valid macros expanded, or a null string
* if a shell syntax error was detected in the command
*
* \code
* // Code example
* QHash<QChar,QString> map;
* map.insert('u', "/tmp/myfile.txt");
* map.insert('n', "My File");
* QString s = "kedit --caption %n %u";
* s = KMacroExpander::expandMacrosShellQuote(s, map);
* // s is now "kedit --caption 'My File' '/tmp/myfile.txt'";
* system(QFile::encodeName(s));
* \endcode
*/
KDECORE_EXPORT QString expandMacrosShellQuote( const QString &str, const QHash<QChar,QString> &map,
QChar c = QLatin1Char('%') );
/**
* Perform safe macro expansion (substitution) on a string.
* The escape char must be quoted with itself to obtain its literal
* representation in the resulting string.
* Macro names can consist of chars in the range [A-Za-z0-9_];
* use braces to delimit macros from following words starting
* with these chars, or to use other chars for macro names.
*
* @param str The string to expand
* @param map map with substitutions
* @param c escape char indicating start of macro, or QChar::null if none
* @return the string with all valid macros expanded
*
* \code
* // Code example
* QHash<QString,QString> map;
* map.insert("url", "/tmp/myfile.txt");
* map.insert("name", "My File");
* QString s = "Title: %{url}-%name";
* s = KMacroExpander::expandMacros(s, map);
* // s is now "Title: /tmp/myfile.txt-My File";
* \endcode
*/
KDECORE_EXPORT QString expandMacros( const QString &str, const QHash<QString,QString> &map,
QChar c = QLatin1Char('%') );
/**
* Perform safe macro expansion (substitution) on a string for use
* in shell commands. See KMacroExpanderBase::expandMacrosShellQuote()
* for the exact semantics.
* The escape char must be quoted with itself to obtain its literal
* representation in the resulting string.
* Macro names can consist of chars in the range [A-Za-z0-9_];
* use braces to delimit macros from following words starting
* with these chars, or to use other chars for macro names.
*
* @param str The string to expand
* @param map map with substitutions
* @param c escape char indicating start of macro, or QChar::null if none
* @return the string with all valid macros expanded, or a null string
* if a shell syntax error was detected in the command
*
* \code
* // Code example
* QHash<QString,QString> map;
* map.insert("url", "/tmp/myfile.txt");
* map.insert("name", "My File");
* QString s = "kedit --caption %name %{url}";
* s = KMacroExpander::expandMacrosShellQuote(s, map);
* // s is now "kedit --caption 'My File' '/tmp/myfile.txt'";
* system(QFile::encodeName(s));
* \endcode
*/
KDECORE_EXPORT QString expandMacrosShellQuote( const QString &str, const QHash<QString,QString> &map,
QChar c = QLatin1Char('%') );
/**
* Same as above, except that the macros expand to string lists that
* are simply join(" ")ed together.
*/
KDECORE_EXPORT QString expandMacros( const QString &str, const QHash<QChar,QStringList> &map,
QChar c = QLatin1Char('%') );
KDECORE_EXPORT QString expandMacros( const QString &str, const QHash<QString,QStringList> &map,
QChar c = QLatin1Char('%') );
/**
* Same as above, except that the macros expand to string lists.
* If the macro appears inside a quoted string, the list is simply
* join(" ")ed together; otherwise every element expands to a separate
* quoted string.
*/
KDECORE_EXPORT QString expandMacrosShellQuote( const QString &str, const QHash<QChar,QStringList> &map,
QChar c = QLatin1Char('%') );
KDECORE_EXPORT QString expandMacrosShellQuote( const QString &str, const QHash<QString,QStringList> &map,
QChar c = QLatin1Char('%') );
}
#endif /* KMACROEXPANDER_H */