/*
* Mark the current position in the current context. Only one mark at a
* time is stored; use GoToMarkContext to return to it.
*/
void MarkPosContext( void )
/*************************/
{
if( !curContextInitialized ) Zoinks();
curContext.markPos = GetPosContext();
}
/*
* Scan a string. No leading whitespace is allowed. Returns a pointer
* to newly allocated memory containing the string. If leading whitespace
* is found, returns NULL. Quotes embedded within a string must be escaped
* by a preceding backslash; two consecutive backslashes are reduced to one.
*/
char *CmdScanString( void )
/*************************/
{
const char quotechar = '"';
int ch;
int inQuote = Quoted; /* true if inside a quoted string */
int backslash = 0; /* true if last char was a '\\' */
int start; /* context offset of string start */
char * buf = DupStrMem( "" );
size_t bufsize = 0;
size_t offset = 0;
/*** Return NULL if there's leading whitespace or no more data ***/
ch = GetCharContext();
if( !Quoted && isspace( ch ) ) {
UngetCharContext();
return( NULL );
} else if( ch != '\0' ) {
UngetCharContext();
} else {
return( NULL );
}
/*** Count the number of characters in the string ***/
start = GetPosContext();
for( ;; ) {
ch = GetCharContext();
if( ch == 0 ) break;
if( !inQuote && isspace( ch ) ) break;
if( ch == quotechar ) {
if( backslash ) {
backslash = 0; /* handle \" within a string */
} else if( inQuote ) {
if( Quoted ) {
Quoted = 0;
return( buf );
}
inQuote = 0; /* end of a quoted portion */
} else {
inQuote = 1; /* start of a quoted portion */
}
buf = got_char( buf, &bufsize, offset, ch );
offset++;
} else if( ch == '\\' ) {
if( backslash ) {
buf = got_char( buf, &bufsize, offset, ch );
offset++;
backslash = 0; /* second '\\' of a pair */
if( GetCharContext() == quotechar )
buf = got_char( buf, &bufsize, offset++, '\\' );
UngetCharContext();
} else {
backslash = 1; /* first '\\' of a pair */
}
} else {
if( backslash ) {
buf = got_char( buf, &bufsize, offset, '\\' );
offset++;
backslash = 0;
}
buf = got_char( buf, &bufsize, offset, ch );
offset++;
}
}
if( backslash ) { /* store any leftover backslash */
buf = got_char( buf, &bufsize, offset, '\\' );
offset++;
}
if( ch != 0 ) UngetCharContext();
return( buf );
}
/*
* Unget a character back into the current context.
*/
void UngetCharContext( void )
/***************************/
{
if( !curContextInitialized ) Zoinks();
SetPosContext( GetPosContext() - 1 );
}
