strparse.c

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/*
 * (c) Copyright 1992, 1993 by Panagiotis Tsirigotis
 * All rights reserved.  The file named COPYRIGHT specifies the terms 
 * and conditions for redistribution.
 */

static char RCSid[] = "strparse.c,v 1.2 1995/03/25 23:45:12 hardy Exp" ;
static char version[] = VERSION ;

#include <string.h>
#include "str.h"
#include "strparse.h"

char *malloc() ;

int str_errno ;


PRIVATE char *new_string( s )
	register char *s ;
{
	register char *p = malloc( (unsigned)strlen( s ) + 1 ) ;

	return( p ? strcpy( p, s ) : p ) ;
}


str_h str_parse( str, separ, flags, errnop )
	register char *str ;
	char *separ ;
	int flags ;
	int *errnop ;
{
	register struct str_handle *hp ;
	int *errp = ( errnop == NULL ) ? &str_errno : errnop ;
	char *malloc() ;

	if ( separ == NULL )
		HANDLE_ERROR( flags, NULL, errp, STR_ENULLSEPAR,
								"STR str_parse: NULL separator\n" ) ;

	hp = (struct str_handle *) malloc( sizeof( struct str_handle ) ) ;
	if ( hp == NULL )
		HANDLE_ERROR( flags, NULL, errp, STR_ENOMEM,
								"STR str_parse: malloc failed\n" ) ;

	hp->string = str ;
	hp->pos = str ;
	hp->separator = new_string( separ ) ;
	if ( hp->separator == NULL )
		if ( flags & STR_RETURN_ERROR )
		{
			free( (char *) hp ) ;
			*errp = STR_ENOMEM ;
			return( NULL ) ;
		}
		else
			TERMINATE( "STR str_parse: malloc failed\n" ) ;
	
	hp->flags = flags ;
	hp->errnop = errp ;
	hp->no_more = ( str == NULL ) ;
	return( (str_h) hp ) ;
}


void str_endparse( handle )
	str_h handle ;
{
	register struct str_handle *hp = (struct str_handle *) handle ;

	free( hp->separator ) ;
	free( (char *) handle ) ;
}


/*
 * Change the string
 */
int str_setstr( handle, newstr )
	str_h handle ;
	char *newstr ;
{
	register struct str_handle *hp = (struct str_handle *) handle ;
	
	if ( newstr == NULL )
		HANDLE_ERROR( hp->flags, STR_ERR, hp->errnop, STR_ENULLSTRING,
								"STR str_setstr: NULL string\n" ) ;
	
	hp->string = newstr ;
	hp->pos = newstr ;
	hp->no_more = FALSE ;
	return( STR_OK ) ;
}



/*
 * Change the separator
 */
int str_separator( handle, separator )
	str_h handle ;
	char *separator ;
{
	register struct str_handle *hp = (struct str_handle *) handle ;
	char *new_separator ;

	if ( separator == NULL )
		HANDLE_ERROR( hp->flags, STR_ERR, hp->errnop, STR_ENULLSEPAR,
								"STR str_separator: NULL separator\n" ) ;
	new_separator = new_string( separator ) ;
	if ( new_separator == NULL )
		HANDLE_ERROR( hp->flags, STR_ERR, hp->errnop, STR_ENOMEM,
			"STR str_separator: malloc failed\n" ) ;

	free( hp->separator ) ;
	hp->separator = new_separator ;
	return( STR_OK ) ;
}


char *str_nextpos( handle )
	str_h handle ;
{
	struct str_handle *hp = (struct str_handle *) handle ;

	if ( hp->no_more || *hp->pos == '\0' )
		return( NULL ) ;
	else
		return( hp->pos ) ;
}


char *str_component( handle )
	str_h handle ;
{
	register struct str_handle *hp = (struct str_handle *) handle ;
	register char *start, *last ;
	register int first_call = ( hp->pos == hp->string ) ;
	register int sep_count ;
	char *retval ;
	int last_char ;

	if ( hp->no_more )
		return( NULL ) ;

	/*
	 * Get number of separator characters.
	 * Find beginning of component.
	 */
	sep_count = strspn( hp->pos, hp->separator ) ;

	/*
	 * If this is the first call, and there are separator characters
	 * at the beginning of the string and the STR_NULL_START flag is set
	 * we return a 0-length string.
	 */
	if ( first_call && sep_count > 0 && ( hp->flags & STR_NULL_START ) )
	{
		start = hp->pos ;
		last = hp->pos ;
	}
	else
	{
		start = hp->pos + sep_count ;

		if ( *start == '\0' )
		{
			last = start ;
			hp->no_more = TRUE ;
			if ( ! ( hp->flags & STR_NULL_END ) )
				return( NULL ) ;
		}
		else
		{
			last = strpbrk( start, hp->separator ) ;
			if ( last == NULL )
				last = start + strlen( start ) ;
		}
	}

	/*
	 * At this point, the following variables must be set:
	 *		start:	beginning of component
	 *		last:   	end of component + 1
	 *
	 * If STR_MALLOC is set, allocate space for the new string.
	 *
	 * NOTE: If STR_MALLOC is not set, the processed string is trashed.
	 */
	last_char = *last ;
	if ( hp->flags & STR_MALLOC )
	{
		int len = last - start ;

		retval = malloc( (unsigned)len + 1 ) ;
		if ( retval == NULL )
			HANDLE_ERROR( hp->flags, NULL, hp->errnop, STR_ENOMEM,
											"STR str_component: malloc failed\n" ) ;
		strncpy( retval, start, len )[ len ] = '\0' ;
	}
	else
	{
		retval = start ;
		*last = '\0' ;
	}

	/*
	 * Check if last_char is NUL to avoid setting hp->pos past the
	 * end of the string
	 */
	hp->pos = ( last_char == '\0' ) ? last : last+1 ;
	return( retval ) ;
}