freebsd-dev/gnu/usr.bin/dc/dc-string.c
1996-11-04 04:24:33 +00:00

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/*
* implement string functions for dc
*
* Copyright (C) 1994 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can either send email to this
* program's author (see below) or write to: The Free Software Foundation,
* Inc.; 675 Mass Ave. Cambridge, MA 02139, USA.
*/
/* This should be the only module that knows the internals of type dc_string */
#include "config.h"
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "dc.h"
#include "dc-proto.h"
struct dc_string {
char *s_ptr; /* pointer to base of string */
size_t s_len; /* length of counted string */
int s_refs; /* reference count to cut down on memory use by duplicates */
};
/* return a duplicate of the string in the passed value */
/* The mismatched data types forces the caller to deal with
* bad dc_type'd dc_data values, and makes it more convenient
* for the caller to not have to do the grunge work of setting
* up a dc_type result.
*/
dc_data
dc_dup_str DC_DECLARG((value))
dc_str value DC_DECLEND
{
dc_data result;
++((struct dc_string *)value)->s_refs;
result.v.string = value;
result.dc_type = DC_STRING;
return result;
}
/* free an instance of a dc_str value */
void
dc_free_str DC_DECLARG((value))
dc_str *value DC_DECLEND
{
struct dc_string *string = *value;
if (--string->s_refs < 1){
free(string->s_ptr);
free(string);
}
}
/* Output a dc_str value.
* Add a trailing newline if "newline" is set.
* Free the value after use if discard_flag is set.
*/
void
dc_out_str DC_DECLARG((value, newline, discard_flag))
dc_str value DC_DECLSEP
dc_boolean newline DC_DECLSEP
dc_boolean discard_flag DC_DECLEND
{
struct dc_string *string = value;
printf("%s", string->s_ptr);
if (newline == DC_TRUE)
printf("\n");
if (discard_flag == DC_TRUE)
dc_free_str(&value);
}
/* make a copy of a string (base s, length len)
* into a dc_str value; return a dc_data result
* with this value
*/
dc_data
dc_makestring DC_DECLARG((s, len))
const char *s DC_DECLSEP
size_t len DC_DECLEND
{
dc_data result;
struct dc_string *string;
string = dc_malloc(sizeof *string);
string->s_ptr = dc_malloc(len+1);
memcpy(string->s_ptr, s, len);
string->s_ptr[len] = '\0'; /* nul terminated for those who need it */
string->s_len = len;
string->s_refs = 1;
result.v.string = string;
result.dc_type = DC_STRING;
return result;
}
/* read a dc_str value from FILE *fp;
* if ldelim == rdelim, then read until a ldelim char or EOF is reached;
* if ldelim != rdelim, then read until a matching rdelim for the
* (already eaten) first ldelim is read.
* Return a dc_data result with the dc_str value as its contents.
*/
dc_data
dc_readstring DC_DECLARG((fp, ldelim, rdelim))
FILE *fp DC_DECLSEP
int ldelim DC_DECLSEP
int rdelim DC_DECLEND
{
static char *line_buf = NULL; /* a buffer to build the string in */
static size_t buflen = 0; /* the current size of line_buf */
int depth=1;
int c;
char *p;
const char *end;
if (!line_buf){
/* initial buflen should be large enough to handle most cases */
buflen = 2016;
line_buf = dc_malloc(buflen);
}
p = line_buf;
end = line_buf + buflen;
for (;;){
c = getc(fp);
if (c == EOF)
break;
else if (c == rdelim && --depth < 1)
break;
else if (c == ldelim)
++depth;
if (p >= end){
ptrdiff_t offset = p - line_buf;
/* buflen increment should be big enough
* to avoid execessive reallocs:
*/
buflen += 2048;
line_buf = realloc(line_buf, buflen);
if (!line_buf)
dc_memfail();
p = line_buf + offset;
end = line_buf + buflen;
}
*p++ = c;
}
return dc_makestring(line_buf, (size_t)(p-line_buf));
}
/* return the base pointer of the dc_str value;
* This function is needed because no one else knows what dc_str
* looks like.
*/
const char *
dc_str2charp DC_DECLARG((value))
dc_str value DC_DECLEND
{
return ((struct dc_string *)value)->s_ptr;
}
/* return the length of the dc_str value;
* This function is needed because no one else knows what dc_str
* looks like, and strlen(dc_str2charp(value)) won't work
* if there's an embedded '\0'.
*/
size_t
dc_strlen DC_DECLARG((value))
dc_str value DC_DECLEND
{
return ((struct dc_string *)value)->s_len;
}
/* initialize the strings subsystem */
void
dc_string_init DC_DECLVOID()
{
/* nothing to do for this implementation */
}