freebsd-src/contrib/cpio/dstring.c
1997-03-29 22:40:46 +00:00

115 lines
2.8 KiB
C

/* dstring.c - The dynamic string handling routines used by cpio.
Copyright (C) 1990, 1991, 1992 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <stdio.h>
#if defined(HAVE_STRING_H) || defined(STDC_HEADERS)
#include <string.h>
#else
#include <strings.h>
#endif
#include "dstring.h"
#if __STDC__
# define P_(s) s
#else
# define P_(s) ()
#endif
char *xmalloc P_((unsigned n));
char *xrealloc P_((char *p, unsigned n));
/* Initialiaze dynamic string STRING with space for SIZE characters. */
void
ds_init (string, size)
dynamic_string *string;
int size;
{
string->ds_length = size;
string->ds_string = (char *) xmalloc (size);
}
/* Expand dynamic string STRING, if necessary, to hold SIZE characters. */
void
ds_resize (string, size)
dynamic_string *string;
int size;
{
if (size > string->ds_length)
{
string->ds_length = size;
string->ds_string = (char *) xrealloc ((char *) string->ds_string, size);
}
}
/* Dynamic string S gets a string terminated by the EOS character
(which is removed) from file F. S will increase
in size during the function if the string from F is longer than
the current size of S.
Return NULL if end of file is detected. Otherwise,
Return a pointer to the null-terminated string in S. */
char *
ds_fgetstr (f, s, eos)
FILE *f;
dynamic_string *s;
char eos;
{
int insize; /* Amount needed for line. */
int strsize; /* Amount allocated for S. */
int next_ch;
/* Initialize. */
insize = 0;
strsize = s->ds_length;
/* Read the input string. */
next_ch = getc (f);
while (next_ch != eos && next_ch != EOF)
{
if (insize >= strsize - 1)
{
ds_resize (s, strsize * 2 + 2);
strsize = s->ds_length;
}
s->ds_string[insize++] = next_ch;
next_ch = getc (f);
}
s->ds_string[insize++] = '\0';
if (insize == 1 && next_ch == EOF)
return NULL;
else
return s->ds_string;
}
char *
ds_fgets (f, s)
FILE *f;
dynamic_string *s;
{
return ds_fgetstr (f, s, '\n');
}
char *
ds_fgetname (f, s)
FILE *f;
dynamic_string *s;
{
return ds_fgetstr (f, s, '\0');
}