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/* sexp-parse.h - S-Exp helper functions
* Copyright (C) 2002 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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 of the License, or
* (at your option) any later version.
*
* GnuPG 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifndef SEXP_PARSE_H
#define SEXP_PARSE_H
#include "../common/util.h"
/* Return the length of the next S-Exp part and update the pointer to
the first data byte. 0 is return on error */
static inline size_t
snext (unsigned char const **buf)
{
const unsigned char *s;
int n;
s = *buf;
for (n=0; *s && *s != ':' && digitp (s); s++)
n = n*10 + atoi_1 (s);
if (!n || *s != ':')
return 0; /* we don't allow empty lengths */
*buf = s+1;
return n;
}
/* Skip over the S-Expression BUF points to and update BUF to point to
the chacter right behind. DEPTH gives the initial number of open
lists and may be passed as a positive number to skip over the
remainder of an S-Expression if the current position is somewhere
in an S-Expression. The function may return an error code if it
encounters an impossible conditions */
static inline int
sskip (unsigned char const **buf, int *depth)
{
const unsigned char *s = *buf;
size_t n;
int d = *depth;
while (d > 0)
{
if (*s == '(')
{
d++;
s++;
}
else if (*s == ')')
{
d--;
s++;
}
else
{
if (!d)
return GNUPG_Invalid_Sexp;
n = snext (&s);
if (!n)
return GNUPG_Invalid_Sexp;
s += n;
}
}
*buf = s;
*depth = d;
return 0;
}
/* Check whether the the string at the address BUF points to matches
the token. Return true on match and update BUF to point behind the
token. */
static inline int
smatch (unsigned char const **buf, size_t buflen, const char *token)
{
size_t toklen = strlen (token);
if (buflen != toklen || memcmp (*buf, token, toklen))
return 0;
*buf += toklen;
return 1;
}
#endif /*SEXP_PARSE_H*/
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