NetBSD-5.0.2/dist/ntp/libopts/cook.c
/* $NetBSD: cook.c,v 1.1.1.2 2007/06/24 15:49:24 kardel Exp $ */
/*
* Id: cook.c,v 4.10 2007/02/04 17:44:12 bkorb Exp
* Time-stamp: "2006-09-24 15:21:02 bkorb"
*
* This file contains the routines that deal with processing quoted strings
* into an internal format.
*/
/*
* Automated Options copyright 1992-2007 Bruce Korb
*
* Automated Options is free software.
* You may 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.
*
* Automated Options 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 Automated Options. See the file "COPYING". If not,
* write to: The Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
* As a special exception, Bruce Korb gives permission for additional
* uses of the text contained in his release of AutoOpts.
*
* The exception is that, if you link the AutoOpts library with other
* files to produce an executable, this does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* Your use of that executable is in no way restricted on account of
* linking the AutoOpts library code into it.
*
* This exception does not however invalidate any other reasons why
* the executable file might be covered by the GNU General Public License.
*
* This exception applies only to the code released by Bruce Korb under
* the name AutoOpts. If you copy code from other sources under the
* General Public License into a copy of AutoOpts, as the General Public
* License permits, the exception does not apply to the code that you add
* in this way. To avoid misleading anyone as to the status of such
* modified files, you must delete this exception notice from them.
*
* If you write modifications of your own for AutoOpts, it is your choice
* whether to permit this exception to apply to your modifications.
* If you do not wish that, delete this exception notice.
*/
/* = = = START-STATIC-FORWARD = = = */
/* static forward declarations maintained by :mkfwd */
/* = = = END-STATIC-FORWARD = = = */
/*=export_func ao_string_cook_escape_char
* private:
*
* what: escape-process a string fragment
* arg: + char const* + pzScan + points to character after the escape +
* arg: + char* + pRes + Where to put the result byte +
* arg: + unsigned int + nl_ch + replacement char if scanned char is \n +
*
* ret-type: unsigned int
* ret-desc: The number of bytes consumed processing the escaped character.
*
* doc:
*
* This function converts "t" into "\t" and all your other favorite
* escapes, including numeric ones: hex and ocatal, too.
* The returned result tells the caller how far to advance the
* scan pointer (passed in). The default is to just pass through the
* escaped character and advance the scan by one.
*
* Some applications need to keep an escaped newline, others need to
* suppress it. This is accomplished by supplying a '\n' replacement
* character that is different from \n, if need be. For example, use
* 0x7F and never emit a 0x7F.
*
* err: @code{NULL} is returned if the string is mal-formed.
=*/
unsigned int
ao_string_cook_escape_char( char const* pzIn, char* pRes, u_int nl )
{
unsigned int res = 1;
switch (*pRes = *pzIn++) {
case NUL: /* NUL - end of input string */
return 0;
case '\r':
if (*pzIn != '\n')
return 1;
res++;
/* FALLTHROUGH */
case '\n': /* NL - emit newline */
*pRes = (char)nl;
return res;
case 'a': *pRes = '\a'; break;
case 'b': *pRes = '\b'; break;
case 'f': *pRes = '\f'; break;
case 'n': *pRes = '\n'; break;
case 'r': *pRes = '\r'; break;
case 't': *pRes = '\t'; break;
case 'v': *pRes = '\v'; break;
case 'x': /* HEX Escape */
if (isxdigit( (int)*pzIn )) {
unsigned int val;
unsigned char ch = *pzIn++;
if ((ch >= 'A') && (ch <= 'F'))
val = 10 + (ch - 'A');
else if ((ch >= 'a') && (ch <= 'f'))
val = 10 + (ch - 'a');
else val = ch - '0';
ch = *pzIn;
if (! isxdigit( ch )) {
*pRes = val;
res = 2;
break;
}
val <<= 4;
if ((ch >= 'A') && (ch <= 'F'))
val += 10 + (ch - 'A');
else if ((ch >= 'a') && (ch <= 'f'))
val += 10 + (ch - 'a');
else val += ch - '0';
res = 3;
*pRes = val;
}
break;
default:
/*
* IF the character copied was an octal digit,
* THEN set the output character to an octal value
*/
if (isdigit( (int)*pRes ) && (*pRes < '8')) {
unsigned int val = *pRes - '0';
unsigned char ch = *pzIn++;
/*
* IF the second character is *not* an octal digit,
* THEN save the value and bail
*/
if ((ch < '0') || (ch > '7')) {
*pRes = val;
break;
}
val = (val<<3) + (ch - '0');
ch = *pzIn;
res = 2;
/*
* IF the THIRD character is *not* an octal digit,
* THEN save the value and bail
*/
if ((ch < '0') || (ch > '7')) {
*pRes = val;
break;
}
/*
* IF the new value would not be too large,
* THEN add on the third and last character value
*/
if ((val<<3) < 0xFF) {
val = (val<<3) + (ch - '0');
res = 3;
}
*pRes = val;
break;
}
}
return res;
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*
* A quoted string has been found.
* Find the end of it and compress any escape sequences.
*/
/*=export_func ao_string_cook
* private:
*
* what: concatenate and escape-process strings
* arg: + char* + pzScan + The *MODIFIABLE* input buffer +
* arg: + int* + pLineCt + The (possibly NULL) pointer to a line count +
*
* ret-type: char*
* ret-desc: The address of the text following the processed strings.
* The return value is NULL if the strings are ill-formed.
*
* doc:
*
* A series of one or more quoted strings are concatenated together.
* If they are quoted with double quotes (@code{"}), then backslash
* escapes are processed per the C programming language. If they are
* single quote strings, then the backslashes are honored only when they
* precede another backslash or a single quote character.
*
* err: @code{NULL} is returned if the string(s) is/are mal-formed.
=*/
char*
ao_string_cook( char* pzScan, int* pLineCt )
{
int l = 0;
char q = *pzScan;
/*
* It is a quoted string. Process the escape sequence characters
* (in the set "abfnrtv") and make sure we find a closing quote.
*/
char* pzD = pzScan++;
char* pzS = pzScan;
if (pLineCt == NULL)
pLineCt = &l;
for (;;) {
/*
* IF the next character is the quote character, THEN we may end the
* string. We end it unless the next non-blank character *after* the
* string happens to also be a quote. If it is, then we will change
* our quote character to the new quote character and continue
* condensing text.
*/
while (*pzS == q) {
*pzD = NUL; /* This is probably the end of the line */
pzS++;
scan_for_quote:
while (isspace((int)*pzS))
if (*(pzS++) == '\n')
(*pLineCt)++;
/*
* IF the next character is a quote character,
* THEN we will concatenate the strings.
*/
switch (*pzS) {
case '"':
case '\'':
break;
case '/':
/*
* Allow for a comment embedded in the concatenated string.
*/
switch (pzS[1]) {
default: return NULL;
case '/':
/*
* Skip to end of line
*/
pzS = strchr( pzS, '\n' );
if (pzS == NULL)
return NULL;
(*pLineCt)++;
break;
case '*':
{
char* p = strstr( pzS+2, "*/" );
/*
* Skip to terminating star slash
*/
if (p == NULL)
return NULL;
while (pzS < p) {
if (*(pzS++) == '\n')
(*pLineCt)++;
}
pzS = p + 2;
}
}
goto scan_for_quote;
default:
/*
* The next non-whitespace character is not a quote.
* The series of quoted strings has come to an end.
*/
return pzS;
}
q = *(pzS++); /* assign new quote character and advance scan */
}
/*
* We are inside a quoted string. Copy text.
*/
switch (*(pzD++) = *(pzS++)) {
case NUL:
return NULL;
case '\n':
(*pLineCt)++;
break;
case '\\':
/*
* IF we are escaping a new line,
* THEN drop both the escape and the newline from
* the result string.
*/
if (*pzS == '\n') {
pzS++;
pzD--;
(*pLineCt)++;
}
/*
* ELSE IF the quote character is '"' or '`',
* THEN we do the full escape character processing
*/
else if (q != '\'') {
int ct = ao_string_cook_escape_char( pzS, pzD-1, (u_int)'\n' );
if (ct == 0)
return NULL;
pzS += ct;
} /* if (q != '\'') */
/*
* OTHERWISE, we only process "\\", "\'" and "\#" sequences.
* The latter only to easily hide preprocessing directives.
*/
else switch (*pzS) {
case '\\':
case '\'':
case '#':
pzD[-1] = *pzS++;
}
} /* switch (*(pzD++) = *(pzS++)) */
} /* for (;;) */
}
/*
* Local Variables:
* mode: C
* c-file-style: "stroustrup"
* indent-tabs-mode: nil
* End:
* end of autoopts/cook.c */