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confparse.cc
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confparse.cc
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// -*- c-basic-offset: 4; related-file-name: "../include/click/confparse.hh" -*-
/*
* confparse.{cc,hh} -- configuration string parsing
* Eddie Kohler
*
* Copyright (c) 1999-2000 Massachusetts Institute of Technology
* Copyright (c) 2000-2001 Mazu Networks, Inc.
* Copyright (c) 2001-2003 International Computer Science Institute
* Copyright (c) 2004-2008 Regents of the University of California
* Copyright (c) 2008 Meraki, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, subject to the conditions
* listed in the Click LICENSE file. These conditions include: you must
* preserve this copyright notice, and you cannot mention the copyright
* holders in advertising related to the Software without their permission.
* The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
* notice is a summary of the Click LICENSE file; the license in that file is
* legally binding.
*/
#include <click/config.h>
#define CLICK_COMPILING_CONFPARSE_CC 1
#include <click/glue.hh>
#include <click/confparse.hh>
#include <click/args.hh>
#include <click/error.hh>
#include <click/straccum.hh>
#include <click/ipaddress.hh>
#include <click/etheraddress.hh>
#include <click/hashtable.hh>
#if HAVE_IP6
# include <click/ip6address.hh>
# include <click/ip6flowid.hh>
#endif
#if !CLICK_TOOL
# include <click/router.hh>
# include <click/handlercall.hh>
# include <click/nameinfo.hh>
# include <click/standard/addressinfo.hh>
# include <click/packet_anno.hh>
# define CP_CONTEXT , const Element *context
# define CP_PASS_CONTEXT , context
#else
# include <click/timestamp.hh>
# if HAVE_NETDB_H
# include <netdb.h>
# endif
# define CP_CONTEXT
# define CP_PASS_CONTEXT
#endif
#if CLICK_USERLEVEL || CLICK_TOOL
# include <pwd.h>
#endif
#if CLICK_BSDMODULE
# include <machine/stdarg.h>
#else
# include <stdarg.h>
#endif
CLICK_DECLS
int cp_errno;
/// @file confparse.hh
/// @brief Support for parsing configuration strings.
///
/// Defines functions and helpers for parsing configuration strings into
/// numbers, IP addresses, and other useful types.
///
/// <h3>cp_va_kparse Introduction</h3>
///
/// Most elements that take configuration strings parse them using the
/// cp_va_kparse() function and friends. These functions take a variable
/// argument list describing the desired arguments and result slots. They
/// parse the configuration, store the results in the slots, report any
/// errors, and return the number of arguments successfully assigned on
/// success or a negative value on failure.
///
/// @note Previous versions of Click used cp_va_parse() and friends instead of
/// cp_va_kparse(). A guide for transitioning from cp_va_parse() to
/// cp_va_kparse() is given in the documentation for cp_va_parse().
///
/// Here are some cp_va_kparse() examples.
///
/// @code
/// int MyElement::configure(Vector<String> &conf, ErrorHandler *errh) {
/// String data; uint32_t limit = 0; bool stop = false;
/// if (cp_va_kparse(conf, this, errh,
/// "DATA", cpkP+cpkM, cpString, &data,
/// "LIMIT", cpkP, cpUnsigned, &limit,
/// "STOP", 0, cpBool, &stop,
/// cpEnd) < 0) // argument list always terminated by cpEnd
/// return -1;
/// ... }
/// @endcode
///
/// This element supports three arguments, <tt>DATA</tt> (a string),
/// <tt>LIMIT</tt> (an unsigned integer), and <tt>STOP</tt> (a boolean). Here
/// are some example element definitions:
///
/// @code
/// MyElement(DATA "blah blah blah", LIMIT 10);
/// /* OK, sets data = "blah blah blah", limit = 10; leaves stop unchanged */
/// MyElement(LIMIT 10, DATA "blah blah blah");
/// /* OK, has the same effect */
/// MyElement(LIMIT 10);
/// /* error "missing mandatory DATA argument" */
/// /* (the cpkM flag marks an argument as mandatory) */
/// MyElement(DATA "blah blah blah");
/// /* OK, sets data = "blah blah blah" and leaves limit unchanged */
/// /* (LIMIT lacks the cpkM flag, so it can be left off) */
/// MyElement(DATA "blah blah blah", STOP true);
/// /* OK, sets data = "blah blah blah" and stop = true */
/// /* (LIMIT lacks the cpkM flag, so it can be left off) */
/// MyElement(DATA "blah blah blah", LIMIT 10, DATA "blah");
/// /* OK, sets data = "blah" (later arguments take precedence) */
/// MyElement(DATA "blah blah blah", LIMIT 10, BOGUS "bogus");
/// /* error "too many arguments" */
/// MyElement("blah blah blah", 10);
/// /* OK, same as MyElement(DATA "blah blah blah", LIMIT 10) */
/// /* (the cpkP flag allows positional arguments) */
/// MyElement("blah blah blah", 10, true);
/// /* error "too many arguments" */
/// /* (STOP lacks the cpkP flag and must be given by name) */
/// @endcode
///
/// <h3>cp_va_kparse Items</h3>
///
/// An item in a cp_va_kparse() argument list consists of:
///
/// <ol>
/// <li><strong>Argument name</strong> (type: const char *). Example: <tt>"DATA"</tt>.</li>
/// <li><strong>Parse flags</strong> (type: int). Zero or more of
/// #cpkP, #cpkM, and #cpkC.</li>
/// <li>If the parse flags contain #cpkC, then a <strong>confirmation
/// flag</strong> comes next (type: bool *). This flag is set to true if an
/// argument successfully matched the item and false if not.</li>
/// <li><strong>Argument type</strong> (type: @ref CpVaParseCmd). Defines the type
/// of argument read from the configuration string. Example: ::cpString.</li>
/// <li>Optional <strong>parse parameters</strong> (determined by the
/// argument type). For example, ::cpUnsignedReal2 takes a parse parameter
/// that defines how many bits of fraction are needed.</li>
/// <li><strong>Result storage</strong> (determined by the argument type).</li>
/// </ol>
///
/// This example uses more of these features.
///
/// @code
/// int MyElement2::configure(Vector<String> &conf, ErrorHandler *errh) {
/// bool p_given; uint32_t p = 0x10000; IPAddress addr, mask;
/// if (cp_va_kparse(conf, this, errh,
/// "P", cpkC, &p_given, cpUnsignedReal2, 16, &p,
/// "NETWORK", 0, cpIPPrefix, &addr, &mask,
/// cpEnd) < 0)
/// return -1;
/// ... }
/// @endcode
///
/// This element supports two arguments, <tt>P</tt> (a fixed-point number with
/// 16 bits of fraction) and <tt>NETWORK</tt> (an IP prefix, defined by
/// address and mask). Here are some example element definitions:
///
/// @code
/// MyElement2();
/// /* OK, since neither argument is mandatory; sets p_given = false */
/// MyElement2(P 0.5, PREFIX 10/8);
/// /* OK, sets p_given = true, p = 0x8000, addr = 10.0.0.0, and mask = 255.0.0.0 */
/// @endcode
///
/// <h3>cp_va_kparse Argument Types</h3>
///
/// cp_va_kparse() argument types are defined by @ref CpVaParseCmd constants.
/// For example, the ::cpInteger argument type parses a 32-bit signed integer.
/// See @ref CpVaParseCmd for more. Elements may also define their own
/// argument types with cp_register_argtype().
///
/// <h3>Direct Parsing Functions</h3>
///
/// You may also call parsing functions directly if cp_va_kparse() doesn't
/// match your needs. These functions have names like cp_bool(), cp_string(),
/// cp_integer(), cp_ip_address(), and so forth, and share a basic interface:
///
/// @li The first argument, const String &@a str, contains the string to be
/// parsed.
/// @li The last argument(s) specify locations where the parsed results should
/// be stored. These @a result arguments have pointer type.
/// @li The return type is bool. True is returned if and only if parsing
/// succeeds, and the @a result slots are modified if and only if parsing
/// succeeds.
/// @li Most parsing functions expect to parse the entire supplied string. Any
/// extraneous characters, such as trailing whitespace, cause parsing to
/// fail.
/// @li Most parsing functions never report errors to any source; they simply
/// return false when parsing fails.
///
/// <h3>Argument Manipulation</h3>
///
/// Finally, functions like cp_uncomment(), cp_unquote(), cp_quote(),
/// cp_argvec(), and cp_is_space() manipulate arguments as strings.
/// cp_uncomment() removes comments and simplifies white space; cp_unquote()
/// removes quotation marks and expands backslash escapes; cp_argvec() splits
/// a configuration string at commas; and so forth.
/** @brief Find the first nonspace character in the string [@a begin, @a end).
* @param begin beginning of string
* @param end one past end of string
* @return Pointer to first non-space character in [@a begin, @a end), or
* @a end if the string is all spaces.
*
* Space characters are defined as by isspace() in the "C" locale, and
* consist of the characters in <tt>[ \\f\\n\\r\\t\\v]</tt>. */
const char *
cp_skip_space(const char *begin, const char *end)
{
while (begin < end && isspace((unsigned char) *begin))
begin++;
return begin;
}
/** @brief Remove spaces from the beginning of @a str.
* @param[in,out] str string
* @return True if the resulting string is nonempty, false otherwise. */
bool
cp_eat_space(String &str)
{
const char *begin = str.begin(), *end = str.end();
const char *space = cp_skip_space(begin, end);
str = str.substring(space, end);
return space != begin;
}
/** @brief Test whether @a str is a valid "word".
*
* A "word" in Click consists of one or more characters in the ASCII range
* '!' through '~', inclusive, except for the quote characters '"' and ''',
* the backslash '\', and the comma ','. */
bool
cp_is_word(const String &str)
{
for (const char *s = str.begin(); s != str.end(); s++)
if (*s == '\"' || *s == '\'' || *s == '\\' || *s == ','
|| *s <= 32 || *s >= 127)
return false;
return str.length() > 0;
}
/** @brief Test if @a str is a valid Click identifier.
*
* A Click identifier consists of one or more characters in the set
* <tt>[A-Za-z0-9/_@]</tt>, with restrictions on where <tt>/</tt> may appear
* (it cannot be the first character or the last character, and two adjacent
* slashes aren't allowed either). */
bool
cp_is_click_id(const String &str)
{
const unsigned char *s = reinterpret_cast<const unsigned char*>(str.data());
int len = str.length();
for (int i = 0; i < len; i++)
if (isalnum(s[i]) || s[i] == '_' || s[i] == '@')
/* character OK */;
else if (s[i] != '/' || i == 0 || i == len - 1 || s[i+1] == '/')
return false;
return len > 0;
}
static const char *
skip_comment(const char *s, const char *end)
{
assert(s + 1 < end && *s == '/' && (s[1] == '/' || s[1] == '*'));
if (s[1] == '/') {
for (s += 2; s + 1 < end && *s != '\n' && *s != '\r'; s++)
/* nada */;
if (s + 1 < end && *s == '\r' && s[1] == '\n')
s++;
return s + 1;
} else { /* s[1] == '*' */
for (s += 2; s + 2 < end && (*s != '*' || s[1] != '/'); s++)
/* nada */;
return s + 2;
}
}
static const char *
skip_backslash(const char *s, const char *end)
{
assert(s < end && *s == '\\');
if (s + 1 >= end)
return s + 1;
else if (s[1] == '<') {
for (s += 2; s < end; )
if (*s == '>')
return s + 1;
else if (*s == '/' && s + 1 < end && (s[1] == '/' || s[1] == '*'))
s = skip_comment(s, end);
else
s++;
return s;
} else if (s[1] == '\r' && s + 2 < end && s[2] == '\n')
return s + 3;
else
return s + 2;
}
/** @brief Return the first character after a double-quoted string starting at @a begin.
* @param begin beginning of double-quoted string
* @param end one past end of string
* @return Pointer to first character in [@a begin, @a end) after the
* double-quoted string, or @a end if the double-quoted portion is not
* correctly terminated.
* @pre @a begin < @a end and *@a begin == '\"'
*
* cp_skip_double_quote() understands all the backslash escapes processed
* by cp_process_backslash(). */
const char *
cp_skip_double_quote(const char *begin, const char *end)
{
assert(begin < end && *begin == '\"');
for (begin++; begin < end; )
if (*begin == '\\')
begin = skip_backslash(begin, end);
else if (*begin == '\"')
return begin + 1;
else
begin++;
return end;
}
static const char *
skip_single_quote(const char *s, const char *end)
{
assert(s < end && *s == '\'');
for (s++; s < end; s++)
if (*s == '\'')
return s + 1;
return end;
}
/// @brief Find the first nonspace, noncomment character in the string [@a begin, @a end).
/// @param begin beginning of string
/// @param end one past end of string
/// @return Pointer to first nonspace and noncomment character in [@a begin,
/// @a end), or @a end if the string is all spaces and comments.
///
/// This function recognizes C-style and C++-style comments:
/// @code
/// /* C style */ // C++ style (runs until newline)
/// @endcode
/// In C++-style comments, the character
/// sequences <tt>"\n"</tt>, <tt>"\r"</tt>, and <tt>"\r\n"</tt> are
/// recognized as newlines. The newline is considered part of the comment.
const char *
cp_skip_comment_space(const char *begin, const char *end)
{
for (; begin < end; begin++) {
if (isspace((unsigned char) *begin))
/* nada */;
else if (*begin == '/' && begin + 1 < end && (begin[1] == '/' || begin[1] == '*'))
begin = skip_comment(begin, end) - 1;
else
break;
}
return begin;
}
static String
partial_uncomment(const String &str, int i, int *comma_pos)
{
const char *s = str.data() + i;
const char *end = str.end();
// skip initial spaces
s = cp_skip_comment_space(s, end);
// accumulate text, skipping comments
StringAccum sa;
const char *left = s;
const char *right = s;
bool closed = false;
while (s < end) {
if (isspace((unsigned char) *s))
s++;
else if (*s == '/' && s + 1 < end && (s[1] == '/' || s[1] == '*')) {
s = skip_comment(s, end);
closed = true;
} else if (*s == ',' && comma_pos)
break;
else {
if (closed) {
sa << str.substring(left, right) << ' ';
left = s;
closed = false;
}
if (*s == '\'')
s = skip_single_quote(s, end);
else if (*s == '\"')
s = cp_skip_double_quote(s, end);
else if (*s == '\\' && s + 1 < end && s[1] == '<')
s = skip_backslash(s, end);
else
s++;
right = s;
}
}
if (comma_pos)
*comma_pos = s - str.begin();
if (!sa)
return str.substring(left, right);
else {
sa << str.substring(left, right);
return sa.take_string();
}
}
/// @brief Simplify @a str's whitespace and replace comments by spaces,
/// returning the result.
/// @return A version of @a str with all initial space removed, all final
/// space removed, and all comments and space-comment sequences
/// replaced by a single space character.
///
/// Adjacent space characters are preserved in the output @em unless they
/// appear next to a comment. For example:
/// @code
/// cp_uncomment(" a b ") == "a b", but:
/// cp_uncomment(" a /* Comment */ b ") == "a b"
/// @endcode
/// Comment characters inside double or single quotes are ignored:
/// @code
/// cp_uncomment(" \" /*??? */ \" ") == "\" /*??? */ \""
/// @endcode
String
cp_uncomment(const String &str)
{
return partial_uncomment(str, 0, 0);
}
/// @brief Process a backslash escape, appending results to @a sa.
/// @param begin beginning of string
/// @param end end of string
/// @param sa string accumulator
/// @pre @a begin < @a end, and @a begin points to a backslash character.
/// @return A pointer to the first character in [@a begin, @a end) following
/// the backslash escape.
///
/// This function understands the following backslash escapes.
/// <ul>
/// <li><tt>"\[newline]"</tt> is ignored (it adds no characters to @a sa),
/// where <tt>[newline]</tt> is one of the sequences <tt>"\n"</tt>,
/// <tt>"\r"</tt>, or <tt>"\r\n"</tt>.</li>
/// <li><tt>"\[C escape]"</tt> is processed as in C, where <tt>[C escape]</tt>
/// is one of the characters in <tt>[abfnrtv]</tt>.</li>
/// <li><tt>"\\"</tt> expands to a single backslash. Similarly,
/// <tt>"\$"</tt>, <tt>"\'"</tt>, <tt>"\\""</tt>, and <tt>"\,"</tt>
/// expand to the escaped character.</li>
/// <li><tt>"\[1-3 octal digits]"</tt> expands to the given character.</li>
/// <li><tt>"\x[hex digits]"</tt> expands to the given character.</li>
/// <li><tt>"\<[hex digits, spaces, and comments]>"</tt> expands to the
/// binary string indicated by the <tt>hex digits</tt>. Spaces and comments
/// are removed. For example,
/// @code
/// "\<48656c6C 6f 2 /* And finally */ 1>" expands to "Hello!"
/// @endcode
/// (This example should begin with <tt>"\<"</tt>; it may not because of Doxygen problems.)</li>
/// <li>A backslash at the end of the string expands to a backslash.</li>
/// </ul>
const char *
cp_process_backslash(const char *begin, const char *end, StringAccum &sa)
{
assert(begin < end && *begin == '\\');
if (begin == end - 1) {
sa << '\\';
return end;
}
switch (begin[1]) {
case '\r':
return (begin + 2 < end && begin[2] == '\n' ? begin + 3 : begin + 2);
case '\n':
return begin + 2;
case 'a': sa << '\a'; return begin + 2;
case 'b': sa << '\b'; return begin + 2;
case 'f': sa << '\f'; return begin + 2;
case 'n': sa << '\n'; return begin + 2;
case 'r': sa << '\r'; return begin + 2;
case 't': sa << '\t'; return begin + 2;
case 'v': sa << '\v'; return begin + 2;
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7': {
int c = 0, d = 0;
for (begin++; begin < end && *begin >= '0' && *begin <= '7' && d < 3;
begin++, d++)
c = c*8 + *begin - '0';
sa << (char)c;
return begin;
}
case 'x': {
int c = 0;
for (begin += 2; begin < end; begin++)
if (*begin >= '0' && *begin <= '9')
c = c*16 + *begin - '0';
else if (*begin >= 'A' && *begin <= 'F')
c = c*16 + *begin - 'A' + 10;
else if (*begin >= 'a' && *begin <= 'f')
c = c*16 + *begin - 'a' + 10;
else
break;
sa << (char)c;
return begin;
}
case '<': {
int c = 0, d = 0;
for (begin += 2; begin < end; begin++) {
if (*begin == '>')
return begin + 1;
else if (*begin >= '0' && *begin <= '9')
c = c*16 + *begin - '0';
else if (*begin >= 'A' && *begin <= 'F')
c = c*16 + *begin - 'A' + 10;
else if (*begin >= 'a' && *begin <= 'f')
c = c*16 + *begin - 'a' + 10;
else if (*begin == '/' && begin + 1 < end && (begin[1] == '/' || begin[1] == '*')) {
begin = skip_comment(begin, end) - 1;
continue;
} else
continue; // space (ignore it) or random (error)
if (++d == 2) {
sa << (char)c;
c = d = 0;
}
}
// ran out of space in string
return end;
}
case '\\': case '\'': case '\"': case '$': case ',':
default:
sa << begin[1];
return begin + 2;
}
}
/// @brief Remove one level of quoting from @a str, returning the result.
///
/// This function acts as cp_uncomment, plus removing one level of quoting.
/// <tt>"..."</tt> and <tt>'...'</tt> sequences are replaced by their contents.
/// Backslash escapes are expanded inside double quotes (see
/// cp_process_backslash). Additionally, <tt>"\<...>"</tt> sequences are
/// expanded outside of any quotes. For example:
/// @code
/// cp_unquote("\"\\n\" abc /* 123 */ '/* def */'") == "\n abc /* def */"
/// @endcode
String
cp_unquote(const String &str)
{
String xtr = partial_uncomment(str, 0, 0);
const char *s = xtr.data();
const char *end = xtr.end();
// accumulate a word
StringAccum sa;
const char *start = s;
int quote_state = 0;
for (; s < end; s++)
switch (*s) {
case '\"':
case '\'':
if (quote_state == 0) {
sa << xtr.substring(start, s); // null string if start >= s
start = s + 1;
quote_state = *s;
} else if (quote_state == *s) {
sa << xtr.substring(start, s);
start = s + 1;
quote_state = 0;
}
break;
case '\\':
if (s + 1 < end && (quote_state == '\"'
|| (quote_state == 0 && s[1] == '<'))) {
sa << xtr.substring(start, s);
start = cp_process_backslash(s, end, sa);
s = start - 1;
}
break;
}
if (start == xtr.begin())
return xtr;
else {
sa << xtr.substring(start, s);
return sa.take_string();
}
}
/// @brief Return a quoted version of @a str.
/// @param str string
/// @param allow_newlines If true, then newline sequences are allowed in
/// in the result. If false, then newline sequences should be
/// translated to their backslash escape equivalents. Default is false.
///
/// Returns a double-quoted string that, when unquoted by cp_unquote(), will
/// equal @a str. The returned string consists of a single double-quoted
/// string, and in particular is never empty.
///
/// @invariant cp_quote(@a str) != "" && cp_unquote(cp_quote(@a str)) == @a str
String
cp_quote(const String &str, bool allow_newlines)
{
if (!str)
return String("\"\"");
const char *s = str.data();
const char *end = str.end();
StringAccum sa;
const char *start = s;
sa << '\"';
for (; s < end; s++)
switch (*s) {
case '\\': case '\"': case '$':
sa << str.substring(start, s) << '\\' << *s;
start = s + 1;
break;
case '\t':
sa << str.substring(start, s) << "\\t";
start = s + 1;
break;
case '\r':
sa << str.substring(start, s) << "\\r";
start = s + 1;
break;
case '\n':
if (!allow_newlines) {
sa << str.substring(start, s) << "\\n";
start = s + 1;
}
break;
default:
if ((unsigned char)*s < 32 || (unsigned char)*s >= 127) {
unsigned u = (unsigned char)*s;
sa << str.substring(start, s)
<< '\\' << (char)('0' + (u >> 6))
<< (char)('0' + ((u >> 3) & 7))
<< (char)('0' + (u & 7));
start = s + 1;
}
break;
}
sa << str.substring(start, s) << '\"';
return sa.take_string();
}
/// @brief Separate a configuration string into arguments at commas.
/// @param str configuration string
/// @param[out] conf arguments
///
/// The configuration string is broken into arguments at unquoted commas.
/// Each argument is passed through cp_uncomment(), then appended to @a conf.
/// If the final argument is empty, it is ignored. For example:
/// @code
/// cp_argvec("a, b, c", v) appends "a", "b", "c"
/// cp_argvec(" a /*?*/ b, c, ", v) appends "a b", "c"
/// cp_argvec("\"x, y\" // ?", v) appends "\"x, y\""
/// @endcode
void
cp_argvec(const String &str, Vector<String> &conf)
{
// common case: no configuration
int len = str.length();
if (len == 0)
return;
for (int pos = 0; pos < len; pos++) {
String arg = partial_uncomment(str, pos, &pos);
// add the argument if it is nonempty or not the last argument
if (arg || pos < len)
conf.push_back(arg);
}
}
static const char *
skip_spacevec_item(const char *s, const char *end)
{
while (s < end)
switch (*s) {
case '/':
// a comment ends the item
if (s + 1 < end && (s[1] == '/' || s[1] == '*'))
return s;
s++;
break;
case '\"':
s = cp_skip_double_quote(s, end);
break;
case '\'':
s = skip_single_quote(s, end);
break;
case '\\': // check for \<...> strings
if (s + 1 < end && s[1] == '<')
s = skip_backslash(s, end);
else
s++;
break;
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
return s;
default:
s++;
break;
}
return s;
}
/// @brief Separate a configuration string into arguments at unquoted spaces.
/// @param str configuration string
/// @param[out] conf arguments
///
/// The configuration string is broken into arguments at unquoted spaces.
/// Each argument is passed through cp_uncomment(), then appended to @a conf.
/// If the final argument is empty, it is ignored. For example:
/// @code
/// cp_spacevec("a b, c", v) appends "a", "b,", "c"
/// cp_spacevec(" 'a /*?*/ b'c", v) appends "'a /*?*/ b'c"
/// @endcode
void
cp_spacevec(const String &str, Vector<String> &conf)
{
// common case: no configuration
if (str.length() == 0)
return;
// collect arguments like cp_shift_spacevec
const char *s = str.data();
const char *end = str.end();
while ((s = cp_skip_comment_space(s, end)) < end) {
const char *t = skip_spacevec_item(s, end);
conf.push_back(str.substring(s, t));
s = t;
}
}
String
cp_shift_spacevec(String &str)
{
const char *item = cp_skip_comment_space(str.begin(), str.end());
const char *item_end = skip_spacevec_item(item, str.end());
String answer = str.substring(item, item_end);
item_end = cp_skip_comment_space(item_end, str.end());
str = str.substring(item_end, str.end());
return answer;
}
/// @brief Join the strings of @a conf with commas and return the result.
///
/// This function does not quote or otherwise protect the strings in @a conf.
/// The caller should do that if necessary.
String
cp_unargvec(const Vector<String> &conf)
{
if (conf.size() == 0)
return String();
else if (conf.size() == 1)
return conf[0];
else {
StringAccum sa;
sa << conf[0];
for (int i = 1; i < conf.size(); i++)
sa << ", " << conf[i];
return sa.take_string();
}
}
/// @brief Join the strings in [@a begin, @a end) with spaces and return the result.
/// @param begin first string in range
/// @param end one past last string in range
///
/// This function does not quote or otherwise protect the strings in [@a
/// begin, @a end). The caller should do that if necessary.
/// @sa cp_unspacevec(const Vector<String> &)
String
cp_unspacevec(const String *begin, const String *end)
{
StringAccum sa;
for (; begin < end; begin++)
sa << *begin << ' ';
sa.pop_back();
return sa.take_string();
}
// PARSING STRINGS
/** @brief Parse a string from @a str.
* @param str string
* @param[out] result stores parsed result
* @param[out] rest (optional) stores unparsed portion of @a str
* @return True if @a str parsed correctly, false otherwise.
*
* Parses a string from @a str. The first unquoted space encountered ends the
* string, but spaces are allowed within single or double quotes. Unquoted
* empty strings are not accepted. If the string fully parses, then the
* result is unquoted by cp_unquote() and stored in *@a result and the function
* returns true. Otherwise, *@a result remains unchanged and the function
* returns false.
*
* If @a rest is nonnull, then the string doesn't need to fully parse; the
* part of the string starting with the first unquoted space is stored in *@a
* rest and the function returns true.
*/
bool
cp_string(const String &str, String *result, String *rest)
{
const char *s = str.data();
const char *end = str.end();
// accumulate a word
while (s < end)
switch (*s) {
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
goto done;
case '\"':
s = cp_skip_double_quote(s, end);
break;
case '\'':
s = skip_single_quote(s, end);
break;
case '\\':
if (s + 1 < end && s[1] == '<')
s = skip_backslash(s, end);
else
s++;
break;
default:
s++;
break;
}
done:
if (s == str.begin() || (!rest && s != end))
return false;
else {
if (rest)
*rest = str.substring(s, end);
*result = cp_unquote(str.substring(str.begin(), s));
return true;
}
}
/** @brief Parse a word from @a str.
* @param str string
* @param[out] result stores parsed result
* @param[out] rest (optional) stores unparsed portion of @a str
* @return True if @a str parsed correctly, false otherwise.
*
* Parses a word from @a str. The first unquoted space encountered ends the
* word. Single and double quotes are removed as by cp_unquote, but the
* unquoted string must satisfy cp_is_word. If the string fully parses, then
* the resulting value is stored in *@a result and the function returns true.
* Otherwise, *@a result remains unchanged and the function returns false.
*
* If @a rest is nonnull, then the string doesn't need to fully parse; the
* part of the string starting with the first unquoted space is stored in *@a
* rest and the function returns true (assuming cp_is_word succeeds on the
* initial portion).
*/
bool
cp_word(const String &str, String *result, String *rest)
{
String word;
if (!cp_string(str, &word, rest))
return false;
else if (!cp_is_word(word))
return false;
else {
*result = word;
return true;
}
}
/** @brief Parse a keyword from @a str.
* @param str string
* @param[out] result stores parsed result
* @param[out] rest (optional) stores unparsed portion of @a str
* @return True if @a str parsed correctly, false otherwise.
*
* Parses a keyword from @a str. Keywords consist of characters in
* <tt>[A-Za-z0-9_.:?!]</tt>. Quotes and spaces are not allowed; neither is the
* empty string. If the string fully parses as a keyword, then the resulting
* value is stored in *@a result and the function returns true. Otherwise,
* *@a result remains unchanged and the function returns false.
*
* If @a rest is nonnull, then the string doesn't need to fully parse; the
* part of the string starting with the first unquoted space is stored in *@a
* rest and the function returns true (assuming the initial portion is a valid
* keyword).
*/
bool
cp_keyword(const String &str, String *result, String *rest)
{
const char *s = str.data();
const char *end = str.end();
// accumulate a word
for (; s < end; s++)
switch (*s) {
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
goto done;
// characters allowed unquoted in keywords
case '_':
case '.':
case ':':
case '?':
case '!':
break;
default:
if (!isalnum((unsigned char) *s))
return false;
break;
}
done:
if (s == str.begin() || (!rest && s < end))
return false;
else {
*result = str.substring(str.begin(), s);
if (rest) {
for (; s < end; s++)
if (!isspace((unsigned char) *s))
break;
*rest = str.substring(s, end);
}
return true;
}
}
// PARSING INTEGERS