Poodletooth-iLand/build/nirai/panda3d/ppremake/sedCommand.cxx

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2015-11-14 13:28:53 -06:00
// Filename: sedCommand.cxx
// Created by: drose (24Oct00)
//
////////////////////////////////////////////////////////////////////
#include "sedCommand.h"
#include "sedAddress.h"
#include "sedContext.h"
#include "sedScript.h"
////////////////////////////////////////////////////////////////////
// Function: SedCommand::Constructor
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
SedCommand::
SedCommand() {
_addr1 = (SedAddress *)NULL;
_addr2 = (SedAddress *)NULL;
_command = '\0';
_flags = 0;
_active = false;
}
////////////////////////////////////////////////////////////////////
// Function: SedCommand::Destructor
// Access: Public
// Description:
////////////////////////////////////////////////////////////////////
SedCommand::
~SedCommand() {
if (_addr1 != (SedAddress *)NULL) {
delete _addr1;
}
if (_addr2 != (SedAddress *)NULL) {
delete _addr2;
}
if ((_flags & F_have_re) != 0) {
regfree(&_re);
}
}
////////////////////////////////////////////////////////////////////
// Function: SedCommand::parse_command
// Access: Public
// Description: Scans the indicated string at the given character
// position for a legal command. If a legal command is
// found, stores it and increments p to the first
// non-whitespace character after the command, returning
// true. Otherwise, returns false.
////////////////////////////////////////////////////////////////////
bool SedCommand::
parse_command(const string &line, size_t &p) {
// First, skip initial whitespace.
while (p < line.length() && isspace(line[p])) {
p++;
}
// Now, check for an address.
if (p < line.length() &&
(isdigit(line[p]) || line[p] == '/' || line[p] == '\\')) {
_addr1 = new SedAddress;
if (!_addr1->parse_address(line, p)) {
return false;
}
if (p < line.length() && line[p] == ',') {
// Another address.
// Skip the comma and more whitespace.
p++;
while (p < line.length() && isspace(line[p])) {
p++;
}
_addr2 = new SedAddress;
if (!_addr2->parse_address(line, p)) {
return false;
}
}
}
if (p >= line.length()) {
// It's a null command, which is acceptable; ignore it.
return true;
}
_command = line[p];
// Skip more whitespace after the command letter.
p++;
while (p < line.length() && isspace(line[p])) {
p++;
}
// At the moment, we only accept a small subset of sed commands. We
// can add more later as we see the need.
switch (_command) {
case 'd':
// No arguments.
return true;
case 's':
// /regexp/repl/flags
return parse_s_params(line, p);
default:
cerr << "Unknown command: " << _command << "\n";
return false;
}
}
////////////////////////////////////////////////////////////////////
// Function: SedCommand::run
// Access: Public
// Description: Runs the script command, modifying the context and/or
// the script position as appropriate.
////////////////////////////////////////////////////////////////////
void SedCommand::
run(SedScript &script, SedContext &context) {
// First, see if this command matches the pattern space.
bool matches = false;
if (_addr1 != (SedAddress *)NULL && _addr2 != (SedAddress *)NULL) {
// If the user supplied two addresses, all lines inclusive between
// the lines matched by the two addresses are considered matching.
if (_active) {
// We have previously matched _addr1. Therefore this line is
// in, but are the rest of the lines following this one?
matches = true;
if (_addr2->matches(context)) {
// If this line matches addr2, that's the end of our range for
// next time.
_active = false;
}
} else {
// We have not yet matched _addr1. This line and subsequent
// lines are in only if we match now.
if (_addr1->matches(context)) {
matches = true;
if (!_addr2->precedes(context)) {
_active = true;
}
}
}
} else if (_addr1 != (SedAddress *)NULL) {
// If the user supplied only one address, only those lines that
// exactly match the address are considered matching.
matches = _addr1->matches(context);
} else {
// If the user supplied no addresses, all lines are considered
// matching.
matches = true;
}
if (matches) {
do_command(script, context);
}
}
////////////////////////////////////////////////////////////////////
// Function: SedCommand::parse_s_params
// Access: Private
// Description: Parses the /regexp/replacement/flags parameters that
// follow the 's' command.
////////////////////////////////////////////////////////////////////
bool SedCommand::
parse_s_params(const string &line, size_t &p) {
size_t p0 = p;
char delimiter = line[p];
p++;
if (p < line.length() && delimiter == '\\') {
// A backslash might escape the opening character.
delimiter = line[p];
p++;
}
size_t begin = p;
while (p < line.length() && line[p] != delimiter) {
if (line[p] == '\\') {
p++;
// A backslash could escape the closing character.
}
p++;
}
if (p >= line.length()) {
cerr << "Could not find terminating character '" << delimiter
<< "' in regular expression: " << line.substr(p0) << "\n";
return false;
}
string re = line.substr(begin, p - begin);
p++;
int error = regcomp(&_re, re.c_str(), 0);
if (error != 0) {
static const int errbuf_size = 512;
char errbuf[errbuf_size];
regerror(error, &_re, errbuf, errbuf_size);
cerr << "Invalid regular expression: " << re << "\n"
<< errbuf << "\n";
return false;
}
_flags |= F_have_re;
// Get the replacement string.
begin = p;
while (p < line.length() && line[p] != delimiter) {
if (line[p] == '\\') {
p++;
// A backslash could escape the closing character.
}
p++;
}
if (p >= line.length()) {
cerr << "Could not find terminating character '" << delimiter
<< "' in replacement string: " << line.substr(p0) << "\n";
return false;
}
_string2 = line.substr(begin, p - begin);
// Skip the final delimiter.
p++;
if (p < line.length() && line[p] == 'g') {
// Global flag.
p++;
_flags |= F_g;
}
// Skip any more whitespace after the parameters.
while (p < line.length() && isspace(line[p])) {
p++;
}
return true;
}
////////////////////////////////////////////////////////////////////
// Function: SedCommand::do_command
// Access: Private
// Description: Actually invokes the command, once it has been
// determined that the command applied to the current
// pattern space.
////////////////////////////////////////////////////////////////////
void SedCommand::
do_command(SedScript &script, SedContext &context) {
switch (_command) {
case '\0':
// Null command.
return;
case 'd':
// Delete line.
context._deleted = true;
script._next_command = script._commands.end();
return;
case 's':
// Substitute.
do_s_command(context);
return;
}
cerr << "Undefined command: " << _command << "\n";
}
////////////////////////////////////////////////////////////////////
// Function: SedCommand::do_s_command
// Access: Private
// Description: Invokes the s command, which performs a
// pattern/replacement substitution.
////////////////////////////////////////////////////////////////////
void SedCommand::
do_s_command(SedContext &context) {
size_t nmatch = _re.re_nsub + 1;
regmatch_t *pmatch = new regmatch_t[nmatch];
string result;
const char *str = context._pattern_space.c_str();
int error = regexec(&_re, str, nmatch, pmatch, 0);
while (error == 0) {
// Here's a match. Determine the replacement.
string repl;
size_t p = 0;
while (p < _string2.length()) {
if (_string2[p] == '\\') {
p++;
if (p < _string2.length()) {
if (isdigit(_string2[p])) {
// Here's a subexpression reference.
const char *numstr = _string2.c_str() + p;
char *numend;
int ref = strtol(numstr, &numend, 10);
p += (numend - numstr);
if (ref <= 0 || ref >= (int)nmatch) {
cerr << "Invalid subexpression number: " << ref << "\n";
} else {
repl += string(str + pmatch[ref].rm_so,
pmatch[ref].rm_eo - pmatch[ref].rm_so);
}
} else {
// Here's an escaped character.
repl += _string2[p];
p++;
}
}
} else {
// Here's a normal character.
repl += _string2[p];
p++;
}
}
// Store the result so far.
result += string(str, pmatch[0].rm_so);
result += repl;
str += pmatch[0].rm_eo;
if ((_flags & F_g) == 0) {
// If we don't have the global flag set, stop after the first iteration.
result += str;
context._pattern_space = result;
delete[] pmatch;
return;
}
error = regexec(&_re, str, nmatch, pmatch, 0);
}
// All done.
result += str;
context._pattern_space = result;
delete[] pmatch;
}