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/*
* tclParse.c --
*
* This file contains a collection of procedures that are used
* to parse Tcl commands or parts of commands (like quoted
* strings or nested sub-commands).
*
* Copyright 1991 Regents of the University of California.
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies. The University of California
* makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without
* express or implied warranty.
*/
#ifndef lint
static char rcsid[] = "$Header: /user6/ouster/tcl/RCS/tclParse.c,v 1.25 93/01/06 15:23:03 ouster Exp $ SPRITE (Berkeley)";
#endif
#include "tclInt.h"
/*
* The following table assigns a type to each character. Only types
* meaningful to Tcl parsing are represented here. The table indexes
* all 256 characters, with the negative ones first, then the positive
* ones.
*/
char tclTypeTable[] = {
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_COMMAND_END, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_SPACE, TCL_COMMAND_END, TCL_SPACE,
TCL_SPACE, TCL_SPACE, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_SPACE, TCL_NORMAL, TCL_QUOTE, TCL_NORMAL,
TCL_DOLLAR, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_COMMAND_END,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_OPEN_BRACKET,
TCL_BACKSLASH, TCL_COMMAND_END, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_NORMAL,
TCL_NORMAL, TCL_NORMAL, TCL_NORMAL, TCL_OPEN_BRACE,
TCL_NORMAL, TCL_CLOSE_BRACE, TCL_NORMAL, TCL_NORMAL,
};
/*
* Function prototypes for procedures local to this file:
*/
static char * QuoteEnd _ANSI_ARGS_((char *string, int term));
static char * VarNameEnd _ANSI_ARGS_((char *string));
/*
*----------------------------------------------------------------------
*
* Tcl_Backslash --
*
* Figure out how to handle a backslash sequence.
*
* Results:
* The return value is the character that should be substituted
* in place of the backslash sequence that starts at src, or 0
* if the backslash sequence should be replace by nothing (e.g.
* backslash followed by newline). If readPtr isn't NULL then
* it is filled in with a count of the number of characters in
* the backslash sequence. Note: if the backslash isn't followed
* by characters that are understood here, then the backslash
* sequence is only considered to be one character long, and it
* is replaced by a backslash char.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
char
Tcl_Backslash(src, readPtr)
char *src; /* Points to the backslash character of
* a backslash sequence. */
int *readPtr; /* Fill in with number of characters read
* from src, unless NULL. */
{
register char *p = src+1;
char result;
int count;
count = 2;
switch (*p) {
case 'b':
result = '\b';
break;
case 'e':
result = 033;
break;
case 'f':
result = '\f';
break;
case 'n':
result = '\n';
break;
case 'r':
result = '\r';
break;
case 't':
result = '\t';
break;
case 'v':
result = '\v';
break;
case 'C':
p++;
if (isspace(*p) || (*p == 0)) {
result = 'C';
count = 1;
break;
}
count = 3;
if (*p == 'M') {
p++;
if (isspace(*p) || (*p == 0)) {
result = 'M' & 037;
break;
}
count = 4;
result = (*p & 037) | '\200';
break;
}
count = 3;
result = *p & 037;
break;
case 'M':
p++;
if (isspace(*p) || (*p == 0)) {
result = 'M';
count = 1;
break;
}
count = 3;
result = *p + '\200';
break;
case '}':
case '{':
case ']':
case '[':
case '$':
case ' ':
case ';':
case '"':
case '\\':
result = *p;
break;
case '\n':
result = 0;
break;
default:
if (isdigit(*p)) {
result = *p - '0';
p++;
if (!isdigit(*p)) {
break;
}
count = 3;
result = (result << 3) + (*p - '0');
p++;
if (!isdigit(*p)) {
break;
}
count = 4;
result = (result << 3) + (*p - '0');
break;
}
result = '\\';
count = 1;
break;
}
if (readPtr != NULL) {
*readPtr = count;
}
return result;
}
/*
*--------------------------------------------------------------
*
* TclParseQuotes --
*
* This procedure parses a double-quoted string such as a
* quoted Tcl command argument or a quoted value in a Tcl
* expression. This procedure is also used to parse array
* element names within parentheses, or anything else that
* needs all the substitutions that happen in quotes.
*
* Results:
* The return value is a standard Tcl result, which is
* TCL_OK unless there was an error while parsing the
* quoted string. If an error occurs then interp->result
* contains a standard error message. *TermPtr is filled
* in with the address of the character just after the
* last one successfully processed; this is usually the
* character just after the matching close-quote. The
* fully-substituted contents of the quotes are stored in
* standard fashion in *pvPtr, null-terminated with
* pvPtr->next pointing to the terminating null character.
*
* Side effects:
* The buffer space in pvPtr may be enlarged by calling its
* expandProc.
*
*--------------------------------------------------------------
*/
int
TclParseQuotes(interp, string, termChar, flags, termPtr, pvPtr)
Tcl_Interp *interp; /* Interpreter to use for nested command
* evaluations and error messages. */
char *string; /* Character just after opening double-
* quote. */
int termChar; /* Character that terminates "quoted" string
* (usually double-quote, but sometimes
* right-paren or something else). */
int flags; /* Flags to pass to nested Tcl_Eval calls. */
char **termPtr; /* Store address of terminating character
* here. */
ParseValue *pvPtr; /* Information about where to place
* fully-substituted result of parse. */
{
register char *src, *dst, c;
src = string;
dst = pvPtr->next;
while (1) {
if (dst == pvPtr->end) {
/*
* Target buffer space is about to run out. Make more space.
*/
pvPtr->next = dst;
(*pvPtr->expandProc)(pvPtr, 1);
dst = pvPtr->next;
}
c = *src;
src++;
if (c == termChar) {
*dst = '\0';
pvPtr->next = dst;
*termPtr = src;
return TCL_OK;
} else if (CHAR_TYPE(c) == TCL_NORMAL) {
copy:
*dst = c;
dst++;
continue;
} else if (c == '$') {
int length;
char *value;
value = Tcl_ParseVar(interp, src-1, termPtr);
if (value == NULL) {
return TCL_ERROR;
}
src = *termPtr;
length = strlen(value);
if ((pvPtr->end - dst) <= length) {
pvPtr->next = dst;
(*pvPtr->expandProc)(pvPtr, length);
dst = pvPtr->next;
}
strcpy(dst, value);
dst += length;
continue;
} else if (c == '[') {
int result;
pvPtr->next = dst;
result = TclParseNestedCmd(interp, src, flags, termPtr, pvPtr);
if (result != TCL_OK) {
return result;
}
src = *termPtr;
dst = pvPtr->next;
continue;
} else if (c == '\\') {
int numRead;
src--;
*dst = Tcl_Backslash(src, &numRead);
if (*dst != 0) {
dst++;
}
src += numRead;
continue;
} else if (c == '\0') {
Tcl_ResetResult(interp);
sprintf(interp->result, "missing %c", termChar);
*termPtr = string-1;
return TCL_ERROR;
} else {
goto copy;
}
}
}
/*
*--------------------------------------------------------------
*
* TclParseNestedCmd --
*
* This procedure parses a nested Tcl command between
* brackets, returning the result of the command.
*
* Results:
* The return value is a standard Tcl result, which is
* TCL_OK unless there was an error while executing the
* nested command. If an error occurs then interp->result
* contains a standard error message. *TermPtr is filled
* in with the address of the character just after the
* last one processed; this is usually the character just
* after the matching close-bracket, or the null character
* at the end of the string if the close-bracket was missing
* (a missing close bracket is an error). The result returned
* by the command is stored in standard fashion in *pvPtr,
* null-terminated, with pvPtr->next pointing to the null
* character.
*
* Side effects:
* The storage space at *pvPtr may be expanded.
*
*--------------------------------------------------------------
*/
int
TclParseNestedCmd(interp, string, flags, termPtr, pvPtr)
Tcl_Interp *interp; /* Interpreter to use for nested command
* evaluations and error messages. */
char *string; /* Character just after opening bracket. */
int flags; /* Flags to pass to nested Tcl_Eval. */
char **termPtr; /* Store address of terminating character
* here. */
register ParseValue *pvPtr; /* Information about where to place
* result of command. */
{
int result, length, shortfall;
Interp *iPtr = (Interp *) interp;
result = Tcl_Eval(interp, string, flags | TCL_BRACKET_TERM, termPtr);
if (result != TCL_OK) {
/*
* The increment below results in slightly cleaner message in
* the errorInfo variable (the close-bracket will appear).
*/
if (**termPtr == ']') {
*termPtr += 1;
}
return result;
}
(*termPtr) += 1;
length = strlen(iPtr->result);
shortfall = length + 1 - (pvPtr->end - pvPtr->next);
if (shortfall > 0) {
(*pvPtr->expandProc)(pvPtr, shortfall);
}
strcpy(pvPtr->next, iPtr->result);
pvPtr->next += length;
Tcl_FreeResult(iPtr);
iPtr->result = iPtr->resultSpace;
iPtr->resultSpace[0] = '\0';
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* TclParseBraces --
*
* This procedure scans the information between matching
* curly braces.
*
* Results:
* The return value is a standard Tcl result, which is
* TCL_OK unless there was an error while parsing string.
* If an error occurs then interp->result contains a
* standard error message. *TermPtr is filled
* in with the address of the character just after the
* last one successfully processed; this is usually the
* character just after the matching close-brace. The
* information between curly braces is stored in standard
* fashion in *pvPtr, null-terminated with pvPtr->next
* pointing to the terminating null character.
*
* Side effects:
* The storage space at *pvPtr may be expanded.
*
*--------------------------------------------------------------
*/
int
TclParseBraces(interp, string, termPtr, pvPtr)
Tcl_Interp *interp; /* Interpreter to use for nested command
* evaluations and error messages. */
char *string; /* Character just after opening bracket. */
char **termPtr; /* Store address of terminating character
* here. */
register ParseValue *pvPtr; /* Information about where to place
* result of command. */
{
int level;
register char *src, *dst, *end;
register char c;
src = string;
dst = pvPtr->next;
end = pvPtr->end;
level = 1;
/*
* Copy the characters one at a time to the result area, stopping
* when the matching close-brace is found.
*/
while (1) {
c = *src;
src++;
if (dst == end) {
pvPtr->next = dst;
(*pvPtr->expandProc)(pvPtr, 20);
dst = pvPtr->next;
end = pvPtr->end;
}
*dst = c;
dst++;
if (CHAR_TYPE(c) == TCL_NORMAL) {
continue;
} else if (c == '{') {
level++;
} else if (c == '}') {
level--;
if (level == 0) {
dst--; /* Don't copy the last close brace. */
break;
}
} else if (c == '\\') {
int count;
/*
* Must always squish out backslash-newlines, even when in
* braces. This is needed so that this sequence can appear
* anywhere in a command, such as the middle of an expression.
*/
if (*src == '\n') {
dst--;
src++;
} else {
(void) Tcl_Backslash(src-1, &count);
while (count > 1) {
if (dst == end) {
pvPtr->next = dst;
(*pvPtr->expandProc)(pvPtr, 20);
dst = pvPtr->next;
end = pvPtr->end;
}
*dst = *src;
dst++;
src++;
count--;
}
}
} else if (c == '\0') {
Tcl_SetResult(interp, "missing close-brace", TCL_STATIC);
*termPtr = string-1;
return TCL_ERROR;
}
}
*dst = '\0';
pvPtr->next = dst;
*termPtr = src;
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* TclParseWords --
*
* This procedure parses one or more words from a command
* string and creates argv-style pointers to fully-substituted
* copies of those words.
*
* Results:
* The return value is a standard Tcl result.
*
* *argcPtr is modified to hold a count of the number of words
* successfully parsed, which may be 0. At most maxWords words
* will be parsed. If 0 <= *argcPtr < maxWords then it
* means that a command separator was seen. If *argcPtr
* is maxWords then it means that a command separator was
* not seen yet.
*
* *TermPtr is filled in with the address of the character
* just after the last one successfully processed in the
* last word. This is either the command terminator (if
* *argcPtr < maxWords), the character just after the last
* one in a word (if *argcPtr is maxWords), or the vicinity
* of an error (if the result is not TCL_OK).
*
* The pointers at *argv are filled in with pointers to the
* fully-substituted words, and the actual contents of the
* words are copied to the buffer at pvPtr.
*
* If an error occurrs then an error message is left in
* interp->result and the information at *argv, *argcPtr,
* and *pvPtr may be incomplete.
*
* Side effects:
* The buffer space in pvPtr may be enlarged by calling its
* expandProc.
*
*--------------------------------------------------------------
*/
int
TclParseWords(interp, string, flags, maxWords, termPtr, argcPtr, argv, pvPtr)
Tcl_Interp *interp; /* Interpreter to use for nested command
* evaluations and error messages. */
char *string; /* First character of word. */
int flags; /* Flags to control parsing (same values as
* passed to Tcl_Eval). */
int maxWords; /* Maximum number of words to parse. */
char **termPtr; /* Store address of terminating character
* here. */
int *argcPtr; /* Filled in with actual number of words
* parsed. */
char **argv; /* Store addresses of individual words here. */
register ParseValue *pvPtr; /* Information about where to place
* fully-substituted word. */
{
register char *src, *dst;
register char c;
int type, result, argc;
char *oldBuffer; /* Used to detect when pvPtr's buffer gets
* reallocated, so we can adjust all of the
* argv pointers. */
src = string;
oldBuffer = pvPtr->buffer;
dst = pvPtr->next;
for (argc = 0; argc < maxWords; argc++) {
argv[argc] = dst;
/*
* Skip leading space.
*/
skipSpace:
c = *src;
type = CHAR_TYPE(c);
while (type == TCL_SPACE) {
src++;
c = *src;
type = CHAR_TYPE(c);
}
/*
* Handle the normal case (i.e. no leading double-quote or brace).
*/
if (type == TCL_NORMAL) {
normalArg:
while (1) {
if (dst == pvPtr->end) {
/*
* Target buffer space is about to run out. Make
* more space.
*/
pvPtr->next = dst;
(*pvPtr->expandProc)(pvPtr, 1);
dst = pvPtr->next;
}
if (type == TCL_NORMAL) {
copy:
*dst = c;
dst++;
src++;
} else if (type == TCL_SPACE) {
goto wordEnd;
} else if (type == TCL_DOLLAR) {
int length;
char *value;
value = Tcl_ParseVar(interp, src, termPtr);
if (value == NULL) {
return TCL_ERROR;
}
src = *termPtr;
length = strlen(value);
if ((pvPtr->end - dst) <= length) {
pvPtr->next = dst;
(*pvPtr->expandProc)(pvPtr, length);
dst = pvPtr->next;
}
strcpy(dst, value);
dst += length;
} else if (type == TCL_COMMAND_END) {
if ((c == ']') && !(flags & TCL_BRACKET_TERM)) {
goto copy;
}
/*
* End of command; simulate a word-end first, so
* that the end-of-command can be processed as the
* first thing in a new word.
*/
goto wordEnd;
} else if (type == TCL_OPEN_BRACKET) {
pvPtr->next = dst;
result = TclParseNestedCmd(interp, src+1, flags, termPtr,
pvPtr);
if (result != TCL_OK) {
return result;
}
src = *termPtr;
dst = pvPtr->next;
} else if (type == TCL_BACKSLASH) {
int numRead;
*dst = Tcl_Backslash(src, &numRead);
if (*dst != 0) {
dst++;
}
src += numRead;
} else {
goto copy;
}
c = *src;
type = CHAR_TYPE(c);
}
} else {
/*
* Check for the end of the command.
*/
if (type == TCL_COMMAND_END) {
if (flags & TCL_BRACKET_TERM) {
if (c == '\0') {
Tcl_SetResult(interp, "missing close-bracket",
TCL_STATIC);
return TCL_ERROR;
}
} else {
if (c == ']') {
goto normalArg;
}
}
goto done;
}
/*
* Now handle the special cases: open braces, double-quotes,
* and backslash-newline.
*/
pvPtr->next = dst;
if (type == TCL_QUOTE) {
result = TclParseQuotes(interp, src+1, '"', flags,
termPtr, pvPtr);
} else if (type == TCL_OPEN_BRACE) {
result = TclParseBraces(interp, src+1, termPtr, pvPtr);
} else if ((type == TCL_BACKSLASH) && (src[1] == '\n')) {
src += 2;
goto skipSpace;
} else {
goto normalArg;
}
if (result != TCL_OK) {
return result;
}
/*
* Back from quotes or braces; make sure that the terminating
* character was the end of the word. Have to be careful here
* to handle continuation lines (i.e. lines ending in backslash).
*/
c = **termPtr;
if ((c == '\\') && ((*termPtr)[1] == '\n')) {
c = (*termPtr)[2];
}
type = CHAR_TYPE(c);
if ((type != TCL_SPACE) && (type != TCL_COMMAND_END)) {
if (*src == '"') {
Tcl_SetResult(interp, "extra characters after close-quote",
TCL_STATIC);
} else {
Tcl_SetResult(interp, "extra characters after close-brace",
TCL_STATIC);
}
return TCL_ERROR;
}
src = *termPtr;
dst = pvPtr->next;
}
/*
* We're at the end of a word, so add a null terminator. Then
* see if the buffer was re-allocated during this word. If so,
* update all of the argv pointers.
*/
wordEnd:
*dst = '\0';
dst++;
if (oldBuffer != pvPtr->buffer) {
int i;
for (i = 0; i <= argc; i++) {
argv[i] = pvPtr->buffer + (argv[i] - oldBuffer);
}
oldBuffer = pvPtr->buffer;
}
}
done:
pvPtr->next = dst;
*termPtr = src;
*argcPtr = argc;
return TCL_OK;
}
/*
*--------------------------------------------------------------
*
* TclExpandParseValue --
*
* This procedure is commonly used as the value of the
* expandProc in a ParseValue. It uses malloc to allocate
* more space for the result of a parse.
*
* Results:
* The buffer space in *pvPtr is reallocated to something
* larger, and if pvPtr->clientData is non-zero the old
* buffer is freed. Information is copied from the old
* buffer to the new one.
*
* Side effects:
* None.
*
*--------------------------------------------------------------
*/
void
TclExpandParseValue(pvPtr, needed)
register ParseValue *pvPtr; /* Information about buffer that
* must be expanded. If the clientData
* in the structure is non-zero, it
* means that the current buffer is
* dynamically allocated. */
int needed; /* Minimum amount of additional space
* to allocate. */
{
int newSpace;
char *new;
/*
* Either double the size of the buffer or add enough new space
* to meet the demand, whichever produces a larger new buffer.
*/
newSpace = (pvPtr->end - pvPtr->buffer) + 1;
if (newSpace < needed) {
newSpace += needed;
} else {
newSpace += newSpace;
}
new = (char *) ckalloc((unsigned) newSpace);
/*
* Copy from old buffer to new, free old buffer if needed, and
* mark new buffer as malloc-ed.
*/
memcpy((VOID *) new, (VOID *) pvPtr->buffer, pvPtr->next - pvPtr->buffer);
pvPtr->next = new + (pvPtr->next - pvPtr->buffer);
if (pvPtr->clientData != 0) {
ckfree(pvPtr->buffer);
}
pvPtr->buffer = new;
pvPtr->end = new + newSpace - 1;
pvPtr->clientData = (ClientData) 1;
}
/*
*----------------------------------------------------------------------
*
* TclWordEnd --
*
* Given a pointer into a Tcl command, find the end of the next
* word of the command.
*
* Results:
* The return value is a pointer to the last character that's part
* of the word pointed to by "start". If the word doesn't end
* properly within the string then the return value is the address
* of the null character at the end of the string.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
char *
TclWordEnd(start, nested)
char *start; /* Beginning of a word of a Tcl command. */
int nested; /* Zero means this is a top-level command.
* One means this is a nested command (close
* brace is a word terminator). */
{
register char *p;
int count;
p = start;
while (isspace(*p)) {
p++;
}
/*
* Handle words beginning with a double-quote or a brace.
*/
if (*p == '"') {
p = QuoteEnd(p+1, '"');
if (*p == 0) {
return p;
}
p++;
} else if (*p == '{') {
int braces = 1;
while (braces != 0) {
p++;
while (*p == '\\') {
(void) Tcl_Backslash(p, &count);
p += count;
}
if (*p == '}') {
braces--;
} else if (*p == '{') {
braces++;
} else if (*p == 0) {
return p;
}
}
p++;
}
/*
* Handle words that don't start with a brace or double-quote.
* This code is also invoked if the word starts with a brace or
* double-quote and there is garbage after the closing brace or
* quote. This is an error as far as Tcl_Eval is concerned, but
* for here the garbage is treated as part of the word.
*/
while (1) {
if (*p == '[') {
for (p++; *p != ']'; p++) {
p = TclWordEnd(p, 1);
if (*p == 0) {
return p;
}
}
p++;
} else if (*p == '\\') {
(void) Tcl_Backslash(p, &count);
p += count;
if ((*p == 0) && (count == 2) && (p[-1] == '\n')) {
return p;
}
} else if (*p == '$') {
p = VarNameEnd(p);
if (*p == 0) {
return p;
}
p++;
} else if (*p == ';') {
/*
* Include the semi-colon in the word that is returned.
*/
return p;
} else if (isspace(*p)) {
return p-1;
} else if ((*p == ']') && nested) {
return p-1;
} else if (*p == 0) {
if (nested) {
/*
* Nested commands can't end because of the end of the
* string.
*/
return p;
}
return p-1;
} else {
p++;
}
}
}
/*
*----------------------------------------------------------------------
*
* QuoteEnd --
*
* Given a pointer to a string that obeys the parsing conventions
* for quoted things in Tcl, find the end of that quoted thing.
* The actual thing may be a quoted argument or a parenthesized
* index name.
*
* Results:
* The return value is a pointer to the last character that is
* part of the quoted string (i.e the character that's equal to
* term). If the quoted string doesn't terminate properly then
* the return value is a pointer to the null character at the
* end of the string.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static char *
QuoteEnd(string, term)
char *string; /* Pointer to character just after opening
* "quote". */
int term; /* This character will terminate the
* quoted string (e.g. '"' or ')'). */
{
register char *p = string;
int count;
while (*p != term) {
if (*p == '\\') {
(void) Tcl_Backslash(p, &count);
p += count;
} else if (*p == '[') {
for (p++; *p != ']'; p++) {
p = TclWordEnd(p, 1);
if (*p == 0) {
return p;
}
}
p++;
} else if (*p == '$') {
p = VarNameEnd(p);
if (*p == 0) {
return p;
}
p++;
} else if (*p == 0) {
return p;
} else {
p++;
}
}
return p-1;
}
/*
*----------------------------------------------------------------------
*
* VarNameEnd --
*
* Given a pointer to a variable reference using $-notation, find
* the end of the variable name spec.
*
* Results:
* The return value is a pointer to the last character that
* is part of the variable name. If the variable name doesn't
* terminate properly then the return value is a pointer to the
* null character at the end of the string.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static char *
VarNameEnd(string)
char *string; /* Pointer to dollar-sign character. */
{
register char *p = string+1;
if (*p == '{') {
for (p++; (*p != '}') && (*p != 0); p++) {
/* Empty loop body. */
}
return p;
}
while (isalnum(*p) || (*p == '_')) {
p++;
}
if ((*p == '(') && (p != string+1)) {
return QuoteEnd(p+1, ')');
}
return p-1;
}
/*
*----------------------------------------------------------------------
*
* Tcl_ParseVar --
*
* Given a string starting with a $ sign, parse off a variable
* name and return its value.
*
* Results:
* The return value is the contents of the variable given by
* the leading characters of string. If termPtr isn't NULL,
* *termPtr gets filled in with the address of the character
* just after the last one in the variable specifier. If the
* variable doesn't exist, then the return value is NULL and
* an error message will be left in interp->result.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
char *
Tcl_ParseVar(interp, string, termPtr)
Tcl_Interp *interp; /* Context for looking up variable. */
register char *string; /* String containing variable name.
* First character must be "$". */
char **termPtr; /* If non-NULL, points to word to fill
* in with character just after last
* one in the variable specifier. */
{
char *name1, *name1End, c, *result;
register char *name2;
#define NUM_CHARS 200
char copyStorage[NUM_CHARS];
ParseValue pv;
/*
* There are three cases:
* 1. The $ sign is followed by an open curly brace. Then the variable
* name is everything up to the next close curly brace, and the
* variable is a scalar variable.
* 2. The $ sign is not followed by an open curly brace. Then the
* variable name is everything up to the next character that isn't
* a letter, digit, or underscore. If the following character is an
* open parenthesis, then the information between parentheses is
* the array element name, which can include any of the substitutions
* permissible between quotes.
* 3. The $ sign is followed by something that isn't a letter, digit,
* or underscore: in this case, there is no variable name, and "$"
* is returned.
*/
name2 = NULL;
string++;
if (*string == '{') {
string++;
name1 = string;
while (*string != '}') {
if (*string == 0) {
Tcl_SetResult(interp, "missing close-brace for variable name",
TCL_STATIC);
if (termPtr != 0) {
*termPtr = string;
}
return NULL;
}
string++;
}
name1End = string;
string++;
} else {
name1 = string;
while (isalnum(*string) || (*string == '_')) {
string++;
}
if (string == name1) {
if (termPtr != 0) {
*termPtr = string;
}
return "$";
}
name1End = string;
if (*string == '(') {
char *end;
/*
* Perform substitutions on the array element name, just as
* is done for quotes.
*/
pv.buffer = pv.next = copyStorage;
pv.end = copyStorage + NUM_CHARS - 1;
pv.expandProc = TclExpandParseValue;
pv.clientData = (ClientData) NULL;
if (TclParseQuotes(interp, string+1, ')', 0, &end, &pv)
!= TCL_OK) {
char msg[100];
sprintf(msg, "\n (parsing index for array \"%.*s\")",
string-name1, name1);
Tcl_AddErrorInfo(interp, msg);
result = NULL;
name2 = pv.buffer;
if (termPtr != 0) {
*termPtr = end;
}
goto done;
}
string = end;
name2 = pv.buffer;
}
}
if (termPtr != 0) {
*termPtr = string;
}
if (((Interp *) interp)->noEval) {
return "";
}
c = *name1End;
*name1End = 0;
result = Tcl_GetVar2(interp, name1, name2, TCL_LEAVE_ERR_MSG);
*name1End = c;
done:
if ((name2 != NULL) && (pv.buffer != copyStorage)) {
ckfree(pv.buffer);
}
return result;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.