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tclUtil.c
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1990-12-28
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/*
* tclUtil.c --
*
* This file contains utility procedures that are used by many Tcl
* commands.
*
* Copyright 1987, 1989 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: /sprite/src/lib/tcl/RCS/tclUtil.c,v 1.27 90/01/07 12:05:20 ouster Exp $ SPRITE (Berkeley)";
#endif /* not lint */
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "tcl.h"
#include "tclInt.h"
/*
*----------------------------------------------------------------------
*
* TclFindElement --
*
* Given a pointer into a Tcl list, locate the first (or next)
* element in the list.
*
* Results:
* The return value is normally TCL_OK, which means that the
* element was successfully located. If TCL_ERROR is returned
* it means that list didn't have proper list structure;
* interp->result contains a more detailed error message.
*
* If TCL_OK is returned, then *elementPtr will be set to point
* to the first element of list, and *nextPtr will be set to point
* to the character just after any white space following the last
* character that's part of the element. If this is the last argument
* in the list, then *nextPtr will point to the NULL character at the
* end of list. If sizePtr is non-NULL, *sizePtr is filled in with
* the number of characters in the element. If the element is in
* braces, then *elementPtr will point to the character after the
* opening brace and *sizePtr will not include either of the braces.
* If there isn't an element in the list, *sizePtr will be zero, and
* both *elementPtr and *termPtr will refer to the null character at
* the end of list. Note: this procedure does NOT collapse backslash
* sequences.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
TclFindElement(interp, list, elementPtr, nextPtr, sizePtr, bracePtr)
Tcl_Interp *interp; /* Interpreter to use for error reporting. */
register char *list; /* String containing Tcl list with zero
* or more elements (possibly in braces). */
char **elementPtr; /* Fill in with location of first significant
* character in first element of list. */
char **nextPtr; /* Fill in with location of character just
* after all white space following end of
* argument (i.e. next argument or end of
* list). */
int *sizePtr; /* If non-zero, fill in with size of
* element. */
int *bracePtr; /* If non-zero fill in with non-zero/zero
* to indicate that arg was/wasn't
* in braces. */
{
register char *p;
int openBraces = 0;
int size;
/*
* Skim off leading white space and check for an opening brace.
*/
while (isspace(*list)) {
list++;
}
if (*list == '{') {
openBraces = 1;
list++;
}
if (bracePtr != 0) {
*bracePtr = openBraces;
}
p = list;
/*
* Find the end of the element (either a space or a close brace or
* the end of the string).
*/
while (1) {
switch (*p) {
/*
* Open brace: don't treat specially unless the element is
* in braces. In this case, keep a nesting count.
*/
case '{':
if (openBraces != 0) {
openBraces++;
}
break;
/*
* Close brace: if element is in braces, keep nesting
* count and quit when the last close brace is seen.
*/
case '}':
if (openBraces == 1) {
char *p2;
size = p - list;
p++;
if (isspace(*p) || (*p == 0)) {
goto done;
}
for (p2 = p; (*p2 != 0) && (!isspace(*p2)) && (p2 < p+20);
p2++) {
/* null body */
}
Tcl_Return(interp, (char *) NULL, TCL_STATIC);
sprintf(interp->result,
"list element in braces followed by \"%.*s\" instead of space",
p2-p, p);
return TCL_ERROR;
} else if (openBraces != 0) {
openBraces--;
}
break;
/*
* Backslash: skip over everything up to the end of the
* backslash sequence.
*/
case '\\': {
int size;
(void) Tcl_Backslash(p, &size);
p += size - 1;
break;
}
/*
* Space: ignore if element is in braces; otherwise
* terminate element.
*/
case ' ':
case '\t':
case '\n':
if (openBraces == 0) {
size = p - list;
goto done;
}
break;
/*
* End of list: terminate element.
*/
case 0:
if (openBraces != 0) {
Tcl_Return(interp, "unmatched open brace in list",
TCL_STATIC);
return TCL_ERROR;
}
size = p - list;
goto done;
}
p++;
}
done:
while (isspace(*p)) {
p++;
}
*elementPtr = list;
*nextPtr = p;
if (sizePtr != 0) {
*sizePtr = size;
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* TclCopyAndCollapse --
*
* Copy a string and eliminate any backslashes that aren't in braces.
*
* Results:
* There is no return value. Count chars. get copied from src
* to dst. Along the way, if backslash sequences are found outside
* braces, the backslashes are eliminated in the copy.
* After scanning count chars. from source, a null character is
* placed at the end of dst.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TclCopyAndCollapse(count, src, dst)
register char *src; /* Copy from here... */
register char *dst; /* ... to here. */
{
register char c;
int numRead;
for (c = *src; count > 0; dst++, src++, c = *src, count--) {
if (c == '\\') {
*dst = Tcl_Backslash(src, &numRead);
src += numRead-1;
count -= numRead-1;
} else {
*dst = c;
}
}
*dst = 0;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Merge --
*
* Given a collection of strings, merge them together into a
* single string that has proper Tcl list structured (i.e.
* TclFindElement and TclCopyAndCollapse may be used to retrieve
* strings equal to the original elements, and Tcl_Eval will
* parse the string back into its original elements).
*
* Results:
* The return value is the address of a dynamically-allocated
* string containing the merged list.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
char *
Tcl_Merge(argc, argv)
int argc; /* How many strings to merge. */
char **argv; /* Array of string values. */
{
/*
* This procedure operates in two passes. In the first pass it figures
* out how many bytes will be needed to store the result (actually,
* it overestimates slightly). The first pass also collects information
* about each element in the form of a flags word. If there are only
* a few elements, local storage gets used for the flags; if there are
* a lot of elements, a new array is dynamically allocated.
*
* In the second pass this procedure copies the arguments into the
* result string. The special cases to worry about are:
*
* 1. Argument contains embedded spaces, or starts with a brace: must
* add another level of braces when copying to the result.
*
* 2. Argument contains unbalanced braces: backslash all of the
* braces when copying to the result. In this case, don't add another
* level of braces (they would prevent the backslash from
* being removed when the argument is extracted from the list later).
*
* 3. Argument contains backslashed brace/bracket: if possible,
* group the argument in braces: then no special action needs to be taken
* with the backslashes. If the argument can't be put in braces, then
* add another backslash in front of the sequence, so that upon
* extraction the original sequence will be restored.
*
* These potential problems are the reasons why particular information
* is gathered during pass 1.
*/
# define WANT_PARENS 1
# define PARENS_UNBALANCED 2
# define PARENTHESIZED 4
# define CANT_PARENTHESIZE 8
# define LOCAL_SIZE 20
int localFlags[LOCAL_SIZE];
int *flagPtr;
int numChars;
char *result;
register char *src, *dst;
register int curFlags;
int i;
/*
* Pass 1: estimate space, gather information.
*/
if (argc <= LOCAL_SIZE) {
flagPtr = localFlags;
} else {
flagPtr = (int *) ckalloc((unsigned) argc*sizeof(int));
}
numChars = 0;
for (i = 0; i < argc; i++) {
int braceCount, nestingLevel, nestedBS, whiteSpace, brackets, dollars;
curFlags = braceCount = nestingLevel = nestedBS = whiteSpace = 0;
brackets = dollars = 0;
src = argv[i];
if (*src == '{') {
curFlags |= PARENTHESIZED|WANT_PARENS;
}
if (*src == 0) {
curFlags |= WANT_PARENS;
} else {
for (; ; src++) {
switch (*src) {
case '{':
braceCount++;
nestingLevel++;
break;
case '}':
braceCount++;
nestingLevel--;
break;
case ']':
case '[':
curFlags |= WANT_PARENS;
brackets++;
break;
case '$':
curFlags |= WANT_PARENS;
dollars++;
break;
case ' ':
case '\n':
case '\t':
curFlags |= WANT_PARENS;
whiteSpace++;
break;
case '\\':
src++;
if (*src == 0) {
goto elementDone;
} else if ((*src == '{') || (*src == '}')
|| (*src == '[') || (*src == ']')) {
curFlags |= WANT_PARENS;
nestedBS++;
}
break;
case 0:
goto elementDone;
}
}
}
elementDone:
numChars += src - argv[i];
if (nestingLevel != 0) {
numChars += braceCount + nestedBS + whiteSpace
+ brackets + dollars;
curFlags = CANT_PARENTHESIZE;
}
if (curFlags & WANT_PARENS) {
numChars += 2;
}
numChars++; /* Space to separate arguments. */
flagPtr[i] = curFlags;
}
/*
* Pass two: copy into the result area.
*/
result = (char *) ckalloc((unsigned) numChars + 1);
dst = result;
for (i = 0; i < argc; i++) {
curFlags = flagPtr[i];
if (curFlags & WANT_PARENS) {
*dst = '{';
dst++;
}
for (src = argv[i]; *src != 0 ; src++) {
if (curFlags & CANT_PARENTHESIZE) {
switch (*src) {
case '{':
case '}':
case ']':
case '[':
case '$':
case ' ':
*dst = '\\';
dst++;
break;
case '\n':
*dst = '\\';
dst++;
*dst = 'n';
goto loopBottom;
case '\t':
*dst = '\\';
dst++;
*dst = 't';
goto loopBottom;
case '\\':
*dst = '\\';
dst++;
src++;
if ((*src == '{') || (*src == '}') || (*src == '[')
|| (*src == ']')) {
*dst = '\\';
dst++;
} else if (*src == 0) {
goto pass2ElementDone;
}
break;
}
}
*dst = *src;
loopBottom:
dst++;
}
pass2ElementDone:
if (curFlags & WANT_PARENS) {
*dst = '}';
dst++;
}
*dst = ' ';
dst++;
}
if (dst == result) {
*dst = 0;
} else {
dst[-1] = 0;
}
if (flagPtr != localFlags) {
ckfree((char *) flagPtr);
}
return result;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Concat --
*
* Concatenate a set of strings into a single large string.
*
* Results:
* The return value is dynamically-allocated string containing
* a concatenation of all the strings in argv, with spaces between
* the original argv elements.
*
* Side effects:
* Memory is allocated for the result; the caller is responsible
* for freeing the memory.
*
*----------------------------------------------------------------------
*/
char *
Tcl_Concat(argc, argv)
int argc; /* Number of strings to concatenate. */
char **argv; /* Array of strings to concatenate. */
{
int totalSize, i;
register char *p;
char *result;
for (totalSize = 1, i = 0; i < argc; i++) {
totalSize += strlen(argv[i]) + 1;
}
result = (char *)ckalloc((unsigned) totalSize);
for (p = result, i = 0; i < argc; i++) {
(void) strcpy(p, argv[i]);
p += strlen(argv[i]);
*p = ' ';
p++;
}
p[-1] = 0;
return result;
}
/*
*----------------------------------------------------------------------
*
* Tcl_Return --
*
* Arrange for "string" to be the Tcl return value.
*
* Results:
* None.
*
* Side effects:
* interp->result is left pointing either to "string" (if "copy" is 0)
* or to a copy of string.
*
*----------------------------------------------------------------------
*/
void
Tcl_Return(interp, string, status)
Tcl_Interp *interp; /* Interpreter with which to associate the
* return value. */
char *string; /* Value to be returned. If NULL,
* the result is set to an empty string. */
int status; /* Gives information about the string:
* TCL_STATIC, TCL_DYNAMIC, TCL_VOLATILE.
* Ignored if string is NULL. */
{
register Interp *iPtr = (Interp *) interp;
int length;
int wasDynamic = iPtr->dynamic;
char *oldResult = iPtr->result;
if (string == NULL) {
iPtr->resultSpace[0] = 0;
iPtr->result = iPtr->resultSpace;
iPtr->dynamic = 0;
} else if (status == TCL_STATIC) {
iPtr->result = string;
iPtr->dynamic = 0;
} else if (status == TCL_DYNAMIC) {
iPtr->result = string;
iPtr->dynamic = 1;
} else {
length = strlen(string);
if (length > TCL_RESULT_SIZE) {
iPtr->result = (char *) ckalloc((unsigned) length+1);
iPtr->dynamic = 1;
} else {
iPtr->dynamic = 0;
}
strcpy(iPtr->result, string);
}
/*
* If the old result was dynamically-allocated, ckfree it up. Do it
* here, rather than at the beginning, in case the new result value
* was part of the old result value.
*/
if (wasDynamic) {
ckfree(oldResult);
}
}
/*
*----------------------------------------------------------------------
*
* 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. 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 'n':
result = '\n';
break;
case 't':
result = '\t';
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) | 0200;
break;
}
count = 3;
result = *p & 037;
break;
case 'M':
p++;
if (isspace(*p) || (*p == 0)) {
result = 'M';
count = 1;
break;
}
count = 3;
result = *p + 0200;
break;
case '}':
case '{':
case ']':
case '[':
case '$':
case ' ':
case ';':
case '"':
case '\\':
result = *p;
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;
}
/*
*----------------------------------------------------------------------
*
* Tcl_SplitList --
*
* Splits a list up into its constituent fields.
*
* Results
* The return value is normally TCL_OK, which means that
* the list was successfully split up. If TCL_ERROR is
* returned, it means that "list" didn't have proper list
* structure; interp->result will contain a more detailed
* error message.
*
* *argvPtr will be filled in with the address of an array
* whose elements point to the elements of list, in order.
* *argcPtr will get filled in with the number of valid elements
* in the array. A single block of memory is dynamically allocated
* to hold both the argv array and a copy of the list (with
* backslashes and braces removed in the standard way).
* The caller must eventually ckfree this memory by calling ckfree()
* on *argvPtr. Note: *argvPtr and *argcPtr are only modified
* if the procedure returns normally.
*
* Side effects:
* Memory is allocated.
*
*----------------------------------------------------------------------
*/
int
Tcl_SplitList(interp, list, argcPtr, argvPtr)
Tcl_Interp *interp; /* Interpreter to use for error reporting. */
char *list; /* Pointer to string with list structure. */
int *argcPtr; /* Pointer to location to fill in with
* the number of elements in the list. */
char ***argvPtr; /* Pointer to place to store pointer to array
* of pointers to list elements. */
{
char **argv;
register char *p;
int size, i, result, elSize, brace;
char *element;
/*
* Figure out how much space to allocate. There must be enough
* space for both the array of pointers and also for a copy of
* the list. To estimate the number of pointers needed, count
* the number of space characters in the list.
*/
for (size = 1, p = list; *p != 0; p++) {
if (isspace(*p)) {
size++;
}
}
argv = (char **) ckalloc((unsigned)
((size * sizeof(char *)) + (p - list) + 1));
for (i = 0, p = ((char *) argv) + size*sizeof(char *);
*list != 0; i++) {
result = TclFindElement(interp, list, &element, &list, &elSize, &brace);
if (result != TCL_OK) {
ckfree((char *) argv);
return result;
}
if (*element == 0) {
break;
}
if (i >= size) {
Tcl_Return(interp, "internal error in Tcl_SplitList", TCL_STATIC);
return TCL_ERROR;
}
argv[i] = p;
if (brace) {
strncpy(p, element, elSize);
p += elSize;
*p = 0;
p++;
} else {
TclCopyAndCollapse(elSize, element, p);
p += elSize+1;
}
}
*argvPtr = argv;
*argcPtr = i;
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_StringMatch --
*
* See if a particular string matches a particular pattern.
*
* Results:
* The return value is 1 if string matches pattern, and
* 0 otherwise. The matching operation permits the following
* special characters in the pattern: *?\[] (see the manual
* entry for details on what these mean).
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
Tcl_StringMatch(string, pattern)
register char *string; /* String. */
register char *pattern; /* Pattern, which may contain
* special characters. */
{
char c2;
while (1) {
/* See if we're at the end of both the pattern and the string.
* If so, we succeeded. If we're at the end of the pattern
* but not at the end of the string, we failed.
*/
if (*pattern == 0) {
if (*string == 0) {
return 1;
} else {
return 0;
}
}
if ((*string == 0) && (*pattern != '*')) {
return 0;
}
/* Check for a "*" as the next pattern character. It matches
* any substring. We handle this by calling ourselves
* recursively for each postfix of string, until either we
* match or we reach the end of the string.
*/
if (*pattern == '*') {
pattern += 1;
if (*pattern == 0) {
return 1;
}
while (*string != 0) {
if (Tcl_StringMatch(string, pattern)) {
return 1;
}
string += 1;
}
return 0;
}
/* Check for a "?" as the next pattern character. It matches
* any single character.
*/
if (*pattern == '?') {
goto thisCharOK;
}
/* Check for a "[" as the next pattern character. It is followed
* by a list of characters that are acceptable, or by a range
* (two characters separated by "-").
*/
if (*pattern == '[') {
pattern += 1;
while (1) {
if ((*pattern == ']') || (*pattern == 0)) {
return 0;
}
if (*pattern == *string) {
break;
}
if (pattern[1] == '-') {
c2 = pattern[2];
if (c2 == 0) {
return 0;
}
if ((*pattern <= *string) && (c2 >= *string)) {
break;
}
if ((*pattern >= *string) && (c2 <= *string)) {
break;
}
pattern += 2;
}
pattern += 1;
}
while ((*pattern != ']') && (*pattern != 0)) {
pattern += 1;
}
goto thisCharOK;
}
/* If the next pattern character is '/', just strip off the '/'
* so we do exact matching on the character that follows.
*/
if (*pattern == '\\') {
pattern += 1;
if (*pattern == 0) {
return 0;
}
}
/* There's no special character. Just make sure that the next
* characters of each string match.
*/
if (*pattern != *string) {
return 0;
}
thisCharOK: pattern += 1;
string += 1;
}
}