| 1 | /* |
| 2 | * tclAssem.c -- |
| 3 | * |
| 4 | * This file contains procedures to help assemble Tcl commands |
| 5 | * from an input source where commands may arrive in pieces, e.g. |
| 6 | * several lines of type-in corresponding to one command. |
| 7 | * |
| 8 | * Copyright 1990-1991 Regents of the University of California |
| 9 | * Permission to use, copy, modify, and distribute this |
| 10 | * software and its documentation for any purpose and without |
| 11 | * fee is hereby granted, provided that the above copyright |
| 12 | * notice appear in all copies. The University of California |
| 13 | * makes no representations about the suitability of this |
| 14 | * software for any purpose. It is provided "as is" without |
| 15 | * express or implied warranty. |
| 16 | */ |
| 17 | |
| 18 | #ifndef lint |
| 19 | static char rcsid[] = "$Header: /user6/ouster/tcl/RCS/tclAssem.c,v 1.9 92/07/02 09:14:05 ouster Exp $ SPRITE (Berkeley)"; |
| 20 | #endif /* not lint */ |
| 21 | |
| 22 | #include "tclint.h" |
| 23 | |
| 24 | /* |
| 25 | * The structure below is the internal representation for a command |
| 26 | * buffer, which is used to hold a piece of a command until a full |
| 27 | * command is available. When a full command is available, it will |
| 28 | * be returned to the user, but it will also be retained in the buffer |
| 29 | * until the NEXT call to Tcl_AssembleCmd, at which point it will be |
| 30 | * removed. |
| 31 | */ |
| 32 | |
| 33 | typedef struct { |
| 34 | char *buffer; /* Storage for command being assembled. |
| 35 | * Malloc-ed, and grows as needed. */ |
| 36 | int bufSize; /* Total number of bytes in buffer. */ |
| 37 | int bytesUsed; /* Number of bytes in buffer currently |
| 38 | * occupied (0 means there is not a |
| 39 | * buffered incomplete command). */ |
| 40 | } CmdBuf; |
| 41 | |
| 42 | /* |
| 43 | * Default amount of space to allocate in command buffer: |
| 44 | */ |
| 45 | |
| 46 | #define CMD_BUF_SIZE 100 |
| 47 | \f |
| 48 | /* |
| 49 | *---------------------------------------------------------------------- |
| 50 | * |
| 51 | * Tcl_CreateCmdBuf -- |
| 52 | * |
| 53 | * Allocate and initialize a command buffer. |
| 54 | * |
| 55 | * Results: |
| 56 | * The return value is a token that may be passed to |
| 57 | * Tcl_AssembleCmd and Tcl_DeleteCmdBuf. |
| 58 | * |
| 59 | * Side effects: |
| 60 | * Memory is allocated. |
| 61 | * |
| 62 | *---------------------------------------------------------------------- |
| 63 | */ |
| 64 | |
| 65 | Tcl_CmdBuf |
| 66 | Tcl_CreateCmdBuf() |
| 67 | { |
| 68 | register CmdBuf *cbPtr; |
| 69 | |
| 70 | cbPtr = (CmdBuf *) ckalloc(sizeof(CmdBuf)); |
| 71 | cbPtr->buffer = (char *) ckalloc(CMD_BUF_SIZE); |
| 72 | cbPtr->buffer[0] = '\0'; |
| 73 | cbPtr->bufSize = CMD_BUF_SIZE; |
| 74 | cbPtr->bytesUsed = 0; |
| 75 | return (Tcl_CmdBuf) cbPtr; |
| 76 | } |
| 77 | \f |
| 78 | /* |
| 79 | *---------------------------------------------------------------------- |
| 80 | * |
| 81 | * Tcl_DeleteCmdBuf -- |
| 82 | * |
| 83 | * Release all of the resources associated with a command buffer. |
| 84 | * The caller should never again use buffer again. |
| 85 | * |
| 86 | * Results: |
| 87 | * None. |
| 88 | * |
| 89 | * Side effects: |
| 90 | * Memory is released. |
| 91 | * |
| 92 | *---------------------------------------------------------------------- |
| 93 | */ |
| 94 | |
| 95 | void |
| 96 | Tcl_DeleteCmdBuf(buffer) |
| 97 | Tcl_CmdBuf buffer; /* Token for command buffer (return value |
| 98 | * from previous call to Tcl_CreateCmdBuf). */ |
| 99 | { |
| 100 | register CmdBuf *cbPtr = (CmdBuf *) buffer; |
| 101 | |
| 102 | ckfree(cbPtr->buffer); |
| 103 | ckfree((char *) cbPtr); |
| 104 | } |
| 105 | \f |
| 106 | /* |
| 107 | *---------------------------------------------------------------------- |
| 108 | * |
| 109 | * Tcl_AssembleCmd -- |
| 110 | * |
| 111 | * This is a utility procedure to assist in situations where |
| 112 | * commands may be read piece-meal from some input source. Given |
| 113 | * some input text, it adds the text to an input buffer and returns |
| 114 | * whole commands when they are ready. |
| 115 | * |
| 116 | * Results: |
| 117 | * If the addition of string to any currently-buffered information |
| 118 | * results in one or more complete Tcl commands, then the return value |
| 119 | * is a pointer to the complete command(s). The command value will |
| 120 | * only be valid until the next call to this procedure with the |
| 121 | * same buffer. If the addition of string leaves an incomplete |
| 122 | * command at the end of the buffer, then NULL is returned. |
| 123 | * |
| 124 | * Side effects: |
| 125 | * If string leaves a command incomplete, the partial command |
| 126 | * information is buffered for use in later calls to this procedure. |
| 127 | * Once a command has been returned, that command is deleted from |
| 128 | * the buffer on the next call to this procedure. |
| 129 | * |
| 130 | *---------------------------------------------------------------------- |
| 131 | */ |
| 132 | |
| 133 | char * |
| 134 | Tcl_AssembleCmd(buffer, string) |
| 135 | Tcl_CmdBuf buffer; /* Token for a command buffer previously |
| 136 | * created by Tcl_CreateCmdBuf. */ |
| 137 | char *string; /* Bytes to be appended to command stream. |
| 138 | * Note: if the string is zero length, |
| 139 | * then whatever is buffered will be |
| 140 | * considered to be a complete command |
| 141 | * regardless of whether parentheses are |
| 142 | * matched or not. */ |
| 143 | { |
| 144 | register CmdBuf *cbPtr = (CmdBuf *) buffer; |
| 145 | int length, totalLength; |
| 146 | register char *p; |
| 147 | |
| 148 | /* |
| 149 | * If an empty string is passed in, just pretend the current |
| 150 | * command is complete, whether it really is or not. |
| 151 | */ |
| 152 | |
| 153 | length = strlen(string); |
| 154 | if (length == 0) { |
| 155 | cbPtr->bytesUsed = 0; |
| 156 | return cbPtr->buffer; |
| 157 | } |
| 158 | |
| 159 | /* |
| 160 | * Add the new information to the buffer. If the current buffer |
| 161 | * isn't large enough, grow it by at least a factor of two, or |
| 162 | * enough to hold the new text. |
| 163 | */ |
| 164 | |
| 165 | length = strlen(string); |
| 166 | totalLength = cbPtr->bytesUsed + length + 1; |
| 167 | if (totalLength > cbPtr->bufSize) { |
| 168 | unsigned int newSize; |
| 169 | char *newBuf; |
| 170 | |
| 171 | newSize = cbPtr->bufSize*2; |
| 172 | if (newSize < totalLength) { |
| 173 | newSize = totalLength; |
| 174 | } |
| 175 | newBuf = (char *) ckalloc(newSize); |
| 176 | strcpy(newBuf, cbPtr->buffer); |
| 177 | ckfree(cbPtr->buffer); |
| 178 | cbPtr->buffer = newBuf; |
| 179 | cbPtr->bufSize = newSize; |
| 180 | } |
| 181 | strcpy(cbPtr->buffer+cbPtr->bytesUsed, string); |
| 182 | cbPtr->bytesUsed += length; |
| 183 | |
| 184 | /* |
| 185 | * See if there is now a complete command in the buffer. |
| 186 | */ |
| 187 | |
| 188 | p = cbPtr->buffer; |
| 189 | while (1) { |
| 190 | int gotNewLine = 0; |
| 191 | |
| 192 | while (isspace(*p)) { |
| 193 | if (*p == '\n') { |
| 194 | gotNewLine = 1; |
| 195 | } |
| 196 | p++; |
| 197 | } |
| 198 | if (*p == 0) { |
| 199 | if (gotNewLine) { |
| 200 | cbPtr->bytesUsed = 0; |
| 201 | return cbPtr->buffer; |
| 202 | } |
| 203 | return NULL; |
| 204 | } |
| 205 | p = TclWordEnd(p, 0); |
| 206 | } |
| 207 | } |