tclMain.c Go to the documentation of this file. /* * tclMain.c -- * * Main program for Tcl shells and other Tcl-based applications. * * Copyright (c) 1988-1994 The Regents of the University of California. * Copyright (c) 1994-1997 Sun Microsystems, Inc. * Copyright (c) 2000 Ajuba Solutions. * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tclMain.c,v 1.44 2007/12/13 15:23:19 dgp Exp $ */ #include "tclInt.h" #undef TCL_STORAGE_CLASS #define TCL_STORAGE_CLASS DLLEXPORT /* * The default prompt used when the user has not overridden it. */ #define DEFAULT_PRIMARY_PROMPT "% " /* * Declarations for various library functions and variables (don't want to * include tclPort.h here, because people might copy this file out of the Tcl * source directory to make their own modified versions). */ extern CRTIMPORT int isatty(int fd); static Tcl_Obj *tclStartupScriptPath = NULL; static Tcl_Obj *tclStartupScriptEncoding = NULL; static Tcl_MainLoopProc *mainLoopProc = NULL; /* * Structure definition for information used to keep the state of an * interactive command processor that reads lines from standard input and * writes prompts and results to standard output. */ typedef enum { PROMPT_NONE, /* Print no prompt */ PROMPT_START, /* Print prompt for command start */ PROMPT_CONTINUE /* Print prompt for command continuation */ } PromptType; typedef struct InteractiveState { Tcl_Channel input; /* The standard input channel from which lines * are read. */ int tty; /* Non-zero means standard input is a * terminal-like device. Zero means it's a * file. */ Tcl_Obj *commandPtr; /* Used to assemble lines of input into Tcl * commands. */ PromptType prompt; /* Next prompt to print */ Tcl_Interp *interp; /* Interpreter that evaluates interactive * commands. */ } InteractiveState; /* * Forward declarations for functions defined later in this file. */ static void Prompt(Tcl_Interp *interp, PromptType *promptPtr); static void StdinProc(ClientData clientData, int mask);  /* *---------------------------------------------------------------------- * * Tcl_SetStartupScript -- * * Sets the path and encoding of the startup script to be evaluated by * Tcl_Main, used to override the command line processing. * * Results: * None. * * Side effects: * *---------------------------------------------------------------------- */ void Tcl_SetStartupScript( Tcl_Obj *path, /* Filesystem path of startup script file */ CONST char *encoding) /* Encoding of the data in that file */ { Tcl_Obj *newEncoding = NULL; if (encoding != NULL) { newEncoding = Tcl_NewStringObj(encoding, -1); } if (tclStartupScriptPath != NULL) { Tcl_DecrRefCount(tclStartupScriptPath); } tclStartupScriptPath = path; if (tclStartupScriptPath != NULL) { Tcl_IncrRefCount(tclStartupScriptPath); } if (tclStartupScriptEncoding != NULL) { Tcl_DecrRefCount(tclStartupScriptEncoding); } tclStartupScriptEncoding = newEncoding; if (tclStartupScriptEncoding != NULL) { Tcl_IncrRefCount(tclStartupScriptEncoding); } }  /* *---------------------------------------------------------------------- * * Tcl_GetStartupScript -- * * Gets the path and encoding of the startup script to be evaluated by * Tcl_Main. * * Results: * The path of the startup script; NULL if none has been set. * * Side effects: * If encodingPtr is not NULL, stores a (CONST char *) in it pointing to * the encoding name registered for the startup script. Tcl retains * ownership of the string, and may free it. Caller should make a copy * for long-term use. * *---------------------------------------------------------------------- */ Tcl_Obj * Tcl_GetStartupScript( CONST char **encodingPtr) /* When not NULL, points to storage for the * (CONST char *) that points to the * registered encoding name for the startup * script */ { if (encodingPtr != NULL) { if (tclStartupScriptEncoding == NULL) { *encodingPtr = NULL; } else { *encodingPtr = Tcl_GetString(tclStartupScriptEncoding); } } return tclStartupScriptPath; }  /* *---------------------------------------------------------------------- * * TclSetStartupScriptPath -- * * Primes the startup script VFS path, used to override the command line * processing. * * Results: * None. * * Side effects: * This function initializes the VFS path of the Tcl script to run at * startup. * *---------------------------------------------------------------------- */ void TclSetStartupScriptPath( Tcl_Obj *path) { Tcl_SetStartupScript(path, NULL); }  /* *---------------------------------------------------------------------- * * TclGetStartupScriptPath -- * * Gets the startup script VFS path, used to override the command line * processing. * * Results: * The startup script VFS path, NULL if none has been set. * * Side effects: * None. * *---------------------------------------------------------------------- */ Tcl_Obj * TclGetStartupScriptPath(void) { return Tcl_GetStartupScript(NULL); }  /* *---------------------------------------------------------------------- * * TclSetStartupScriptFileName -- * * Primes the startup script file name, used to override the command line * processing. * * Results: * None. * * Side effects: * This function initializes the file name of the Tcl script to run at * startup. * *---------------------------------------------------------------------- */ void TclSetStartupScriptFileName( CONST char *fileName) { Tcl_Obj *path = Tcl_NewStringObj(fileName,-1); Tcl_SetStartupScript(path, NULL); }  /* *---------------------------------------------------------------------- * * TclGetStartupScriptFileName -- * * Gets the startup script file name, used to override the command line * processing. * * Results: * The startup script file name, NULL if none has been set. * * Side effects: * None. * *---------------------------------------------------------------------- */ CONST char * TclGetStartupScriptFileName(void) { Tcl_Obj *path = Tcl_GetStartupScript(NULL); if (path == NULL) { return NULL; } return Tcl_GetString(path); }  /*---------------------------------------------------------------------- * * Tcl_SourceRCFile -- * * This function is typically invoked by Tcl_Main of Tk_Main function to * source an application specific rc file into the interpreter at startup * time. * * Results: * None. * * Side effects: * Depends on what's in the rc script. * *---------------------------------------------------------------------- */ void Tcl_SourceRCFile( Tcl_Interp *interp) /* Interpreter to source rc file into. */ { Tcl_DString temp; CONST char *fileName; Tcl_Channel errChannel; fileName = Tcl_GetVar(interp, "tcl_rcFileName", TCL_GLOBAL_ONLY); if (fileName != NULL) { Tcl_Channel c; CONST char *fullName; Tcl_DStringInit(&temp); fullName = Tcl_TranslateFileName(interp, fileName, &temp); if (fullName == NULL) { /* * Couldn't translate the file name (e.g. it referred to a bogus * user or there was no HOME environment variable). Just do * nothing. */ } else { /* * Test for the existence of the rc file before trying to read it. */ c = Tcl_OpenFileChannel(NULL, fullName, "r", 0); if (c != (Tcl_Channel) NULL) { Tcl_Close(NULL, c); if (Tcl_EvalFile(interp, fullName) != TCL_OK) { errChannel = Tcl_GetStdChannel(TCL_STDERR); if (errChannel) { Tcl_WriteObj(errChannel, Tcl_GetObjResult(interp)); Tcl_WriteChars(errChannel, "\n", 1); } } } } Tcl_DStringFree(&temp); } }  /*---------------------------------------------------------------------- * * Tcl_Main -- * * Main program for tclsh and most other Tcl-based applications. * * Results: * None. This function never returns (it exits the process when it's * done). * * Side effects: * This function initializes the Tcl world and then starts interpreting * commands; almost anything could happen, depending on the script being * interpreted. * *---------------------------------------------------------------------- */ void Tcl_Main( int argc, /* Number of arguments. */ char **argv, /* Array of argument strings. */ Tcl_AppInitProc *appInitProc) /* Application-specific initialization * function to call after most initialization * but before starting to execute commands. */ { Tcl_Obj *path, *resultPtr, *argvPtr, *commandPtr = NULL; CONST char *encodingName = NULL; PromptType prompt = PROMPT_START; int code, length, tty, exitCode = 0; Tcl_Channel inChannel, outChannel, errChannel; Tcl_Interp *interp; Tcl_DString appName; Tcl_FindExecutable(argv[0]); interp = Tcl_CreateInterp(); Tcl_InitMemory(interp); /* * If the application has not already set a startup script, parse the * first few command line arguments to determine the script path and * encoding. */ if (NULL == Tcl_GetStartupScript(NULL)) { /* * Check whether first 3 args (argv[1] - argv[3]) look like * -encoding ENCODING FILENAME * or like * FILENAME */ if ((argc > 3) && (0 == strcmp("-encoding", argv[1])) && ('-' != argv[3][0])) { Tcl_SetStartupScript(Tcl_NewStringObj(argv[3], -1), argv[2]); argc -= 3; argv += 3; } else if ((argc > 1) && ('-' != argv[1][0])) { Tcl_SetStartupScript(Tcl_NewStringObj(argv[1], -1), NULL); argc--; argv++; } } path = Tcl_GetStartupScript(&encodingName); if (path == NULL) { Tcl_ExternalToUtfDString(NULL, argv[0], -1, &appName); } else { CONST char *pathName = Tcl_GetStringFromObj(path, &length); Tcl_ExternalToUtfDString(NULL, pathName, length, &appName); path = Tcl_NewStringObj(Tcl_DStringValue(&appName), -1); Tcl_SetStartupScript(path, encodingName); } Tcl_SetVar(interp, "argv0", Tcl_DStringValue(&appName), TCL_GLOBAL_ONLY); Tcl_DStringFree(&appName); argc--; argv++; Tcl_SetVar2Ex(interp, "argc", NULL, Tcl_NewIntObj(argc), TCL_GLOBAL_ONLY); argvPtr = Tcl_NewListObj(0, NULL); while (argc--) { Tcl_DString ds; Tcl_ExternalToUtfDString(NULL, *argv++, -1, &ds); Tcl_ListObjAppendElement(NULL, argvPtr, Tcl_NewStringObj( Tcl_DStringValue(&ds), Tcl_DStringLength(&ds))); Tcl_DStringFree(&ds); } Tcl_SetVar2Ex(interp, "argv", NULL, argvPtr, TCL_GLOBAL_ONLY); /* * Set the "tcl_interactive" variable. */ tty = isatty(0); Tcl_SetVar(interp, "tcl_interactive", ((path == NULL) && tty) ? "1" : "0", TCL_GLOBAL_ONLY); /* * Invoke application-specific initialization. */ Tcl_Preserve((ClientData) interp); if ((*appInitProc)(interp) != TCL_OK) { errChannel = Tcl_GetStdChannel(TCL_STDERR); if (errChannel) { Tcl_WriteChars(errChannel, "application-specific initialization failed: ", -1); Tcl_WriteObj(errChannel, Tcl_GetObjResult(interp)); Tcl_WriteChars(errChannel, "\n", 1); } } if (Tcl_InterpDeleted(interp)) { goto done; } if (Tcl_LimitExceeded(interp)) { goto done; } /* * If a script file was specified then just source that file and quit. * Must fetch it again, as the appInitProc might have reset it. */ path = Tcl_GetStartupScript(&encodingName); if (path != NULL) { code = Tcl_FSEvalFileEx(interp, path, encodingName); if (code != TCL_OK) { errChannel = Tcl_GetStdChannel(TCL_STDERR); if (errChannel) { Tcl_Obj *options = Tcl_GetReturnOptions(interp, code); Tcl_Obj *keyPtr, *valuePtr; TclNewLiteralStringObj(keyPtr, "-errorinfo"); Tcl_IncrRefCount(keyPtr); Tcl_DictObjGet(NULL, options, keyPtr, &valuePtr); Tcl_DecrRefCount(keyPtr); if (valuePtr) { Tcl_WriteObj(errChannel, valuePtr); } Tcl_WriteChars(errChannel, "\n", 1); } exitCode = 1; } goto done; } /* * We're running interactively. Source a user-specific startup file if the * application specified one and if the file exists. */ Tcl_SourceRCFile(interp); if (Tcl_LimitExceeded(interp)) { goto done; } /* * Process commands from stdin until there's an end-of-file. Note that we * need to fetch the standard channels again after every eval, since they * may have been changed. */ commandPtr = Tcl_NewObj(); Tcl_IncrRefCount(commandPtr); /* * Get a new value for tty if anyone writes to ::tcl_interactive */ Tcl_LinkVar(interp, "tcl_interactive", (char *) &tty, TCL_LINK_BOOLEAN); inChannel = Tcl_GetStdChannel(TCL_STDIN); outChannel = Tcl_GetStdChannel(TCL_STDOUT); while ((inChannel != (Tcl_Channel) NULL) && !Tcl_InterpDeleted(interp)) { if (mainLoopProc == NULL) { if (tty) { Prompt(interp, &prompt); if (Tcl_InterpDeleted(interp)) { break; } if (Tcl_LimitExceeded(interp)) { break; } inChannel = Tcl_GetStdChannel(TCL_STDIN); if (inChannel == (Tcl_Channel) NULL) { break; } } if (Tcl_IsShared(commandPtr)) { Tcl_DecrRefCount(commandPtr); commandPtr = Tcl_DuplicateObj(commandPtr); Tcl_IncrRefCount(commandPtr); } length = Tcl_GetsObj(inChannel, commandPtr); if (length < 0) { if (Tcl_InputBlocked(inChannel)) { /* * This can only happen if stdin has been set to * non-blocking. In that case cycle back and try again. * This sets up a tight polling loop (since we have no * event loop running). If this causes bad CPU hogging, * we might try toggling the blocking on stdin instead. */ continue; } /* * Either EOF, or an error on stdin; we're done */ break; } /* * Add the newline removed by Tcl_GetsObj back to the string. * Have to add it back before testing completeness, because * it can make a difference. [Bug 1775878]. */ if (Tcl_IsShared(commandPtr)) { Tcl_DecrRefCount(commandPtr); commandPtr = Tcl_DuplicateObj(commandPtr); Tcl_IncrRefCount(commandPtr); } Tcl_AppendToObj(commandPtr, "\n", 1); if (!TclObjCommandComplete(commandPtr)) { prompt = PROMPT_CONTINUE; continue; } prompt = PROMPT_START; /* * The final newline is syntactically redundant, and causes * some error messages troubles deeper in, so lop it back off. */ Tcl_GetStringFromObj(commandPtr, &length); Tcl_SetObjLength(commandPtr, --length); code = Tcl_RecordAndEvalObj(interp, commandPtr, TCL_EVAL_GLOBAL); inChannel = Tcl_GetStdChannel(TCL_STDIN); outChannel = Tcl_GetStdChannel(TCL_STDOUT); errChannel = Tcl_GetStdChannel(TCL_STDERR); Tcl_DecrRefCount(commandPtr); commandPtr = Tcl_NewObj(); Tcl_IncrRefCount(commandPtr); if (code != TCL_OK) { if (errChannel) { Tcl_WriteObj(errChannel, Tcl_GetObjResult(interp)); Tcl_WriteChars(errChannel, "\n", 1); } } else if (tty) { resultPtr = Tcl_GetObjResult(interp); Tcl_IncrRefCount(resultPtr); Tcl_GetStringFromObj(resultPtr, &length); if ((length > 0) && outChannel) { Tcl_WriteObj(outChannel, resultPtr); Tcl_WriteChars(outChannel, "\n", 1); } Tcl_DecrRefCount(resultPtr); } } else { /* (mainLoopProc != NULL) */ /* * If a main loop has been defined while running interactively, we * want to start a fileevent based prompt by establishing a * channel handler for stdin. */ InteractiveState *isPtr = NULL; if (inChannel) { if (tty) { Prompt(interp, &prompt); } isPtr = (InteractiveState *) ckalloc((int) sizeof(InteractiveState)); isPtr->input = inChannel; isPtr->tty = tty; isPtr->commandPtr = commandPtr; isPtr->prompt = prompt; isPtr->interp = interp; Tcl_UnlinkVar(interp, "tcl_interactive"); Tcl_LinkVar(interp, "tcl_interactive", (char *) &(isPtr->tty), TCL_LINK_BOOLEAN); Tcl_CreateChannelHandler(inChannel, TCL_READABLE, StdinProc, (ClientData) isPtr); } (*mainLoopProc)(); mainLoopProc = NULL; if (inChannel) { tty = isPtr->tty; Tcl_UnlinkVar(interp, "tcl_interactive"); Tcl_LinkVar(interp, "tcl_interactive", (char *) &tty, TCL_LINK_BOOLEAN); prompt = isPtr->prompt; commandPtr = isPtr->commandPtr; if (isPtr->input != (Tcl_Channel) NULL) { Tcl_DeleteChannelHandler(isPtr->input, StdinProc, (ClientData) isPtr); } ckfree((char *)isPtr); } inChannel = Tcl_GetStdChannel(TCL_STDIN); outChannel = Tcl_GetStdChannel(TCL_STDOUT); errChannel = Tcl_GetStdChannel(TCL_STDERR); } #ifdef TCL_MEM_DEBUG /* * This code here only for the (unsupported and deprecated) [checkmem] * command. */ if (tclMemDumpFileName != NULL) { mainLoopProc = NULL; Tcl_DeleteInterp(interp); } #endif } done: if ((exitCode == 0) && (mainLoopProc != NULL) && !Tcl_LimitExceeded(interp)) { /* * If everything has gone OK so far, call the main loop proc, if it * exists. Packages (like Tk) can set it to start processing events at * this point. */ (*mainLoopProc)(); mainLoopProc = NULL; } if (commandPtr != NULL) { Tcl_DecrRefCount(commandPtr); } /* * Rather than calling exit, invoke the "exit" command so that users can * replace "exit" with some other command to do additional cleanup on * exit. The Tcl_EvalObjEx call should never return. */ if (!Tcl_InterpDeleted(interp)) { if (!Tcl_LimitExceeded(interp)) { Tcl_Obj *cmd = Tcl_ObjPrintf("exit %d", exitCode); Tcl_IncrRefCount(cmd); Tcl_EvalObjEx(interp, cmd, TCL_EVAL_GLOBAL); Tcl_DecrRefCount(cmd); } /* * If Tcl_EvalObjEx returns, trying to eval [exit], something unusual * is happening. Maybe interp has been deleted; maybe [exit] was * redefined, maybe we've blown up because of an exceeded limit. We * still want to cleanup and exit. */ if (!Tcl_InterpDeleted(interp)) { Tcl_DeleteInterp(interp); } } Tcl_SetStartupScript(NULL, NULL); /* * If we get here, the master interp has been deleted. Allow its * destruction with the last matching Tcl_Release. */ Tcl_Release((ClientData) interp); Tcl_Exit(exitCode); }  /* *--------------------------------------------------------------- * * Tcl_SetMainLoop -- * * Sets an alternative main loop function. * * Results: * Returns the previously defined main loop function. * * Side effects: * This function will be called before Tcl exits, allowing for the * creation of an event loop. * *--------------------------------------------------------------- */ void Tcl_SetMainLoop( Tcl_MainLoopProc *proc) { mainLoopProc = proc; }  /* *---------------------------------------------------------------------- * * StdinProc -- * * This function is invoked by the event dispatcher whenever standard * input becomes readable. It grabs the next line of input characters, * adds them to a command being assembled, and executes the command if * it's complete. * * Results: * None. * * Side effects: * Could be almost arbitrary, depending on the command that's typed. * *---------------------------------------------------------------------- */ /* ARGSUSED */ static void StdinProc( ClientData clientData, /* The state of interactive cmd line */ int mask) /* Not used. */ { InteractiveState *isPtr = (InteractiveState *) clientData; Tcl_Channel chan = isPtr->input; Tcl_Obj *commandPtr = isPtr->commandPtr; Tcl_Interp *interp = isPtr->interp; int code, length; if (Tcl_IsShared(commandPtr)) { Tcl_DecrRefCount(commandPtr); commandPtr = Tcl_DuplicateObj(commandPtr); Tcl_IncrRefCount(commandPtr); } length = Tcl_GetsObj(chan, commandPtr); if (length < 0) { if (Tcl_InputBlocked(chan)) { return; } if (isPtr->tty) { /* * Would be better to find a way to exit the mainLoop? Or perhaps * evaluate [exit]? Leaving as is for now due to compatibility * concerns. */ Tcl_Exit(0); } Tcl_DeleteChannelHandler(chan, StdinProc, (ClientData) isPtr); return; } if (Tcl_IsShared(commandPtr)) { Tcl_DecrRefCount(commandPtr); commandPtr = Tcl_DuplicateObj(commandPtr); Tcl_IncrRefCount(commandPtr); } Tcl_AppendToObj(commandPtr, "\n", 1); if (!TclObjCommandComplete(commandPtr)) { isPtr->prompt = PROMPT_CONTINUE; goto prompt; } isPtr->prompt = PROMPT_START; Tcl_GetStringFromObj(commandPtr, &length); Tcl_SetObjLength(commandPtr, --length); /* * Disable the stdin channel handler while evaluating the command; * otherwise if the command re-enters the event loop we might process * commands from stdin before the current command is finished. Among other * things, this will trash the text of the command being evaluated. */ Tcl_CreateChannelHandler(chan, 0, StdinProc, (ClientData) isPtr); code = Tcl_RecordAndEvalObj(interp, commandPtr, TCL_EVAL_GLOBAL); isPtr->input = chan = Tcl_GetStdChannel(TCL_STDIN); Tcl_DecrRefCount(commandPtr); isPtr->commandPtr = commandPtr = Tcl_NewObj(); Tcl_IncrRefCount(commandPtr); if (chan != (Tcl_Channel) NULL) { Tcl_CreateChannelHandler(chan, TCL_READABLE, StdinProc, (ClientData) isPtr); } if (code != TCL_OK) { Tcl_Channel errChannel = Tcl_GetStdChannel(TCL_STDERR); if (errChannel != (Tcl_Channel) NULL) { Tcl_WriteObj(errChannel, Tcl_GetObjResult(interp)); Tcl_WriteChars(errChannel, "\n", 1); } } else if (isPtr->tty) { Tcl_Obj *resultPtr = Tcl_GetObjResult(interp); Tcl_Channel outChannel = Tcl_GetStdChannel(TCL_STDOUT); Tcl_IncrRefCount(resultPtr); Tcl_GetStringFromObj(resultPtr, &length); if ((length >0) && (outChannel != (Tcl_Channel) NULL)) { Tcl_WriteObj(outChannel, resultPtr); Tcl_WriteChars(outChannel, "\n", 1); } Tcl_DecrRefCount(resultPtr); } /* * If a tty stdin is still around, output a prompt. */ prompt: if (isPtr->tty && (isPtr->input != (Tcl_Channel) NULL)) { Prompt(interp, &(isPtr->prompt)); isPtr->input = Tcl_GetStdChannel(TCL_STDIN); } }  /* *---------------------------------------------------------------------- * * Prompt -- * * Issue a prompt on standard output, or invoke a script to issue the * prompt. * * Results: * None. * * Side effects: * A prompt gets output, and a Tcl script may be evaluated in interp. * *---------------------------------------------------------------------- */ static void Prompt( Tcl_Interp *interp, /* Interpreter to use for prompting. */ PromptType *promptPtr) /* Points to type of prompt to print. Filled * with PROMPT_NONE after a prompt is * printed. */ { Tcl_Obj *promptCmdPtr; int code; Tcl_Channel outChannel, errChannel; if (*promptPtr == PROMPT_NONE) { return; } promptCmdPtr = Tcl_GetVar2Ex(interp, ((*promptPtr == PROMPT_CONTINUE) ? "tcl_prompt2" : "tcl_prompt1"), NULL, TCL_GLOBAL_ONLY); if (Tcl_InterpDeleted(interp)) { return; } if (promptCmdPtr == NULL) { defaultPrompt: outChannel = Tcl_GetStdChannel(TCL_STDOUT); if ((*promptPtr == PROMPT_START) && (outChannel != (Tcl_Channel) NULL)) { Tcl_WriteChars(outChannel, DEFAULT_PRIMARY_PROMPT, strlen(DEFAULT_PRIMARY_PROMPT)); } } else { code = Tcl_EvalObjEx(interp, promptCmdPtr, TCL_EVAL_GLOBAL); if (code != TCL_OK) { Tcl_AddErrorInfo(interp, "\n (script that generates prompt)"); errChannel = Tcl_GetStdChannel(TCL_STDERR); if (errChannel != (Tcl_Channel) NULL) { Tcl_WriteObj(errChannel, Tcl_GetObjResult(interp)); Tcl_WriteChars(errChannel, "\n", 1); } goto defaultPrompt; } } outChannel = Tcl_GetStdChannel(TCL_STDOUT); if (outChannel != (Tcl_Channel) NULL) { Tcl_Flush(outChannel); } *promptPtr = PROMPT_NONE; }  /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */

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