shell.c

nedit 是一款linux下的开发源码的功能强大的编辑器

    kill(- cmdData->childPid, SIGTERM);
    finishCmdExecution(window, True);
}

/*
** Issue a shell command and feed it the string "input".  Output can be
** directed either to text widget "textW" where it replaces the text between
** the positions "replaceLeft" and "replaceRight", to a separate pop-up dialog
** (OUTPUT_TO_DIALOG), or to a macro-language string (OUTPUT_TO_STRING).  If
** "input" is NULL, no input is fed to the process.  If an input string is
** provided, it is freed when the command completes.  Flags:
**
**   ACCUMULATE     	Causes output from the command to be saved up until
**  	    	    	the command completes.
**   ERROR_DIALOGS  	Presents stderr output separately in popup a dialog,
**  	    	    	and also reports failed exit status as a popup dialog
**  	    	    	including the command output.
**   REPLACE_SELECTION  Causes output to replace the selection in textW.
**   RELOAD_FILE_AFTER  Causes the file to be completely reloaded after the
**  	    	    	command completes.
**   OUTPUT_TO_DIALOG   Send output to a pop-up dialog instead of textW
**   OUTPUT_TO_STRING   Output to a macro-language string instead of a text
**  	    	    	widget or dialog.
**
** REPLACE_SELECTION, ERROR_DIALOGS, and OUTPUT_TO_STRING can only be used
** along with ACCUMULATE (these operations can't be done incrementally).
*/
static void issueCommand(WindowInfo *window, const char *command, char *input,
	int inputLen, int flags, Widget textW, int replaceLeft,
	int replaceRight, int fromMacro)
{
    int stdinFD, stdoutFD, stderrFD;
    XtAppContext context = XtWidgetToApplicationContext(window->shell);
    shellCmdInfo *cmdData;
    pid_t childPid;
    
    /* verify consistency of input parameters */
    if ((flags & ERROR_DIALOGS || flags & REPLACE_SELECTION ||
	    flags & OUTPUT_TO_STRING) && !(flags & ACCUMULATE))
    	return;
    
    /* a shell command called from a macro must be executed in the same
       window as the macro, regardless of where the output is directed,
       so the user can cancel them as a unit */
    if (fromMacro)
    	window = MacroRunWindow();
    
    /* put up a watch cursor over the waiting window */
    if (!fromMacro)
    	BeginWait(window->shell);
    
    /* enable the cancel menu item */
    if (!fromMacro)
    	XtSetSensitive(window->cancelShellItem, True);

    /* fork the subprocess and issue the command */
    childPid = forkCommand(window->shell, command, window->path, &stdinFD,
	    &stdoutFD, (flags & ERROR_DIALOGS) ? &stderrFD : NULL);
    
    /* set the pipes connected to the process for non-blocking i/o */
    if (fcntl(stdinFD, F_SETFL, O_NONBLOCK) < 0)
    	perror("NEdit: Internal error (fcntl)");
    if (fcntl(stdoutFD, F_SETFL, O_NONBLOCK) < 0)
    	perror("NEdit: Internal error (fcntl1)");
    if (flags & ERROR_DIALOGS) {
	if (fcntl(stderrFD, F_SETFL, O_NONBLOCK) < 0)
    	    perror("NEdit: Internal error (fcntl2)");
    }
    
    /* if there's nothing to write to the process' stdin, close it now */
    if (input == NULL)
    	close(stdinFD);
    
    /* Create a data structure for passing process information around
       amongst the callback routines which will process i/o and completion */
    cmdData = (shellCmdInfo *)XtMalloc(sizeof(shellCmdInfo));
    window->shellCmdData = cmdData;
    cmdData->flags = flags;
    cmdData->stdinFD = stdinFD;
    cmdData->stdoutFD = stdoutFD;
    cmdData->stderrFD = stderrFD;
    cmdData->childPid = childPid;
    cmdData->outBufs = NULL;
    cmdData->errBufs = NULL;
    cmdData->input = input;
    cmdData->inPtr = input;
    cmdData->textW = textW;
    cmdData->bannerIsUp = False;
    cmdData->fromMacro = fromMacro;
    cmdData->leftPos = replaceLeft;
    cmdData->rightPos = replaceRight;
    cmdData->inLength = inputLen;
    
    /* Set up timer proc for putting up banner when process takes too long */
    if (fromMacro)
    	cmdData->bannerTimeoutID = 0;
    else
    	cmdData->bannerTimeoutID = XtAppAddTimeOut(context, BANNER_WAIT_TIME,
    	    	bannerTimeoutProc, window);

    /* Set up timer proc for flushing output buffers periodically */
    if ((flags & ACCUMULATE) || textW == NULL)
    	cmdData->flushTimeoutID = 0;
    else
	cmdData->flushTimeoutID = XtAppAddTimeOut(context, OUTPUT_FLUSH_FREQ,
	    	flushTimeoutProc, window);
    	
    /* set up callbacks for activity on the file descriptors */
    cmdData->stdoutInputID = XtAppAddInput(context, stdoutFD,
    	    (XtPointer)XtInputReadMask, stdoutReadProc, window);
    if (input != NULL)
    	cmdData->stdinInputID = XtAppAddInput(context, stdinFD,
    	    	(XtPointer)XtInputWriteMask, stdinWriteProc, window);
    else
    	cmdData->stdinInputID = 0;
    if (flags & ERROR_DIALOGS)
	cmdData->stderrInputID = XtAppAddInput(context, stderrFD,
    		(XtPointer)XtInputReadMask, stderrReadProc, window);
    else
    	cmdData->stderrInputID = 0;
    
    /* If this was called from a macro, preempt the macro untill shell
       command completes */
    if (fromMacro)
    	PreemptMacro();
}

/*
** Called when the shell sub-process stdout stream has data.  Reads data into
** the "outBufs" buffer chain in the window->shellCommandData data structure.
*/
static void stdoutReadProc(XtPointer clientData, int *source, XtInputId *id)
{
    WindowInfo *window = (WindowInfo *)clientData;
    shellCmdInfo *cmdData = window->shellCmdData;
    buffer *buf;
    int nRead;

    /* read from the process' stdout stream */
    buf = (buffer *)XtMalloc(sizeof(buffer));
    nRead = read(cmdData->stdoutFD, buf->contents, IO_BUF_SIZE);
    
    /* error in read */
    if (nRead == -1) { /* error */
	if (errno != EWOULDBLOCK && errno != EAGAIN) {
	    perror("NEdit: Error reading shell command output");
	    XtFree((char *)buf);
	    finishCmdExecution(window, True);
	}
	return;
    }
    
    /* end of data.  If the stderr stream is done too, execution of the
       shell process is complete, and we can display the results */
    if (nRead == 0) {
    	XtFree((char *)buf);
    	XtRemoveInput(cmdData->stdoutInputID);
    	cmdData->stdoutInputID = 0;
    	if (cmdData->stderrInputID == 0)
    	    finishCmdExecution(window, False);
    	return;
    }
    
    /* characters were read successfully, add buf to linked list of buffers */
    buf->length = nRead;
    addOutput(&cmdData->outBufs, buf);
}

/*
** Called when the shell sub-process stderr stream has data.  Reads data into
** the "errBufs" buffer chain in the window->shellCommandData data structure.
*/
static void stderrReadProc(XtPointer clientData, int *source, XtInputId *id)
{
    WindowInfo *window = (WindowInfo *)clientData;
    shellCmdInfo *cmdData = window->shellCmdData;
    buffer *buf;
    int nRead;
    
    /* read from the process' stderr stream */
    buf = (buffer *)XtMalloc(sizeof(buffer));
    nRead = read(cmdData->stderrFD, buf->contents, IO_BUF_SIZE);
    
    /* error in read */
    if (nRead == -1) {
	if (errno != EWOULDBLOCK && errno != EAGAIN) {
	    perror("NEdit: Error reading shell command error stream");
	    XtFree((char *)buf);
	    finishCmdExecution(window, True);
	}
	return;
    }
    
    /* end of data.  If the stdout stream is done too, execution of the
       shell process is complete, and we can display the results */
    if (nRead == 0) {
    	XtFree((char *)buf);
    	XtRemoveInput(cmdData->stderrInputID);
    	cmdData->stderrInputID = 0;
    	if (cmdData->stdoutInputID == 0)
    	    finishCmdExecution(window, False);
    	return;
    }
    
    /* characters were read successfully, add buf to linked list of buffers */
    buf->length = nRead;
    addOutput(&cmdData->errBufs, buf);
}

/*
** Called when the shell sub-process stdin stream is ready for input.  Writes
** data from the "input" text string passed to issueCommand.
*/
static void stdinWriteProc(XtPointer clientData, int *source, XtInputId *id)
{
    WindowInfo *window = (WindowInfo *)clientData;
    shellCmdInfo *cmdData = window->shellCmdData;
    int nWritten;

    nWritten = write(cmdData->stdinFD, cmdData->inPtr, cmdData->inLength);
    if (nWritten == -1) {
	if (errno == EPIPE) {
	    /* Just shut off input to broken pipes.  User is likely feeding
	       it to a command which does not take input */
	    XtRemoveInput(cmdData->stdinInputID);
	    cmdData->stdinInputID = 0;
    	    close(cmdData->stdinFD);
    	    cmdData->inPtr = NULL;
    	} else if (errno != EWOULDBLOCK && errno != EAGAIN) {
    	    perror("NEdit: Write to shell command failed");
    	    finishCmdExecution(window, True);
    	}
    } else {
	cmdData->inPtr += nWritten;
	cmdData->inLength -= nWritten;
	if (cmdData->inLength <= 0) {
	    XtRemoveInput(cmdData->stdinInputID);
	    cmdData->stdinInputID = 0;
    	    close(cmdData->stdinFD);
    	    cmdData->inPtr = NULL;
    	}
    }
}

/*
** Timer proc for putting up the "Shell Command in Progress" banner if
** the process is taking too long.
*/
static void bannerTimeoutProc(XtPointer clientData, XtIntervalId *id)
{
    WindowInfo *window = (WindowInfo *)clientData;
    shellCmdInfo *cmdData = window->shellCmdData;
    
    cmdData->bannerIsUp = True;
    SetModeMessage(window,
    	    "Shell Command in Progress -- Press Ctrl+. to Cancel");
    cmdData->bannerTimeoutID = 0;
}

/*
** Buffer replacement wrapper routine to be used for inserting output from 
** a command into the buffer, which takes into account that the buffer may 
** have been shrunken by the user (eg, by Undo). If necessary, the starting
** and ending positions (part of the state of the command) are corrected.
*/
static void safeBufReplace(textBuffer *buf, int *start, int *end, 
	const char *text)
{
    if (*start > buf->length)
	*start = buf->length;
    if (*end > buf->length)
	*end = buf->length;
    BufReplace(buf, *start, *end, text);
}

/*
** Timer proc for flushing output buffers periodically when the process
** takes too long.
*/
static void flushTimeoutProc(XtPointer clientData, XtIntervalId *id)
{
    WindowInfo *window = (WindowInfo *)clientData;
    shellCmdInfo *cmdData = window->shellCmdData;
    textBuffer *buf = TextGetBuffer(cmdData->textW);
    int len;
    char *outText;
    
    /* shouldn't happen, but it would be bad if it did */
    if (cmdData->textW == NULL)
    	return;

    outText = coalesceOutput(&cmdData->outBufs, &len);
    if (len != 0) {
	if (BufSubstituteNullChars(outText, len, buf)) {
	    safeBufReplace(buf, &cmdData->leftPos, &cmdData->rightPos, outText);
	    TextSetCursorPos(cmdData->textW, cmdData->leftPos+strlen(outText));
	    cmdData->leftPos += len;
	    cmdData->rightPos = cmdData->leftPos;
	} else
	    fprintf(stderr, "NEdit: Too much binary data\n");
    }
    XtFree(outText);

    /* re-establish the timer proc (this routine) to continue processing */
    cmdData->flushTimeoutID = XtAppAddTimeOut(
    	    XtWidgetToApplicationContext(window->shell),
    	    OUTPUT_FLUSH_FREQ, flushTimeoutProc, clientData);
}

/*
** Clean up after the execution of a shell command sub-process and present
** the output/errors to the user as requested in the initial issueCommand
** call.  If "terminatedOnError" is true, don't bother trying to read the
** output, just close the i/o descriptors, free the memory, and restore the
** user interface state.
*/
static void finishCmdExecution(WindowInfo *window, int terminatedOnError)
{
    shellCmdInfo *cmdData = window->shellCmdData;
    textBuffer *buf;
    int status, failure, errorReport, reselectStart, outTextLen, errTextLen;
    int resp, cancel = False, fromMacro = cmdData->fromMacro;
    char *outText, *errText = NULL;

    /* Cancel any pending i/o on the file descriptors */
    if (cmdData->stdoutInputID != 0)
    	XtRemoveInput(cmdData->stdoutInputID);
    if (cmdData->stdinInputID != 0)
    	XtRemoveInput(cmdData->stdinInputID);
    if (cmdData->stderrInputID != 0)
    	XtRemoveInput(cmdData->stderrInputID);

    /* Close any file descriptors remaining open */
    close(cmdData->stdoutFD);
    if (cmdData->flags & ERROR_DIALOGS)
    	close(cmdData->stderrFD);
    if (cmdData->inPtr != NULL)
    	close(cmdData->stdinFD);

    /* Free the provided input text */
    if (cmdData->input != NULL)
	XtFree(cmdData->input);
    
    /* Cancel pending timeouts */
    if (cmdData->flushTimeoutID != 0)
    	XtRemoveTimeOut(cmdData->flushTimeoutID);
    if (cmdData->bannerTimeoutID != 0)
    	XtRemoveTimeOut(cmdData->bannerTimeoutID);
    
    /* Clean up waiting-for-shell-command-to-complete mode */
    if (!cmdData->fromMacro) {
	EndWait(window->shell);
	XtSetSensitive(window->cancelShellItem, False);
	if (cmdData->bannerIsUp)
    	    ClearModeMessage(window);
    }
    
    /* If the process was killed or became inaccessable, give up */
    if (terminatedOnError) {
	freeBufList(&cmdData->outBufs);
	freeBufList(&cmdData->errBufs);
    	waitpid(cmdData->childPid, &status, 0);
	goto cmdDone;
    }

    /* Assemble the output from the process' stderr and stdout streams into
       null terminated strings, and free the buffer lists used to collect it */
    outText = coalesceOutput(&cmdData->outBufs, &outTextLen);
    if (cmdData->flags & ERROR_DIALOGS)
    	errText = coalesceOutput(&cmdData->errBufs, &errTextLen);

    /* Wait for the child process to complete and get its return status */
    waitpid(cmdData->childPid, &status, 0);
    
    /* Present error and stderr-information dialogs.  If a command returned
       error output, or if the process' exit status indicated failure,
       present the information to the user. */
    if (cmdData->flags & ERROR_DIALOGS)
    {
        failure = WIFEXITED(status) && WEXITSTATUS(status) != 0;
        errorReport = *errText != '\0';

        if (failure && errorReport)
        {
            removeTrailingNewlines(errText);
            truncateString(errText, DF_MAX_MSG_LENGTH);
            resp = DialogF(DF_WARN, window->shell, 2, "Warning", "%s", "Cancel",
                    "Proceed", errText);
            cancel = resp == 1;
        } else if (failure)
        {
            truncateString(outText, DF_MAX_MSG_LENGTH-70);
            resp = DialogF(DF_WARN, window->shell, 2, "Command Failure",
                    "Command reported failed exit status.\n"
                    "Output from command:\n%s", "Cancel", "Proceed", outText);
            cancel = resp == 1;
        } else if (errorReport)
        {
            removeTrailingNewlines(errText);
            truncateString(errText, DF_MAX_MSG_LENGTH);
            resp = DialogF(DF_INF, window->shell, 2, "Information", "%s",
                    "Proceed", "Cancel", errText);
            cancel = resp == 2;
        }

        XtFree(errText);
        if (cancel)
        {
            XtFree(outText);
            goto cmdDone;
        }
    }
    
    /* If output is to a dialog, present the dialog.  Otherwise insert the
       (remaining) output in the text widget as requested, and move the
       insert point to the end */
    if (cmdData->flags & OUTPUT_TO_DIALOG) {
    	removeTrailingNewlines(outText);
	if (*outText != '\0')
    	    createOutputDialog(window->shell, outText);
    } else if (cmdData->flags & OUTPUT_TO_STRING) {
    	ReturnShellCommandOutput(window,outText, WEXITSTATUS(status));
    } else {
	buf = TextGetBuffer(cmdData->textW);
	if (!BufSubstituteNullChars(outText, outTextLen, buf)) {
	    fprintf(stderr,"NEdit: Too much binary data in shell cmd output\n");
	    outText[0] = '\0';
	}
	if (cmdData->flags & REPLACE_SELECTION) {
	    reselectStart = buf->primary.rectangular ? -1 : buf->primary.start;
	    BufReplaceSelected(buf, outText);
	    TextSetCursorPos(cmdData->textW, buf->cursorPosHint);
	    if (reselectStart != -1)
	    	BufSelect(buf, reselectStart, reselectStart + strlen(outText));
	} else {
	    safeBufReplace(buf, &cmdData->leftPos, &cmdData->rightPos, outText);
	    TextSetCursorPos(cmdData->textW, cmdData->leftPos+strlen(outText));
	}
    }

    /* If the command requires the file to be reloaded afterward, reload it */
    if (cmdData->flags & RELOAD_FILE_AFTER)
    	RevertToSaved(window);

    /* Command is complete, free data structure and continue macro execution */
    XtFree(outText);