motif2.c

/* cmd_area.c -- use a ScrolledText object to view the 
** output of commands input by the user in a Command window. 
*/

#include <Xm/Text.h>
#include <Xm/MainW.h>
#include <Xm/Command.h>
#include <stdio.h> /* For popen() */

/* main() -- initialize toolkit, create a main window, menubar,
** a Command Area and a ScrolledText to view the output of commands. 
*/

void main(int argc, char *argv[])
{
    Widget toplevel, main_w, menubar, menu, command_w, text_w;
    XtAppContext app;
    XmString file, quit;
    extern void exit(int);
    void exec_cmd(Widget, XtPointer, XtPointer);
    Arg args[5];
    int n = 0;

    XtSetLanguageProc(NULL, NULL, NULL);

    /* initialize toolkit and create toplevel shell */
    toplevel = XtVaOpenApplication(&app, "Demos", NULL, 0, &argc, argv, NULL,
                                   sessionShellWidgetClass, NULL);

    (void)close(0); /* don't let commands read from stdin */

    /* MainWindow for the application -- contains menubar, ScrolledText     
    ** and CommandArea (which prompts for filename).     
    */
    n = 0;
    XtSetArg(args[n], XmNcommandWindowLocation,
             XmCOMMAND_BELOW_WORKSPACE);
    n++;
    main_w = XmCreateMainWindow(toplevel, "main_w", args, n);

    /* Create a simple MenuBar that contains one menu */
    file = XmStringCreateLocalized("File");
    menubar = XmVaCreateSimpleMenuBar(main_w, "menubar",
                                      XmVaCASCADEBUTTON, file, 'F', NULL);
    XmStringFree(file);

    /* "File" menu has only one item (Quit), so make callback exit() */
    quit = XmStringCreateLocalized("Quit");
    menu = XmVaCreateSimplePulldownMenu(menubar, "file_menu", 0,
                                        (void (*)())exit,
                                        XmVaPUSHBUTTON, quit, 'Q', NULL, NULL, NULL);
    XmStringFree(quit);

    /* Menubar is done -- manage it */
    XtManageChild(menubar);

    /* Create ScrolledText -- this is work area for the MainWindow */
    n = 0;
    XtSetArg(args[n], XmNrows, 24);
    n++;
    XtSetArg(args[n], XmNcolumns, 80);
    n++;
    XtSetArg(args[n], XmNeditable, False);
    n++;
    XtSetArg(args[n], XmNeditMode, XmMULTI_LINE_EDIT);
    n++;
    text_w = XmCreateScrolledText(main_w, "text_w", args, n);
    XtManageChild(text_w);

    /* store text_w as user data in "File" menu for file_cb() callback */
    XtVaSetValues(menu, XmNuserData, text_w, NULL);

    /* Create the command area -- this must be a Command class widget */
    file = XmStringCreateLocalized("Command:");
    n = 0;
    XtSetArg(args[n], XmNpromptString, file);
    n++;
    command_w = XmCreateCommand(main_w, "command_w", args, n);
    XmStringFree(file);
    XtAddCallback(command_w, XmNcommandEnteredCallback, exec_cmd,
                  (XtPointer)text_w);
    XtVaSetValues(command_w,
                  XmNmenuBar, menubar,
                  XmNcommandWindow, command_w,
                  XmNworkWindow, XtParent(text_w),
                  NULL);
    XtManageChild(command_w);
    XtManageChild(main_w);
    XtRealizeWidget(toplevel);
    XtAppMainLoop(app);
}

/* execute the command and redirect output to the ScrolledText window */
void exec_cmd(Widget cmd_widget,     /* command, not Text widget */
              XtPointer client_data, /* passed text_w client_data */
              XtPointer call_data)
{
    char *cmd, buf[BUFSIZ];
    XmTextPosition pos;
    FILE *pp, *popen();
    Widget text_w = (Widget)client_data;
    XmCommandCallbackStruct *cbs = (XmCommandCallbackStruct *)call_data;

    cmd = (char *)XmStringUnparse(cbs->value, XmFONTLIST_DEFAULT_TAG,
                                  XmCHARSET_TEXT, XmCHARSET_TEXT, NULL, 0, XmOUTPUT_ALL);

    if (!cmd || !*cmd)
    {
        /* nothing typed? */
        if (cmd)
            XtFree(cmd);
        return;
    }
    /* make sure the file is a regular text file and open it */
    if ((pp = popen(cmd, "r")) == (FILE *)0)
        perror(cmd);
    XtFree(cmd);
    if (pp == (FILE *)0)
        return;
    /* Clear output from any previous command */
    XmTextSetString(text_w, "");

    /* put the output of the command in the Text widget by reading     
    ** until EOF (meaning that the command has terminated).     
    */
    for (pos = 0; fgets(buf, sizeof(buf), pp); pos += strlen(buf))
        XmTextReplace(text_w, pos, pos, buf);

    (void)pclose(pp);
}