/* 
 * tclUnixTest.c --
 *
 *	Contains platform specific test commands for the Unix platform.
 *
 * Copyright (c) 1996-1997 Sun Microsystems, Inc.
 * Copyright (c) 1998 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclUnixTest.c,v 1.14.2.2 2006/03/19 22:47:30 vincentdarley Exp $
 */

#include "tclInt.h"
#include "tclPort.h"

/*
 * The headers are needed for the testalarm command that verifies the
 * use of SA_RESTART in signal handlers.
 */

#include <signal.h>
#include <sys/resource.h>

/*
 * The following macros convert between TclFile's and fd's.  The conversion
 * simple involves shifting fd's up by one to ensure that no valid fd is ever
 * the same as NULL.  Note that this code is duplicated from tclUnixPipe.c
 */

#define MakeFile(fd) ((TclFile)((fd)+1))
#define GetFd(file) (((int)file)-1)

/*
 * The stuff below is used to keep track of file handlers created and
 * exercised by the "testfilehandler" command.
 */

typedef struct Pipe {
    TclFile readFile;		/* File handle for reading from the
				 * pipe.  NULL means pipe doesn't exist yet. */
    TclFile writeFile;		/* File handle for writing from the
				 * pipe. */
    int readCount;		/* Number of times the file handler for
				 * this file has triggered and the file
				 * was readable. */
    int writeCount;		/* Number of times the file handler for
				 * this file has triggered and the file
				 * was writable. */
} Pipe;

#define MAX_PIPES 10
static Pipe testPipes[MAX_PIPES];

/*
 * The stuff below is used by the testalarm and testgotsig ommands.
 */

static char *gotsig = "0";

/*
 * Forward declarations of procedures defined later in this file:
 */

static void		TestFileHandlerProc _ANSI_ARGS_((ClientData clientData,
			    int mask));
static int		TestfilehandlerCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static int		TestfilewaitCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static int		TestfindexecutableCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static int		TestgetopenfileCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static int		TestgetdefencdirCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static int		TestsetdefencdirCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
int			TclplatformtestInit _ANSI_ARGS_((Tcl_Interp *interp));
static int		TestalarmCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static int		TestgotsigCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));
static void 		AlarmHandler _ANSI_ARGS_(());
static int		TestchmodCmd _ANSI_ARGS_((ClientData dummy,
			    Tcl_Interp *interp, int argc, CONST char **argv));

/*
 *----------------------------------------------------------------------
 *
 * TclplatformtestInit --
 *
 *	Defines commands that test platform specific functionality for
 *	Unix platforms.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	Defines new commands.
 *
 *----------------------------------------------------------------------
 */

int
TclplatformtestInit(interp)
    Tcl_Interp *interp;		/* Interpreter to add commands to. */
{
    Tcl_CreateCommand(interp, "testchmod", TestchmodCmd,
	    (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testfilehandler", TestfilehandlerCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testfilewait", TestfilewaitCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testfindexecutable", TestfindexecutableCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testgetopenfile", TestgetopenfileCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testgetdefenc", TestgetdefencdirCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testsetdefenc", TestsetdefencdirCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testalarm", TestalarmCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    Tcl_CreateCommand(interp, "testgotsig", TestgotsigCmd,
            (ClientData) 0, (Tcl_CmdDeleteProc *) NULL);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TestfilehandlerCmd --
 *
 *	This procedure implements the "testfilehandler" command. It is
 *	used to test Tcl_CreateFileHandler, Tcl_DeleteFileHandler, and
 *	TclWaitForFile.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TestfilehandlerCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    Pipe *pipePtr;
    int i, mask, timeout;
    static int initialized = 0;
    char buffer[4000];
    TclFile file;

    /*
     * NOTE: When we make this code work on Windows also, the following
     * variable needs to be made Unix-only.
     */
    
    if (!initialized) {
	for (i = 0; i < MAX_PIPES; i++) {
	    testPipes[i].readFile = NULL;
	}
	initialized = 1;
    }

    if (argc < 2) {
	Tcl_AppendResult(interp, "wrong # arguments: should be \"", argv[0],
                " option ... \"", (char *) NULL);
        return TCL_ERROR;
    }
    pipePtr = NULL;
    if (argc >= 3) {
	if (Tcl_GetInt(interp, argv[2], &i) != TCL_OK) {
	    return TCL_ERROR;
	}
	if (i >= MAX_PIPES) {
	    Tcl_AppendResult(interp, "bad index ", argv[2], (char *) NULL);
	    return TCL_ERROR;
	}
	pipePtr = &testPipes[i];
    }

    if (strcmp(argv[1], "close") == 0) {
	for (i = 0; i < MAX_PIPES; i++) {
	    if (testPipes[i].readFile != NULL) {
		TclpCloseFile(testPipes[i].readFile);
		testPipes[i].readFile = NULL;
		TclpCloseFile(testPipes[i].writeFile);
		testPipes[i].writeFile = NULL;
	    }
	}
    } else if (strcmp(argv[1], "clear") == 0) {
	if (argc != 3) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " clear index\"", (char *) NULL);
	    return TCL_ERROR;
	}
	pipePtr->readCount = pipePtr->writeCount = 0;
    } else if (strcmp(argv[1], "counts") == 0) {
	char buf[TCL_INTEGER_SPACE * 2];
	
	if (argc != 3) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " counts index\"", (char *) NULL);
	    return TCL_ERROR;
	}
	sprintf(buf, "%d %d", pipePtr->readCount, pipePtr->writeCount);
	Tcl_SetResult(interp, buf, TCL_VOLATILE);
    } else if (strcmp(argv[1], "create") == 0) {
	if (argc != 5) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " create index readMode writeMode\"",
                    (char *) NULL);
	    return TCL_ERROR;
	}
	if (pipePtr->readFile == NULL) {
	    if (!TclpCreatePipe(&pipePtr->readFile, &pipePtr->writeFile)) {
		Tcl_AppendResult(interp, "couldn't open pipe: ",
			Tcl_PosixError(interp), (char *) NULL);
		return TCL_ERROR;
	    }
#ifdef O_NONBLOCK
	    fcntl(GetFd(pipePtr->readFile), F_SETFL, O_NONBLOCK);
	    fcntl(GetFd(pipePtr->writeFile), F_SETFL, O_NONBLOCK);
#else
	    Tcl_SetResult(interp, "can't make pipes non-blocking",
		    TCL_STATIC);
	    return TCL_ERROR;
#endif
	}
	pipePtr->readCount = 0;
	pipePtr->writeCount = 0;

	if (strcmp(argv[3], "readable") == 0) {
	    Tcl_CreateFileHandler(GetFd(pipePtr->readFile), TCL_READABLE,
		    TestFileHandlerProc, (ClientData) pipePtr);
	} else if (strcmp(argv[3], "off") == 0) {
	    Tcl_DeleteFileHandler(GetFd(pipePtr->readFile));
	} else if (strcmp(argv[3], "disabled") == 0) {
	    Tcl_CreateFileHandler(GetFd(pipePtr->readFile), 0,
		    TestFileHandlerProc, (ClientData) pipePtr);
	} else {
	    Tcl_AppendResult(interp, "bad read mode \"", argv[3], "\"",
		    (char *) NULL);
	    return TCL_ERROR;
	}
	if (strcmp(argv[4], "writable") == 0) {
	    Tcl_CreateFileHandler(GetFd(pipePtr->writeFile), TCL_WRITABLE,
		    TestFileHandlerProc, (ClientData) pipePtr);
	} else if (strcmp(argv[4], "off") == 0) {
	    Tcl_DeleteFileHandler(GetFd(pipePtr->writeFile));
	} else if (strcmp(argv[4], "disabled") == 0) {
	    Tcl_CreateFileHandler(GetFd(pipePtr->writeFile), 0,
		    TestFileHandlerProc, (ClientData) pipePtr);
	} else {
	    Tcl_AppendResult(interp, "bad read mode \"", argv[4], "\"",
		    (char *) NULL);
	    return TCL_ERROR;
	}
    } else if (strcmp(argv[1], "empty") == 0) {
	if (argc != 3) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " empty index\"", (char *) NULL);
	    return TCL_ERROR;
	}

        while (read(GetFd(pipePtr->readFile), buffer, 4000) > 0) {
            /* Empty loop body. */
        }
    } else if (strcmp(argv[1], "fill") == 0) {
	if (argc != 3) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " fill index\"", (char *) NULL);
	    return TCL_ERROR;
	}

	memset((VOID *) buffer, 'a', 4000);
        while (write(GetFd(pipePtr->writeFile), buffer, 4000) > 0) {
            /* Empty loop body. */
        }
    } else if (strcmp(argv[1], "fillpartial") == 0) {
	char buf[TCL_INTEGER_SPACE];
	
	if (argc != 3) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " fillpartial index\"", (char *) NULL);
	    return TCL_ERROR;
	}

	memset((VOID *) buffer, 'b', 10);
	TclFormatInt(buf, write(GetFd(pipePtr->writeFile), buffer, 10));
	Tcl_SetResult(interp, buf, TCL_VOLATILE);
    } else if (strcmp(argv[1], "oneevent") == 0) {
	Tcl_DoOneEvent(TCL_FILE_EVENTS|TCL_DONT_WAIT);
    } else if (strcmp(argv[1], "wait") == 0) {
	if (argc != 5) {
	    Tcl_AppendResult(interp, "wrong # arguments: should be \"",
                    argv[0], " wait index readable|writable timeout\"",
                    (char *) NULL);
	    return TCL_ERROR;
	}
	if (pipePtr->readFile == NULL) {
	    Tcl_AppendResult(interp, "pipe ", argv[2], " doesn't exist",
		    (char *) NULL);
	    return TCL_ERROR;
	}
	if (strcmp(argv[3], "readable") == 0) {
	    mask = TCL_READABLE;
	    file = pipePtr->readFile;
	} else {
	    mask = TCL_WRITABLE;
	    file = pipePtr->writeFile;
	}
	if (Tcl_GetInt(interp, argv[4], &timeout) != TCL_OK) {
	    return TCL_ERROR;
	}
	i = TclUnixWaitForFile(GetFd(file), mask, timeout);
	if (i & TCL_READABLE) {
	    Tcl_AppendElement(interp, "readable");
	}
	if (i & TCL_WRITABLE) {
	    Tcl_AppendElement(interp, "writable");
	}
    } else if (strcmp(argv[1], "windowevent") == 0) {
	Tcl_DoOneEvent(TCL_WINDOW_EVENTS|TCL_DONT_WAIT);
    } else {
	Tcl_AppendResult(interp, "bad option \"", argv[1],
		"\": must be close, clear, counts, create, empty, fill, ",
		"fillpartial, oneevent, wait, or windowevent",
		(char *) NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

static void TestFileHandlerProc(clientData, mask)
    ClientData clientData;	/* Points to a Pipe structure. */
    int mask;			/* Indicates which events happened:
				 * TCL_READABLE or TCL_WRITABLE. */
{
    Pipe *pipePtr = (Pipe *) clientData;

    if (mask & TCL_READABLE) {
	pipePtr->readCount++;
    }
    if (mask & TCL_WRITABLE) {
	pipePtr->writeCount++;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TestfilewaitCmd --
 *
 *	This procedure implements the "testfilewait" command. It is
 *	used to test TclUnixWaitForFile.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TestfilewaitCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    int mask, result, timeout;
    Tcl_Channel channel;
    int fd;
    ClientData data;

    if (argc != 4) {
	Tcl_AppendResult(interp, "wrong # arguments: should be \"", argv[0],
		" file readable|writable|both timeout\"", (char *) NULL);
	return TCL_ERROR;
    }
    channel = Tcl_GetChannel(interp, argv[1], NULL);
    if (channel == NULL) {
	return TCL_ERROR;
    }
    if (strcmp(argv[2], "readable") == 0) {
	mask = TCL_READABLE;
    } else if (strcmp(argv[2], "writable") == 0){
	mask = TCL_WRITABLE;
    } else if (strcmp(argv[2], "both") == 0){
	mask = TCL_WRITABLE|TCL_READABLE;
    } else {
	Tcl_AppendResult(interp, "bad argument \"", argv[2],
		"\": must be readable, writable, or both", (char *) NULL);
	return TCL_ERROR;
    }
    if (Tcl_GetChannelHandle(channel, 
	    (mask & TCL_READABLE) ? TCL_READABLE : TCL_WRITABLE,
	    (ClientData*) &data) != TCL_OK) {
	Tcl_SetResult(interp, "couldn't get channel file", TCL_STATIC);
	return TCL_ERROR;
    }
    fd = (int) data;
    if (Tcl_GetInt(interp, argv[3], &timeout) != TCL_OK) {
	return TCL_ERROR;
    }
    result = TclUnixWaitForFile(fd, mask, timeout);
    if (result & TCL_READABLE) {
	Tcl_AppendElement(interp, "readable");
    }
    if (result & TCL_WRITABLE) {
	Tcl_AppendElement(interp, "writable");
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TestfindexecutableCmd --
 *
 *	This procedure implements the "testfindexecutable" command. It is
 *	used to test Tcl_FindExecutable.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TestfindexecutableCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    char *oldName;
    char *oldNativeName;

    if (argc != 2) {
	Tcl_AppendResult(interp, "wrong # arguments: should be \"", argv[0],
		" argv0\"", (char *) NULL);
	return TCL_ERROR;
    }

    oldName       = tclExecutableName;
    oldNativeName = tclNativeExecutableName;

    tclExecutableName       = NULL;
    tclNativeExecutableName = NULL;

    Tcl_FindExecutable(argv[1]);
    if (tclExecutableName != NULL) {
	Tcl_SetResult(interp, tclExecutableName, TCL_VOLATILE);
	ckfree(tclExecutableName);
    }
    if (tclNativeExecutableName != NULL) {
	ckfree(tclNativeExecutableName);
    }

    tclExecutableName       = oldName;
    tclNativeExecutableName = oldNativeName;

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TestgetopenfileCmd --
 *
 *	This procedure implements the "testgetopenfile" command. It is
 *	used to get a FILE * value from a registered channel.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TestgetopenfileCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    ClientData filePtr;

    if (argc != 3) {
        Tcl_AppendResult(interp,
                "wrong # args: should be \"", argv[0],
                " channelName forWriting\"",
                (char *) NULL);
        return TCL_ERROR;
    }
    if (Tcl_GetOpenFile(interp, argv[1], atoi(argv[2]), 1, &filePtr)
            == TCL_ERROR) {
        return TCL_ERROR;
    }
    if (filePtr == (ClientData) NULL) {
        Tcl_AppendResult(interp,
                "Tcl_GetOpenFile succeeded but FILE * NULL!", (char *) NULL);
        return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TestsetdefencdirCmd --
 *
 *	This procedure implements the "testsetdefenc" command. It is
 *	used to set the value of tclDefaultEncodingDir.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TestsetdefencdirCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    if (argc != 2) {
        Tcl_AppendResult(interp,
                "wrong # args: should be \"", argv[0],
                " defaultDir\"",
                (char *) NULL);
        return TCL_ERROR;
    }

    if (tclDefaultEncodingDir != NULL) {
	ckfree(tclDefaultEncodingDir);
	tclDefaultEncodingDir = NULL;
    }
    if (*argv[1] != '\0') {
	tclDefaultEncodingDir = (char *)
	    ckalloc((unsigned) strlen(argv[1]) + 1);
	strcpy(tclDefaultEncodingDir, argv[1]);
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TestgetdefencdirCmd --
 *
 *	This procedure implements the "testgetdefenc" command. It is
 *	used to get the value of tclDefaultEncodingDir.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TestgetdefencdirCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    if (argc != 1) {
        Tcl_AppendResult(interp,
                "wrong # args: should be \"", argv[0],
                (char *) NULL);
        return TCL_ERROR;
    }

    if (tclDefaultEncodingDir != NULL) {
        Tcl_AppendResult(interp, tclDefaultEncodingDir, (char *) NULL);
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 * TestalarmCmd --
 *
 *	Test that EINTR is handled correctly by generating and
 *	handling a signal.  This requires using the SA_RESTART
 *	flag when registering the signal handler.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	Sets up an signal and async handlers.
 *
 *----------------------------------------------------------------------
 */

static int
TestalarmCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
#ifdef SA_RESTART
    unsigned int sec;
    struct sigaction action;

    if (argc > 1) {
	Tcl_GetInt(interp, argv[1], (int *)&sec);
    } else {
	sec = 1;
    }

    /*
     * Setup the signal handling that automatically retries
     * any interupted I/O system calls.
     */
    action.sa_handler = AlarmHandler;
    memset((void *)&action.sa_mask, 0, sizeof(sigset_t));
    action.sa_flags = SA_RESTART;

    if (sigaction(SIGALRM, &action, NULL) < 0) {
	Tcl_AppendResult(interp, "sigaction: ", Tcl_PosixError(interp), NULL);
	return TCL_ERROR;
    }
    (void)alarm(sec);
    return TCL_OK;
#else
    Tcl_AppendResult(interp, "warning: sigaction SA_RESTART not support on this platform", NULL);
    return TCL_ERROR;
#endif
}

/*
 *----------------------------------------------------------------------
 *
 * AlarmHandler --
 *
 *	Signal handler for the alarm command.
 *
 * Results:
 *	None.
 *
 * Side effects:
 * 	Calls the Tcl Async handler.
 *
 *----------------------------------------------------------------------
 */

static void
AlarmHandler()
{
    gotsig = "1";
}

/*
 *----------------------------------------------------------------------
 * TestgotsigCmd --
 *
 * 	Verify the signal was handled after the testalarm command.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	Resets the value of gotsig back to '0'.
 *
 *----------------------------------------------------------------------
 */

static int
TestgotsigCmd(clientData, interp, argc, argv)
    ClientData clientData;		/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    Tcl_AppendResult(interp, gotsig, (char *) NULL);
    gotsig = "0";
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * TestchmodCmd --
 *
 *	Implements the "testchmod" cmd.  Used when testing "file" command.
 *	The only attribute used by the Windows platform is the user write
 *	flag; if this is not set, the file is made read-only.  Otehrwise, the
 *	file is made read-write.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	Changes permissions of specified files.
 *
 *---------------------------------------------------------------------------
 */

static int
TestchmodCmd(dummy, interp, argc, argv)
    ClientData dummy;			/* Not used. */
    Tcl_Interp *interp;			/* Current interpreter. */
    int argc;				/* Number of arguments. */
    CONST char **argv;			/* Argument strings. */
{
    int i, mode;
    char *rest;

    if (argc < 2) {
	usage:
	Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
		" mode file ?file ...?", NULL);
	return TCL_ERROR;
    }

    mode = (int) strtol(argv[1], &rest, 8);
    if ((rest == argv[1]) || (*rest != '\0')) {
	goto usage;
    }

    for (i = 2; i < argc; i++) {
	Tcl_DString buffer;
	CONST char *translated;

	translated = Tcl_TranslateFileName(interp, argv[i], &buffer);
	if (translated == NULL) {
	    return TCL_ERROR;
	}
	if (chmod(translated, (unsigned) mode) != 0) {
	    Tcl_AppendResult(interp, translated, ": ", Tcl_PosixError(interp),
		    NULL);
	    return TCL_ERROR;
	}
	Tcl_DStringFree(&buffer);
    }
    return TCL_OK;
}