shell.c

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/* shell.c
 *
 * Copyright (c) 1992-2001 by Mike Gleason.
 * All rights reserved.
 *
 */

#include "syshdrs.h"

#include "shell.h"
#include "util.h"
#include "bookmark.h"
#include "cmds.h"
#include "readln.h"
#include "trace.h"
#include "main.h"

/* We keep running the command line interpreter until gDoneApplication
 * is non-zero.
 */
int gDoneApplication = 0;

/* Track how many times they use ^C. */
int gNumInterruptions = 0;

/* Keep a count of the number of commands the user has entered. */
int gEventNumber = 0;


#if defined(WIN32) || defined(_WINDOWS)
#elif defined(HAVE_SIGSETJMP)
/* A command function can set this to have a user generated signal
 * cause execution to jump here.
 */
sigjmp_buf gCancelJmp;

/* This is used by the shell so that an unexpected signal can have
 * execution come back to the main shell prompt.
 */
sigjmp_buf gBackToTopJmp;
#else   /* HAVE_SIGSETJMP */
/* A command function can set this to have a user generated signal
 * cause execution to jump here.
 */
jmp_buf gCancelJmp;

/* This is used by the shell so that an unexpected signal can have
 * execution come back to the main shell prompt.
 */
jmp_buf gBackToTopJmp;
#endif  /* HAVE_SIGSETJMP */

/* Flag specifying whether the jmp has been set. */
int gMayCancelJmp = 0;

/* Flag specifying whether the jmp has been set. */
int gMayBackToTopJmp = 0;

/* Save the last signal number. */
int gGotSig = 0;

/* If the shell is running one of our commands, this is set to non-zero. */
int gRunningCommand = 0;

/* If set, we need to abort the current session. */
int gCancelCtrl = 0;

extern Command gCommands[];
extern size_t gNumCommands;
extern int gStartupUrlParameterGiven;
extern FTPLibraryInfo gLib;
extern FTPConnectionInfo gConn;
extern LineList gStartupURLCdList;
extern int gNumProgramRuns;
extern char gCopyright[];


/* This is used as the comparison function when we sort the name list. */
static int
CommandSortCmp(const CommandPtr a, const CommandPtr b)
{
    return (strcmp((*a).name, (*b).name));
}   /* CommandSortCmp */




/* Sort the command list, in case it wasn't hard-coded that way. */
void
InitCommandList(void)
{
    qsort(gCommands, gNumCommands, sizeof(Command), (qsort_proc_t) CommandSortCmp);
}   /* InitCommandList */




/* This is used as the comparison function when we lookup something
 * in the command list, and when we want an exact match.
 */
static int
CommandExactSearchCmp(const char *const key, const CommandPtr b)
{
    return (strcmp(key, (*b).name));
}   /* CommandExactSearchCmp */




/* This is used as the comparison function when we lookup something
 * in the command list, and when the key can be just the first few
 * letters of one or more commands.  So a key of "qu" might would match
 * "quit" and "quote" for example.
 */
static int
CommandSubSearchCmp(const char *const key, const CommandPtr a)
{
    register const char *kcp, *cp;
    int d;

    for (cp = (*a).name, kcp = key; ; ) {
        if (*kcp == 0)
            break;
        d = *kcp++ - *cp++;
        if (d)
            return d;
    }
    return (0);
}   /* CommandSubSearchCmp */




/* This returns a pointer to a Command, if the name supplied was long
 * enough to be a unique name.  We return a 0 CommandPtr if we did not
 * find any matches, a -1 CommandPtr if we found more than one match,
 * or the unique CommandPtr.
 */
CommandPtr
GetCommandByIndex(const int i)
{
    if ((i < 0) || (i >= (int) gNumCommands))
        return (kNoCommand);
    return (&gCommands[i]);
}                                      /* GetCommandByIndex */




/* This returns a pointer to a Command, if the name supplied was long
 * enough to be a unique name.  We return a 0 CommandPtr if we did not
 * find any matches, a -1 CommandPtr if we found more than one match,
 * or the unique CommandPtr.
 */
CommandPtr
GetCommandByName(const char *const name, int wantExactMatch)
{
    CommandPtr canp, canp2;

    /* First check for an exact match.  Otherwise if you if asked for
     * 'cd', it would match both 'cd' and 'cdup' and return an
     * ambiguous name error, despite having the exact name for 'cd.'
     */
    canp = (CommandPtr) bsearch(name, gCommands, gNumCommands, sizeof(Command), (bsearch_proc_t) CommandExactSearchCmp);

    if (canp == kNoCommand && !wantExactMatch) {
        /* Now see if the user typed an abbreviation unique enough
         * to match only one name in the list.
         */
        canp = (CommandPtr) bsearch(name, gCommands, gNumCommands, sizeof(Command), (bsearch_proc_t) CommandSubSearchCmp);

        if (canp != kNoCommand) {
            /* Check the entry above us and see if the name we're looking
             * for would match that, too.
             */
            if (canp != &gCommands[0]) {
                canp2 = canp - 1;
                if (CommandSubSearchCmp(name, canp2) == 0)
                    return kAmbiguousCommand;
            }
            /* Check the entry below us and see if the name we're looking
             * for would match that one.
             */
            if (canp != &gCommands[gNumCommands - 1]) {
                canp2 = canp + 1;
                if (CommandSubSearchCmp(name, canp2) == 0)
                    return kAmbiguousCommand;
            }
        }
    }
    return canp;
}                                      /* GetCommandByName */




/* Print the help string for the command specified. */

void
PrintCmdHelp(CommandPtr c)
{
    (void) printf("%s: %s.\n", c->name, c->help);
}                                      /* PrintCmdHelp */




/* Print the usage string for the command specified. */
void
PrintCmdUsage(CommandPtr c)
{
    if (c->usage != NULL)
        (void) printf("Usage: %s %s\n", c->name, c->usage);
}                                      /* PrintCmdUsage */




/* Parse a command line into an array of arguments. */
int
MakeArgv(char *line, int *cargc, const char **cargv, int cargcmax, char *dbuf, size_t dbufsize, int *noglobargv, int readlineHacks)
{
    int c;
    int retval;
    char *dlim;
    char *dcp;
    char *scp;
    char *arg;

    *cargc = 0;
    scp = line;
    dlim = dbuf + dbufsize - 1;
    dcp = dbuf;

    for (*cargc = 0; *cargc < cargcmax; ) {
        /* Eat preceding junk. */
        for ( ; ; scp++) {
            c = *scp;
            if (c == '\0')
                goto done;
            if (isspace(c))
                continue;
            if ((c == ';') || (c == '\n')) {
                scp++;
                goto done;
            }
            break;
        }

        arg = dcp;
        cargv[*cargc] = arg;
        noglobargv[*cargc] = 0;
        (*cargc)++;

        /* Special hack so that "!cmd" is always split into "!" "cmd" */
        if ((*cargc == 1) && (*scp == '!')) {
            if (scp[1] == '!') {
                scp[1] = '\0';
            } else if ((scp[1] != '\0') && (!isspace((int) scp[1]))) {
                cargv[0] = "!";
                scp++;
                arg = dcp;
                cargv[*cargc] = arg;
                noglobargv[*cargc] = 0;
                (*cargc)++;
            }
        }

        /* Add characters to the new argument. */
        for ( ; ; ) {
            c = *scp;
            if (c == '\0')
                break;
            if (isspace(c))
                break;
            if ((c == ';') || (c == '\n')) {
                break;
            }

            scp++;

            if (c == '\'') {
                for ( ; ; ) {
                    c = *scp++;
                    if (c == '\0') {
                        if (readlineHacks != 0)
                            break;
                        /* Syntax error */
                        (void) fprintf(stderr, "Error: Unbalanced quotes.\n");
                        return (-1);
                    }
                    if (c == '\'')
                        break;

                    /* Add char. */
                    if (dcp >= dlim)
                        goto toolong;
                    *dcp++ = c;

                    if (strchr(kGlobChars, c) != NULL) {
                        /* User quoted glob characters,
                         * so mark this argument for
                         * noglob.
                         */
                        noglobargv[*cargc - 1] = 1;
                    }
                }
            } else if (c == '"') {
                for ( ; ; ) {
                    c = *scp++;
                    if (c == '\0') {
                        if (readlineHacks != 0)
                            break;
                        /* Syntax error */
                        (void) fprintf(stderr, "Error: Unbalanced quotes.\n");
                        return (-1);
                    }
                    if (c == '"')
                        break;

                    /* Add char. */
                    if (dcp >= dlim)
                        goto toolong;
                    *dcp++ = c;

                    if (strchr(kGlobChars, c) != NULL) {
                        /* User quoted glob characters,
                         * so mark this argument for
                         * noglob.
                         */
                        noglobargv[*cargc - 1] = 1;
                    }
                }
            } else
#if defined(WIN32) || defined(_WINDOWS)
                if (c == '|') {
#else
                if (c == '\\') {
#endif
                /* Add next character, verbatim. */
                c = *scp++;
                if (c == '\0')
                    break;

                /* Add char. */
                if (dcp >= dlim)
                    goto toolong;
                *dcp++ = c;
            } else {
                /* Add char. */
                if (dcp >= dlim)
                    goto toolong;
                *dcp++ = c;
            }
        }

        *dcp++ = '\0';
    }

    (void) fprintf(stderr, "Error: Argument list too long.\n");
    *cargc = 0;
    cargv[*cargc] = NULL;
    return (-1);

done:
    retval = (int) (scp - line);
    cargv[*cargc] = NULL;
    return (retval);

toolong:
    (void) fprintf(stderr, "Error: Line too long.\n");
    *cargc = 0;
    cargv[*cargc] = NULL;
    return (-1);
}   /* MakeArgv */




static int
DoCommand(const ArgvInfoPtr aip)
{
    CommandPtr cmdp;
    int flags;
    int cargc, cargcm1;

    cmdp = GetCommandByName(aip->cargv[0], 0);
    if (cmdp == kAmbiguousCommand) {
        (void) printf("%s: ambiguous command name.\n", aip->cargv[0]);
        return (-1);
    } else if (cmdp == kNoCommand) {
        (void) printf("%s: no such command.\n", aip->cargv[0]);
        return (-1);
    }

    cargc = aip->cargc;
    cargcm1 = cargc - 1;
    flags = cmdp->flags;

    if (((flags & kCmdMustBeConnected) != 0) && (gConn.connected == 0)) {
        (void) printf("%s: must be connected to do that.\n", aip->cargv[0]);
    } else if (((flags & kCmdMustBeDisconnected) != 0) && (gConn.connected != 0)) {
        (void) printf("%s: must be disconnected to do that.\n", aip->cargv[0]);
    } else if ((cmdp->minargs != kNoMin) && (cmdp->minargs > cargcm1)) {
        PrintCmdUsage(cmdp);
    } else if ((cmdp->maxargs != kNoMax) && (cmdp->maxargs < cargcm1)) {
        PrintCmdUsage(cmdp);
    } else {
        (*cmdp->proc)(cargc, aip->cargv, cmdp, aip);
    }
    return (0);
}   /* DoCommand */




/* Allows the user to cancel a data transfer. */
void
XferCanceller(int sigNum)
{
    gGotSig = sigNum;
    if (gConn.cancelXfer > 0) {
#if defined(WIN32) || defined(_WINDOWS)
        signal(SIGINT, SIG_DFL);
#else
        /* User already tried it once, they
         * must think it's locked up.
         *
         * Jump back to the top, and
         * close down the current session.
         */
        gCancelCtrl = 1;
        if (gMayBackToTopJmp > 0) {
#ifdef HAVE_SIGSETJMP
            siglongjmp(gBackToTopJmp, 1);
#else   /* HAVE_SIGSETJMP */
            longjmp(gBackToTopJmp, 1);
#endif  /* HAVE_SIGSETJMP */
        }
#endif
    }
    gConn.cancelXfer++;
}   /* XferCanceller */



#if defined(WIN32) || defined(_WINDOWS)
#else

/* Allows the user to cancel a long operation and get back to the shell. */
void
BackToTop(int sigNum)
{
    gGotSig = sigNum;
    if (sigNum == SIGPIPE) {
        if (gRunningCommand == 1) {
            (void) fprintf(stderr, "Unexpected broken pipe.\n");
            gRunningCommand = 0;
        } else {
            SetXtermTitle("RESTORE");
            exit(1);
        }
    } else if (sigNum == SIGINT) {
        if (gRunningCommand == 0)
            gDoneApplication = 1;
    }
    if (gMayBackToTopJmp > 0) {
#ifdef HAVE_SIGSETJMP
        siglongjmp(gBackToTopJmp, 1);
#else   /* HAVE_SIGSETJMP */
        longjmp(gBackToTopJmp, 1);
#endif  /* HAVE_SIGSETJMP */
    }
}   /* BackToTop */




/* Some commands may want to jump back to the start too. */
void
Cancel(int sigNum)
{
    if (gMayCancelJmp != 0) {
        gGotSig = sigNum;
        gMayCancelJmp = 0;
#ifdef HAVE_SIGSETJMP
        siglongjmp(gCancelJmp, 1);
#else   /* HAVE_SIGSETJMP */
        longjmp(gCancelJmp, 1);
#endif  /* HAVE_SIGSETJMP */
    }
}   /* Cancel */

#endif



void
CommandShell(void)
{
    int tUsed, bUsed;
    ArgvInfo ai;
    char prompt[64];
    char *lineRead;
#if defined(WIN32) || defined(_WINDOWS)
#else
    int sj;
#endif
    time_t cmdStart, cmdStop;

    /* Execution may jump back to this point to restart the shell. */
#if defined(WIN32) || defined(_WINDOWS)

#elif defined(HAVE_SIGSETJMP)
    sj = sigsetjmp(gBackToTopJmp, 1);
#else   /* HAVE_SIGSETJMP */
    sj = setjmp(gBackToTopJmp);
#endif  /* HAVE_SIGSETJMP */

#if defined(WIN32) || defined(_WINDOWS)
#else
    if (sj != 0) {
        Trace(0, "Caught signal %d, back at top.\n", gGotSig);
        if (gGotSig == SIGALRM) {
            (void) printf("\nRemote host was not responding, closing down the session.");
            FTPShutdownHost(&gConn);
        } else{
            (void) printf("\nInterrupted.\n");
            if (gCancelCtrl != 0) {
                gCancelCtrl = 0;
                (void) printf("Closing down the current FTP session: ");
                FTPShutdownHost(&gConn);
                (void) sleep(1);
                (void) printf("done.\n");
            }
        }
    }

    gMayBackToTopJmp = 1;
#endif


    ++gEventNumber;

    while (gDoneApplication == 0) {
#if defined(WIN32) || defined(_WINDOWS)
#else
        (void) NcSignal(SIGINT, BackToTop);
        (void) NcSignal(SIGPIPE, BackToTop);
        (void) NcSignal(SIGALRM, BackToTop);
#endif

        MakePrompt(prompt, sizeof(prompt));

        if (gConn.connected == 0) {
            SetXtermTitle("DEFAULT");
        } else {
            SetXtermTitle("%s - NcFTP", gConn.host);
        }

        lineRead = Readline(prompt);
        if (lineRead == NULL) {
            /* EOF, Control-D */
            (void) printf("\n");
            break;
        }
        Trace(0, "> %s\n", lineRead);
        AddHistory(lineRead);
        for (tUsed = 0;;) {
            (void) memset(&ai, 0, sizeof(ai));
            bUsed = MakeArgv(lineRead + tUsed, &ai.cargc, ai.cargv,
                (int) (sizeof(ai.cargv) / sizeof(char *)),
                ai.argbuf, sizeof(ai.argbuf),
                ai.noglobargv, 0);
            if (bUsed <= 0)
                break;
            tUsed += bUsed;
            if (ai.cargc == 0)
                continue;
            gRunningCommand = 1;
            (void) time(&cmdStart);
            if (DoCommand(&ai) < 0) {
                (void) time(&cmdStop);
                gRunningCommand = 0;
                break;
            }
            (void) time(&cmdStop);
            gRunningCommand = 0;
            if ((cmdStop - cmdStart) > kBeepAfterCmdTime) {
                /* Let the user know that a time-consuming
                 * operation has completed.
                 */
#if defined(WIN32) || defined(_WINDOWS)
                MessageBeep(MB_OK);
#else
                (void) fprintf(stderr, "\007");
#endif
            }
            ++gEventNumber;
        }

        free(lineRead);
    }

    CloseHost();
    gMayBackToTopJmp = 0;
}   /* Shell */