csh.c

早期freebsd实现

}

Char   *jobargv[2] = {STRjobs, 0};

/*
 * Catch an interrupt, e.g. during lexical input.
 * If we are an interactive shell, we reset the interrupt catch
 * immediately.  In any case we drain the shell output,
 * and finally go through the normal error mechanism, which
 * gets a chance to make the shell go away.
 */
/* ARGSUSED */
void
pintr(notused)
	int notused;
{
    pintr1(1);
}

void
pintr1(wantnl)
    bool    wantnl;
{
    Char **v;
    sigset_t omask;

    omask = sigblock((sigset_t) 0);
    if (setintr) {
	(void) sigsetmask(omask & ~sigmask(SIGINT));
	if (pjobs) {
	    pjobs = 0;
	    (void) fprintf(cshout, "\n");
	    dojobs(jobargv, NULL);
	    stderror(ERR_NAME | ERR_INTR);
	}
    }
    (void) sigsetmask(omask & ~sigmask(SIGCHLD));
    (void) fpurge(cshout);
    (void) endpwent();

    /*
     * If we have an active "onintr" then we search for the label. Note that if
     * one does "onintr -" then we shan't be interruptible so we needn't worry
     * about that here.
     */
    if (gointr) {
	gotolab(gointr);
	timflg = 0;
	if ((v = pargv) != NULL)
	    pargv = 0, blkfree(v);
	if ((v = gargv) != NULL)
	    gargv = 0, blkfree(v);
	reset();
    }
    else if (intty && wantnl) {
	(void) fputc('\r', cshout);
	(void) fputc('\n', cshout);
    }
    stderror(ERR_SILENT);
}

/*
 * Process is the main driving routine for the shell.
 * It runs all command processing, except for those within { ... }
 * in expressions (which is run by a routine evalav in sh.exp.c which
 * is a stripped down process), and `...` evaluation which is run
 * also by a subset of this code in sh.glob.c in the routine backeval.
 *
 * The code here is a little strange because part of it is interruptible
 * and hence freeing of structures appears to occur when none is necessary
 * if this is ignored.
 *
 * Note that if catch is not set then we will unwind on any error.
 * If an end-of-file occurs, we return.
 */
static struct command *savet = NULL;
void
process(catch)
    bool    catch;
{
    jmp_buf osetexit;
    struct command *t = savet;

    savet = NULL;
    getexit(osetexit);
    for (;;) {
	pendjob();
	paraml.next = paraml.prev = &paraml;
	paraml.word = STRNULL;
	(void) setexit();
	justpr = enterhist;	/* execute if not entering history */

	/*
	 * Interruptible during interactive reads
	 */
	if (setintr)
	    (void) sigsetmask(sigblock((sigset_t) 0) & ~sigmask(SIGINT));

	/*
	 * For the sake of reset()
	 */
	freelex(&paraml);
	if (savet)
	    freesyn(savet), savet = NULL;

	if (haderr) {
	    if (!catch) {
		/* unwind */
		doneinp = 0;
		resexit(osetexit);
		savet = t;
		reset();
	    }
	    haderr = 0;
	    /*
	     * Every error is eventually caught here or the shell dies.  It is
	     * at this point that we clean up any left-over open files, by
	     * closing all but a fixed number of pre-defined files.  Thus
	     * routines don't have to worry about leaving files open due to
	     * deeper errors... they will get closed here.
	     */
	    closem();
	    continue;
	}
	if (doneinp) {
	    doneinp = 0;
	    break;
	}
	if (chkstop)
	    chkstop--;
	if (neednote)
	    pnote();
	if (intty && prompt && evalvec == 0) {
	    mailchk();
	    /*
	     * If we are at the end of the input buffer then we are going to
	     * read fresh stuff. Otherwise, we are rereading input and don't
	     * need or want to prompt.
	     */
	    if (aret == F_SEEK && fseekp == feobp)
		printprompt();
	    (void) fflush(cshout);
	}
	if (seterr) {
	    xfree((ptr_t) seterr);
	    seterr = NULL;
	}

	/*
	 * Echo not only on VERBOSE, but also with history expansion. If there
	 * is a lexical error then we forego history echo.
	 */
	if ((lex(&paraml) && !seterr && intty) || adrof(STRverbose)) {
	    prlex(csherr, &paraml);
	}

	/*
	 * The parser may lose space if interrupted.
	 */
	if (setintr)
	    (void) sigblock(sigmask(SIGINT));

	/*
	 * Save input text on the history list if reading in old history, or it
	 * is from the terminal at the top level and not in a loop.
	 *
	 * PWP: entry of items in the history list while in a while loop is done
	 * elsewhere...
	 */
	if (enterhist || (catch && intty && !whyles))
	    savehist(&paraml);

	/*
	 * Print lexical error messages, except when sourcing history lists.
	 */
	if (!enterhist && seterr)
	    stderror(ERR_OLD);

	/*
	 * If had a history command :p modifier then this is as far as we
	 * should go
	 */
	if (justpr)
	    reset();

	alias(&paraml);

	/*
	 * Parse the words of the input into a parse tree.
	 */
	savet = syntax(paraml.next, &paraml, 0);
	if (seterr)
	    stderror(ERR_OLD);

	execute(savet, (tpgrp > 0 ? tpgrp : -1), NULL, NULL);

	/*
	 * Made it!
	 */
	freelex(&paraml);
	freesyn((struct command *) savet), savet = NULL;
    }
    resexit(osetexit);
    savet = t;
}

void
/*ARGSUSED*/
dosource(v, t)
    Char **v;
    struct command *t;

{
    register Char *f;
    bool    hflg = 0;
    Char    buf[BUFSIZ];

    v++;
    if (*v && eq(*v, STRmh)) {
	if (*++v == NULL)
	    stderror(ERR_NAME | ERR_HFLAG);
	hflg++;
    }
    (void) Strcpy(buf, *v);
    f = globone(buf, G_ERROR);
    (void) strcpy((char *) buf, short2str(f));
    xfree((ptr_t) f);
    if (!srcfile((char *) buf, 0, hflg) && !hflg)
	stderror(ERR_SYSTEM, (char *) buf, strerror(errno));
}

/*
 * Check for mail.
 * If we are a login shell, then we don't want to tell
 * about any mail file unless its been modified
 * after the time we started.
 * This prevents us from telling the user things he already
 * knows, since the login program insists on saying
 * "You have mail."
 */
static void
mailchk()
{
    register struct varent *v;
    register Char **vp;
    time_t  t;
    int     intvl, cnt;
    struct stat stb;
    bool    new;

    v = adrof(STRmail);
    if (v == 0)
	return;
    (void) time(&t);
    vp = v->vec;
    cnt = blklen(vp);
    intvl = (cnt && number(*vp)) ? (--cnt, getn(*vp++)) : MAILINTVL;
    if (intvl < 1)
	intvl = 1;
    if (chktim + intvl > t)
	return;
    for (; *vp; vp++) {
	if (stat(short2str(*vp), &stb) < 0)
	    continue;
	new = stb.st_mtime > time0.tv_sec;
	if (stb.st_size == 0 || stb.st_atime > stb.st_mtime ||
	    (stb.st_atime < chktim && stb.st_mtime < chktim) ||
	    (loginsh && !new))
	    continue;
	if (cnt == 1)
	    (void) fprintf(cshout, "You have %smail.\n", new ? "new " : "");
	else
	    (void) fprintf(cshout, "%s in %s.\n", new ? "New mail" : "Mail",
			   vis_str(*vp));
    }
    chktim = t;
}

/*
 * Extract a home directory from the password file
 * The argument points to a buffer where the name of the
 * user whose home directory is sought is currently.
 * We write the home directory of the user back there.
 */
int
gethdir(home)
    Char   *home;
{
    Char   *h;
    struct passwd *pw;

    /*
     * Is it us?
     */
    if (*home == '\0') {
	if ((h = value(STRhome)) != NULL) {
	    (void) Strcpy(home, h);
	    return 0;
	}
	else
	    return 1;
    }

    if ((pw = getpwnam(short2str(home))) != NULL) {
	(void) Strcpy(home, str2short(pw->pw_dir));
	return 0;
    }
    else
	return 1;
}

/*
 * When didfds is set, we do I/O from 0, 1, 2 otherwise from 15, 16, 17
 * We also check if the shell has already changed the decriptor to point to
 * 0, 1, 2 when didfds is set.
 */
#define DESC(a) (*((int *) (a)) - (didfds && *((int *) a) >= FSHIN ? FSHIN : 0))

static int
readf(oreo, buf, siz)
    void *oreo;
    char *buf;
    int siz;
{
    return read(DESC(oreo), buf, siz);
}


static int
writef(oreo, buf, siz)
    void *oreo;
    const char *buf;
    int siz;
{
    return write(DESC(oreo), buf, siz);
}

static fpos_t
seekf(oreo, off, whence)
    void *oreo;
    fpos_t off;
    int whence;
{
    return lseek(DESC(oreo), off, whence);
}


static int
closef(oreo)
    void *oreo;
{
    return close(DESC(oreo));
}


/*
 * Print the visible version of a string.
 */
int
vis_fputc(ch, fp)
    int ch;
    FILE *fp;
{
    char uenc[5];	/* 4 + NULL */

    if (ch & QUOTE) 
	return fputc(ch & TRIM, fp);
    /* 
     * XXX: When we are in AsciiOnly we want all characters >= 0200 to
     * be encoded, but currently there is no way in vis to do that.
     */
    (void) vis(uenc, ch & TRIM, VIS_NOSLASH, 0);
    return fputs(uenc, fp);
}

/*
 * Move the initial descriptors to their eventual
 * resting places, closin all other units.
 */
void
initdesc()
{

    didfds = 0;			/* 0, 1, 2 aren't set up */
    (void) ioctl(SHIN = dcopy(0, FSHIN), FIOCLEX, NULL);
    (void) ioctl(SHOUT = dcopy(1, FSHOUT), FIOCLEX, NULL);
    (void) ioctl(SHERR = dcopy(2, FSHERR), FIOCLEX, NULL);
    (void) ioctl(OLDSTD = dcopy(SHIN, FOLDSTD), FIOCLEX, NULL);
    closem();
}


void
#ifdef PROF
done(i)
#else
xexit(i)
#endif
    int     i;
{
    untty();
    _exit(i);
}

static Char **
defaultpath()
{
    char   *ptr;
    Char  **blk, **blkp;
    struct stat stb;

    blkp = blk = (Char **) xmalloc((size_t) sizeof(Char *) * 10);

#define DIRAPPEND(a)  \
	if (stat(ptr = a, &stb) == 0 && (stb.st_mode & S_IFMT) == S_IFDIR) \
		*blkp++ = SAVE(ptr)

    DIRAPPEND(_PATH_BIN);
    DIRAPPEND(_PATH_USRBIN);

#undef DIRAPPEND

    if (euid != 0 && uid != 0)
	*blkp++ = Strsave(STRdot);
    *blkp = NULL;
    return (blk);
}

void
printprompt()
{
    register Char *cp;

    if (!whyles) {
	for (cp = value(STRprompt); *cp; cp++)
	    if (*cp == HIST)
		(void) fprintf(cshout, "%d", eventno + 1);
	    else {
		if (*cp == '\\' && cp[1] == HIST)
		    cp++;
		(void) vis_fputc(*cp | QUOTE, cshout);
	    }
    }
    else
	/*
	 * Prompt for forward reading loop body content.
	 */
	(void) fprintf(cshout, "? ");
    (void) fflush(cshout);
}