main.c

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/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1991 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)main.c      5.2 (Berkeley) 3/13/91";
#endif /* not lint */

#include <sys/types.h>
#include <signal.h>
#include <fcntl.h>
#include "shell.h"
#include "main.h"
#include "mail.h"
#include "options.h"
#include "output.h"
#include "parser.h"
#include "nodes.h"
#include "eval.h"
#include "jobs.h"
#include "input.h"
#include "trap.h"
#if ATTY
#include "var.h"
#endif
#include "memalloc.h"
#include "error.h"
#include "init.h"
#include "mystring.h"

#define PROFILE 0

int rootpid;
int rootshell;
STATIC union node *curcmd;
STATIC union node *prevcmd;
extern int errno;
#if PROFILE
short profile_buf[16384];
extern int etext();
#endif

#ifdef __STDC__
STATIC void read_profile(char *);
char *getenv(char *);
#else
STATIC void read_profile();
char *getenv();
#endif


/*
 * Main routine.  We initialize things, parse the arguments, execute
 * profiles if we're a login shell, and then call cmdloop to execute
 * commands.  The setjmp call sets up the location to jump to when an
 * exception occurs.  When an exception occurs the variable "state"
 * is used to figure out how far we had gotten.
 */

main(argc, argv)  char **argv; {
        struct jmploc jmploc;
        struct stackmark smark;
        volatile int state;
        char *shinit, *home;
        char *profile = NULL, *ashrc = NULL;

#if PROFILE
        monitor(4, etext, profile_buf, sizeof profile_buf, 50);
#endif
        state = 0;
        if (setjmp(jmploc.loc)) {
                /*
                 * When a shell procedure is executed, we raise the
                 * exception EXSHELLPROC to clean up before executing
                 * the shell procedure.
                 */
                if (exception == EXSHELLPROC) {
                        rootpid = getpid();
                        rootshell = 1;
                        minusc = NULL;
                        state = 3;
                } else if (state == 0 || iflag == 0 || ! rootshell)
                        exitshell(2);
                reset();
#if ATTY
                if (exception == EXINT
                 && (! attyset() || equal(termval(), "emacs"))) {
#else
                if (exception == EXINT) {
#endif
                        out2c('\n');
                        flushout(&errout);
                }
                popstackmark(&smark);
                FORCEINTON;                             /* enable interrupts */
                if (state == 1)
                        goto state1;
                else if (state == 2)
                        goto state2;
                else if (state == 3)
                        goto state3;
                else
                        goto state4;
        }
        handler = &jmploc;
#if DEBUG
        opentrace();
        trputs("Shell args:  ");  trargs(argv);
#endif
        rootpid = getpid();
        rootshell = 1;
        init();
        setstackmark(&smark);
        procargs(argc, argv);
        if (eflag) eflag = 2;   /* Truly enable [ex]flag after init. */
        if (xflag) xflag = 2;
        if (argv[0] && argv[0][0] == '-') {
                state = 1;
                read_profile("/etc/profile");
state1:
                state = 2;
                if ((home = getenv("HOME")) != NULL
                    && (profile = (char *) malloc(strlen(home) + 10)) != NULL)
                {
                        strcpy(profile, home);
                        strcat(profile, "/.profile");
                        read_profile(profile);
                } else {
                        read_profile(".profile");
                }
        } else if ((sflag || minusc) && (shinit = getenv("SHINIT")) != NULL) {
                state = 2;
                evalstring(shinit);
        }
state2:
        if (profile != NULL) free(profile);

        state = 3;
        if (!argv[0] || argv[0][0] != '-') {
                if ((home = getenv("HOME")) != NULL
                        && (ashrc = (char *) malloc(strlen(home) + 8)) != NULL)
                {
                        strcpy(ashrc, home);
                        strcat(ashrc, "/.ashrc");
                        read_profile(ashrc);
                }
        }
state3:
        if (ashrc != NULL) free(ashrc);
        if (eflag) eflag = 1;   /* Init done, enable [ex]flag */
        if (xflag) xflag = 1;
        exitstatus = 0;         /* Init shouldn't influence initial $? */

        state = 4;
        if (minusc) {
                evalstring(minusc);
        }
        if (sflag || minusc == NULL) {
state4:
                cmdloop(1);
        }
#if PROFILE
        monitor(0);
#endif
        exitshell(exitstatus);
}


/*
 * Read and execute commands.  "Top" is nonzero for the top level command
 * loop; it turns on prompting if the shell is interactive.
 */

void
cmdloop(top) {
        union node *n;
        struct stackmark smark;
        int inter;
        int numeof;

        TRACE(("cmdloop(%d) called\n", top));
        setstackmark(&smark);
        numeof = 0;
        for (;;) {
                if (pendingsigs)
                        dotrap();
                inter = 0;
                if (iflag && top) {
                        inter++;
                        showjobs(1);
                        chkmail(0);
                        flushout(&output);
                }
                n = parsecmd(inter);
#if DEBUG
                /* showtree(n); */
#endif
                if (n == NEOF) {
                        if (Iflag == 0 || numeof >= 50)
                                break;
                        out2str("\nUse \"exit\" to leave shell.\n");
                        numeof++;
                } else if (n != NULL && nflag == 0) {
                        if (inter) {
                                INTOFF;
                                if (prevcmd)
                                        freefunc(prevcmd);
                                prevcmd = curcmd;
                                curcmd = copyfunc(n);
                                INTON;
                        }
                        evaltree(n, 0);
#ifdef notdef
                        if (exitstatus)                               /*DEBUG*/
                                outfmt(&errout, "Exit status 0x%X\n", exitstatus);
#endif
                }
                popstackmark(&smark);
        }
        popstackmark(&smark);           /* unnecessary */
}



/*
 * Read /etc/profile or .profile.  Return on error.
 */

STATIC void
read_profile(name)
        char *name;
        {
        int fd;

        INTOFF;
        if ((fd = open(name, O_RDONLY)) >= 0)
                setinputfd(fd, 1);
        INTON;
        if (fd < 0)
                return;
        cmdloop(0);
        popfile();
}



/*
 * Read a file containing shell functions.
 */

void
readcmdfile(name)
        char *name;
        {
        int fd;

        INTOFF;
        if ((fd = open(name, O_RDONLY)) >= 0)
                setinputfd(fd, 1);
        else
                error("Can't open %s", name);
        INTON;
        cmdloop(0);
        popfile();
}


/*
 * Take commands from a file.  To be compatable we should do a path
 * search for the file, but a path search doesn't make any sense.
 */

dotcmd(argc, argv)  char **argv; {
        exitstatus = 0;
        if (argc >= 2) {                /* That's what SVR2 does */
                setinputfile(argv[1], 1);
                commandname = argv[1];
                cmdloop(0);
                popfile();
        }
        return exitstatus;
}


exitcmd(argc, argv)  char **argv; {
        extern int oexitstatus;
        if (argc > 1)
                exitstatus = number(argv[1]);
        else
                exitstatus = oexitstatus;
        exitshell(exitstatus);
}


lccmd(argc, argv)  char **argv; {
        if (argc > 1) {
                defun(argv[1], prevcmd);
                return 0;
        } else {
                INTOFF;
                freefunc(curcmd);
                curcmd = prevcmd;
                prevcmd = NULL;
                INTON;
                evaltree(curcmd, 0);
                return exitstatus;
        }
}



#ifdef notdef
/*
 * Should never be called.
 */

void
exit(exitstatus) {
        _exit(exitstatus);
}
#endif

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