Merge branch 'cleanups'

[unleashed.git] / usr / src / cmd / csh / sh.c

/*
 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley Software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#include <locale.h>
#include "sh.h"
/* #include <sys/ioctl.h> */
#include <fcntl.h>
#include <sys/filio.h>
#include "sh.tconst.h"
#include <pwd.h>
#include <stdlib.h>
#ifdef  TRACE
#include <stdio.h>
#endif

/*
 * We use these csh(1) private versions of the select macros, (see select(3C))
 * so as not to be limited by the size of struct fd_set (ie 1024).
 */
#define CSH_FD_SET(n, p)   ((*((p) + ((n)/NFDBITS))) |= (1 << ((n) % NFDBITS)))
#define CSH_FD_CLR(n, p)   ((*((p) + ((n)/NFDBITS))) &= ~(1 << ((n) % NFDBITS)))
#define CSH_FD_ISSET(n, p) ((*((p) + ((n)/NFDBITS))) & (1 << ((n) % NFDBITS)))
#define CSH_FD_ZERO(p, n)  memset((void *)(p), 0,  (n))

tchar *pathlist[] =     { S_usrbin /* "/usr/bin" */, S_DOT /* "." */, 0 };
tchar *dumphist[] =     { S_history /* "history" */, S_h /* "-h" */, 0, 0 };
tchar *loadhist[] =     { S_source /* "source" */, S_h /* "-h" */,
    S_NDOThistory /* "~/.history" */, 0 };
tchar HIST = '!';
tchar HISTSUB = '^';
int     nofile;
bool    reenter;
bool    nverbose;
bool    nexececho;
bool    quitit;
bool    fast;
bool    batch;
bool    prompt = 1;
bool    enterhist = 0;

extern  gid_t getegid(), getgid();
extern  uid_t geteuid(), getuid();
extern tchar **strblktotsblk(/* char **, int */);

extern void hupforegnd(void);
void interactive_hup(void);
void interactive_login_hup(void);

void    importpath(tchar *);
void    srccat(tchar *, tchar *);
void    srccat_inlogin(tchar *, tchar *);
void    srcunit(int, bool, bool);
void    rechist(void);
void    goodbye(void);
void    pintr1(bool);
void    process(bool);
void    dosource(tchar **);
void    mailchk(void);
void    printprompt(void);
void    sigwaiting(void);
void    siglwp(void);
void    initdesc(int, char *[]);
void    initdesc_x(int, char *[], int);
void    closem(void);
void    unsetfd(int);
void    phup(void);

#ifdef  TRACE
FILE *trace;
/*
 * Trace routines
 */
#define TRACEFILE       "/tmp/trace.XXXXXX"

/*
 * Initialize trace file.
 * Called from main.
 */
void
trace_init(void)
{
        char name[128];
        char *p;

        strcpy(name, TRACEFILE);
        p = mktemp(name);
        trace = fopen(p, "w");
}

/*
 * write message to trace file
 */
/*VARARGS1*/
void
tprintf(fmt, a, b, c, d, e, f, g, h, i, j)
        char *fmt;
{
        if (trace) {
                fprintf(trace, fmt, a, b, c, d, e, f, g, h, i, j);
                fflush(trace);
        }
}
#endif

int
main(int c, char **av)
{
        tchar **v, *cp, *r;
        int f;
        struct sigvec osv;
        struct sigaction sa;
        tchar s_prompt[MAXHOSTNAMELEN+3];
        char *c_max_var_len;
        int c_max_var_len_size;

        /*
         * set up the error exit, if there is an error before
         * this is done, it will core dump, and we don't
         * tolerate core dumps
         */
        haderr = 0;
        setexit();
        if (haderr) {
                /*
                 *  if were here, there was an error in the csh
                 *  startup so just punt
                 */
                printf("csh startup error, csh exiting...\n");
                flush();
                exitstat();
        }


        (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)       /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST"  /* Use this only if it weren't */
#endif
        (void) textdomain(TEXT_DOMAIN);

        /* Copy arguments */
        v = strblktotsblk(av, c);

        /*
         * Initialize paraml list
         */
        paraml.next = paraml.prev = &paraml;

        settimes();                     /* Immed. estab. timing base */

        if (eq(v[0], S_aout /* "a.out" */))     /* A.out's are quittable */
                quitit = 1;
        uid = getuid();
        loginsh = **v == '-';
        if (loginsh)
                (void) time(&chktim);

        /*
         * Move the descriptors to safe places.
         * The variable didfds is 0 while we have only FSH* to work with.
         * When didfds is true, we have 0,1,2 and prefer to use these.
         *
         * Also, setup data for csh internal file descriptor book keeping.
         */
        initdesc(c, av);

        /*
         * Initialize the shell variables.
         * ARGV and PROMPT are initialized later.
         * STATUS is also munged in several places.
         * CHILD is munged when forking/waiting
         */

        c_max_var_len_size = snprintf(NULL, 0, "%ld", MAX_VAR_LEN);
        c_max_var_len = (char *)xalloc(c_max_var_len_size + 1);
        (void) snprintf(c_max_var_len, (c_max_var_len_size + 1),
            "%ld", MAX_VAR_LEN);
        set(S_SUNW_VARLEN,  strtots(NOSTR, c_max_var_len));
        xfree(c_max_var_len);

        /* don't do globbing here, just set exact copies */
        setNS(S_noglob);

        set(S_status /* "status" */, S_0 /* "0" */);
        dinit(cp = getenvs_("HOME"));   /* dinit thinks that HOME==cwd in a */
                                        /* login shell */
        if (cp == NOSTR)
                fast++;                 /* No home -> can't read scripts */
        else {
                if (strlen_(cp) >= BUFSIZ - 10) {
                        cp = NOSTR;
                        fast++;
                        printf("%s\n", gettext("Pathname too long"));
                        set(S_home /* "home" */, savestr(cp));
                        local_setenv(S_HOME, savestr(cp));
                }
                set(S_home /* "home" */, savestr(cp));
        }
        /*
         * Grab other useful things from the environment.
         * Should we grab everything??
         */
        if ((cp = getenvs_("USER")) != NOSTR)
                set(S_user /* "user" */, savestr(cp));
        else {
                /*
                 * If USER is not defined, set it here.
                 */
                struct passwd *pw;
                pw = getpwuid(getuid());

                if (pw != NULL) {
                        set(S_user, strtots((tchar *)0, pw->pw_name));
                        local_setenv(S_USER, strtots((tchar *)0, pw->pw_name));
                } else if (loginsh) { /* Give up setting USER variable. */
        printf("Warning: USER environment variable could not be set.\n");
                }
        }
        if ((cp = getenvs_("TERM")) != NOSTR)
                set(S_term /* "term" */, savestr(cp));
        /*
         * Re-initialize path if set in environment
         */
        if ((cp = getenvs_("PATH")) == NOSTR)
                set1(S_path /* "path" */, saveblk(pathlist), &shvhed);
        else
                importpath(cp);
        set(S_shell /* "shell" */, S_SHELLPATH);

        doldol = putn(getpid());                /* For $$ */

        /* restore globbing until the user says otherwise */
        unsetv(S_noglob);

        /*
         * Record the interrupt states from the parent process.
         * If the parent is non-interruptible our hand must be forced
         * or we (and our children) won't be either.
         * Our children inherit termination from our parent.
         * We catch it only if we are the login shell.
         */
                /* parents interruptibility */
        (void) sigvec(SIGINT, NULL, &osv);
        parintr = osv.sv_handler;
                /* parents terminability */
        (void) sigvec(SIGTERM, NULL, &osv);
        parterm = osv.sv_handler;

        _signal(SIGLWP, siglwp);
        _signal(SIGWAITING, sigwaiting);
        if (loginsh) {
                (void) signal(SIGHUP, phup);    /* exit processing on HUP */
                (void) signal(SIGXCPU, phup);   /* ...and on XCPU */
                (void) signal(SIGXFSZ, phup);   /* ...and on XFSZ */
        }

        /*
         * Process the arguments.
         *
         * Note that processing of -v/-x is actually delayed till after
         * script processing.
         */
        c--, v++;
        while (c > 0 && (cp = v[0])[0] == '-' && *++cp != '\0' && !batch) {
                do switch (*cp++) {

                case 'b':               /* -b   Next arg is input file */
                        batch++;
                        break;

                case 'c':               /* -c   Command input from arg */
                        if (c == 1)
                                exit(0);
                        c--, v++;
                        arginp = v[0];
                        prompt = 0;
                        nofile++;
                        cflg++;
                        break;

                case 'e':               /* -e   Exit on any error */
                        exiterr++;
                        break;

                case 'f':               /* -f   Fast start */
                        fast++;
                        break;

                case 'i':               /* -i   Interactive, even if !intty */
                        intact++;
                        nofile++;
                        break;

                case 'n':               /* -n   Don't execute */
                        noexec++;
                        break;

                case 'q':               /* -q   (Undoc'd) ... die on quit */
                        quitit = 1;
                        break;

                case 's':               /* -s   Read from std input */
                        nofile++;
                        break;

                case 't':               /* -t   Read one line from input */
                        onelflg = 2;
                        prompt = 0;
                        nofile++;
                        break;
#ifdef TRACE
                case 'T':               /* -T   trace switch on */
                        trace_init();
                        break;
#endif

                case 'v':               /* -v   Echo hist expanded input */
                        nverbose = 1;                   /* ... later */
                        break;

                case 'x':               /* -x   Echo just before execution */
                        nexececho = 1;                  /* ... later */
                        break;

                case 'V':               /* -V   Echo hist expanded input */
                        setNS(S_verbose /* "verbose" */);       /* NOW! */
                        break;

                case 'X':               /* -X   Echo just before execution */
                        setNS(S_echo /* "echo" */);             /* NOW! */
                        break;

                } while (*cp);
                v++, c--;
        }

        if (quitit)                     /* With all due haste, for debugging */
                (void) signal(SIGQUIT, SIG_DFL);

        /*
         * Unless prevented by -c, -i, -s, or -t, if there
         * are remaining arguments the first of them is the name
         * of a shell file from which to read commands.
         */
        if (!batch && (uid != geteuid() || getgid() != getegid())) {
                errno = EACCES;
                child++;                        /* So this ... */
                Perror(S_csh /* "csh" */);      /* ... doesn't return */
        }

        if (nofile == 0 && c > 0) {
                nofile = open_(v[0], 0);
                if (nofile < 0) {
                        child++;                /* So this ... */
                        Perror(v[0]);           /* ... doesn't return */
                }
                file = v[0];
                SHIN = dmove(nofile, FSHIN);    /* Replace FSHIN */
                (void) fcntl(SHIN, F_SETFD, 1);
                prompt = 0;
                c--, v++;
        }

        /*
         * Consider input a tty if it really is or we are interactive.
         */
        intty = intact || isatty(SHIN);

        /*
         * Decide whether we should play with signals or not.
         * If we are explicitly told (via -i, or -) or we are a login
         * shell (arg0 starts with -) or the input and output are both
         * the ttys("csh", or "csh</dev/ttyx>/dev/ttyx")
         * Note that in only the login shell is it likely that parent
         * may have set signals to be ignored
         */
        if (loginsh || intact || intty && isatty(SHOUT))
                setintr = 1;
#ifdef TELL
        settell();
#endif
        /*
         * Save the remaining arguments in argv.
         */
        setq(S_argv /* "argv" */, copyblk(v), &shvhed);

        /*
         * Set up the prompt.
         */
        if (prompt) {
                gethostname_(s_prompt, MAXHOSTNAMELEN);
                strcat_(s_prompt,
                    uid == 0 ? S_SHARPSP /* "# " */ : S_PERSENTSP /* "% " */);
                set(S_prompt /* "prompt" */, s_prompt);
        }

        /*
         * If we are an interactive shell, then start fiddling
         * with the signals; this is a tricky game.
         */
        shpgrp = getpgid(0);
        opgrp = tpgrp = -1;
        if (setintr) {
                **av = '-';
                if (!quitit)            /* Wary! */
                        (void) signal(SIGQUIT, SIG_IGN);
                (void) signal(SIGINT, pintr);
                (void) sigblock(sigmask(SIGINT));
                (void) signal(SIGTERM, SIG_IGN);

                /*
                 * Explicitly terminate foreground jobs and exit if we are
                 * interactive shell
                 */
                if (loginsh) {
                        (void) signal(SIGHUP, interactive_login_hup);
                } else {
                        (void) signal(SIGHUP, interactive_hup);
                }

                if (quitit == 0 && arginp == 0) {
                        (void) signal(SIGTSTP, SIG_IGN);
                        (void) signal(SIGTTIN, SIG_IGN);
                        (void) signal(SIGTTOU, SIG_IGN);
                        /*
                         * Wait till in foreground, in case someone
                         * stupidly runs
                         *      csh &
                         * dont want to try to grab away the tty.
                         */
                        if (isatty(FSHDIAG))
                                f = FSHDIAG;
                        else if (isatty(FSHOUT))
                                f = FSHOUT;
                        else if (isatty(OLDSTD))
                                f = OLDSTD;
                        else
                                f = -1;
retry:
                        if (ioctl(f, TIOCGPGRP,  (char *)&tpgrp) == 0 &&
                            tpgrp != -1) {
                                if (tpgrp != shpgrp) {
                                        void (*old)() = (void (*)())
                                            signal(SIGTTIN, SIG_DFL);
                                        (void) kill(0, SIGTTIN);
                                        (void) signal(SIGTTIN, old);
                                        goto retry;
                                }
                                opgrp = shpgrp;
                                shpgrp = getpid();
                                tpgrp = shpgrp;
                                (void) setpgid(0, shpgrp);
                                (void) ioctl(f, TIOCSPGRP,  (char *)&shpgrp);
                                (void) fcntl(dcopy(f, FSHTTY), F_SETFD, 1);
                        } else {
notty:
printf("Warning: no access to tty; thus no job control in this shell...\n");
                                tpgrp = -1;
                        }
                }
        }
        if (setintr == 0 && parintr == SIG_DFL)
                setintr++;

        /*
         * Set SIGCHLD handler, making sure that reads restart after it runs.
         */
        sigemptyset(&sa.sa_mask);
        sa.sa_handler = pchild;
        sa.sa_flags = SA_RESTART;
        (void) sigaction(SIGCHLD, &sa, NULL);

        /*
         * Set an exit here in case of an interrupt or error reading
         * the shell start-up scripts.
         */
        setexit();
        haderr = 0;             /* In case second time through */
        if (!fast && reenter == 0) {
                reenter++;

                /*
                 * If this is a login csh, and /etc/.login exists,
                 * source /etc/.login first.
                 */
                if (loginsh) {
                        tchar tmp_etc[4+1];     /* strlen("/etc")+1 */
                        tchar tmp_login[7+1];   /* strlen("/.login")+1 */

                        strtots(tmp_etc, "/etc");
                        strtots(tmp_login, "/.login");
                        srccat_inlogin(tmp_etc, tmp_login);
                }

                /* Will have value("home") here because set fast if don't */
                srccat(value(S_home /* "home" */),
                    S_SLADOTcshrc /* "/.cshrc" */);

                /* Hash path */
                if (!fast && !arginp && !onelflg && !havhash)
                        dohash(xhash);


                /*
                 * Reconstruct the history list now, so that it's
                 * available from within .login.
                 */
                dosource(loadhist);
                if (loginsh) {
                        srccat_inlogin(value(S_home /* "home" */),
                            S_SLADOTlogin /* "/.login" */);
                }

                /*
                 * To get cdpath hashing $cdpath must have a
                 * value, not $CDPATH.  So if after reading
                 * the startup files ( .cshrc ), and
                 * user has specified a value for cdpath, then
                 * cache $cdpath paths. xhash2 is global array
                 * for $cdpath caching.
                 */
                if (!fast && !arginp && !onelflg && !havhash2)
                                dohash(xhash2);
        }

        /*
         * Now are ready for the -v and -x flags
         */
        if (nverbose)
                setNS(S_verbose /* "verbose" */);
        if (nexececho)
                setNS(S_echo /* "echo" */);

        /*
         * All the rest of the world is inside this call.
         * The argument to process indicates whether it should
         * catch "error unwinds".  Thus if we are a interactive shell
         * our call here will never return by being blown past on an error.
         */
        process(setintr);

        /*
         * Mop-up.
         */
        if (loginsh) {
                printf("logout\n");
                (void) close(SHIN);     /* No need for unsetfd(). */
                child++;
                goodbye();
        }
        rechist();
        exitstat();
}

void
untty(void)
{

        if (tpgrp > 0) {
                (void) setpgid(0, opgrp);
                (void) ioctl(FSHTTY, TIOCSPGRP,  (char *)&opgrp);
        }
}

void
importpath(tchar *cp)
{
        int i = 0;
        tchar *dp;
        tchar **pv;
        int c;
        static tchar dot[2] = {'.', 0};

        for (dp = cp; *dp; dp++)
                if (*dp == ':')
                        i++;
        /*
         * i+2 where i is the number of colons in the path.
         * There are i+1 directories in the path plus we need
         * room for a zero terminator.
         */
        pv =  (tchar **)xcalloc((unsigned)(i + 2), sizeof (tchar **));
        dp = cp;
        i = 0;
        if (*dp)
        for (;;) {
                if ((c = *dp) == ':' || c == 0) {
                        *dp = 0;
                        pv[i++] = savestr(*cp ? cp : dot);
                        if (c) {
                                cp = dp + 1;
                                *dp = ':';
                        } else
                                break;
                }
                dp++;
        }
        pv[i] = 0;
        set1(S_path /* "path" */, pv, &shvhed);
}

/*
 * Source to the file which is the catenation of the argument names.
 */
void
srccat(tchar *cp, tchar *dp)
{
        tchar *ep = strspl(cp, dp);
        int unit = dmove(open_(ep, 0), -1);

        (void) fcntl(unit, F_SETFD, 1);
        xfree(ep);
#ifdef INGRES
        srcunit(unit, 0, 0);
#else
        srcunit(unit, 1, 0);
#endif
}

/*
 * Source to the file which is the catenation of the argument names.
 *      This one does not check the ownership.
 */
void
srccat_inlogin(tchar *cp, tchar *dp)
{
        tchar *ep = strspl(cp, dp);
        int unit = dmove(open_(ep, 0), -1);

        (void) fcntl(unit, F_SETFD, 1);
        xfree(ep);
        srcunit(unit, 0, 0);
}

/*
 * Source to a unit.  If onlyown it must be our file or our group or
 * we don't chance it.  This occurs on ".cshrc"s and the like.
 */
void
srcunit(int unit, bool onlyown, bool hflg)
{
        /* We have to push down a lot of state here */
        /* All this could go into a structure */
        int oSHIN = -1, oldintty = intty;
        struct whyle *oldwhyl = whyles;
        tchar *ogointr = gointr, *oarginp = arginp;
        tchar *oevalp = evalp, **oevalvec = evalvec;
        int oonelflg = onelflg;
        bool oenterhist = enterhist;
        tchar OHIST = HIST;
#ifdef TELL
        bool otell = cantell;
#endif
        struct Bin saveB;

        /* The (few) real local variables */
        jmp_buf oldexit;
        int reenter, omask;

        if (unit < 0)
                return;
        if (didfds)
                donefds();
        if (onlyown) {
                struct stat stb;

                if (fstat(unit, &stb) < 0 ||
                    (stb.st_uid != uid && stb.st_gid != getgid())) {
                        (void) close(unit);
                        unsetfd(unit);
                        return;
                }
        }

        /*
         * There is a critical section here while we are pushing down the
         * input stream since we have stuff in different structures.
         * If we weren't careful an interrupt could corrupt SHIN's Bin
         * structure and kill the shell.
         *
         * We could avoid the critical region by grouping all the stuff
         * in a single structure and pointing at it to move it all at
         * once.  This is less efficient globally on many variable references
         * however.
         */
        getexit(oldexit);
        reenter = 0;
        if (setintr)
                omask = sigblock(sigmask(SIGINT));
        setexit();
        reenter++;
        if (reenter == 1) {
                /* Setup the new values of the state stuff saved above */
                copy((char *)&saveB, (char *)&B, sizeof (saveB));
                fbuf =  (tchar **) 0;
                fseekp = feobp = fblocks = 0;
                oSHIN = SHIN, SHIN = unit, arginp = 0, onelflg = 0;
                intty = isatty(SHIN), whyles = 0, gointr = 0;
                evalvec = 0; evalp = 0;
                enterhist = hflg;
                if (enterhist)
                        HIST = '\0';
                /*
                 * Now if we are allowing commands to be interrupted,
                 * we let ourselves be interrupted.
                 */
                if (setintr)
                        (void) sigsetmask(omask);
#ifdef TELL
                settell();
#endif
                process(0);             /* 0 -> blow away on errors */
        }
        if (setintr)
                (void) sigsetmask(omask);
        if (oSHIN >= 0) {
                int i;

                /* We made it to the new state... free up its storage */
                /* This code could get run twice but xfree doesn't care */
                for (i = 0; i < fblocks; i++)
                        xfree(fbuf[i]);
                xfree((char *)fbuf);

                /* Reset input arena */
                copy((char *)&B, (char *)&saveB, sizeof (B));

                (void) close(SHIN), SHIN = oSHIN;
                unsetfd(SHIN);
                arginp = oarginp, onelflg = oonelflg;
                evalp = oevalp, evalvec = oevalvec;
                intty = oldintty, whyles = oldwhyl, gointr = ogointr;
                if (enterhist)
                        HIST = OHIST;
                enterhist = oenterhist;
#ifdef TELL
                cantell = otell;
#endif
        }

        resexit(oldexit);
        /*
         * If process reset() (effectively an unwind) then
         * we must also unwind.
         */
        if (reenter >= 2)
                error(NULL);
}

void
rechist(void)
{
        tchar buf[BUFSIZ];
        int fp, ftmp, oldidfds;

        if (!fast) {
                if (value(S_savehist /* "savehist" */)[0] == '\0')
                        return;
                (void) strcpy_(buf, value(S_home /* "home" */));
                (void) strcat_(buf, S_SLADOThistory /* "/.history" */);
                fp = creat_(buf, 0666);
                if (fp == -1)
                        return;
                oldidfds = didfds;
                didfds = 0;
                ftmp = SHOUT;
                SHOUT = fp;
                (void) strcpy_(buf, value(S_savehist /* "savehist" */));
                dumphist[2] = buf;
                dohist(dumphist);
                (void) close(fp);
                unsetfd(fp);
                SHOUT = ftmp;
                didfds = oldidfds;
        }
}

void
goodbye(void)
{
        if (loginsh) {
                (void) signal(SIGQUIT, SIG_IGN);
                (void) signal(SIGINT, SIG_IGN);
                (void) signal(SIGTERM, SIG_IGN);
                setintr = 0;            /* No interrupts after "logout" */
                if (adrof(S_home /* "home" */))
                        srccat(value(S_home /* "home" */),
                            S_SLADOTlogout /* "/.logout" */);
        }
        rechist();
        exitstat();
}

void
exitstat(void)
{

#ifdef PROF
        monitor(0);
#endif
        /*
         * Note that if STATUS is corrupted (i.e. getn bombs)
         * then error will exit directly because we poke child here.
         * Otherwise we might continue unwarrantedly (sic).
         */
        child++;
        untty();
        exit(getn(value(S_status /* "status" */)));
}

/*
 * in the event of a HUP we want to save the history
 */
void
phup(void)
{
        rechist();
        exit(1);
}

void
interactive_hup(void)
{
        hupforegnd();
        exit(1);
}

void
interactive_login_hup(void)
{
        rechist();
        hupforegnd();
        exit(1);
}

tchar *jobargv[2] = { S_jobs /* "jobs" */, 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.
 */
void
pintr(void)
{
        pintr1(1);
}

void
pintr1(bool wantnl)
{
        tchar **v;
        int omask;

        omask = sigblock(0);
        if (setintr) {
                (void) sigsetmask(omask & ~sigmask(SIGINT));
                if (pjobs) {
                        pjobs = 0;
                        printf("\n");
                        dojobs(jobargv);
                        bferr("Interrupted");
                }
        }
        (void) sigsetmask(omask & ~sigmask(SIGCHLD));
        draino();

        /*
         * 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) {
                search(ZGOTO, 0, gointr);
                timflg = 0;
                if (v = pargv)
                        pargv = 0, blkfree(v);
                if (v = gargv)
                        gargv = 0, blkfree(v);
                reset();
        } else if (intty && wantnl)
                printf("\n");           /* Some like this, others don't */
        error(NULL);
}

/*
 * 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.
 */
void
process(bool catch)
{
        jmp_buf osetexit;
        struct command *t;

        getexit(osetexit);
        for (;;) {
                pendjob();
                freelex(&paraml);
                paraml.next = paraml.prev = &paraml;
                paraml.word = S_ /* "" */;
                t = 0;
                setexit();
                justpr = enterhist;     /* execute if not entering history */

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

                /*
                 * For the sake of reset()
                 */
                freelex(&paraml), freesyn(t), t = 0;

                if (haderr) {
                        if (!catch) {
                                /* unwind */
                                doneinp = 0;
                                resexit(osetexit);
                                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 (fseekp == feobp)
                                printprompt();
                }
                err = 0;

                /*
                 * Echo not only on VERBOSE, but also with history expansion.
                 */
                if (lex(&paraml) && intty ||
                    adrof(S_verbose /* "verbose" */)) {
                        haderr = 1;
                        prlex(&paraml);
                        haderr = 0;
                }

                /*
                 * 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.
                 */
                if (enterhist || catch && intty && !whyles)
                        savehist(&paraml);

                /*
                 * Print lexical error messages, except when sourcing
                 * history lists.
                 */
                if (!enterhist && err)
                        error("%s", gettext(err));

                /*
                 * 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.
                 */
                t = syntax(paraml.next, &paraml, 0);
                if (err)
                        error("%s", gettext(err));

                /*
                 * Execute the parse tree
                 */
                {
                        /*
                         * POSIX requires SIGCHLD to be held
                         * until all processes have joined the
                         * process group in order to avoid race
                         * condition.
                         */
                        int omask;

                        omask = sigblock(sigmask(SIGCHLD));
                        execute(t, tpgrp);
                        (void) sigsetmask(omask &~ sigmask(SIGCHLD));
                }

                if (err)
                        error("%s", gettext(err));
                /*
                 * Made it!
                 */
                freelex(&paraml), freesyn(t);
        }
        resexit(osetexit);
}

void
dosource(tchar **t)
{
        tchar *f;
        int u;
        bool hflg = 0;
        tchar buf[BUFSIZ];

        t++;
        if (*t && eq(*t, S_h /* "-h" */)) {
                if (*++t == NOSTR)
                        bferr("Too few arguments.");
                hflg++;
        }
        (void) strcpy_(buf, *t);
        f = globone(buf);
        u = dmove(open_(f, 0), -1);
        xfree(f);
        freelex(&paraml);
        if (u < 0 && !hflg)
                Perror(f);
        (void) fcntl(u, F_SETFD, 1);
        srcunit(u, 0, hflg);
}

/*
 * 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 they already
 * know, since the login program insists on saying
 * "You have mail."
 */
void
mailchk(void)
{
        struct varent *v;
        tchar **vp;
        time_t t;
        int intvl, cnt;
        struct stat stb;
        bool new;

        v = adrof(S_mail /* "mail" */);
        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_(*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)
                        printf("You have %smail.\n", new ? "new " : "");
                else
                        printf("%s in %t.\n", new ? "New mail" : "Mail", *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(tchar *home)
{
        /* getpwname will not be modified, so we need temp. buffer */
        char home_str[BUFSIZ];
        tchar home_ts[BUFSIZ];
        struct passwd *pp /* = getpwnam(home) */;

        pp = getpwnam(tstostr(home_str, home));
        if (pp == 0)
                return (1);
        (void) strcpy_(home, strtots(home_ts, pp->pw_dir));
        return (0);
}


#if 0
void
#ifdef PROF
done(int i)
#else
exit(int i)
#endif
{

        untty();
        _exit(i);
}
#endif

void
printprompt(void)
{
        tchar *cp;

        if (!whyles) {
                /*
                 * Print the prompt string
                 */
                for (cp = value(S_prompt /* "prompt" */); *cp; cp++)
                        if (*cp == HIST)
                                printf("%d", eventno + 1);
                        else {
                                if (*cp == '\\' && cp[1] == HIST)
                                        cp++;
                                Putchar(*cp | QUOTE);
                        }
        } else
                /*
                 * Prompt for forward reading loop
                 * body content.
                 */
                printf("? ");
        flush();
}

/*
 * Save char * block.
 */
tchar **
strblktotsblk(char **v, int num)
{
        tchar **newv =
            (tchar **)xcalloc((unsigned)(num+ 1), sizeof (tchar **));
        tchar **onewv = newv;

        while (*v && num--)
                *newv++ = strtots(NOSTR, *v++);
        *newv = 0;
        return (onewv);
}

void
sigwaiting(void)
{
        _signal(SIGWAITING, sigwaiting);
}

void
siglwp(void)
{
        _signal(SIGLWP, siglwp);
}


/*
 * Following functions and data are used for csh to do its
 * file descriptors book keeping.
 */

static int *fdinuse = NULL;     /* The list of files opened by csh */
static int nbytesused = 0;      /* no of bytes allocated to fdinuse */
static int max_fd = 0;          /* The maximum descriptor in fdinuse */
static int my_pid;              /* The process id set in initdesc() */
static int NoFile = NOFILE;     /* The number of files I can use. */

/*
 * Get the number of files this csh can use.
 *
 * Move the initial descriptors to their eventual
 * resting places, closing all other units.
 *
 * Also, reserve 0/1/2, so NIS+ routines do not get
 * hold of them. And initialize fdinuse list and set
 * the current process id.
 *
 * If this csh was invoked from setuid'ed script file,
 * do not close the third argument passed. The file
 * must be one of /dev/fd/0,1,2,,,
 *      (execv() always passes three arguments when it execs a script
 *       file in a form of #! /bin/csh -b.)
 *
 * If is_reinit is set in initdesc_x(), then we only close the file
 * descriptors that we actually opened (as recorded in fdinuse).
 */
void
initdesc(int argc, char *argv[])
{
        initdesc_x(argc, argv, 0);
}

void
reinitdesc(int argc, char *argv[])
{
        initdesc_x(argc, argv, 1);
}

/*
 * Callback functions for closing all file descriptors.
 */
static int
close_except(void *cd, int fd)
{
        int script_fd = *(int *)cd;

        if (fd >= 3 && fd < NoFile && fd != script_fd)
                (void) close(fd);
        return (0);
}

static int
close_inuse(void *cd, int fd)
{
        int script_fd = *(int *)cd;

        if (fd >= 3 && fd < NoFile && fd != script_fd &&
            CSH_FD_ISSET(fd, fdinuse)) {
                (void) close(fd);
                unsetfd(fd);
        }
        return (0);
}

void
initdesc_x(int argc, char *argv[], int is_reinit)
{

        int script_fd = -1;
        struct stat buf;
        struct rlimit rlp;

        /*
         * Get pid of this shell
         */
        my_pid = getpid();

        /*
         * Get the hard limit numbers of descriptors
         * this csh can use.
         */
        if (getrlimit(RLIMIT_NOFILE, &rlp) == 0)
                NoFile = rlp.rlim_cur;

        /*
         * If this csh was invoked for executing setuid script file,
         * the third argument passed is the special file name
         * which should not be closed.  This special file name is
         * in the form /dev/fd/X.
         */
        if (argc >= 3)
                if (sscanf(argv[2], "/dev/fd/%d", &script_fd) != 1)
                        script_fd = -1;
                else
                        /* Make sure to close this file on exec.  */
                        fcntl(script_fd, F_SETFD, 1);

        if (fdinuse == NULL) {
                nbytesused = sizeof (int) *
                    howmany(NoFile, sizeof (int) * NBBY);
                fdinuse = (int *)xalloc(nbytesused);
        }

        /*
         * Close all files except 0/1/2 to get a clean
         * file descritor space.
         */
        if (!is_reinit)
                (void) fdwalk(close_except, &script_fd);
        else
                (void) fdwalk(close_inuse, &script_fd);

        didfds = 0;                     /* 0, 1, 2 aren't set up */

        if (fstat(0, &buf) < 0)
                open("/dev/null", O_RDONLY);

        (void) fcntl(SHIN = dcopy(0, FSHIN), F_SETFD,  1);
        (void) fcntl(SHOUT = dcopy(1, FSHOUT), F_SETFD,  1);
        (void) fcntl(SHDIAG = dcopy(2, FSHDIAG), F_SETFD,  1);
        (void) fcntl(OLDSTD = dcopy(SHIN, FOLDSTD), F_SETFD,  1);

        /*
         * Open 0/1/2 to avoid Nis+ functions to pick them up.
         *      Now, 0/1/2 are saved, close them and open them.
         */
        close(0); close(1); close(2);
        open("/dev/null", O_RDONLY);
        dup(0);
        dup(0);

        /*
         * Clear fd_set mask
         */
        if (!is_reinit)
                CSH_FD_ZERO(fdinuse, nbytesused);
}

/*
 * This routine is called after an error to close up
 * any units which may have been left open accidentally.
 *
 * You only need to remove files in fdinuse list.
 * After you have removed the files, you can clear the
 * list and max_fd.
 */
void
closem(void)
{
        int f;

        for (f = 3; f <= max_fd; f++) {
                if (CSH_FD_ISSET(f, fdinuse) &&
                    f != SHIN && f != SHOUT && f != SHDIAG &&
                    f != OLDSTD && f != FSHTTY)
                        close(f);
        }
        CSH_FD_ZERO(fdinuse, nbytesused);
        max_fd = 0;
}

/*
 * Reset my_pid when a new process is created.  Only call this
 * if you want the process to affect fdinuse (e.g., fork, but
 * not vfork).
 */
void
new_process(void)
{
        my_pid = getpid();
}


/*
 * Whenever Csh open/create/dup/pipe a file or files,
 * Csh keeps track of its open files. The open files
 * are kept in "fdinuse, Fd In Use" list.
 *
 * When a file descriptor is newly allocated, setfd() is
 * used to mark the fact in "fdinuse" list.
 *      For example,
 *              fd = open("newfile", O_RDONLY);
 *              setfd(fd);
 *
 * When a file is freed by close() function, unsetfd() is
 * used to remove the fd from "fdinuse" list.
 *      For example,
 *              close(fd);
 *              unsetfd(fd);
 */
void
setfd(int fd)
{
        /*
         * Because you want to avoid
         * conflict due to vfork().
         */
        if (my_pid != getpid())
                return;

        if (fd >= NoFile || fd < 0)
                return;

        if (fd > max_fd)
                max_fd = fd;
        CSH_FD_SET(fd, fdinuse);
}

void
unsetfd(int fd)
{
        int i;

        /*
         * Because you want to avoid
         * conflict due to vfork().
         */
        if (my_pid != getpid())
                return;

        if (fd >= NoFile || fd < 0)
                return;

        CSH_FD_CLR(fd, fdinuse);
        if (fd == max_fd) {
                for (i = max_fd-1; i >= 3; i--)
                        if (CSH_FD_ISSET(i, fdinuse)) {
                                max_fd = i;
                                return;
                        }
                max_fd = 0;
        }
}