+ nlpp = &bqlist;
+ while (*nlpp)
+ nlpp = &(*nlpp)->next;
+ *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
+ (*nlpp)->next = NULL;
+ parsebackquote = oldstyle;
+
+ if (oldstyle) {
+ saveprompt = doprompt;
+ doprompt = 0;
+ }
+
+ n = list(2);
+
+ if (oldstyle)
+ doprompt = saveprompt;
+ else {
+ if (readtoken() != TRP)
+ synexpect(TRP);
+ }
+
+ (*nlpp)->n = n;
+ if (oldstyle) {
+ /*
+ * Start reading from old file again, ignoring any pushed back
+ * tokens left from the backquote parsing
+ */
+ popfile();
+ tokpushback = 0;
+ }
+ while (stackblocksize() <= savelen)
+ growstackblock();
+ STARTSTACKSTR(out);
+ if (str) {
+ memcpy(out, str, savelen);
+ STADJUST(savelen, out);
+ INTOFF;
+ ckfree(str);
+ str = NULL;
+ INTON;
+ }
+ parsebackquote = savepbq;
+ handler = savehandler;
+ if (arinest || dblquote)
+ USTPUTC(CTLBACKQ | CTLQUOTE, out);
+ else
+ USTPUTC(CTLBACKQ, out);
+ if (oldstyle)
+ goto parsebackq_oldreturn;
+ else
+ goto parsebackq_newreturn;
+}
+
+#ifdef CONFIG_ASH_MATH_SUPPORT
+/*
+ * Parse an arithmetic expansion (indicate start of one and set state)
+ */
+parsearith: {
+
+ if (++arinest == 1) {
+ prevsyntax = syntax;
+ syntax = ARISYNTAX;
+ USTPUTC(CTLARI, out);
+ if (dblquote)
+ USTPUTC('"',out);
+ else
+ USTPUTC(' ',out);
+ } else {
+ /*
+ * we collapse embedded arithmetic expansion to
+ * parenthesis, which should be equivalent
+ */
+ USTPUTC('(', out);
+ }
+ goto parsearith_return;
+}
+#endif
+
+} /* end of readtoken */
+
+
+
+/*
+ * Returns true if the text contains nothing to expand (no dollar signs
+ * or backquotes).
+ */
+
+static int
+noexpand(char *text)
+{
+ char *p;
+ char c;
+
+ p = text;
+ while ((c = *p++) != '\0') {
+ if (c == CTLQUOTEMARK)
+ continue;
+ if (c == CTLESC)
+ p++;
+ else if (SIT(c, BASESYNTAX) == CCTL)
+ return 0;
+ }
+ return 1;
+}
+
+
+/*
+ * Return of a legal variable name (a letter or underscore followed by zero or
+ * more letters, underscores, and digits).
+ */
+
+char *
+endofname(const char *name)
+{
+ char *p;
+
+ p = (char *) name;
+ if (! is_name(*p))
+ return p;
+ while (*++p) {
+ if (! is_in_name(*p))
+ break;
+ }
+ return p;
+}
+
+
+/*
+ * Called when an unexpected token is read during the parse. The argument
+ * is the token that is expected, or -1 if more than one type of token can
+ * occur at this point.
+ */
+
+static void synexpect(int token)
+{
+ char msg[64];
+ int l;
+
+ l = sprintf(msg, "%s unexpected", tokname(lasttoken));
+ if (token >= 0)
+ sprintf(msg + l, " (expecting %s)", tokname(token));
+ synerror(msg);
+ /* NOTREACHED */
+}
+
+static void
+synerror(const char *msg)
+{
+ error("Syntax error: %s", msg);
+ /* NOTREACHED */
+}
+
+
+/*
+ * called by editline -- any expansions to the prompt
+ * should be added here.
+ */
+
+static void setprompt(int whichprompt)
+{
+ const char *prompt;
+
+ switch (whichprompt) {
+ case 1:
+ prompt = ps1val();
+ break;
+ case 2:
+ prompt = ps2val();
+ break;
+ default: /* 0 */
+ prompt = nullstr;
+ }
+ putprompt(prompt);
+}
+
+
+static const char *const *findkwd(const char *s)
+{
+ return bsearch(s, tokname_array + KWDOFFSET,
+ (sizeof(tokname_array) / sizeof(const char *)) - KWDOFFSET,
+ sizeof(const char *), pstrcmp);
+}
+
+/* $NetBSD: redir.c,v 1.27 2002/11/24 22:35:42 christos Exp $ */
+
+/*
+ * Code for dealing with input/output redirection.
+ */
+
+#define EMPTY -2 /* marks an unused slot in redirtab */
+#ifndef PIPE_BUF
+# define PIPESIZE 4096 /* amount of buffering in a pipe */
+#else
+# define PIPESIZE PIPE_BUF
+#endif
+
+/*
+ * Open a file in noclobber mode.
+ * The code was copied from bash.
+ */
+static inline int
+noclobberopen(const char *fname)
+{
+ int r, fd;
+ struct stat finfo, finfo2;
+
+ /*
+ * If the file exists and is a regular file, return an error
+ * immediately.
+ */
+ r = stat(fname, &finfo);
+ if (r == 0 && S_ISREG(finfo.st_mode)) {
+ errno = EEXIST;
+ return -1;
+ }
+
+ /*
+ * If the file was not present (r != 0), make sure we open it
+ * exclusively so that if it is created before we open it, our open
+ * will fail. Make sure that we do not truncate an existing file.
+ * Note that we don't turn on O_EXCL unless the stat failed -- if the
+ * file was not a regular file, we leave O_EXCL off.
+ */
+ if (r != 0)
+ return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
+ fd = open(fname, O_WRONLY|O_CREAT, 0666);
+
+ /* If the open failed, return the file descriptor right away. */
+ if (fd < 0)
+ return fd;
+
+ /*
+ * OK, the open succeeded, but the file may have been changed from a
+ * non-regular file to a regular file between the stat and the open.
+ * We are assuming that the O_EXCL open handles the case where FILENAME
+ * did not exist and is symlinked to an existing file between the stat
+ * and open.
+ */
+
+ /*
+ * If we can open it and fstat the file descriptor, and neither check
+ * revealed that it was a regular file, and the file has not been
+ * replaced, return the file descriptor.
+ */
+ if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode) &&
+ finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino)
+ return fd;
+
+ /* The file has been replaced. badness. */
+ close(fd);
+ errno = EEXIST;
+ return -1;
+}
+
+/*
+ * Handle here documents. Normally we fork off a process to write the
+ * data to a pipe. If the document is short, we can stuff the data in
+ * the pipe without forking.
+ */
+
+static inline int
+openhere(union node *redir)
+{
+ int pip[2];
+ size_t len = 0;
+
+ if (pipe(pip) < 0)
+ error("Pipe call failed");
+ if (redir->type == NHERE) {
+ len = strlen(redir->nhere.doc->narg.text);
+ if (len <= PIPESIZE) {
+ xwrite(pip[1], redir->nhere.doc->narg.text, len);
+ goto out;
+ }
+ }
+ if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
+ close(pip[0]);
+ signal(SIGINT, SIG_IGN);
+ signal(SIGQUIT, SIG_IGN);
+ signal(SIGHUP, SIG_IGN);
+#ifdef SIGTSTP
+ signal(SIGTSTP, SIG_IGN);
+#endif
+ signal(SIGPIPE, SIG_DFL);
+ if (redir->type == NHERE)
+ xwrite(pip[1], redir->nhere.doc->narg.text, len);
+ else
+ expandhere(redir->nhere.doc, pip[1]);
+ _exit(0);
+ }
+out:
+ close(pip[1]);
+ return pip[0];
+}
+
+static int
+openredirect(union node *redir)
+{
+ char *fname;
+ int f;
+
+ switch (redir->nfile.type) {
+ case NFROM:
+ fname = redir->nfile.expfname;
+ if ((f = open(fname, O_RDONLY)) < 0)
+ goto eopen;
+ break;
+ case NFROMTO:
+ fname = redir->nfile.expfname;
+ if ((f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666)) < 0)
+ goto ecreate;
+ break;
+ case NTO:
+ /* Take care of noclobber mode. */
+ if (Cflag) {
+ fname = redir->nfile.expfname;
+ if ((f = noclobberopen(fname)) < 0)
+ goto ecreate;
+ break;
+ }
+ /* FALLTHROUGH */
+ case NCLOBBER:
+ fname = redir->nfile.expfname;
+ if ((f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0)
+ goto ecreate;
+ break;
+ case NAPPEND:
+ fname = redir->nfile.expfname;
+ if ((f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0)
+ goto ecreate;
+ break;
+ default:
+#ifdef DEBUG
+ abort();
+#endif
+ /* Fall through to eliminate warning. */
+ case NTOFD:
+ case NFROMFD:
+ f = -1;
+ break;
+ case NHERE:
+ case NXHERE:
+ f = openhere(redir);
+ break;
+ }
+
+ return f;
+ecreate:
+ error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
+eopen:
+ error("cannot open %s: %s", fname, errmsg(errno, E_OPEN));
+}
+
+static inline void
+dupredirect(union node *redir, int f)
+{
+ int fd = redir->nfile.fd;
+
+ if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
+ if (redir->ndup.dupfd >= 0) { /* if not ">&-" */
+ copyfd(redir->ndup.dupfd, fd);
+ }
+ return;
+ }
+
+ if (f != fd) {
+ copyfd(f, fd);
+ close(f);
+ }
+ return;
+}
+
+/*
+ * Process a list of redirection commands. If the REDIR_PUSH flag is set,
+ * old file descriptors are stashed away so that the redirection can be
+ * undone by calling popredir. If the REDIR_BACKQ flag is set, then the
+ * standard output, and the standard error if it becomes a duplicate of
+ * stdout, is saved in memory.
+ */
+
+static void
+redirect(union node *redir, int flags)
+{
+ union node *n;
+ struct redirtab *sv;
+ int i;
+ int fd;
+ int newfd;
+ int *p;
+ nullredirs++;
+ if (!redir) {
+ return;
+ }
+ sv = NULL;
+ INTOFF;
+ if (flags & REDIR_PUSH) {
+ struct redirtab *q;
+ q = ckmalloc(sizeof (struct redirtab));
+ q->next = redirlist;
+ redirlist = q;
+ q->nullredirs = nullredirs - 1;
+ for (i = 0 ; i < 10 ; i++)
+ q->renamed[i] = EMPTY;
+ nullredirs = 0;
+ sv = q;
+ }
+ n = redir;
+ do {
+ fd = n->nfile.fd;
+ if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) &&
+ n->ndup.dupfd == fd)
+ continue; /* redirect from/to same file descriptor */
+
+ newfd = openredirect(n);
+ if (fd == newfd)
+ continue;
+ if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
+ i = fcntl(fd, F_DUPFD, 10);
+
+ if (i == -1) {
+ i = errno;
+ if (i != EBADF) {
+ close(newfd);
+ errno = i;
+ error("%d: %m", fd);
+ /* NOTREACHED */
+ }
+ } else {
+ *p = i;
+ close(fd);
+ }
+ } else {
+ close(fd);
+ }
+ dupredirect(n, newfd);
+ } while ((n = n->nfile.next));
+ INTON;
+ if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
+ preverrout_fd = sv->renamed[2];
+}
+
+
+/*
+ * Undo the effects of the last redirection.
+ */
+
+void
+popredir(int drop)
+{
+ struct redirtab *rp;
+ int i;
+
+ if (--nullredirs >= 0)
+ return;
+ INTOFF;
+ rp = redirlist;
+ for (i = 0 ; i < 10 ; i++) {
+ if (rp->renamed[i] != EMPTY) {
+ if (!drop) {
+ close(i);
+ copyfd(rp->renamed[i], i);
+ }
+ close(rp->renamed[i]);
+ }
+ }
+ redirlist = rp->next;
+ nullredirs = rp->nullredirs;
+ ckfree(rp);
+ INTON;
+}
+
+/*
+ * Undo all redirections. Called on error or interrupt.
+ */
+
+/*
+ * Discard all saved file descriptors.
+ */
+
+void
+clearredir(int drop)
+{
+ for (;;) {
+ nullredirs = 0;
+ if (!redirlist)
+ break;
+ popredir(drop);
+ }
+}
+
+
+/*
+ * Copy a file descriptor to be >= to. Returns -1
+ * if the source file descriptor is closed, EMPTY if there are no unused
+ * file descriptors left.
+ */
+
+int
+copyfd(int from, int to)
+{
+ int newfd;
+
+ newfd = fcntl(from, F_DUPFD, to);
+ if (newfd < 0) {
+ if (errno == EMFILE)
+ return EMPTY;
+ else
+ error("%d: %m", from);
+ }
+ return newfd;
+}
+
+
+int
+redirectsafe(union node *redir, int flags)
+{
+ int err;
+ volatile int saveint;
+ struct jmploc *volatile savehandler = handler;
+ struct jmploc jmploc;
+
+ SAVEINT(saveint);
+ if (!(err = setjmp(jmploc.loc) * 2)) {
+ handler = &jmploc;
+ redirect(redir, flags);
+ }
+ handler = savehandler;
+ if (err && exception != EXERROR)
+ longjmp(handler->loc, 1);
+ RESTOREINT(saveint);
+ return err;
+}
+
+/* $NetBSD: show.c,v 1.24 2003/01/22 20:36:04 dsl Exp $ */
+
+#ifdef DEBUG
+static void shtree(union node *, int, char *, FILE*);
+static void shcmd(union node *, FILE *);
+static void sharg(union node *, FILE *);
+static void indent(int, char *, FILE *);
+static void trstring(char *);
+
+
+void
+showtree(union node *n)
+{
+ trputs("showtree called\n");
+ shtree(n, 1, NULL, stdout);
+}
+
+
+static void
+shtree(union node *n, int ind, char *pfx, FILE *fp)
+{
+ struct nodelist *lp;
+ const char *s;
+
+ if (n == NULL)
+ return;
+
+ indent(ind, pfx, fp);
+ switch(n->type) {
+ case NSEMI:
+ s = "; ";
+ goto binop;
+ case NAND:
+ s = " && ";
+ goto binop;
+ case NOR:
+ s = " || ";
+binop:
+ shtree(n->nbinary.ch1, ind, NULL, fp);
+ /* if (ind < 0) */
+ fputs(s, fp);
+ shtree(n->nbinary.ch2, ind, NULL, fp);
+ break;
+ case NCMD:
+ shcmd(n, fp);
+ if (ind >= 0)
+ putc('\n', fp);
+ break;
+ case NPIPE:
+ for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
+ shcmd(lp->n, fp);
+ if (lp->next)
+ fputs(" | ", fp);
+ }
+ if (n->npipe.backgnd)
+ fputs(" &", fp);
+ if (ind >= 0)
+ putc('\n', fp);
+ break;
+ default:
+ fprintf(fp, "<node type %d>", n->type);
+ if (ind >= 0)
+ putc('\n', fp);
+ break;
+ }
+}
+
+
+static void
+shcmd(union node *cmd, FILE *fp)
+{
+ union node *np;
+ int first;
+ const char *s;
+ int dftfd;
+
+ first = 1;
+ for (np = cmd->ncmd.args ; np ; np = np->narg.next) {
+ if (! first)
+ putchar(' ');
+ sharg(np, fp);
+ first = 0;
+ }
+ for (np = cmd->ncmd.redirect ; np ; np = np->nfile.next) {
+ if (! first)
+ putchar(' ');
+ switch (np->nfile.type) {
+ case NTO: s = ">"; dftfd = 1; break;
+ case NCLOBBER: s = ">|"; dftfd = 1; break;
+ case NAPPEND: s = ">>"; dftfd = 1; break;
+ case NTOFD: s = ">&"; dftfd = 1; break;
+ case NFROM: s = "<"; dftfd = 0; break;
+ case NFROMFD: s = "<&"; dftfd = 0; break;
+ case NFROMTO: s = "<>"; dftfd = 0; break;
+ default: s = "*error*"; dftfd = 0; break;
+ }
+ if (np->nfile.fd != dftfd)
+ fprintf(fp, "%d", np->nfile.fd);
+ fputs(s, fp);
+ if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) {
+ fprintf(fp, "%d", np->ndup.dupfd);
+ } else {
+ sharg(np->nfile.fname, fp);
+ }
+ first = 0;
+ }
+}
+
+
+
+static void
+sharg(union node *arg, FILE *fp)
+{
+ char *p;
+ struct nodelist *bqlist;
+ int subtype;
+
+ if (arg->type != NARG) {
+ out1fmt("<node type %d>\n", arg->type);
+ abort();
+ }
+ bqlist = arg->narg.backquote;
+ for (p = arg->narg.text ; *p ; p++) {
+ switch (*p) {
+ case CTLESC:
+ putc(*++p, fp);
+ break;
+ case CTLVAR:
+ putc('$', fp);
+ putc('{', fp);
+ subtype = *++p;
+ if (subtype == VSLENGTH)
+ putc('#', fp);
+
+ while (*p != '=')
+ putc(*p++, fp);
+
+ if (subtype & VSNUL)
+ putc(':', fp);
+
+ switch (subtype & VSTYPE) {
+ case VSNORMAL:
+ putc('}', fp);
+ break;
+ case VSMINUS:
+ putc('-', fp);
+ break;
+ case VSPLUS:
+ putc('+', fp);
+ break;
+ case VSQUESTION:
+ putc('?', fp);
+ break;
+ case VSASSIGN:
+ putc('=', fp);
+ break;
+ case VSTRIMLEFT:
+ putc('#', fp);
+ break;
+ case VSTRIMLEFTMAX:
+ putc('#', fp);
+ putc('#', fp);
+ break;
+ case VSTRIMRIGHT:
+ putc('%', fp);
+ break;
+ case VSTRIMRIGHTMAX:
+ putc('%', fp);
+ putc('%', fp);
+ break;
+ case VSLENGTH:
+ break;
+ default:
+ out1fmt("<subtype %d>", subtype);
+ }
+ break;
+ case CTLENDVAR:
+ putc('}', fp);
+ break;
+ case CTLBACKQ:
+ case CTLBACKQ|CTLQUOTE:
+ putc('$', fp);
+ putc('(', fp);
+ shtree(bqlist->n, -1, NULL, fp);
+ putc(')', fp);
+ break;
+ default:
+ putc(*p, fp);
+ break;
+ }
+ }
+}
+
+
+static void
+indent(int amount, char *pfx, FILE *fp)
+{
+ int i;
+
+ for (i = 0 ; i < amount ; i++) {
+ if (pfx && i == amount - 1)
+ fputs(pfx, fp);
+ putc('\t', fp);
+ }
+}
+
+
+
+/*
+ * Debugging stuff.
+ */
+
+
+FILE *tracefile;
+
+
+void
+trputc(int c)
+{
+ if (debug != 1)
+ return;
+ putc(c, tracefile);
+}
+
+void
+trace(const char *fmt, ...)
+{
+ va_list va;
+
+ if (debug != 1)
+ return;
+ va_start(va, fmt);
+ (void) vfprintf(tracefile, fmt, va);
+ va_end(va);
+}
+
+void
+tracev(const char *fmt, va_list va)
+{
+ if (debug != 1)
+ return;
+ (void) vfprintf(tracefile, fmt, va);
+}
+
+
+void
+trputs(const char *s)
+{
+ if (debug != 1)
+ return;
+ fputs(s, tracefile);
+}
+
+
+static void
+trstring(char *s)
+{
+ char *p;
+ char c;
+
+ if (debug != 1)
+ return;
+ putc('"', tracefile);
+ for (p = s ; *p ; p++) {
+ switch (*p) {
+ case '\n': c = 'n'; goto backslash;
+ case '\t': c = 't'; goto backslash;
+ case '\r': c = 'r'; goto backslash;
+ case '"': c = '"'; goto backslash;
+ case '\\': c = '\\'; goto backslash;
+ case CTLESC: c = 'e'; goto backslash;
+ case CTLVAR: c = 'v'; goto backslash;
+ case CTLVAR+CTLQUOTE: c = 'V'; goto backslash;
+ case CTLBACKQ: c = 'q'; goto backslash;
+ case CTLBACKQ+CTLQUOTE: c = 'Q'; goto backslash;
+backslash: putc('\\', tracefile);
+ putc(c, tracefile);
+ break;
+ default:
+ if (*p >= ' ' && *p <= '~')
+ putc(*p, tracefile);
+ else {
+ putc('\\', tracefile);
+ putc(*p >> 6 & 03, tracefile);
+ putc(*p >> 3 & 07, tracefile);
+ putc(*p & 07, tracefile);
+ }
+ break;
+ }
+ }
+ putc('"', tracefile);
+}
+
+
+void
+trargs(char **ap)
+{
+ if (debug != 1)
+ return;
+ while (*ap) {
+ trstring(*ap++);
+ if (*ap)
+ putc(' ', tracefile);
+ else
+ putc('\n', tracefile);
+ }
+}
+
+
+void
+opentrace(void)
+{
+ char s[100];
+#ifdef O_APPEND
+ int flags;
+#endif
+
+ if (debug != 1) {
+ if (tracefile)
+ fflush(tracefile);
+ /* leave open because libedit might be using it */
+ return;
+ }
+ scopy("./trace", s);
+ if (tracefile) {
+ if (!freopen(s, "a", tracefile)) {
+ fprintf(stderr, "Can't re-open %s\n", s);
+ debug = 0;
+ return;
+ }
+ } else {
+ if ((tracefile = fopen(s, "a")) == NULL) {
+ fprintf(stderr, "Can't open %s\n", s);
+ debug = 0;
+ return;
+ }
+ }
+#ifdef O_APPEND
+ if ((flags = fcntl(fileno(tracefile), F_GETFL, 0)) >= 0)
+ fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND);
+#endif
+ setlinebuf(tracefile);
+ fputs("\nTracing started.\n", tracefile);
+}
+#endif /* DEBUG */
+
+
+/* $NetBSD: trap.c,v 1.28 2002/11/24 22:35:43 christos Exp $ */
+
+/*
+ * Sigmode records the current value of the signal handlers for the various
+ * modes. A value of zero means that the current handler is not known.
+ * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
+ */
+
+#define S_DFL 1 /* default signal handling (SIG_DFL) */
+#define S_CATCH 2 /* signal is caught */
+#define S_IGN 3 /* signal is ignored (SIG_IGN) */
+#define S_HARD_IGN 4 /* signal is ignored permenantly */
+#define S_RESET 5 /* temporary - to reset a hard ignored sig */
+
+
+
+/*
+ * The trap builtin.
+ */
+
+int
+trapcmd(int argc, char **argv)
+{
+ char *action;
+ char **ap;
+ int signo;
+
+ nextopt(nullstr);
+ ap = argptr;
+ if (!*ap) {
+ for (signo = 0 ; signo < NSIG ; signo++) {
+ if (trap[signo] != NULL) {
+ const char *sn;
+
+ sn = u_signal_names(0, &signo, 0);
+ if (sn == NULL)
+ sn = "???";
+ out1fmt("trap -- %s %s\n",
+ single_quote(trap[signo]), sn);
+ }
+ }
+ return 0;
+ }
+ if (!ap[1])
+ action = NULL;
+ else
+ action = *ap++;
+ while (*ap) {
+ if ((signo = decode_signal(*ap, 0)) < 0)
+ error("%s: bad trap", *ap);
+ INTOFF;
+ if (action) {
+ if (action[0] == '-' && action[1] == '\0')
+ action = NULL;
+ else
+ action = savestr(action);
+ }
+ if (trap[signo])
+ ckfree(trap[signo]);
+ trap[signo] = action;
+ if (signo != 0)
+ setsignal(signo);
+ INTON;
+ ap++;
+ }
+ return 0;
+}
+
+
+/*
+ * Clear traps on a fork.
+ */
+
+void
+clear_traps(void)
+{
+ char **tp;
+
+ for (tp = trap ; tp < &trap[NSIG] ; tp++) {
+ if (*tp && **tp) { /* trap not NULL or SIG_IGN */
+ INTOFF;
+ ckfree(*tp);
+ *tp = NULL;
+ if (tp != &trap[0])
+ setsignal(tp - trap);
+ INTON;
+ }
+ }
+}
+
+
+/*
+ * Set the signal handler for the specified signal. The routine figures
+ * out what it should be set to.
+ */
+
+void
+setsignal(int signo)
+{
+ int action;
+ char *t, tsig;
+ struct sigaction act;
+
+ if ((t = trap[signo]) == NULL)
+ action = S_DFL;
+ else if (*t != '\0')
+ action = S_CATCH;
+ else
+ action = S_IGN;
+ if (rootshell && action == S_DFL) {
+ switch (signo) {
+ case SIGINT:
+ if (iflag || minusc || sflag == 0)
+ action = S_CATCH;
+ break;
+ case SIGQUIT:
+#ifdef DEBUG
+ if (debug)
+ break;
+#endif
+ /* FALLTHROUGH */
+ case SIGTERM:
+ if (iflag)
+ action = S_IGN;
+ break;
+#if JOBS
+ case SIGTSTP:
+ case SIGTTOU:
+ if (mflag)
+ action = S_IGN;
+ break;
+#endif
+ }
+ }
+
+ t = &sigmode[signo - 1];
+ tsig = *t;
+ if (tsig == 0) {
+ /*
+ * current setting unknown
+ */
+ if (sigaction(signo, 0, &act) == -1) {
+ /*
+ * Pretend it worked; maybe we should give a warning
+ * here, but other shells don't. We don't alter
+ * sigmode, so that we retry every time.
+ */
+ return;
+ }
+ if (act.sa_handler == SIG_IGN) {
+ if (mflag && (signo == SIGTSTP ||
+ signo == SIGTTIN || signo == SIGTTOU)) {
+ tsig = S_IGN; /* don't hard ignore these */
+ } else
+ tsig = S_HARD_IGN;
+ } else {
+ tsig = S_RESET; /* force to be set */
+ }
+ }
+ if (tsig == S_HARD_IGN || tsig == action)
+ return;
+ switch (action) {
+ case S_CATCH:
+ act.sa_handler = onsig;
+ break;
+ case S_IGN:
+ act.sa_handler = SIG_IGN;
+ break;
+ default:
+ act.sa_handler = SIG_DFL;
+ }
+ *t = action;
+ act.sa_flags = 0;
+ sigfillset(&act.sa_mask);
+ sigaction(signo, &act, 0);
+}
+
+/*
+ * Ignore a signal.
+ */
+
+void
+ignoresig(int signo)
+{
+ if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
+ signal(signo, SIG_IGN);
+ }
+ sigmode[signo - 1] = S_HARD_IGN;
+}