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-rw-r--r--sh/eval.c1257
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diff --git a/sh/eval.c b/sh/eval.c
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+++ b/sh/eval.c
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+/* $NetBSD: eval.c,v 1.81.2.1 2005/06/13 22:03:51 tron Exp $ */
+
+/*-
+ * Copyright (c) 1993
+ * 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. 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.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
+#else
+__RCSID("$NetBSD: eval.c,v 1.81.2.1 2005/06/13 22:03:51 tron Exp $");
+#endif
+#endif /* not lint */
+
+#include <stdlib.h>
+#include <signal.h>
+#include <stdio.h>
+#include <unistd.h>
+#ifdef __linux__
+#include <fcntl.h>
+#else
+#include <sys/fcntl.h>
+#endif
+#include <sys/times.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+/*
+ * Evaluate a command.
+ */
+
+#include "shell.h"
+#include "nodes.h"
+#include "syntax.h"
+#include "expand.h"
+#include "parser.h"
+#include "jobs.h"
+#include "eval.h"
+#include "builtins.h"
+#include "options.h"
+#include "exec.h"
+#include "redir.h"
+#include "input.h"
+#include "output.h"
+#include "trap.h"
+#include "var.h"
+#include "memalloc.h"
+#include "error.h"
+#include "show.h"
+#include "mystring.h"
+#include "main.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+
+
+/* flags in argument to evaltree */
+#define EV_EXIT 01 /* exit after evaluating tree */
+#define EV_TESTED 02 /* exit status is checked; ignore -e flag */
+#define EV_BACKCMD 04 /* command executing within back quotes */
+
+int evalskip; /* set if we are skipping commands */
+STATIC int skipcount; /* number of levels to skip */
+MKINIT int loopnest; /* current loop nesting level */
+int funcnest; /* depth of function calls */
+
+
+char *commandname;
+struct strlist *cmdenviron;
+int exitstatus; /* exit status of last command */
+int back_exitstatus; /* exit status of backquoted command */
+
+
+STATIC void evalloop(union node *, int);
+STATIC void evalfor(union node *, int);
+STATIC void evalcase(union node *, int);
+STATIC void evalsubshell(union node *, int);
+STATIC void expredir(union node *);
+STATIC void evalpipe(union node *);
+STATIC void evalcommand(union node *, int, struct backcmd *);
+STATIC void prehash(union node *);
+
+
+/*
+ * Called to reset things after an exception.
+ */
+
+#ifdef mkinit
+INCLUDE "eval.h"
+
+RESET {
+ evalskip = 0;
+ loopnest = 0;
+ funcnest = 0;
+}
+
+SHELLPROC {
+ exitstatus = 0;
+}
+#endif
+
+static int
+sh_pipe(int fds[2])
+{
+ int nfd;
+
+ if (pipe(fds))
+ return -1;
+
+ if (fds[0] < 3) {
+ nfd = fcntl(fds[0], F_DUPFD, 3);
+ if (nfd != -1) {
+ close(fds[0]);
+ fds[0] = nfd;
+ }
+ }
+
+ if (fds[1] < 3) {
+ nfd = fcntl(fds[1], F_DUPFD, 3);
+ if (nfd != -1) {
+ close(fds[1]);
+ fds[1] = nfd;
+ }
+ }
+ return 0;
+}
+
+
+/*
+ * The eval commmand.
+ */
+
+int
+evalcmd(int argc, char **argv)
+{
+ char *p;
+ char *concat;
+ char **ap;
+
+ if (argc > 1) {
+ p = argv[1];
+ if (argc > 2) {
+ STARTSTACKSTR(concat);
+ ap = argv + 2;
+ for (;;) {
+ while (*p)
+ STPUTC(*p++, concat);
+ if ((p = *ap++) == NULL)
+ break;
+ STPUTC(' ', concat);
+ }
+ STPUTC('\0', concat);
+ p = grabstackstr(concat);
+ }
+ evalstring(p, EV_TESTED);
+ }
+ return exitstatus;
+}
+
+
+/*
+ * Execute a command or commands contained in a string.
+ */
+
+void
+evalstring(char *s, int flag)
+{
+ union node *n;
+ struct stackmark smark;
+
+ setstackmark(&smark);
+ setinputstring(s, 1);
+
+ while ((n = parsecmd(0)) != NEOF) {
+ evaltree(n, flag);
+ popstackmark(&smark);
+ }
+ popfile();
+ popstackmark(&smark);
+}
+
+
+
+/*
+ * Evaluate a parse tree. The value is left in the global variable
+ * exitstatus.
+ */
+
+void
+evaltree(union node *n, int flags)
+{
+ if (n == NULL) {
+ TRACE(("evaltree(NULL) called\n"));
+ exitstatus = 0;
+ goto out;
+ }
+#ifdef WITH_HISTORY
+ displayhist = 1; /* show history substitutions done with fc */
+#endif
+ TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
+ getpid(), n, n->type, flags));
+ switch (n->type) {
+ case NSEMI:
+ evaltree(n->nbinary.ch1, flags & EV_TESTED);
+ if (evalskip)
+ goto out;
+ evaltree(n->nbinary.ch2, flags);
+ break;
+ case NAND:
+ evaltree(n->nbinary.ch1, EV_TESTED);
+ if (evalskip || exitstatus != 0)
+ goto out;
+ evaltree(n->nbinary.ch2, flags);
+ break;
+ case NOR:
+ evaltree(n->nbinary.ch1, EV_TESTED);
+ if (evalskip || exitstatus == 0)
+ goto out;
+ evaltree(n->nbinary.ch2, flags);
+ break;
+ case NREDIR:
+ expredir(n->nredir.redirect);
+ redirect(n->nredir.redirect, REDIR_PUSH);
+ evaltree(n->nredir.n, flags);
+ popredir();
+ break;
+ case NSUBSHELL:
+ evalsubshell(n, flags);
+ break;
+ case NBACKGND:
+ evalsubshell(n, flags);
+ break;
+ case NIF: {
+ evaltree(n->nif.test, EV_TESTED);
+ if (evalskip)
+ goto out;
+ if (exitstatus == 0)
+ evaltree(n->nif.ifpart, flags);
+ else if (n->nif.elsepart)
+ evaltree(n->nif.elsepart, flags);
+ else
+ exitstatus = 0;
+ break;
+ }
+ case NWHILE:
+ case NUNTIL:
+ evalloop(n, flags);
+ break;
+ case NFOR:
+ evalfor(n, flags);
+ break;
+ case NCASE:
+ evalcase(n, flags);
+ break;
+ case NDEFUN:
+ defun(n->narg.text, n->narg.next);
+ exitstatus = 0;
+ break;
+ case NNOT:
+ evaltree(n->nnot.com, EV_TESTED);
+ exitstatus = !exitstatus;
+ break;
+ case NPIPE:
+ evalpipe(n);
+ break;
+ case NCMD:
+ evalcommand(n, flags, (struct backcmd *)NULL);
+ break;
+ default:
+ out1fmt("Node type = %d\n", n->type);
+ flushout(&output);
+ break;
+ }
+out:
+ if (pendingsigs)
+ dotrap();
+ if ((flags & EV_EXIT) != 0)
+ exitshell(exitstatus);
+}
+
+
+STATIC void
+evalloop(union node *n, int flags)
+{
+ int status;
+
+ loopnest++;
+ status = 0;
+ for (;;) {
+ evaltree(n->nbinary.ch1, EV_TESTED);
+ if (evalskip) {
+skipping: if (evalskip == SKIPCONT && --skipcount <= 0) {
+ evalskip = 0;
+ continue;
+ }
+ if (evalskip == SKIPBREAK && --skipcount <= 0)
+ evalskip = 0;
+ break;
+ }
+ if (n->type == NWHILE) {
+ if (exitstatus != 0)
+ break;
+ } else {
+ if (exitstatus == 0)
+ break;
+ }
+ evaltree(n->nbinary.ch2, flags & EV_TESTED);
+ status = exitstatus;
+ if (evalskip)
+ goto skipping;
+ }
+ loopnest--;
+ exitstatus = status;
+}
+
+
+
+STATIC void
+evalfor(union node *n, int flags)
+{
+ struct arglist arglist;
+ union node *argp;
+ struct strlist *sp;
+ struct stackmark smark;
+ int status = 0;
+
+ setstackmark(&smark);
+ arglist.lastp = &arglist.list;
+ for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
+ expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+ if (evalskip)
+ goto out;
+ }
+ *arglist.lastp = NULL;
+
+ loopnest++;
+ for (sp = arglist.list ; sp ; sp = sp->next) {
+ setvar(n->nfor.var, sp->text, 0);
+ evaltree(n->nfor.body, flags & EV_TESTED);
+ status = exitstatus;
+ if (evalskip) {
+ if (evalskip == SKIPCONT && --skipcount <= 0) {
+ evalskip = 0;
+ continue;
+ }
+ if (evalskip == SKIPBREAK && --skipcount <= 0)
+ evalskip = 0;
+ break;
+ }
+ }
+ loopnest--;
+ exitstatus = status;
+out:
+ popstackmark(&smark);
+}
+
+
+
+STATIC void
+evalcase(union node *n, int flags)
+{
+ union node *cp;
+ union node *patp;
+ struct arglist arglist;
+ struct stackmark smark;
+ int status = 0;
+
+ setstackmark(&smark);
+ arglist.lastp = &arglist.list;
+ expandarg(n->ncase.expr, &arglist, EXP_TILDE);
+ for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
+ for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
+ if (casematch(patp, arglist.list->text)) {
+ if (evalskip == 0) {
+ evaltree(cp->nclist.body, flags);
+ status = exitstatus;
+ }
+ goto out;
+ }
+ }
+ }
+out:
+ exitstatus = status;
+ popstackmark(&smark);
+}
+
+
+
+/*
+ * Kick off a subshell to evaluate a tree.
+ */
+
+STATIC void
+evalsubshell(union node *n, int flags)
+{
+ struct job *jp;
+ int backgnd = (n->type == NBACKGND);
+
+ expredir(n->nredir.redirect);
+ INTOFF;
+ jp = makejob(n, 1);
+ if (forkshell(jp, n, backgnd) == 0) {
+ INTON;
+ if (backgnd)
+ flags &=~ EV_TESTED;
+ redirect(n->nredir.redirect, 0);
+ /* never returns */
+ evaltree(n->nredir.n, flags | EV_EXIT);
+ }
+ if (! backgnd)
+ exitstatus = waitforjob(jp);
+ INTON;
+}
+
+
+
+/*
+ * Compute the names of the files in a redirection list.
+ */
+
+STATIC void
+expredir(union node *n)
+{
+ union node *redir;
+
+ for (redir = n ; redir ; redir = redir->nfile.next) {
+ struct arglist fn;
+ fn.lastp = &fn.list;
+ switch (redir->type) {
+ case NFROMTO:
+ case NFROM:
+ case NTO:
+ case NCLOBBER:
+ case NAPPEND:
+ expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
+ redir->nfile.expfname = fn.list->text;
+ break;
+ case NFROMFD:
+ case NTOFD:
+ if (redir->ndup.vname) {
+ expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
+ fixredir(redir, fn.list->text, 1);
+ }
+ break;
+ }
+ }
+}
+
+
+
+/*
+ * Evaluate a pipeline. All the processes in the pipeline are children
+ * of the process creating the pipeline. (This differs from some versions
+ * of the shell, which make the last process in a pipeline the parent
+ * of all the rest.)
+ */
+
+STATIC void
+evalpipe(union node *n)
+{
+ struct job *jp;
+ struct nodelist *lp;
+ int pipelen;
+ int prevfd;
+ int pip[2];
+
+ TRACE(("evalpipe(0x%lx) called\n", (long)n));
+ pipelen = 0;
+ for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
+ pipelen++;
+ INTOFF;
+ jp = makejob(n, pipelen);
+ prevfd = -1;
+ for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
+ prehash(lp->n);
+ pip[1] = -1;
+ if (lp->next) {
+ if (sh_pipe(pip) < 0) {
+ close(prevfd);
+ error("Pipe call failed");
+ }
+ }
+ if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
+ INTON;
+ if (prevfd > 0) {
+ close(0);
+ copyfd(prevfd, 0);
+ close(prevfd);
+ }
+ if (pip[1] >= 0) {
+ close(pip[0]);
+ if (pip[1] != 1) {
+ close(1);
+ copyfd(pip[1], 1);
+ close(pip[1]);
+ }
+ }
+ evaltree(lp->n, EV_EXIT);
+ }
+ if (prevfd >= 0)
+ close(prevfd);
+ prevfd = pip[0];
+ close(pip[1]);
+ }
+ if (n->npipe.backgnd == 0) {
+ exitstatus = waitforjob(jp);
+ TRACE(("evalpipe: job done exit status %d\n", exitstatus));
+ }
+ INTON;
+}
+
+
+
+/*
+ * Execute a command inside back quotes. If it's a builtin command, we
+ * want to save its output in a block obtained from malloc. Otherwise
+ * we fork off a subprocess and get the output of the command via a pipe.
+ * Should be called with interrupts off.
+ */
+
+void
+evalbackcmd(union node *n, struct backcmd *result)
+{
+ int pip[2];
+ struct job *jp;
+ struct stackmark smark; /* unnecessary */
+
+ setstackmark(&smark);
+ result->fd = -1;
+ result->buf = NULL;
+ result->nleft = 0;
+ result->jp = NULL;
+ if (n == NULL) {
+ goto out;
+ }
+#ifdef notyet
+ /*
+ * For now we disable executing builtins in the same
+ * context as the shell, because we are not keeping
+ * enough state to recover from changes that are
+ * supposed only to affect subshells. eg. echo "`cd /`"
+ */
+ if (n->type == NCMD) {
+ exitstatus = oexitstatus;
+ evalcommand(n, EV_BACKCMD, result);
+ } else
+#endif
+ {
+ INTOFF;
+ if (sh_pipe(pip) < 0)
+ error("Pipe call failed");
+ jp = makejob(n, 1);
+ if (forkshell(jp, n, FORK_NOJOB) == 0) {
+ FORCEINTON;
+ close(pip[0]);
+ if (pip[1] != 1) {
+ close(1);
+ copyfd(pip[1], 1);
+ close(pip[1]);
+ }
+ eflag = 0;
+ evaltree(n, EV_EXIT);
+ /* NOTREACHED */
+ }
+ close(pip[1]);
+ result->fd = pip[0];
+ result->jp = jp;
+ INTON;
+ }
+out:
+ popstackmark(&smark);
+ TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
+ result->fd, result->buf, result->nleft, result->jp));
+}
+
+static const char *
+syspath(void)
+{
+ static char *sys_path = NULL;
+#ifndef __linux__
+ static int mib[] = {CTL_USER, USER_CS_PATH};
+#endif
+ static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin";
+
+ if (sys_path == NULL) {
+#ifndef __linux__
+ size_t len;
+ if (sysctl(mib, 2, 0, &len, 0, 0) != -1 &&
+ (sys_path = ckmalloc(len + 5)) != NULL &&
+ sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) {
+ memcpy(sys_path, "PATH=", 5);
+ } else
+#endif
+ {
+ ckfree(sys_path);
+ /* something to keep things happy */
+ sys_path = def_path;
+ }
+ }
+ return sys_path;
+}
+
+static int
+parse_command_args(int argc, char **argv, int *use_syspath)
+{
+ int sv_argc = argc;
+ char *cp, c;
+
+ *use_syspath = 0;
+
+ for (;;) {
+ argv++;
+ if (--argc == 0)
+ break;
+ cp = *argv;
+ if (*cp++ != '-')
+ break;
+ if (*cp == '-' && cp[1] == 0) {
+ argv++;
+ argc--;
+ break;
+ }
+ while ((c = *cp++)) {
+ switch (c) {
+ case 'p':
+ *use_syspath = 1;
+ break;
+ default:
+ /* run 'typecmd' for other options */
+ return 0;
+ }
+ }
+ }
+ return sv_argc - argc;
+}
+
+int vforked = 0;
+
+/*
+ * Execute a simple command.
+ */
+
+STATIC void
+evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
+{
+ struct stackmark smark;
+ union node *argp;
+ struct arglist arglist;
+ struct arglist varlist;
+ char **argv;
+ int argc;
+ char **envp;
+ int varflag;
+ struct strlist *sp;
+ int mode;
+ int pip[2];
+ struct cmdentry cmdentry;
+ struct job *jp;
+ struct jmploc jmploc;
+ struct jmploc *volatile savehandler;
+ char *volatile savecmdname;
+ volatile struct shparam saveparam;
+ struct localvar *volatile savelocalvars;
+ volatile int e;
+ char *lastarg;
+ const char *path = pathval();
+ volatile int temp_path;
+#if __GNUC__
+ /* Avoid longjmp clobbering */
+ (void) &argv;
+ (void) &argc;
+ (void) &lastarg;
+ (void) &flags;
+#endif
+
+ vforked = 0;
+ /* First expand the arguments. */
+ TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
+ setstackmark(&smark);
+ back_exitstatus = 0;
+
+ arglist.lastp = &arglist.list;
+ varflag = 1;
+ /* Expand arguments, ignoring the initial 'name=value' ones */
+ for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
+ char *p = argp->narg.text;
+ if (varflag && is_name(*p)) {
+ do {
+ p++;
+ } while (is_in_name(*p));
+ if (*p == '=')
+ continue;
+ }
+ expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+ varflag = 0;
+ }
+ *arglist.lastp = NULL;
+
+ expredir(cmd->ncmd.redirect);
+
+ /* Now do the initial 'name=value' ones we skipped above */
+ varlist.lastp = &varlist.list;
+ for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
+ char *p = argp->narg.text;
+ if (!is_name(*p))
+ break;
+ do
+ p++;
+ while (is_in_name(*p));
+ if (*p != '=')
+ break;
+ expandarg(argp, &varlist, EXP_VARTILDE);
+ }
+ *varlist.lastp = NULL;
+
+ argc = 0;
+ for (sp = arglist.list ; sp ; sp = sp->next)
+ argc++;
+ argv = stalloc(sizeof (char *) * (argc + 1));
+
+ for (sp = arglist.list ; sp ; sp = sp->next) {
+ TRACE(("evalcommand arg: %s\n", sp->text));
+ *argv++ = sp->text;
+ }
+ *argv = NULL;
+ lastarg = NULL;
+ if (iflag && funcnest == 0 && argc > 0)
+ lastarg = argv[-1];
+ argv -= argc;
+
+ /* Print the command if xflag is set. */
+ if (xflag) {
+ char sep = 0;
+ out2str(ps4val());
+ for (sp = varlist.list ; sp ; sp = sp->next) {
+ if (sep != 0)
+ outc(sep, &errout);
+ out2str(sp->text);
+ sep = ' ';
+ }
+ for (sp = arglist.list ; sp ; sp = sp->next) {
+ if (sep != 0)
+ outc(sep, &errout);
+ out2str(sp->text);
+ sep = ' ';
+ }
+ outc('\n', &errout);
+ flushout(&errout);
+ }
+
+ /* Now locate the command. */
+ if (argc == 0) {
+ cmdentry.cmdtype = CMDSPLBLTIN;
+ cmdentry.u.bltin = bltincmd;
+ } else {
+ static const char PATH[] = "PATH=";
+ int cmd_flags = DO_ERR;
+
+ /*
+ * Modify the command lookup path, if a PATH= assignment
+ * is present
+ */
+ for (sp = varlist.list; sp; sp = sp->next)
+ if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
+ path = sp->text + sizeof(PATH) - 1;
+
+ do {
+ int argsused, use_syspath;
+ find_command(argv[0], &cmdentry, cmd_flags, path);
+ if (cmdentry.cmdtype == CMDUNKNOWN) {
+ exitstatus = 127;
+ flushout(&errout);
+ goto out;
+ }
+
+ /* implement the 'command' builtin here */
+ if (cmdentry.cmdtype != CMDBUILTIN ||
+ cmdentry.u.bltin != bltincmd)
+ break;
+ cmd_flags |= DO_NOFUNC;
+ argsused = parse_command_args(argc, argv, &use_syspath);
+ if (argsused == 0) {
+ /* use 'type' builting to display info */
+ cmdentry.u.bltin = typecmd;
+ break;
+ }
+ argc -= argsused;
+ argv += argsused;
+ if (use_syspath)
+ path = syspath() + 5;
+ } while (argc != 0);
+ if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
+ /* posix mandates that 'command <splbltin>' act as if
+ <splbltin> was a normal builtin */
+ cmdentry.cmdtype = CMDBUILTIN;
+ }
+
+ /* Fork off a child process if necessary. */
+ if (cmd->ncmd.backgnd
+ || (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
+ || ((flags & EV_BACKCMD) != 0
+ && ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
+ || cmdentry.u.bltin == dotcmd
+ || cmdentry.u.bltin == evalcmd))) {
+ INTOFF;
+ jp = makejob(cmd, 1);
+ mode = cmd->ncmd.backgnd;
+ if (flags & EV_BACKCMD) {
+ mode = FORK_NOJOB;
+ if (sh_pipe(pip) < 0)
+ error("Pipe call failed");
+ }
+#ifdef DO_SHAREDVFORK
+ /* It is essential that if DO_SHAREDVFORK is defined that the
+ * child's address space is actually shared with the parent as
+ * we rely on this.
+ */
+ if (cmdentry.cmdtype == CMDNORMAL) {
+ pid_t pid;
+
+ savelocalvars = localvars;
+ localvars = NULL;
+ vforked = 1;
+ switch (pid = vfork()) {
+ case -1:
+ TRACE(("Vfork failed, errno=%d\n", errno));
+ INTON;
+ error("Cannot vfork");
+ break;
+ case 0:
+ /* Make sure that exceptions only unwind to
+ * after the vfork(2)
+ */
+ if (setjmp(jmploc.loc)) {
+ if (exception == EXSHELLPROC) {
+ /* We can't progress with the vfork,
+ * so, set vforked = 2 so the parent
+ * knows, and _exit();
+ */
+ vforked = 2;
+ _exit(0);
+ } else {
+ _exit(exerrno);
+ }
+ }
+ savehandler = handler;
+ handler = &jmploc;
+ listmklocal(varlist.list, VEXPORT | VNOFUNC);
+ forkchild(jp, cmd, mode, vforked);
+ break;
+ default:
+ handler = savehandler; /* restore from vfork(2) */
+ poplocalvars();
+ localvars = savelocalvars;
+ if (vforked == 2) {
+ vforked = 0;
+
+ (void)waitpid(pid, NULL, 0);
+ /* We need to progress in a normal fork fashion */
+ goto normal_fork;
+ }
+ vforked = 0;
+ forkparent(jp, cmd, mode, pid);
+ goto parent;
+ }
+ } else {
+normal_fork:
+#endif
+ if (forkshell(jp, cmd, mode) != 0)
+ goto parent; /* at end of routine */
+ FORCEINTON;
+#ifdef DO_SHAREDVFORK
+ }
+#endif
+ if (flags & EV_BACKCMD) {
+ if (!vforked) {
+ FORCEINTON;
+ }
+ close(pip[0]);
+ if (pip[1] != 1) {
+ close(1);
+ copyfd(pip[1], 1);
+ close(pip[1]);
+ }
+ }
+ flags |= EV_EXIT;
+ }
+
+ /* This is the child process if a fork occurred. */
+ /* Execute the command. */
+ switch (cmdentry.cmdtype) {
+ case CMDFUNCTION:
+#ifdef DEBUG
+ trputs("Shell function: "); trargs(argv);
+#endif
+ redirect(cmd->ncmd.redirect, REDIR_PUSH);
+ saveparam = shellparam;
+ shellparam.malloc = 0;
+ shellparam.reset = 1;
+ shellparam.nparam = argc - 1;
+ shellparam.p = argv + 1;
+ shellparam.optnext = NULL;
+ INTOFF;
+ savelocalvars = localvars;
+ localvars = NULL;
+ INTON;
+ if (setjmp(jmploc.loc)) {
+ if (exception == EXSHELLPROC) {
+ freeparam((volatile struct shparam *)
+ &saveparam);
+ } else {
+ freeparam(&shellparam);
+ shellparam = saveparam;
+ }
+ poplocalvars();
+ localvars = savelocalvars;
+ handler = savehandler;
+ longjmp(handler->loc, 1);
+ }
+ savehandler = handler;
+ handler = &jmploc;
+ listmklocal(varlist.list, 0);
+ /* stop shell blowing its stack */
+ if (++funcnest > 1000)
+ error("too many nested function calls");
+ evaltree(cmdentry.u.func, flags & EV_TESTED);
+ funcnest--;
+ INTOFF;
+ poplocalvars();
+ localvars = savelocalvars;
+ freeparam(&shellparam);
+ shellparam = saveparam;
+ handler = savehandler;
+ popredir();
+ INTON;
+ if (evalskip == SKIPFUNC) {
+ evalskip = 0;
+ skipcount = 0;
+ }
+ if (flags & EV_EXIT)
+ exitshell(exitstatus);
+ break;
+
+ case CMDBUILTIN:
+ case CMDSPLBLTIN:
+#ifdef DEBUG
+ trputs("builtin command: "); trargs(argv);
+#endif
+ mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
+ if (flags == EV_BACKCMD) {
+ memout.nleft = 0;
+ memout.nextc = memout.buf;
+ memout.bufsize = 64;
+ mode |= REDIR_BACKQ;
+ }
+ e = -1;
+ savehandler = handler;
+ savecmdname = commandname;
+ handler = &jmploc;
+ if (!setjmp(jmploc.loc)) {
+ /* We need to ensure the command hash table isn't
+ * corruped by temporary PATH assignments.
+ * However we must ensure the 'local' command works!
+ */
+ if (path != pathval() && (cmdentry.u.bltin == hashcmd ||
+ cmdentry.u.bltin == typecmd)) {
+ savelocalvars = localvars;
+ localvars = 0;
+ mklocal(path - 5 /* PATH= */, 0);
+ temp_path = 1;
+ } else
+ temp_path = 0;
+ redirect(cmd->ncmd.redirect, mode);
+
+ /* exec is a special builtin, but needs this list... */
+ cmdenviron = varlist.list;
+ /* we must check 'readonly' flag for all builtins */
+ listsetvar(varlist.list,
+ cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
+ commandname = argv[0];
+ /* initialize nextopt */
+ argptr = argv + 1;
+ optptr = NULL;
+ /* and getopt */
+#ifndef __linux__
+ optreset = 1;
+#endif
+ optind = 1;
+ exitstatus = cmdentry.u.bltin(argc, argv);
+ } else {
+ e = exception;
+ exitstatus = e == EXINT ? SIGINT + 128 :
+ e == EXEXEC ? exerrno : 2;
+ }
+ handler = savehandler;
+ flushall();
+ out1 = &output;
+ out2 = &errout;
+ freestdout();
+ if (temp_path) {
+ poplocalvars();
+ localvars = savelocalvars;
+ }
+ cmdenviron = NULL;
+ if (e != EXSHELLPROC) {
+ commandname = savecmdname;
+ if (flags & EV_EXIT)
+ exitshell(exitstatus);
+ }
+ if (e != -1) {
+ if ((e != EXERROR && e != EXEXEC)
+ || cmdentry.cmdtype == CMDSPLBLTIN)
+ exraise(e);
+ FORCEINTON;
+ }
+ if (cmdentry.u.bltin != execcmd)
+ popredir();
+ if (flags == EV_BACKCMD) {
+ backcmd->buf = memout.buf;
+ backcmd->nleft = memout.nextc - memout.buf;
+ memout.buf = NULL;
+ }
+ break;
+
+ default:
+#ifdef DEBUG
+ trputs("normal command: "); trargs(argv);
+#endif
+ clearredir(vforked);
+ redirect(cmd->ncmd.redirect, vforked ? REDIR_VFORK : 0);
+ if (!vforked)
+ for (sp = varlist.list ; sp ; sp = sp->next)
+ setvareq(sp->text, VEXPORT|VSTACK);
+ envp = environment();
+ shellexec(argv, envp, path, cmdentry.u.index, vforked);
+ break;
+ }
+ goto out;
+
+parent: /* parent process gets here (if we forked) */
+ if (mode == FORK_FG) { /* argument to fork */
+ exitstatus = waitforjob(jp);
+ } else if (mode == FORK_NOJOB) {
+ backcmd->fd = pip[0];
+ close(pip[1]);
+ backcmd->jp = jp;
+ }
+ FORCEINTON;
+
+out:
+ if (lastarg)
+ /* dsl: I think this is intended to be used to support
+ * '_' in 'vi' command mode during line editing...
+ * However I implemented that within libedit itself.
+ */
+ setvar("_", lastarg, 0);
+ popstackmark(&smark);
+
+ if (eflag && exitstatus && !(flags & EV_TESTED))
+ exitshell(exitstatus);
+}
+
+
+/*
+ * Search for a command. This is called before we fork so that the
+ * location of the command will be available in the parent as well as
+ * the child. The check for "goodname" is an overly conservative
+ * check that the name will not be subject to expansion.
+ */
+
+STATIC void
+prehash(union node *n)
+{
+ struct cmdentry entry;
+
+ if (n->type == NCMD && n->ncmd.args)
+ if (goodname(n->ncmd.args->narg.text))
+ find_command(n->ncmd.args->narg.text, &entry, 0,
+ pathval());
+}
+
+
+
+/*
+ * Builtin commands. Builtin commands whose functions are closely
+ * tied to evaluation are implemented here.
+ */
+
+/*
+ * No command given.
+ */
+
+int
+bltincmd(int argc, char **argv)
+{
+ /*
+ * Preserve exitstatus of a previous possible redirection
+ * as POSIX mandates
+ */
+ return back_exitstatus;
+}
+
+
+/*
+ * Handle break and continue commands. Break, continue, and return are
+ * all handled by setting the evalskip flag. The evaluation routines
+ * above all check this flag, and if it is set they start skipping
+ * commands rather than executing them. The variable skipcount is
+ * the number of loops to break/continue, or the number of function
+ * levels to return. (The latter is always 1.) It should probably
+ * be an error to break out of more loops than exist, but it isn't
+ * in the standard shell so we don't make it one here.
+ */
+
+int
+breakcmd(int argc, char **argv)
+{
+ int n = argc > 1 ? number(argv[1]) : 1;
+
+ if (n > loopnest)
+ n = loopnest;
+ if (n > 0) {
+ evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
+ skipcount = n;
+ }
+ return 0;
+}
+
+
+/*
+ * The return command.
+ */
+
+int
+returncmd(int argc, char **argv)
+{
+ int ret = argc > 1 ? number(argv[1]) : exitstatus;
+
+ if (funcnest) {
+ evalskip = SKIPFUNC;
+ skipcount = 1;
+ return ret;
+ }
+ else {
+ /* Do what ksh does; skip the rest of the file */
+ evalskip = SKIPFILE;
+ skipcount = 1;
+ return ret;
+ }
+}
+
+
+int
+falsecmd(int argc, char **argv)
+{
+ return 1;
+}
+
+
+int
+truecmd(int argc, char **argv)
+{
+ return 0;
+}
+
+
+int
+execcmd(int argc, char **argv)
+{
+ if (argc > 1) {
+ struct strlist *sp;
+
+ iflag = 0; /* exit on error */
+ mflag = 0;
+ optschanged();
+ for (sp = cmdenviron; sp; sp = sp->next)
+ setvareq(sp->text, VEXPORT|VSTACK);
+ shellexec(argv + 1, environment(), pathval(), 0, 0);
+ }
+ return 0;
+}
+
+static int
+conv_time(clock_t ticks, char *seconds, size_t l)
+{
+ static clock_t tpm = 0;
+ clock_t mins;
+ int i;
+
+ mins = ticks / tpm;
+ snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
+
+ if (seconds[0] == '6' && seconds[1] == '0') {
+ /* 59.99995 got rounded up... */
+ mins++;
+ strlcpy(seconds, "0.0", l);
+ return mins;
+ }
+
+ /* suppress trailing zeros */
+ i = strlen(seconds) - 1;
+ for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
+ seconds[i] = 0;
+ return mins;
+}
+
+int
+timescmd(int argc, char **argv)
+{
+ struct tms tms;
+ int u, s, cu, cs;
+ char us[8], ss[8], cus[8], css[8];
+
+ nextopt("");
+
+ times(&tms);
+
+ u = conv_time(tms.tms_utime, us, sizeof(us));
+ s = conv_time(tms.tms_stime, ss, sizeof(ss));
+ cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
+ cs = conv_time(tms.tms_cstime, css, sizeof(css));
+
+ outfmt(out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
+ u, us, s, ss, cu, cus, cs, css);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-06-27 09:53:51 +0000